Pygrus malvae can be found throughout Western Europe in northern Scandinavia, parts of Greece, and some of the Mediterranean Islands. Its populations in many European countries appear to be quite stable. It is also present in Korea, as well as throughout the Mediterranean up to Middle Finland, and rarely in parts of Germany.


Although grizzled skippers occupy three major forms of habitats, they tend to settle in environments with spring nectar plants, larval food plants (agrimony, creeping cinquefoil, wild strawberry, tormentil), ranker vegetation, and edges with scrub or woodland. Host plants are from the family Rosaceae with a focus on Agrimonia eupatoria as well as Potentilla.
Woodland: This mainly consists of sparsely distributed vegetation and can have regions of bare ground that result from cutting or windblow.
Grassland: These can result from three different patterns that involve animal grazing, scrub cutting, or disturbance by animals: 1) Scrubby grassland that includes bramble and wild strawberry 2) Unimproved grassland that include creeping cinquefoil 3) Unimproved grassland that includes agrimony.
Industrial: Sparse vegetation with mainly wild strawberry or creeping cinquefoil depending on whether the environment is along a railway or clay working. These environments have typically been abandoned fairly recently.
Other possible environments for the butterflies are heathland, shingle, sand dunes, and acidic, neutral and marshy grassland.


Studies support a concentrated preference for specifically coloured flowers by grizzled skippers. They are most attracted to blue and violet while showing little or no attraction to white, yellow, or red. Butterflies have ultraviolet and blue receptors that may be responsible for Hesperiidae butterflies favoring blue. This evidence indicates that when butterflies from this species forage for food, they are particularly attentive to short-wavelength light that is reflected off flowers. In fact, this particular preference aligns with a prominent attentiveness that members of Hesperiidae have for blue. This preference may be a result of phylogenetic adaptations, foraging signals, and learning abilities. Specifically, the prevalence of blue flowers in lowlands could further intensify this preference, especially for grizzled skippers that tend to be found in lowland grasslands.


An overarching theme in behavioral ecology can be seen through female grizzled skipper investment in host plant selection. Females tend to lay eggs on host plants that are viewed as larger and more nutritionally rich. However, this nutritional advantage for caterpillars must be balanced with the presence of a warm microclimate that is suitable for the species. Warm microclimates align with P. tabernaemontani plants, but these may also have an increased chance of desiccation. On the other hand, A. eupatoria is a larger plant when near molehills and can be found in more suitable environments. As a result, A. eupatoria provides an appropriate balance for both of these requirements and is preferred as a host plant by P. malvae, particularly near molehills. Females consider optical conspicuousness, or plant visibility, through prominence (height differences between host plants and vegetation). More prominent host plants, like A. eupatoria over P. tabernaemontani, are favored. However, these two different habitats are used significantly and may be evolutionary adaptations to offset the grizzled skippers’ risk of extinction imposed by a polarized weather pattern.


Eggs are mainly found on agrimony, creeping cinquefoil, and wild strawberry plants, which provide nourishment for larvae. Other plants that can be considered include barren strawberry, tormentil, salad burnet, bramble, dog rose, and wood avens. Plants favored by mothers are typically located in bare ground or short vegetation environments, can have high nitrogen contents, and tend to be located in warmer microclimates. The eggs for grizzled skippers are laid one at a time, although females can lay them on more than two species of plants. Preferred plants have been observed to contain up to 22 eggs.


This stage continues for two to three months in its entirety. At first, larvae live and spend the vast majority of their time within ‘tents’ that they build on the host leaf, and this partially feeds into their restricted mobility. The two reasons for leaving this shelter are 1.) to feed on another leaf, or 2.) to create another tent.  Later on in this stage, larvae expand their mobility and are no longer restricted in diet or habitat. Plants that are higher in nitrogen content and nutrition are more highly incorporated into the diets of larger larvae, as are coarser shrubs. Host plants located on molehills are favored for early larval stages due to open vegetation that is available as well as bare ground and warmer microclimates.


Pupal cocoons spun by larvae can be located on or within low vegetation. Generally, these cocoons are not found near the larvae's last tent. The location of these cocoons can consequently affect adult emergence patterns. Pupal cocoons on shorter vegetation will facilitate adult emergence earlier in the spring than pupal cocoons on longer vegetation.


Grizzled skippers produce one brood per season and are in flight from the middle of March to the middle of July. Active during the day and focused on feeding or basking, they roost on tall vegetation like marjoram, knapweed, and St John's-wort. In particular, adults spend days basking on bare ground and afternoons on taller vegetation. This provides them favorable microclimates and visibility.


Butterflies move away from open spaces to the case of increasing wind speeds to seek shelter. Shelter may be particularly important because of vegetation; for example, they can support herbs and bramble. They are also useful in connecting multiple separated habitats. In fact, shelters are associated with higher activity amongst the butterflies.


Grizzled skippers belong in family Hesperiidae, but another group of butterflies (family Lycaenidae) uses the mechanism of wing expansion to produce vibrations and communicate with ants. Similar to this behavior, grizzled skippers also produce vibrations upon expanding their wings. This resembles the ‘ant-attendant’ behaviour that is specific to butterflies in the Lycaenidae.  Ants are recognized as potential predators for lycaenid caterpillars, therefore, vibration signaling most likely functions as an anti-predatory survival mechanism. Similarly, grizzled skippers also exhibit this kind of vibratory communication. Although the behavior is absent during the caterpillar stage, grizzled skippers are able to produce vibrations upon wing expansion. Akin to lycaenids, grizzled skippers may use these vibrations as signals to communicate with ants and potentially as an attempt to temper aggression.


Grizzled skippers are known to contain organs called androconia that are responsible for producing chemicals within the thorax as well as the abdomen. They are found in males at the forewing costal fold. The organs release sex pheromones that can be used as a sexual recognition mechanism and drive evolution. The process involves the male first locating a female visually, then using low concentrations of the pheromones at a relatively close proximity to indicate its viability as a mate. While courting the female, male butterflies have specialized hairlike structures called ‘tibial tufts’ on their hind legs that can be used to steer these chemicals directly to the female. However, this chemical communication cannot be differentiated between P. malvae and P. malvoides, a close relative considered a subspecies of P. malvae and not separated by isolation reproductive barriers.


There are two main mating strategies that are used by grizzled skippers, which ultimately illustrate mechanisms of sexual selection by this species. In both, males demonstrate territorial behaviours. In the case of perching, males wait on taller plants for females to come to them in order to begin courting. In the case of patrolling, males locate a desired female and fly down to her.
The type of behaviour that they use in mating depends upon the pattern of food plant availability in their respective habitats.
Perching Approach: This is used in habitats that are poor for food plants. Males will engage in more of a perching approach where they await females above scrub edges that afford them with shelter, warmth, and visible range.
Patrolling Approach: This is used in habitats that are rich for food plants. Males will engage in more of a patrolling strategy by mingling with females.


Pyrgus malvae is particularly receptive to warmer and drier climates. Warmer summers are more favorable for the grizzled skipper and are positively correlated with the species. This could result from relationships between warmth and the success of the mother's ability to lay the egg as well as of larvae survival. Warmer climates also tend to hasten the development of larvae and allow for earlier onset of the pupal stage. Cooler northern weather may explain the concentration of this butterfly in southern regions. As a result of climate warming, the grizzled skipper appears to show decreases in northern range margin, distribution area, and abundance. This response appears to be dependent upon climatic as well as nonclimatic driving forces.


The wings of Pygrus malvae are only mildly adhesive, rough, and highly hydrophobic. These qualities prevent their wings from sticking to external surfaces, support their resistance to water damage, and allow the butterfly to self-clean its wings without risking desiccation. Additionally, these properties enable the grizzled skipper to avoid excess weight bearing, consequently promoting secure and efficient flight patterns.


1- Decreased woodland clearings, unimproved grassland, scrub habitats
2- Unimproved grasslands and scrub habitats that have been changed
3- Woodland and grassland sites that have been broken apart or deserted
4- Artificial habitats that have been deteriorated


1- Further changes that reduce open areas and spread apart clearings
2- Reductions in coppice produce
3- Further deteriorating unimproved grassland, scrub, and artificial habitats
4- Further breaking apart and deserting habitats


The grizzled skipper has notably been decreasing in its prevalence in several other European countries over the past 25 years. The species has experienced significant declines (ranging from 25% to over 50%) in Britain, Croatia, Belgium, European Turkey, and the Netherlands. Less severe decline can be seen in the Czech Republic, Germany, Denmark, Finland, Luxembourg, Romania, Sweden, Slovakia, and Asian Turkey. Once found across England as well as regions in Wales, the grizzled skipper is now concentrated in Central and Southern England only. In fact, five of England's counties have already experienced extinction of the species, and the butterfly can only be found in less than five sites in another five English counties. However, between 1995 and 1997, evidence of recolonization by the grizzled skipper has emerged, specifically in several counties in England.


Grazing has been applied as an approach to conservation, especially in the Netherlands where it is used to monitor the biodiversity of open habitats. Pyrgus malvae is important in these studied because it is considered as a threatened to susceptible species in the Netherlands. Grazing appears to be positively associated with populations of Pyrgus malvae that are concentrated more in habitats with grazed vegetation rather than those with cut and ungrazed regions. The trend may be reflective of the fact that grizzled skippers prefer open grassland habitats. With its endangered status in the Netherlands, the grizzled skipper may benefit from extensive grazing as a nature restoration project.


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Wallisdevries, Michiel F., and Ivo Raemakers. “Does Extensive Grazing Benefit Butterflies in Coastal Dunes?” Restoration Ecology, vol. 9, no. 2, 2001, pp. 179–188., doi:10.1046/j.1526-100x.2001.009002179.x.
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Pyrgus malvoides, the Southern Grizzled Skipper, is a species of skipper (family Hesperiidae).


The wingspan of this butterfly is 24–26 mm. Pyrgus malvoides cannot be distinguished from Pyrgus malvae by external characteristics, but this is quite possible on the basis of the genital structures. From the other species of the genus Pyrgus, both species can be clearly differentiated by the presence of the mostly clear submarginal points on the upper side of the wing.


Pyrgus malvoides is distributed from Portugal and Spain via southern and central France, southern Switzerland (south of the main Alpine ridge) and Austria (Vorarlberg, Tyrol) to Italy and Istria.


