Biological Station Rybachy
Biological Station Rybachy belongs to the Zoological Institute of the Russian Academy of Sciences in St. Petersburg. It employs 10 biologists and 12 persons of administration and technicians. Apart from them, undergraduate and graduate students from different universities do research and study for their theses here.
The station occupies a two-storey building in Rybachy. The station has facilities for keeping experimental birds and experimental work. The digitised database includes information on sex, age, biometrics and moult status of more than 3 million individual birds of 200 species. Some 30 000 – 40 000 new records are added to the database annually.
Eleven kilometres south-west of Rybachy, and 23 km from the base of the Courish Spit, is located the Fringilla field station that is in operation since 1957. It now operates two large Rybachy-type traps for catching transient migrants. The field station is maintained by the researchers of the station and volunteers.
The Courish = Curonian Spit on the Baltic Sea is a strip of sandy terrain, 97 km in length and 0.4 to 3.6 km in width separating the Courish Lagoon from the Baltic Sea. It has been known since the end of 19th century for its huge concentration of migrating birds. The chain of sand dunes up to 68 m in height stretches from north-east to south-west which corresponds to the main direction of bird migration in this part of Europe. Annually during autumn migration, over 10 million landbirds of various species that avoid sea crossings during daytime, use the Courish Spit as a bridge for their flight. On some autumn days the number of birds flying along the spit may reach 500 000 per day.
The importance of the Courish Spit for bird migration research became obvious before the end of the 19th century, when it was first visited by Johanness Thienemann, who later became a prominent German ornithologist. In 1901 he established ‘Vogelwarte Rossitten’, the world’s first bird observatory, in Rossitten, now Rybachy, for the study of bird migration. Thienemann was the head of the station until 1929, followed by Prof. