1. The bird you saw was common - unless you can prove otherwise. There is no exception to this rule.
2. If you're uncertain about you bird's identification, it was probably what you first thought it was. Whatever it was, it must have been common.
3. The more gorgeous a bird's plumage, the less melodious the song; and conversely, the more drab the plumage, the more mellifluous the song. The European exception to this rule is the gorgeous Golden Oriole, which includes a loud, fluty yodel amongst his repertoire. The American exception is the colourful Cardinal, that sings beautifully. And the Australian exception is the Golden Whistler.
4. When males and females of a species duet, they look the same. The exceptions are Europe's Linnet and Australia's Magpie-lark.
5. Where males and females look different, the plainer bird rears the young. When the sexes look alike, they share parenting. The exception to this rule is the South American Chachalaca, where both sexes look the same and the female is left to do all the parenting alone.
|Where the sexes look alike (such as these Apostlebirds) they share parenting.|
6. Birds won't nest in trees or shrubs that are flowering or fruiting. You'll have fun finding your own exceptions to this rash generalisation. Personally, I haven't found one yet. I don't think the Californian Phainopepla that nests in trees with fruiting mistletoe really counts.
7. Birds that nest in dark hollows lay white, rounded eggs. The exception is Australia's treecreepers that lay glossy googies, which are splotched brown.
8. Migrating birds always breed in the colder area. The exceptions to this rule are Arctic Terns that breed in the Artic then migrate to the Antarctic, and some Eurasian Curlews that breed on continential Europe then winter in Iceland.
9. Nocturnal birds have large eyes to allow them to see well at night. The exception is New Zealand's kiwis that have tiny eyes: they feed by touch and smell.
10. Only non-passerines regularly feed at night, and they are all carnivorous. The exceptions are non-passerines that are not carnivorous. These are some nocturnal vegetarian parrots, and South America's nocturnal Oilbird that feeds on fruit.