According to previous knowledge, Pyrgus malvoides colonizes various fresh and above all moist habitats in the Alps if these have structures that are favorable to the microclimate, such as open ground on gravel, rocks, obstructions from cattle kicking or erosion, etc. A syntopic occurrence with Pyrgus malvae could not be determined so far. Because of the identification problems in the field, no sucking plants were noted. It is assumed that there are no essential differences to Pyrgus malvae here.
The known altitudinal distribution extends from 800 m to about 2000 m in Bavaria. It is found up to heights of 2500 m in the central Alps.


Adults are on wing from April to September. In Bavaria Pyrgus malvoides flies in one generation from around mid-May to mid-July. A second or even third generation per year, as described e.g. in Italy, was not observed in Bavaria.
The larva feed on Potentilla, Agrimonia and Fragaria species, but primarily Potentilla erecta. It is reported from Switzerland that the caterpillars have been found on various cinquefoil species (Potentilla neumanniana [= tabernaemontani], Potentilla pusilla, Potentilla erecta) and have eaten Fragaria vesca during breeding.
Proven forage plants of the caterpillars are:
Potentilla tabernaemontani (= Potentilla neumanniana, Potentilla verna) [Switzerland, France], Potentilla pusilla [Switzerland, France, Italy], Potentilla erecta [Switzerland, Spain], Potentilla aurea [Austria], Potentilla reptans [France, Italy, Spain], Potentilla rupestris [Switzerland], Potentilla argentea [France], Potentilla grandiflora [Switzerland], Potentilla hirta [France], Potentilla pensylvanica [Spain], Potentilla recta [Spain], Fragaria vesca [Spain, Switzerland], Alchemilla hybrida [Switzerland], Agrimonia eupatoria [France, Spain], Filipendula vulgaris [Spain], Geum montanum [Spain], Rubus caesius [Spain], Rubus idaeus [Switzerland, France, Italy], Rubus ulmifolius [Spain], Sanguisorba minor [Switzerland, Spain]. The information in the above list comes mainly from the combination of Hernández-Roldán et al. (2012). The range of food plants is very similar to that of the sister species Pyrgus malvae. Only Rosaceae and, above all, various Potentilla species are used.
The caterpillars develop quite slowly and can therefore still be found on their food plants in midsummer, often several on one plant.


In Switzerland, Pyrgus malvoides is called a typical representative of the rough meadows and pastures. In Bavaria, too, the species was found in wet meadows, extensive pastures and wet grasslands. A threat can only be assumed if traditional extensive cultivation gives way to intensive use or if the meadows are left without use.


The southern grizzled skipper is also very closely related to the grizzled skipper and has not been separated by significant isolation reproductive barriers. These two species cannot be differentiated according to external characteristics. Regarding their genitalia, however, they differ significantly. And while P. malvoides usually develops two generations per year, the second generation of P. malvae is a very rare exception. The two species can be crossed with each other, but in nature there is only a very narrow band with hybrid finds - otherwise the taxa are spatially clearly separated. P. malvoides is therefore often listed as a (southwestern) subspecies of P. malvae - but mostly as an independent species because of the narrow and constant band of hybrids. Imagos of the species pair from Portugal, Spain, southern France and Italy, but also southern Switzerland and the parts of Austria mentioned, always belong to P. malvoides, those from Germany (with very few exceptions in the border area), from Scandinavia or Poland and northern Switzerland, as well but from Greece to European Russia (and further through Asia) always to Pyrgus malvae. A genital examination is only necessary in the narrow contact belt of the two species.


The name cardinal beetle typically refers to three different species of beetles. The red-headed or 'common' cardinal beetle (Pyrochroa serraticornis) is a red to orange beetle with, as the name suggests, a red head. It is about 20 millimetres (0.79 in) long, and is found throughout Britain. The rarer black-headed cardinal beetle (P. coccinea), similarly found at sites across Britain, is larger and a deeper blood red. The scarce cardinal beetle (Schizotus pectinicornis) also has a black head, but is smaller at around 9 millimetres (0.35 in) long. The scarce cardinal is only found at a few sites in Scotland and Wales.
Cardinal beetles prey on other insects, while their bright red colour prevents them being the target of other predators which believe them to be toxic.


Pyrola americana, the American wintergreen, is a plant species native to Canada and the United States. It has been reported from every Canadian province from Newfoundland to Manitoba, as well as from St. Pierre & Miquelon plus the northeastern US from Maine south along the Appalachian Mountains to extreme northeastern Tennessee. It also occurs in all the Great Lakes states and in the Black Hills of South Dakota. It grows in moist forests up to an elevation of 2100 m.
Pyrola americana is a small herb rarely more than 4 cm tall, spreading by means of underground rhizomes. Leaves are round to egg-shaped, up to 8 cm long, usually dark green with whitish tissue along the veins. Flowers are white to pinkish. Fruit is a dry capsule about 4 mm across.


Pyrola asarifolia, commonly known as liverleaf wintergreen, bog wintergreen or pink wintergreen, is a plant species of the genus Pyrola native to western North America. It is found primarily on forest margins at mid latitude in the Pacific Northwest and northern California.  It is so named simply because its leaves maintain their green color through winter.


Its dust-like seeds are hard to germinate.


Pyrola chlorantha, the greenflowered wintergreen, is a species of the plant genus Pyrola. It has a circumboreal distribution and is found throughout the northern latitudes of Eurasia and North America.
Pyrola chlorantha is found in the Northeastern United States and the Western United States, such as the Sierra Nevada in California. It is considered an endangered species in several of the U.S. states.


Pyrola elliptica, known as shinleaf, shinleaf pyrola, waxflower shinleaf, elliptic shineleaf and white wintergreen is a species of heath.


The plant has 5-petaled white flowers and some what elliptical leaves with petioles shorter than the blade. It grows 6-12 inches tall in dry woods and forest, blooming from June through August.


This species' range includes most of southern Canada and the northern United States, as well as part of the southwestern States.


Pyrola minor, known by the common names snowline wintergreen, lesser wintergreen, and common wintergreen, is a plant species of the genus Pyrola. It has a Circumboreal distribution and can be found throughout the northern latitudes of Eurasia and North America.


Pyrola picta, commonly called whiteveined wintergreen or whitevein shinleaf, is a perennial herb in the heath family. It is native to western North America from southwestern Canada to the southwestern United States.


Pyronia bathseba, the Spanish gatekeeper, is a butterfly of the family Nymphalidae. It is found on the Iberian Peninsula and in France, Morocco, and Algeria.  A similar gatekeeper species is Pyronia tithonus, which is found in northern Europe.


The wingspan is 18–19 mm. The butterfly is on wing from May to July depending on the location.


The larvae feed on Poaceae species, mainly Brachypodium species.


Like all Fulgoridae, P. candelaria feeds on plant sap: including longan and lychee trees (Sapindaceae), among others. Its long, slender proboscis is used to pierce tree bark to reach the phloem.
Members of this genus are sometimes called lanternflies (although lanternflies do not emit light) because of their notable 'cephalic process'. They are often sought-out by collectors, attracted by their fore wings (see figure), yellow-orange hind wings with a black zone around the wing tips, a reddish head and cephalic process with white spots.


Pyrorchis nigricans is a terrestrial, perennial, deciduous, herb with an underground tuber and a single dark green leaf with red markings. The leaf is more or less oval in shape and 50–60 mm (2–2 in) in diameter and lies flat on the ground. Between two and eight flowers are arranged on a thick, fleshy flowering spike 50–300 mm (2–10 in) high. The flowers are reddish-purple and white, about 20–30 mm (0.8–1 in) long and wide with a large bract at the base. The dorsal sepal is light coloured with reddish stripes, broad lance-shaped and 20–25 mm (0.8–1 in) long with its edges turned inwards. The lateral sepals and petals are linear in shape, about the same size as the dorsal sepal but more spreading. The labellum is gently curved near its base, then strongly curved downwards near its tip. It is white with red lines and its tip is frilly. Flowering occurs from August to November usually after fire the previous summer.


Red beaks was first formally described in 1810 by Robert Brown who gave it the name Lyperanthus nigricans and published the description in Prodromus Florae Novae Hollandiae et Insulae Van Diemen. In 1994 David Jones & Mark Clements changed the name to Pyrorchis nigricans. The specific epithet (nigricans) is a Latin word meaning "blackish", "swarthy" or "dark", alluding to the fact that all parts of the plant turn jet black as they age or during the drying process.


Red beaks grows in a range of habitats ranging from heath to forest but normally only after a hot fire the previous summer, although some populations apparently flower without fire. In Western Australia it occurs from Shark Bay to Israelite Bay in the Avon Wheatbelt, Esperance Plains, Geraldton Sandplains, Jarrah Forest, Mallee, Swan Coastal Plain, Warren, and Yalgoo bioregions. It is common in southern and far western Victoria and in New South Wales occurs in coastal districts south from Myall Lakes. It is also found in the south-east of South Australia and in Tasmania and the larger Bass Strait islands.


Pyrorchis nigricans is classified as "not threatened" in Western Australia by the Western Australian Government Department of Parks and Wildlife.


Pyrrharctia isabella, the isabella tiger moth, whose larval form is called the banded woolly bear, woolly bear, or woolly worm, occurs in the United States and southern Canada. It was first formally named by James Edward Smith in 1797.


The thirteen-segment larvae are usually covered with brown hair in their mid-regions and black hair in their anterior and posterior areas. In direct sunlight, the brown hair looks bright reddish brown. Adults are generally dull yellowish through orangish and have robust, scaly thorices; small heads; and bright reddish-orange forelegs. Wings have sparse black spotting.
The isabella tiger moth can be found in many cold regions, including the Arctic. The banded woolly bear larva emerges from the egg in the fall and overwinters in its caterpillar form, when it literally freezes solid. First its heart stops beating, then its gut freezes, then its blood, followed by the rest of the body. It survives being frozen by producing a cryoprotectant in its tissues. In the spring it thaws.
Larval setae do not inject venom and are not urticant; they do not typically cause irritation, injury, inflammation, or swelling. Handling larvae is discouraged, however, because their sharp, spiny hairs may cause dermatitis in some people. When disturbed, larvae defend themselves by playing possum (rolling up into balls and remaining motionless) and quickly crawling away.


This species is a generalist feeder, consuming many plant species, including herbs and trees. Based on the caterpillars' wide range of food plants, this moth could be found almost anywhere that plants grow.


Singer et al. showed that the larvae of a related moth, Grammia incorrupta (whose larvae are also called "woollybears"), consume alkaloid-laden leaves that help fight off internal parasitic fly larvae. This phenomenon has been proposed to be "the first clear demonstration of self-medication among insects." Within the same family, the larvae of the garden tiger moth (Arctia caja) are also known as woollybear caterpillars and consume an alkaloid diet similar to Grammia incorrupta.


The Alpine chough (/ˈtʃʌf/), or yellow-billed chough (Pyrrhocorax graculus) is a bird in the crow family, one of only two species in the genus Pyrrhocorax. Its two subspecies breed in high mountains from Spain eastwards through southern Europe and North Africa to Central Asia and Nepal, and it may nest at a higher altitude than any other bird. The eggs have adaptations to the thin atmosphere that improve oxygen take-up and reduce water loss.
This bird has glossy black plumage, a yellow beak, red legs, and distinctive calls. It has a buoyant acrobatic flight with widely spread flight feathers. The Alpine chough pairs for life and displays fidelity to its breeding site, which is usually a cave or crevice in a cliff face. It builds a lined stick nest and lays three to five brown-blotched whitish eggs. It feeds, usually in flocks, on short grazed grassland, taking mainly invertebrate prey in summer and fruit in winter; it will readily approach tourist sites to find supplementary food.
Although it is subject to predation and parasitism, and changes in agricultural practices have caused local population declines, this widespread and abundant species is not threatened globally. Climate change may present a long-term threat, by shifting the necessary Alpine habitat to higher altitudes.


The Alpine chough was first described as Corvus graculus by Linnaeus in the Systema Naturae in 1766. It was moved to its current genus, Pyrrhocorax, by English ornithologist Marmaduke Tunstall in his 1771 Ornithologia Britannica, along with the only other member of the genus, the red-billed chough, P. pyrrhocorax. The closest relatives of the choughs were formerly thought to be the typical crows, Corvus, especially the jackdaws in the subgenus Coloeus, but DNA and cytochrome b analysis shows that the genus Pyrrhocorax, along with the ratchet-tailed treepie (genus Temnurus), diverged early from the rest of the Corvidae.
The genus name is derived from Greek πύρρος (purrhos), "flame-coloured", and κόραξ (korax), "raven". The species epithet graculus is Latin for a jackdaw. The current binomial name of the Alpine chough was formerly sometimes applied to the red-billed chough. The English word "chough" was originally an alternative onomatopoeic name for the jackdaw, Corvus monedula, based on its call. The red-billed chough, formerly particularly common in Cornwall and known initially as the "Cornish chough", eventually became just "chough", the name transferring from one genus to another.
The Alpine chough has two extant subspecies.
P. g. graculus, the nominate subspecies in Europe, north Africa, Turkey, the Caucasus and northern Iran.
P. g. digitatus, described by the German naturalists Wilhelm Hemprich and Christian Gottfried Ehrenberg as P. alpinus var. digitatus in 1833, is larger and has stronger feet than the nominate race. It breeds in the rest of the depicted Asian range, mainly in the Himalayas.
Moravian palaeontologist Ferdinand Stoliczka separated the Himalayan population as a third subspecies, P. g. forsythi, but this has not been widely accepted and is usually treated as synonymous with digitatus. A Pleistocene form from Europe was similar to the extant subspecies, and is sometimes categorised as P. g. vetus.
The Australian white-winged chough, Corcorax melanorhamphos, despite its similar bill shape and black plumage, is only distantly related to the true choughs.


The adult of the nominate subspecies of the Alpine chough has glossy black plumage, a short yellow bill, dark brown irises, and red legs. It is slightly smaller than red-billed chough, at 37–39 centimetres (15–15 inches) length with a 12–14 cm (4.7–5.5 in) tail and a 75–85 cm (30–33 in) wingspan, but has a proportionally longer tail and shorter wings than its relative. It has a similar buoyant and easy flight. The sexes are identical in appearance although the male averages slightly larger than the female. The juvenile is duller than the adult with a dull yellow bill and brownish legs. The Alpine chough is unlikely to be confused with any other species; although the jackdaw and red-billed chough share its range, the jackdaw is smaller and has unglossed grey plumage, and the red-billed chough has a long red bill.
The subspecies P. g. digitatus averages slightly larger than the nominate form, weighing 191–244 g (6.7–8.6 oz) against 188–252 g (6.6–8.9 oz) for P. g. graculus, and it has stronger feet. This is in accordance with Bergmann's rule, which predicts that the largest birds should be found higher elevations or in colder and more arid regions. The extremities of the body, the bill and tarsus, were longer in warmer areas, in line with Allen's rule. Temperature seemed to be the most important cause of body variation in the Alpine chough.
The flight of the Alpine chough is swift and acrobatic with loose deep wing beats. Its high manoeuvrability is accomplished by fanning the tail, folding its wings, and soaring in the updraughts at cliff faces. Even in flight, it can be distinguished from the red-billed chough by its less rectangular wings, and longer, less square-ended tail.
The rippling preep and whistled sweeeooo calls of the Alpine chough are quite different from the more typically crow-like chee-ow vocalisations of the jackdaw and the red-billed chough. It also has a rolling churr alarm call, and a variety of quiet warbles and squeaks given by resting or feeding birds. In a study of chough calls throughout the Palearctic region it was found that call frequencies in the Alpine chough showed an inverse relationship between body size and frequency, being higher-pitched in smaller-bodied populations.


The Alpine Chough breeds in mountains from Spain eastwards through southern Europe and the Alps across Central Asia and the Himalayas to western China. There are also populations in Morocco, Corsica and Crete. It is a non-migratory resident throughout its range, although Moroccan birds have established a small colony near Málaga in southern Spain, and wanderers have reached Czechoslovakia, Gibraltar, Hungary and Cyprus.
This is a high-altitude species normally breeding between 1,260–2,880 metres (4,130–9,450 ft) in Europe, 2,880–3,900 m (9,450–12,800 ft) in Morocco, and 3,500–5,000 m (11,500–16,400 ft) in the Himalayas. It has nested at 6,500 m (21,300 ft), higher than any other bird species, even surpassing the red-billed chough which has a diet less well adapted to the highest altitudes. It has been observed following mountaineers ascending Mount Everest at an altitude of 8,200 m (26,900 ft). It usually nests in cavities and fissures on inaccessible rock faces, although locally it will use holes between rocks in fields, and forages in open habitats such as alpine meadows and scree slopes to the tree line or lower, and in winter will often congregate around human settlements, ski resorts, hotels and other tourist facilities. Its penchant for waiting by hotel windows for food is popular with tourists, but less so with hotel owners.


The Alpine chough is socially monogamous, showing high partner fidelity in summer and winter and from year to year. Nesting typically starts in early May, and is non-colonial, although in suitable habitat several pairs may nest in close proximity. The bulky nests are composed of roots, sticks and plant stems lined with grass, fine twiglets or hair, and may be constructed on ledges, in a cave or similar fissure in a cliff face, or in an abandoned building. The clutch is 3–5 glossy whitish eggs, averaging 33.9 by 24.9 millimetres (1.33 in × 0.98 in) in size, which are tinged with buff, cream or light-green and marked with small brown blotches; they are incubated by the female for 14–21 days before hatching. The chicks hatch with a dense covering of natal down, in contrast to those of the red-billed chough which are almost naked, and fledge in a further 29–31 days from hatching. The young birds are fed by both parents, and may also be fed by other adults when they have fledged and joined the flock. Breeding is possible in the high mountains because chough eggs have relatively fewer pores than those of lowland species, and lose less water by evaporation at low atmospheric pressure. The embryos of bird species that breed at high altitude also have haemoglobin with a genetically determined high affinity for oxygen.
In the western Italian Alps, the Alpine chough nests in a greater variety of sites than red-billed chough, using natural cliffs, pot-holes and abandoned buildings, whereas the red-billed uses only natural cliffs (although it nests in old buildings elsewhere). The Alpine chough lays its eggs about one month later than its relative, although breeding success and reproductive behaviour are similar. The similarities between the two species presumably arose because of the same strong environmental constraints on breeding behaviour.
A study of three different European populations showed a mean clutch size of 3.6 eggs, producing 2.6 chicks, of which 1.9 fledged. Adult survival rate varied from 83 to 92%, with no significant difference detected between males and females. Survival of first-year birds was, at 77%, lower than that of adults. The availability or otherwise of human food supplied from tourist activities did not affect breeding success.


In the summer, the Alpine chough feeds mainly on invertebrates collected from pasture, such as beetles (Selatosomus aeneus and Otiorhynchus morio have been recorded from pellets), snails, grasshoppers, caterpillars and fly larvae. The diet in autumn, winter and early spring becomes mainly fruit, including berries such as the European Hackberry (Celtis australis) and Sea-buckthorn (Hippophae rhamnoides), rose hips, and domesticated crops such as apples, grapes and pears where available. It has been observed eating flowers of Crocus vernus albiflorus, including the pistils, perhaps as a source of carotenoids. The chough will readily supplement its winter diet with food provided by tourist activities in mountain regions, including ski resorts, refuse dumps and picnic areas. Where additional food is available, winter flocks are larger and contain a high proportion of immature birds. The young birds principally frequent the sites with the greatest food availability, such as refuse dumps. Both chough species will hide food in cracks and fissures, concealing the cache with a few pebbles.
This bird always forages in groups, which are larger in winter than summer, and have constant composition in each season. Where food resources are restricted, adults dominate young birds, and males outrank females. Foraging areas change altitudinally through the year, depending on climatic factors, food availability and food quality. During the breeding season, birds remain above the tree line, although they may use food provided by tourists at refuges and picnic areas.
Movement to lower levels begins after the first snowfalls, and feeding by day is mainly in or near valley bottoms when the snow cover deepens, although the birds return to the mountains to roost. In March and April the choughs frequent villages at valley tops or forage in snow-free patches prior to their return to the high meadows. Feeding trips may cover 20 km (12 mi) distance and 1,600 m (5,200 ft) in altitude. In the Alps, the development of skiing above 3,000 m (9,800 ft) has enabled more birds to remain at high levels in winter.
Where their ranges overlap, the two chough species may feed together in the summer, although there is only limited competition for food. An Italian study showed that the vegetable part of the winter diet for the red-billed chough was almost exclusively Gagea bulbs dug from the ground, whilst the Alpine chough took berries and hips. In June, red-billed choughs fed mainly on caterpillars whereas Alpine choughs ate crane fly pupae. Later in the summer, the Alpine chough consumed large numbers of grasshoppers, while the red-billed chough added cranefly pupae, fly larvae and beetles to its diet. In the eastern Himalayas in November, Alpine choughs occur mainly in juniper forests where they feed on juniper berries, differing ecologically from the red-billed choughs in the same region and at the same time of year, which feed by digging in the soil of terraced pastures of villages.


Predators of the choughs include the peregrine falcon, golden eagle and Eurasian eagle-owl, while the common raven will take nestlings.
Alpine choughs have been observed diving at a Tibetan red fox. It seems likely that this "mobbing" behaviour may be play activity to give practice for when genuine defensive measures may be needed to protect eggs or young.
The Alpine chough is a host of the widespread bird flea Ceratophyllus vagabunda, two specialist chough fleas Frontopsylla frontalis and F. laetus, a cestode Choanotaenia pirinica, and various species of chewing lice in the genera Brueelia, Menacanthus and Philopterus.


The Alpine chough has an extensive though sometimes fragmented range, estimated at 1–10 million square kilometres (0.4–3.8 million sq mi), and a large population, including an estimated 260,000 to 620,000 individuals in Europe. The Corsican population has been estimated to comprise about 2,500 birds. Over its range as a whole, the species is not believed to approach the thresholds for the global population decline criteria of the IUCN Red List (i.e., declining more than 30% in ten years or three generations), and is therefore evaluated as Least Concern.
At the greatest extent of the last glacial period around 18,000 years ago, southern Europe was characterised by cold open habitats, and the Alpine chough was found as far as south as southern Italy, well outside its current range. Some of these peripheral prehistoric populations persisted until recently, only to disappear within the last couple of centuries. In the Polish Tatra Mountains, where a population had survived since the glacial period, it was not found as a breeding bird after the 19th century. In Bulgaria, the number of breeding sites fell from 77 between 1950 and 1981 to just 14 in the 1996 to 2006 period, and the number of pairs in the remaining colonies were much smaller. The decline was thought to be due to the loss of former open grasslands which had reverted to scrubby vegetation once extensive cattle grazing ceased. Foraging habitat can also be lost to human activities such as the construction of ski resorts and other tourist development on former alpine meadows. Populations of choughs are stable or increasing in areas where traditional pastoral or other low intensity agriculture persists, but are declining or have become locally extinct where intensive farming methods have been introduced, such as Brittany, England, south-west Portugal and mainland Scotland.
Choughs can be locally threatened by the accumulation of pesticides and heavy metals in the mountain soils, heavy rain, shooting and other human disturbances, but a longer-term threat comes from global warming, which would cause the species' preferred Alpine climate zone to shift to higher, more restricted areas, or locally to disappear entirely. Fossils of both chough species were found in the mountains of the Canary Islands. The local extinction of the Alpine chough and the reduced range of red-billed chough in the islands may have been due to climate change or human activity.


Pyrrhopappus pauciflorus, commonly known as smallflower desert-chicory or Texas dandelion, is  a species of flowering plant in the family Asteraceae. It is native to the southern United States and northern Mexico. It is a weedy annual found in prairies, clay soils and disturbed habitats.


The Eurasian bullfinch, common bullfinch or bullfinch (Pyrrhula pyrrhula) is a small passerine bird in the finch family, Fringillidae.  In Anglophone Europe it is known simply as the bullfinch, as it is the original bird to bear the name bullfinch.


The Eurasian bullfinch was formally described in 1758 by Linnaeus in the 10th edition of his Systema Naturae under the binomial name Loxia pyrrhula. It is now placed in the genus Pyrrhula that was introduced in 1760 by the French zoologist Mathurin Jacques Brisson. The Latin word pyrrhula comes from the Greek πυρρός (a flame-coloured bird, from πυρρός flame coloured, from πυρ fire : Pyrrha), a 'worm eating bird' that is mentioned by Aristotle. The Latin name pyrrhula for the Eurasian bullfinch had been used in 1555 by the Swiss naturalist Conrad Gesner in his Historiae animalium.


Ten subspecies are recognised:
P. p. pileata MacGillivray, W, 1837 – British Isles
P. p. pyrrhula (Linnaeus, 1758) – north, south central and east Europe across to central Siberia
P. p. europaea Vieillot, 1816 – western Europe
P. p. iberiae Voous, 1951 – southwest France, northern Iberian Peninsula
P. p. rossikowi Derjugin & Bianchi, 1900 – northeast Turkey and the Caucasus
P. p. cineracea Cabanis, 1872 (Baikal bullfinch) – west Siberia and northeast Kazakhstan to east Siberia and northeast China
P. p. caspica Witherby, 1908 – Azerbaijan and north Iran
P. p. cassinii Baird, SF, 1869 – east Siberia
P. p. griseiventris Lafresnaye, 1841 – Kuril Islands and north Japan
P. p. rosacea Seebohm, 1882 – Sakhalin (island north of Japan)
The Azores bullfinch (P. murina), previously regarded as a subspecies of the Eurasian bullfinch, is now recognised as a separate species.


The Eurasian bullfinch is a bulky bull-headed bird. The upper parts are grey; the flight feathers and short thick bill are black; as are the cap and face in adults (they are greyish-brown in juveniles), and the white rump and wing bars are striking in flight. The adult male has red underparts, but females and young birds have grey-buff underparts. It moults between July and October, but males do not have the duller autumn plumage that is typical of some other finches. The song of this unobtrusive bird contains fluted whistles, and is often described as 'mournful'. This Bullfinch’s usual call is a quiet, low, melancholy whistled “peeu” or “pew.” The song is audible only at close range. It is a weak, scratchy warbling, alternating with soft whistles. Tamed bullfinches can be taught to repeat specific melodies.


This bird breeds across Europe and temperate Asia. It is mainly resident, but many northern birds migrate further south in the winter.  Mixed woodland with some conifers is favoured for breeding, including parkland and gardens.


This species does not form large flocks outside the breeding season, and is usually seen as a pair or family group.


The food is mainly seeds and buds of fruit trees, which can make it a pest in orchards: in England, for centuries every parish paid a bounty for every Eurasian bullfinch killed. Ash and hawthorn are favoured in autumn and early winter.  If wild bird cover is planted for it, kale, quinoa and millet are preferred, next to tall hedges or woodland.


Quercus berberidifolia, the California scrub oak, is a small evergreen or semi-evergreen shrubby oak in the white oak section of Quercus. It is a native of the scrubby hills of California, and is a common member of chaparral ecosystems.


Quercus berberidifolia grows to 1–2 metres (3+1⁄2–6+1⁄2 ft) tall, rarely to 4 m (13 ft), and has sharply toothed, dull green leaves which are 1.5–3 centimetres (5⁄8–1+1⁄8 inches) long and 1–2 cm (1⁄2–1 in) broad, leathery on their top surfaces and somewhat hairy underneath. The solitary or paired brown acorns are 1–3 cm (1⁄2–1 in) long and 1–2 cm (1⁄2–1 in) broad, and pointed or egg-shaped with thin caps when mature; they mature in about 6–8 months after pollination. In cooler, more exposed areas, scrub oak is usually a small, compact shrub, but in warm or sheltered areas the plant can spread out and grow several meters high.
The epithet berberidifolia means "barberry-leaved," referring to the spiny leaf margins characteristic of Q. berberidifolia as well as of several species of Berberis.


The species is often known simply as scrub oak, though this name is also applied to other Quercus species, especially several which were formerly grouped under the single name Q. dumosa; all are found in scrubby habitats. Many other scrub-type oaks may be found in these regions, and careful inspection is required to identify individuals of Q. berberidifolia and its hybrids.
Quercus berberidifolia sometimes hybridizes with other species.


Quercus bicolor, the swamp white oak, is a North American species of medium-sized trees in the beech family. It is a common element of America's north central and northeastern mixed forests. It can survive in a variety of habitats. It forms hybrids with bur oak where they occur together in the wild.


Quercus bicolor grows rapidly and can reach 18 to 24 meters (60 to 80 feet) tall with the tallest known reaching 29 m (95 ft) and lives up to 285 years. The bark resembles that of the white oak. The leaves are broad ovoid, 12–18 centimetres (4+3⁄4–7 inches) long and 7–11 cm (2+3⁄4–4+1⁄4 in) broad, always more or less glaucous on the underside, and are shallowly lobed with five to seven lobes on each side, intermediate between the chestnut oak and the white oak. In autumn, they turn brown, yellow-brown, or sometimes reddish, but generally, the color is not as reliable or as brilliant as the white oak can be. The fruit is a peduncled acorn, 1.5–2 cm (5⁄8–3⁄4 in), rarely 2.5 cm (1 in), long and 1–2 cm (3⁄8–3⁄4 in) broad, maturing about six months after pollination.
Swamp white oak may live up to 300 years.


Swamp white oak, a lowland tree, occurs across the eastern and central United States and eastern and central Canada, from Maine to South Carolina, west as far as Ontario, Minnesota, and Tennessee with a few isolated populations in Nebraska and Alabama. This species is most common and reaches its largest size in western New York and northern Ohio.
The swamp white oak generally occurs singly in four different forest types: black ash–American elm–red maple, silver maple–American elm, bur oak, and pin oak–sweetgum. Occasionally the swamp white oak is abundant in small areas. It is found within a very wide range of mean annual temperatures from 16 to 4 °C (61 to 39 °F). Extremes in temperature vary from 41 to −34 °C (106 to −29 °F). Average annual precipitation is from 640 to 1,270 millimetres (25 to 50 in). The frost-free period ranges from 210 days in the southern part of the growing area to 120 days in the northern part. The swamp white oak typically grows on hydromorphic soils. It is not found where flooding is permanent, although it is usually found in broad stream valleys, low-lying fields, and the margins of lakes, ponds, or sloughs. It occupies roughly the same ecological niche as pin oak, which seldom lives longer than 100 years, but is not nearly as abundant.


It is one of the more important white oaks for lumber production. The wood is similar to that of Q. alba and is not differentiated from it in the lumber trade. In recent years, the swamp white oak has become a popular landscaping tree due to its relative ease of transplanting.
Being in the white oak group, wildlife such as deer, bears, turkeys, ducks, and geese as well as other animals are attracted to this tree when acorns are dropping in the fall.


Quercus coccifera, the kermes oak, is an oak bush  in the Quercus section Cerris. It is native to the Mediterranean region and Northern African Maghreb, south to north from Morocco to France and west to east from Portugal to Cyprus and Turkey, crossing Spain, Italy, Libya, Balkans, and Greece, including Crete. The Kermes Oak was historically important as the food plant of the Kermes scale insect, from which a red dye called crimson was obtained. The etymology of the specific name coccifera is related to the production of red cochineal (crimson) dye and derived from Latin coccum which was from Greek κόκκος, the kermes insect. The Latin -fera means 'bearer'.


Quercus coccifera is usually a shrub less than 2 metres (6+1⁄2 feet) high, rarely a small tree, reaching 1–6 metres (3+1⁄2–19+1⁄2 ft) tall (a 10 m or 33 ft specimen recorded in Kouf, Libya) and 50 centimetres (20 inches) in trunk diameter. It is evergreen, with spiny-serrated coriaceous leaves 1.5–4 cm long and 1–3 cm broad. The acorns are 2–3 cm long and 1.5–2 cm in diameter when mature about 18 months after pollination. They are held in a cup covered in dense, elongated, reflexed scales.
It blooms from March to May in weather still wet. It is easily propagated by seed, an acorn that lies dormant until germinated by wet weather. This might occur anywhere from late summer to late autumn or early winter (October, November or December) of the following year. The acorns are very bitter, varying greatly in size and shape from one specimen to another and tasting bad. Acorns can germinate even before falling from the plant, but Q. coccifera is also multiplied by root suckers and layering.


The kermes oak is a scrub oak closely related to the Palestine oak (Quercus calliprinos) of the eastern Mediterranean, with some botanists including the latter in kermes oak as a subspecies or variety. The Palestine oak is distinguished from it by its larger size (more often a tree, up to 18 m) and larger acorns over 2 cm diameter.
It is called "chêne des garrigues" (garrigue oak) in French. The term "garrigue" comes from Catalan or Occitan "garric" (meaning "twisted") the name for Q. coccifera in those languages.
The common Spanish name of Q. coccifera is chaparro, which refers to its small size, a feature it shares with other oak species in similar habitats in other parts of the world, such as the chaparral communities from various parts of the Americas. The word chaparro comes from the Basque txapar meaning "little thicket".


Quercus coccifera is an important Mediterranean bush or dwarf vegetation, where the biome it dominates often bears its name (maquis, coscojar, garrigue, carrascal, chaparral, etc.). Q. coccifera forms monospecific communities or communities integrated with Pinus, mediterranean buckthorns, Myrtus, Arecaceae, junipers, Pistacia, Rosmarinus, Thymus, etc.
It is located throughout the region around the Mediterranean Sea, especially in central southern and eastern halves. It is similarly found on islands in the Mediterranean, from the Balearic Islands to Cyprus. It is common in Crete and can survive heavy sheep and goat grazing for long periods as a ground cover a few centimeters high. The same is true in Mallorca, Ibiza and the Iberian peninsula.
The species grows on dry, sunny slopes. It supports either drought summers and semi-desert climate with rainfall between 400 and 600 millimetres (16 and 24 in), with a maximum in the fall and spring. In its habitat summers are hot and winters are cold with the dry summer season with more than 35 °C, occasionally reaching over 40 °C. In winter the temperatures often drop below 0 °C. It lives in areas with moisture produced by condensation fogs, many Ground frost on clear nights and sporadic snowfalls.
A very hardy species, it grows well in all types of soils as a shrub, withstanding overgrazing.
It is indifferent to soil chemistry, living on calcareous, pebbly, stony and poor soils. A lover of warm weather, it starts to fail from 1,000 m (3,300 ft) above sea level.
It is capable of supporting the continental Mediterranean climate with extreme temperatures and low rainfall, replacing Quercus ilex (holm oak) in drier areas where it excels in drought resistance. It also grows on sea cliffs and in windy areas where other species of Quercus or Pinus cannot resist the harsh weather conditions.


Populations typically occur in desert regions without any inhabited nucleus because crops are not economically profitable and the climate becomes progressively more continental and drier and therefore end in extreme temperatures accompanied by slow-growing dwarf juniper species. It is the last species of genus Quercus to disappear when rainfall is lacking. Their ecological importance is as a habitat and food source in these areas (they have edible acorns, although with a very bitter taste) for nesting birds, foxes, rodents and wild boars. It forms thickets, thorny and dense, some recorded as tall as 5 m. It is sometimes accompanied by other plant species of the same size and climber plants such as asparagus or zarzaparrilla.
Q. coccifera is associated with several asparagus species, Crataegus monogyna, Mediterranean dwarf palm, ephedra, myrtle, several species of Junipers (Juniperus, sabinas...), Pistacia terebinthus, mastic, wild Olea europea, sarsaparilla, Rhamnus atlantica, Rhamnus lycioides, Rhamnus oleoides, Rhamnus catharticus etc. The communities receiving several characteristic names.
Kermes oaks have become scarce due to their replacement in wet zones by larger species such as Holm oak. It has also suffered from extensive culling for use as charcoal. It is the only food and shelter for wildlife in some areas, such as the Ebro valley and other dry areas where chaparral replaces oaks due to low rainfall.
It can survive heavy sheep and goat grazing for a long time as a ground carpet a few cm high, and will grow higher as a bush or a tree according to how much the grazing pressure is slackened.


It is included as an endangered species in the Red Book of Bulgaria.


The Cyprus Government has declared Quercus coccifera as the tree of the year 2014. A four-page leaflet has been published (www.moa.gov.cy/forest) with the code P.I.O. 212/2013, printed by the Government Printing Office. The name of the tree in Greek is Prinos or Pournari (Πουρνάρι). In Cyprus also is one of the biggest tree of this kind, with 17 meters tall and 700 years old, in the village of Kalopanagiotis.


Quercus cornelius-mulleri is a North American species of oak known by the common name Muller oak, or Muller's oak. It was described to science in 1981 when it was segregated from the Quercus dumosa complex and found to warrant species status of its own. It was named after ecologist Cornelius Herman Muller. It is native to southern California and Baja California, where it grows in chaparral, oak woodlands, and other habitat in foothills and mountains. It can most easily be observed in Joshua Tree National Park and in the woodlands along the western margins of the Colorado Desert in San Diego County, California.


Quercus cornelius-mulleri is a bushy shrub not exceeding 3 meters (10 feet) in height. It is densely branched, its tangled twigs gray, brown, or yellowish, fuzzy when new and becoming scaly with age.
The evergreen leaves are leathery and thick. They are bicolored: dull gray or yellow-green and faintly hairy on the upper surfaces, and white and quite woolly on the undersides. The wool on the undersides of the leaves is made up of star-shaped leaf hairs that are fused into microscopic plates. The leaf blades are oval with smooth or toothed edges, and measure 2.5 to 3.5 centimetres (1 to 1+1⁄2 inches) in length.
The fruit is an acorn with a cap up to 2 cm (3⁄4 in) wide covered in light-colored scales and a cylindrical, round-ended nut up to 3 cm (1+1⁄4 in) long.


Quercus douglasii, known as blue oak, is a species of oak endemic to (found only in) California, common in the Coast Ranges and the foothills of the Sierra Nevada. It is California's most drought-tolerant deciduous oak, and is a dominant species in the blue oak woodland ecosystem. It is occasionally known as mountain oak and iron oak.


Quercus douglasii is a medium-sized tree with sparse foliage, generally 6–20 meters (20–66 feet) tall, with a trunk 36–60 centimeters (1–2 ft) in diameter at breast height. Trunks are typically solitary, but some trees have multiple trunks. The tallest recorded specimen was found in Alameda County, at 28.7 m (94 ft). The trees grow slowly, about 30 cm (12 in) per year. Individual trees over 500 years old have been recorded.
The bark is light gray with many medium-sized dark cracks. The blue-green leaves are tough and leathery, deciduous, 4–10 cm (1+1⁄2–4 in) long, and entire or shallowly lobed. The acorns are 2–3 cm (3⁄4–1+1⁄4 in) long, with a moderately sweet kernel, and mature in 6–7 months from pollination.
Q. douglasii is monoecious and wind-pollinated. Flower buds take a growing season to develop into catkins. Blue oak pollen is severely allergenic.


The species is one of over 80 named after Scottish botanist David Douglas. The common name "blue oak" derives from the dark blue-green tint of its leaves.
Taxonomically it is placed in the white oak group (subgenus Quercus, section Quercus).


Q. douglasii prefers dry to moist soil and plenty of sunlight. Its sparse foliage allows more light to reach the ground, and young trees may grow for decades below their parents' canopies. The species often co-habitates with gray pine (Pinus sabiniana), and is also found with interior live oak (Q. wislizeni), coast live oak (Q. agrifolia), valley oak (Q. lobata), Oregon white oak (Q. garryana), and canyon live oak (Q. chrysolepis). Natural hybrids between Q. douglasii and the related Q. lobata, Q. garryana, and shrub live oak (Q. turbinella) often occur where the species grow together in the same area. Sources consider Quercus × alvordiana to be a hybrid of Q. douglasii and either Q. turbinella or Q. john-tuckeri.
Old-growth blue oak woodland may be one of the most widespread old-growth forest ecosystems remaining in the state after European colonization.


Quercus douglasii is the most drought-tolerant of California's deciduous oaks. It has a smaller canopy than less drought-tolerant relatives, and invests proportionally more growth into roots rather than leaves throughout its life cycle. The leathery blue-green leaves contribute to its drought resistance; during drought, the leaf color is more pronounced. Trees can also drop their leaves in summer rather than fall in dry years, but usually continue to develop their acorns through the fall. Drought may cause trees not to flower in spring.


Author Ron Russo writes that Q. douglasii hosts the "largest number of known species" of gall wasps, at more than 50. The wasps trigger the formation of oak galls in a wide variety of shapes, colors, and sizes.


As of 2002, the disease known as sudden oak death, caused by the oomycete Phytophthora ramorum, had not been found in Quercus douglasii or any members of the white oak group. An experiment showed that Q. douglasii and Q. lobata (another white oak) appeared to be resistant to the pathogen.


Native Californians commonly gathered Quercus douglasii acorns, which they considered good-tasting, and processed them into acorn flour. They made baskets out of blue oak seedlings, utensils such as bowls from the wood, and dye from the acorns. Commercially, the blue oak is mainly limited to use as firewood. The acorns are eaten by wildlife and livestock. They can be eaten but, if bitter, may need to have the tannins leached.


Not to be confused with Quercus gambelii Nutt., a separate species.


Quercus durata, commonly known as leather oak, is a species of oak endemic to California, common in the Coast Ranges and the foothills of the Sierra Nevada. The common name "leather oak" is derived from the leathery texture on the lop of its leaves. Taxonomically it is placed in the white oak group (subgenus Quercus, section Quercus).


As described by English horticulturist and botanist Theodore Payne, leather oak is "A rather low spreading shrub with rigid branches, foliage rich deep green. Desirable for hillside planting." Quercus durata is a short species of oak generally growing to 1–2 metres (3+1⁄2–6+1⁄2 feet) in diameter with a height of about 0.5–1.5 m (1+1⁄2–5 ft). In more extreme cases they have been known to grow to be 3–4 m across. The gray or yellowish twigs have scaly bark and are about 1–3 centimetres (1⁄2–1+1⁄4 inches) in diameter with the trunk diameter reaching 4–5 cm; the branches can be densely or sparsely distributed. The buds are smooth brown or reddish brown ovals.
The leaf blades are cupped or convex, rarely somewhat planar; their dimensions are 1.5–3 cm long and 1–1.5 cm broad densely or sparsely distributed along the branches while the margins of the leaves can be entirely or irregularly toothed. The adaxial (upper) surface of the leaves are greenish or yellowish with short semi-erect hairs; the secondary veins are obscure, dense or scattered. The abaxial (lower) surface of the leaves are covered with erect rayed hairs 1–4 millimetres (1⁄16–3⁄16 in) in length that are felty to the touch with prominent secondary veins.
The acorns of the leather oak can be found solitary or paired at the end of a small stalk; the cup which encloses up to half of the nut is reddish or yellowish with a scaly texture. The nut itself is cylindrical, measuring 1.5–2.5 cm in diameter and 1–2.5 cm long, the apex can be rounded or obtuse. Because leather oak is a species of white oak, its acorns mature in about 6 months, are hairless inside the acorn shell, and are sweet or slightly bitter tasting; the shell is mildly toxic. It is a dicot that flowers in the spring, typically April or May.


The range of Quercus durata stretches from Shasta County in Northern California to the bottom of the South Coast Range in Santa Barbara County. The most common variant is found in foothill woodlands and chaparral ecosystems at elevations between 30 and 1,570 m (100 to 5,150 ft). It is especially abundant in Sargent cypress (Hesperocyparis sargentii) woodlands which can be found in portions of Mendocino, Sonoma, San Mateo, Santa Clara, Monterey, San Benito, San Luis Obispo and Santa Barbara counties as well as the San Francisco Bay region. In more sheltered, inland areas like MacNab cypress (Hesperocyparis macnabiana) woodlands this shrub can extend into riparian zones where summer fogs persist. Q. durata is well suited for ultramafic soils which are reddish and typically nutrient poor, having abundant nickel, magnesium, and chromium content while lacking calcium. Ultramafic chaparral communities are found below 500 m (1,500 ft) from Santa Barbara County north through the North Coast Ranges and also within the foothills of the Sierra Nevada and portions of the California Central Valley. Here, Q. durata can be found with shrubs including chamise (Adenostoma fasciculatum), coffeeberry (Frangula californica), buckthorn (Rhamnus crocea) and toyon (Heteromeles arbutifolia). Scattered occurrences of canyon live oak and coast live oak are also found here. In cases outside of serpentine environments, leather oaks typically occur as isolated individuals within a backdrop of plant associations dominated by California scrub oak (Q. berberidifolia) and interior live oak (Q. wislizeni). The climate in Q. durata habitat is characterized by 41 to 170 cm (16 to 67 in) of annual precipitation during a wet season of 3 to 8 months, temperatures range from a December low of 30 °F to a July high of 96 °F. It can sustain life in soil pH between 5.5 and 8.3.
Based on controlled studies done at Jasper Ridge Biological Preserve the harsh environment of Q. durata limits species re-establishment after forest clearing or in colonization of grassland at chaparral-prairie boundaries. Low summer precipitation, high solar insolation, and herbivory are the basis for this difficulty rather than germination rates.


Occurs at elevation 370–2,290 m (1,215–7,515 ft) as a limited distribution taxon in the San Gabriel Mountains within the San Bernardino and Los Angeles counties. The dry, exposed slopes of the San Gabriels stretching from La Cañada to Pomona are covered in a chaparral with non-serpentine soils suitable for Quercus durata var. gabrielensis. The precipitation, temperature, and soil pH ranges for the gabrielensis variant are much narrower than the common variant sitting at approximately 24-47 in of water annually, 44-51 °F, and 6.4 to 6.9 pH respectively. The December low in this region is 36 °F while the July high can reach 90 °F.


When located close to species of pine, Q. durata can be infected by certain species of heteroecious rust fungi (cronartium). Leather oak is a host for the parasitic Gall Wasp Cynips washingtonensis, who deposits its larvae onto the plant and construct small 1–3 mm spherical galls on Q. durata as well as valley oak (Q. lobata) and coastal sage scrub oak (Q. dumosa). These galls appear in early spring and can be quite numerously attached to twigs and leaves; the gall is typically engulfed in a mass of velvety hairs. Crystalline gall wasp larvae (Andricus crystallinus) can form irregularly shaped, pallidal galls that agglomerate into masses, with individual galls being between 8–9 mm in length.
It is also a host plant for the sleepy duskywing (Erynnis brizo) butterfly, which sometimes feeds on nectar, and the Pacific tent caterpillar moth (Malacosoma constricta). Birds and small mammals can be attracted to the acorns.


In a study done by Narvaez et al. in 2000 with a group of goats and sheep at the Hopland Research and Extension Center, it was found that for animals employed in vegetation management programs across grass woodlands and chaparral ecosystems nutritional quality and intake levels of Q. durata and Adenostoma fasciculatum foliage were low and demonstrated a need for diet supplementation in livestock performing as part of vegetation control programs.
Native Americans peoples used leather oak as a source of food and medicine. After leaching tannins from the acorns, they would mash it into a nutritional mush that in tandem with other oak products was a staple in their diets. One prevalent leaching method was to place raw acorns in a cloth pouch and leave it in a stream for several weeks to break down. In modern times the mulch from the leather oak is applied to gardens for its efficacy in repelling slugs and grubs. After pupation the oak's gall extracts can be used in tannins and dyes.


Quercus emoryi, the Emory oak, is a species of oak common in Arizona (including inside Saguaro National Park), New Mexico and western Texas (including inside Big Bend National Park), United States, and northern Mexico (Sonora, Chihuahua, Coahuila (including Parque Nacional Maderas del Carmen), Durango, Nuevo León, and San Luis Potosí). It typically grows in dry hills at moderate altitudes.


Quercus emoryi is an evergreen tree in the red oak group, retaining its leaves through the winter until the new leaves are produced in spring, and is a large shrub or small tree from 5–17 metres (16–56 feet) tall. The leaves are 3–6 centimetres (1–2+1⁄2 inches) long, entire or wavy-toothed, leathery, dark green above, paler below. The acorns are 1.5–2 cm (5⁄8–3⁄4 in) long, blackish-brown, and mature in 6–8 months from pollination; the kernel is sweet, and is an important food for people and for certain other mammals.
The seeds of this tree are called chich’il in Ndee, wi-yo:thi or toa in O’odham, bellotas in Spanish, and acorns in English. The English and Latin botanical names for this tree come from the name of a United States Army surveyor, Lieutenant William Hemsley Emory, who, in the 1840s, surveyed the area that had become known as west Texas.


The Emory acorn is sweet and is an important food for livestock, deer, squirrels, the Gila chipmunk, and birds such as quail and wild turkeys. Deer and livestock also browse the foliage.


Native Americans such as the Apaches eat Emory acorns traditionally, ceremonially, and in contemporary cuisine; these can be ground into meal and used in many ways.
Emory oak health and habitat have been challenged in 2020, none more so than at Oak Flat, Arizona in the Tonto National Forest. The Resolution Copper mining company is planning to clear-cut the best remaining old-growth Emory oak forest in the state at this location in preparation for a destructive copper mine. Although the area at Oak Flat is protected since President Eisenhower proclaimed that it should never be mined in the 1950s, the Resolution Copper company persuaded Arizona politicians to give this federal land to them to mine copper. The oak grove at Oak Flat can never be replaced. In other areas of the Southwest, Resolution Copper is currently trying to drum up some good PR by spending money on caretaking unrelated oaks to make up for the destruction of the oak forest at Oak Flat.

According to the United States Department of Agriculture:
Emory oak acorns are a critically important resource for Western Apache Tribal Nation, both as a food source and due to its cultural and ceremonial uses. For decades, Apache elders watched in frustration as groves produced less acorn yield and declined in overall health. The ... Emory oak Collaborative Tribal Restoration Initiative is restor[ing] and protect[ing] Emory oak stands ... to ensure the long-term persistence of Emory oak. Habitat loss, fire suppression, livestock grazing, groundwater reductions, species competition and climate change have all impacted the Emory oak population. This program uses tribal traditional ecological knowledge to guide goals and activities.


Quercus engelmannii, the Engelmann oak or Pasadena oak, is a species of oak in the white oak section (Quercus sect. Quercus), native to southern California and northwestern Baja California, Mexico.


Quercus engelmannii is a small tree growing to 10 metres (33 feet) tall, generally evergreen, but may be drought-deciduous during the hot, dry local summers, and has a rounded or elliptical canopy. The bark is thick, furrowed, and light gray-brown. The leaves are leathery, 3–6 centimetres (1+1⁄4–2+1⁄4 inches) long and 1–2 cm (1⁄2–3⁄4 in) broad, of a blue-green color, and may be flat or wavy, with smooth margins. The flowers are catkins; the fruit is an acorn 1.5–2.5 cm (1⁄2–1 in) long, maturing 6–8 months after pollination.
The wood is dark brown and strong, but tends to warp and split upon drying, and is of low value as timber.


The Engelmann oak ranges from the foothills of the San Gabriel Mountains in eastern Los Angeles County through the Santa Ana Mountains of Orange County and the western foothills and mesas of the Peninsular Ranges in Riverside and San Diego counties, extending into the Sierra Juárez and Sierra de San Pedro Mártir ranges of northern Baja California. It is generally found in savannas and woodlands above the dry coastal plain, but below the 1,300 m (4,300 ft) elevation where colder winters prevail. The Engelmann oak has a smaller range than most California oaks, and suburban sprawl in the San Gabriel Valley has eliminated the oaks from most of the northern part of the range. The largest remaining stands of Engelmann oaks are on the Santa Rosa Plateau, near Murrieta in Riverside County, and on Black Mountain near Ramona in San Diego County.
Fossil evidence shows that Engelmann oaks once had a wider range, extending through what is now the Mojave and Sonoran deserts into eastern California and Arizona. The Engelmann oak is most closely related to the Arizona white oak (Q. arizonica) and Arizona blue oak (Q. oblongifolia), which are native to the subtropical pine-oak woodlands of Arizona and northern Mexico. The Engelmann oak is considered to be the northernmost species of subtropical oak, which was isolated from its closest relatives to the east by the drying of the southwestern deserts.


Quercus falcata,  also called southern red oak, spanish oak, bottomland red oak or three-lobed red oak is an oak (part of the genus Quercus). Native to the southeastern United States, it gets its name the "Spanish Oak" as these are the areas of early Spanish colonies, whilst "southern red oak" comes from both its range and leaf color during late summer and fall. The southern red oak is a deciduous angiosperm, so has leaves that die after each growing period and come back in the next period of growth.


Quercus falcata is a medium to large-sized deciduous tree 25–30 meters (82–98 feet) tall, with a few forest grown specimens on highly productive sites reaching 35–44 m (115–144 ft), with a trunk up to 1.5 m (5 ft) in diameter, the crown with a broad, round-topped head.
The leaves are 10–30 centimetres (4–12 inches) long and 6–16 cm (2+1⁄4–6+1⁄4 in) wide, with 3 to 5 sharply pointed, often curved, bristle-tipped lobes, the central lobe long and narrow; the small number of long, narrow lobes is diagnostic, readily distinguishing southern red oak from other red oaks. The base of the leaf is distinctly rounded into an inverted bell shape and often lopsided. They are dark green and shiny above, and rusty and hairy below, particularly along the midrib and veins.
The seed is a short acorn 9–16 millimetres (11⁄32–5⁄8 in) long, bright orange-brown, enclosed for one-third to half of its length in a flat cup. The acorn matures at the end of its second season. The bark is dark brownish gray with narrow, shallow ridges.


The southern red oak is a member of the beech family (Fagaceae) and 1 of the 207 oak species in the U.S, and is in the  section of the Quercus genus Lobatae, the red oaks. Quercus falcata has the following synonyms: Quercus aurea, Q. digitate, Q. elongate, Q. hudsoniana, Q. hypophlaeos, Q. nobilis and Q. triloba. Q. falcata was described in 1801 by Andre Michaux. Several southern red oak hybrids have been described including Quercus × caesariensis (Q. falcata × Quercus ilicifolia) and Quercus × beaumontiana (Q. falcata × Quercus laurifolia).


Quercus, is Latin for "oak" and followed by the specific epithet, falcata, which in Latin means "sickle-shaped" in reference to the shape of the lobes that are present on their leaves.


Quercus falcata occurs in sandy, loamy or clay soils of upland sites. These soils are often dry, acidic and nutrient poor. In suitable habitats, the species can be found from southern New York (Long Island) south to central Florida and west to Missouri, Oklahoma, and Texas. In the northeastern portion of its range the species is relatively rare and found almost exclusively along the coast; its highest prevalence is throughout the piedmont region of the Southeast.


Southern red oak has been reported to form occasional hybrids with several other red oaks in the region.
The southern red oak is susceptible to damage as a result of its relatively thin bark. This thinner bark means that fire can easily damage the trees in the form of fire scars and other damage. Bark roughness increases in xeric sites compared to mesic ones potentially an adaptation to fire frequency. The seedlings of southern red oak can survive prescribed fire in winter. The harm caused by fire can leave the tree vulnerable to heart rots.
When exposed to the fungi, Ceratocystis fagacearum, the southern red oak (along with other oak species) will suffer from wilting of leaves, reducing rate of photosynthesis to such a low level that mortality can occur. Fungi invades xylem via infected water, blocking the vessels and prevents normal flow of water up through the tree. This fungus can cause the wilting of oak leaves and eventual death. Oak wilt does not currently appear to be damaging the population, but with the Southern Red Oak being seen as a species of major importance to ecosystems, efforts to prevent oak wilt are being taken. In attempts to manage oak wilt, an integrated approach is adopted, combining root disruption, sanitation, and chemical application to tackle the issue. The goal of root disruption is to prevent any infected trees coming into contact with those that are healthy by root grafts. This means putting trenches, plow line or even a barrier to prevent roots of infected trees coming into contact of those that are healthy. Sanitation measures focus on removing the source of potential spread of disease, the trees that are infected. This can mean just removal of individuals who were infected or even removal of all trees that fall within the infection centre. Finally, there are chemical applications that involve application of fungicides to healthy individuals to prevent them becoming infected, or a therapeutic fungicide that cannot cure the tree but reduces intensity and onset of symptoms. Often the fungicide propiconazole is used.


The southern red oak is cultivated in eastern United States in USDA Zone 5a to USDA Zone 9b.
It can survive lows from -23°c to -28.8 °C (-10°f to -20 °F) and highs of 38° C (100° F).


The southern red oak is a tree with diverse potential uses, such as for manufacturing of floors, furniture, construction materials and lumber thanks to the sturdy, durable and coarse-grained wood it provides. The southern red oak is vital in the southeastern United States due to its abundance, providing around 8.1% of annual hardwood volume. Southern red oak wood is used as a fuel source because of its high heat value. The southern red oak provides tannin, which is used to preserve and treat leather. The southern red oak has a large root system that provides watershed protection to reduce flood damage and soil stability. Other uses for southern red oak include as shade trees and aesthetic uses in gardens. Southern red oak can provide acorn mast for deer, squirrels, turkeys, song birds and quail.


Quercus garryana is an oak tree species of the Pacific Northwest, with a range stretching from southern California to southwestern British Columbia. It is commonly known as the Oregon white oak or Oregon oak or, in Washington state and Canada, the Garry oak. It grows from sea level to an altitude of 690 feet (210 metres) in the northern part of its range, and from 980 to 5,900 ft (300 to 1,800 m) in the south of the range in California. The eponymous Nicholas Garry was deputy governor of the Hudson's Bay Company.


It is typically of medium height, growing slowly to around 80 feet (24 metres) and occasionally as high as 100 ft, or in shrub form to 10 to 15 ft (3 to 4+1⁄2 m) tall. The trunks grow to 3 feet (0.91 m) thick, exceptionally 5 ft (2 m). The bark is gray and fissured. It has the characteristic oval profile of other oaks when solitary, but is also known to grow in groves close enough together that crowns may form a canopy. The leaves are deciduous, 2–6 inches (5.1–15 cm) long and 1–3 inches broad, with 3–7 deep lobes on each side, darker green on top and finely haired below. The flowers are catkins, the fruit a small acorn 3⁄4–1 inch (rarely 1 1⁄2 inches) long and 1⁄2–3⁄4 inch broad, with shallow, scaly cups. Its fall color is unspectacular, with many trees turning plain brown. Other individuals may have subtle mixtures of brown, green and yellow, or in less common cases a fairly bright 'peas and corn' effect.
The Oregon white oak is commonly found in the Willamette Valley hosting the mistletoe Phoradendron flavescens. It is also commonly found hosting galls created by wasps in the family Cynipidae. 'Oak apples', green or yellow ball of up to 5 cm in size, are the most spectacular.  They are attached to the undersides of  leaves.  One common species responsible for these galls is Cynips maculipennis.  Other species create galls on stems and leaves.  Shapes vary from spheres to mushroom-shaped to pencil-shaped.
Individual specimens can grow to around 500 years in age, such as those on Sauvie Island near Portland, Oregon.


David Douglas discovered the species in the 1820s and named it after Nicholas Garry, who was deputy governor of the Hudson's Bay Company from 1822–1835 and a supporter of Douglas.


There are three varieties:
Quercus garryana var. garryana – tree to 65 (100) ft. British Columbia south along the Cascades to the California Coast Ranges.
Quercus garryana var. breweri – shrub to 15 ft; leaves velvety underneath. Siskiyou Mountains.
Quercus garryana var. semota – shrub to 15 ft; leaves not velvety underneath. Sierra Nevada.


In Oregon, the tree grows on the west side of the Cascade Range, primarily in the Willamette, Umpqua and Rogue River valleys, and along the Columbia River Gorge, as well as in canyons adjacent to the gorge.
In California, the garryana variety grows in the foothills of the Siskiyou and Klamath Mountains, the Coast Ranges of Northern California, and of the west slope of the Cascades.  The semota variety grows in the Sierra Nevada and Coast Ranges as far south as Los Angeles County.
In Washington, the tree grows on the west side of the Cascade Range, particularly in the Puget Sound lowlands, the northeastern Olympic Peninsula, Whidbey Island, the Chehalis river valley, and the San Juan Islands. It also grows in the foothills of the southeastern Cascades and along the Columbia River Gorge.
In British Columbia, the Garry oak grows on the Gulf Islands and southeastern Vancouver Island, from west of Victoria along the east side of the island up to the Campbell River area.  There are also small populations along the Fraser River on the British Columbia mainland. The northernmost population of Garry oak can be found just below 50°N on Savary Island, in the northern stretches of the Strait of Georgia. The Garry oak is the only oak native to British Columbia, and one of only two oaks (along with the bur oak) native to western Canada.


It is a drought-tolerant tree. Older specimens are often affected by heart rot.
The acorns are consumed by wildlife and livestock. David Douglas recorded that bears consumed them.
In British Columbia, the Garry oak can be infested by three nonnative insects:  the jumping gall wasp Neuroterus saltatorius, the oak leaf phylloxeran, and the gypsy moth.
While the invasive plant disease commonly called sudden oak death attacks other Pacific Coast native oaks, it has not yet been found on the Oregon white oak.  Most oak hosts of this disease are in the red oak group, while Oregon white oak is in the white oak group.


Oregon white oak is the only native oak species in British Columbia, Washington, and northern Oregon. In these areas, oak woodlands are seral, or early-successional; they depend on disturbance to avoid being overtaken by Douglas-fir (Pseudotsuga menziesii). The disturbance allowing oak to persist in an area that would otherwise succeed to coniferous forest was primarily fire. Natural wildfires are relatively common in the drier portions of the Pacific Northwest where Oregon white oak is found, but fire suppression has made such events much less common. In addition, early settlers' records, soil surveys, and tribal histories indicate that deliberate burning was widely practiced by the indigenous people of these areas. Fire perpetuated the grasslands that produced food sources such as camas, chocolate lily, bracken fern, and oak; and that provided grazing and easy hunting for deer and elk. Mature Oregon white oaks are fire-resistant, and so would not be severely harmed by grass fires of low intensity. Such fires prevented Douglas-fir and most other conifer seedlings from becoming established, allowing bunch grass prairie and oak woodland to persist. Fire also kept oak woodlands on drier soils free of a shrub understory. Wetter oak woodlands historically had a substantial shrub understory, primarily snowberry.
Oregon white oak woodlands in British Columbia and Washington are critical habitats for a number of species that are rare or extirpated in these areas, plant, animal, and bryophyte:
Propertius duskywing butterfly Erynnis propertius, sole larval food plant is oak
Bucculatrix zophopasta leaf-mining moth, sole larval food plant is oak
Lewis woodpecker Melanerpes lewis
Slender billed nuthatch Sitta carolinensis aculeata
Sharp tailed snake Contia tenuis
Western gray squirrel Sciurus griseus
Western tanager Piranga ludoviciana
Western wood peewee Contopus sordidulus
Western bluebird Sialia mexicana
Sessile trillium Trillium parviflorum
Banded cord-moss Entosthodon fascicularis
Apple moss Bartramia stricta
(liverwort) Riccia ciliata
Golden Paintbrush Castilleja levisecta
Quercus garryana woodlands create a landscape mosaic of grassland, savanna, woodland, and closed-canopy forest.  This mosaic of varied habitats, in turn, allows many more species to live in this area than would be possible in coniferous forest alone.  Parks Canada states that Garry oak woodlands support more species of plants than any other terrestrial ecosystem in British Columbia.  It grows in a variety of soil types, for instance, rocky outcrops, glacial gravelly outwash, deep grassland soils, and seasonally flooded riparian areas.
The Donation Land Claim Act of 1850 encouraged settlement of Washington and Oregon by the United States and marked the beginning of the end of regular burning by native peoples of the area. The arrival of Europeans also reduced the number of natural fires that took place in Oregon white oak habitat. With fire suppression and conversion to agriculture, oak woodlands and bunch grass prairies were invaded by Douglas-fir, Oregon ash (Fraxinus latifolia), and imported pasture grasses. Oaks were logged to clear land for pasture, and for firewood and fence posts. Livestock grazing trampled and consumed oak seedlings. By the 1990s, more than half the Oregon white oak woodland habitat in the South Puget Sound area of Washington was gone. On Vancouver Island, more than 90% was gone, and on Whidbey Island up to 99% of native understory Oregon white oak habitat is gone. Remaining Oregon white oak woodlands are threatened by urbanization, conversion to Douglas-fir woodland, and invasion by shrubs, both native and nonnative (Scotch broom Cytisus scoparius, sweetbriar rose Rosa eglanteria, snowberry Symphoricarpos albus, Indian plum Oemleria cerasiformis, poison-oak Toxicodendron diversilobum, English holly Ilex aquifolium, bird cherry Prunus avens).
Conversely, oak groves in wetter areas that historically had closed canopies of large trees are becoming crowded with young oaks that grow thin and spindly, due to lack of fires that would clear out seedlings.
Chionodes petalumensis caterpillars feed on oak leaves, including those of Quercus garryana and valley oak (Q. lobata).


Oregon white oaks and their ecosystems are the focus of conservation efforts, including communities such as Tacoma, Washington, where an Oak Tree Park has been established; Oak Bay, British Columbia, which is named after the tree; and Corvallis, Oregon, which has protected the oak savannah remnants around Bald Hill. Oak Harbor, Washington, named after the tree and home to Smith Park that contains a dense grove of mature Garry Oak trees, is actively pursuing conservation of the city's namesake tree with the formation of the Oak Harbor Garry Oak Society.
In Southwest Washington, significant acreages of Oregon white oaks are preserved in the Scatter Creek Wildlife Area, in sites such as the Scatter Creek Unit, which contain some of the few remaining areas of south Puget Sound prairie.
In Oak Bay, British Columbia, a fine of up to $10,000 may be issued for each Garry oak tree cut or damaged.


The mildly sweet (but perhaps unpalatable) acorns are edible, ideally after leaching. The bitterness of the toxic tannic acid would likely prevent anyone from eating enough to become ill. Native Americans ate the acorns raw and roasted, also using them to make a kind of flour.
The hardwood is hard and heavily ring-porous. It has distinctive growth rings and prominent rays. Heartwood can be a deep chocolate brown color and sapwood will vary from golden brown to nearly white. This makes it particularly attractive to woodworkers, however it can be difficult to use in woodworking without experiencing warping and cracking. Although it was popularly used around the turn of the 20th century, historically, the tree has not been regarded as having significant commercial value and is frequently destroyed as land is cleared for development. The wood is suitable for making fence posts. With similar qualities to those of other white oaks, the wood has been used experimentally in Oregon for creating casks in which to age wine. In Washington, it has been used for aging single malt whiskey since the 2010s. Oregon white oak barrels are said to give the product "burnt sugar notes, marshmallow sweetness, and a light floral character that showcases the best of the Garry oak".
When used as firewood, Oregon white oak produces 28 million British thermal units per cord (2.3 MWh/m³) burned.


Quercus ilex, the evergreen oak, holly oak or holm oak is a large evergreen oak native to the Mediterranean region. It is a member of the Cerris section of the genus, with acorns that mature in a single summer.


An evergreen tree of large size, attaining in favourable places a height of 21–28 metres (69–92 feet), and developing in open situations a huge head of densely leafy branches as much across, the terminal portions of the branches usually pendulous in old trees. The trunk is sometimes over 6 m (20 ft) in girth. The young shoots are clothed with a close gray felt. The leaves are very variable in shape, most frequently narrowly oval or ovate-lanceolate, 4–8 centimetres (1+1⁄2–3 inches) long, 1.2–2.5 cm wide, rounded or broadly tapered at the base, pointed, the margins sometimes entire, sometimes (especially on young trees) more or less remotely toothed. When quite young, both surfaces are clothed with whitish down, which soon falls away entirely from the upper surface leaving it a dark glossy green; on the lower surface it turns gray or tawny, and persists until the fall of the leaf; the petiole is 3–16 millimetres (1⁄8–5⁄8 in) long. The fruits are produced one to three together on a short downy stalk, ripening the first season; the acorns usually 12–18 mm long in the UK, the cups with appressed, downy scales.


The resemblance of the foliage to that of the common European holly, Ilex aquifolium, has led to its common and botanic names. The name ilex was originally the classical Latin name for the holm oak, but later adopted as a botanical genus name for the hollies.
Quercus rotundifolia was previously thought to be part of this species, but was later moved to its own.
The common name 'holm oak' takes its name from holm, an ancient name for holly.


Holm oak grows in pure stands or mixed forest in the Mediterranean and often at low or moderate elevations.
Quercus ilex is prevalent from Greece to certain parts of the Iberian Peninsula, where it mixes with Q. rotundifolia, along the northern Mediterranean coastal belt.


The wood is hard and tough, and has been used since ancient times for general construction purposes as pillars, tools, wagons (as mentioned in Hesiod, Works and Days on page 429), vessels and wine casks. It is also used as firewood and in charcoal manufacture.
The holm oak is one of the top three trees used in the establishment of truffle orchards, or truffières. Truffles grow in an ectomycorrhizal association with the tree's roots.
Q. ilex can be clipped to form a tall hedge, and it is suitable for coastal windbreaks, in any well drained soil. It forms a picturesque rounded head, with pendulous low-hanging branches. Its size and solid evergreen character gives it an imposing architectural presence that makes it valuable in many urban and garden settings. While holm oak can be grown in much of maritime northwestern Europe, it is not tolerant of cold continental winters. It is a parent of Quercus × turneri, along with Quercus robur.

The first trees to be grown from acorns in England are still to be found within the stately grounds of Mamhead Park, Devon. From Britton & Brayley in The Beauties of England and Wales (1803):
The woods and plantations of Mamhead are numerous and extensive. Many of them were introduced by Mr Thomas Balle (sic), the last of that family who, on returning from the continent brought with him a quantity of cork, ilex, wainscot, oak; Spanish chestnut, acacia, and other species of exotic trees.


BBC News (2008) Holm Oak: Garden Invader
Royal Botanic Garden (2008) Flora Europaea: Quercus ilex
W.J. Bean (1976) Trees and shrubs hardy in the British Isles 8th ed., revised. John Murray.
C. Michael Hogan (2008) Barbary Macaque: Macaca sylvanus, Globaltwitcher.com, ed. N. Strõmberg
Holm Oak (2002)
K. Rushforth (1999) Trees of Britain and Europe. HarperCollins ISBN 0-00-220013-9.
Chênes: Quercus ilex (in French)


Quercus ilicifolia, commonly known as bear oak or scrub oak, is a small shrubby oak native to the eastern United States and southeastern Canada. Its range extends in the United States from Maine to North Carolina, with reports of a few populations north of the international frontier in Ontario. The name ilicifolia means "holly-leaved."


Quercus ilicifolia is a deciduous tree or shrub growing occasionally reaching a height of 6 meters (20 feet) but usually much smaller. It is "gangly" and can form a dense thicket. The plant grows from a large taproot which can be up to 20 centimeters (8 inches) thick. The taproot lives a long time, producing several generations of above-ground parts. The alternately arranged leaves are each up to 15 cm (6 in) long by 10 cm (4 in) wide. The species is monoecious, with plants bearing both male catkins and solitary or clustered female flowers. The egg-shaped acorn is 1 to 2 cm (1⁄2 to 3⁄4 in) long with a saucer-shaped cap. The plant reproduces sexually by seed and also vegetatively by sprouting new stems.


Quercus ilicifolia is a dominant plant species in a number of regions and habitat types. In Maine it can be found in deciduous forests alongside red maple (Acer rubrum), gray birch (Betula populifolia), and quaking aspen (Populus tremuloides). In Massachusetts it codominates with black huckleberry (Gaylussacia baccata) on the shrublands of Nantucket and Martha's Vineyard. On Cape Cod it occurs with pitch pine (Pinus rigida) and broom crowberry (Corema conradii). It can be found on the Pine Barrens of New Jersey and pine barrens habitat on Long Island. It also occurs in fire barrens on granite and gneiss further north in Canada. This oak is adapted to disturbance in the habitat, such as wildfire. Hence, it does not tolerate shade and it requires disturbance to remove other plant species so it can receive sunlight. It sprouts prolifically after fire burns away its above-ground parts.
Quercus ilicifolia is also known to rocky summits in the Piedmont of North Carolina where it is listed as a State Endangered Plant.


Quercus ilicifolia provides food and shelter for many animal species. Bears consume the bitter acorns, especially when preparing for hibernation. White-tailed deer eat the acorns and the stems and foliage. Many types of squirrels cache the acorns. Many birds depend on them; wild turkeys prefer them over other types of food. A large number of insect species live on the oak. This oak species is the main food plant for 29% of the rare or endangered Lepidopterans in southern New England and southeastern New York.


Quercus ilicifolia has been used in revegetation projects on the Fresh Kills Landfill on Staten Island.


Quercus imbricaria, the shingle oak, is a deciduous tree in the red oak group of oaks. It is native primarily to the Midwestern and Upper South regions of North America.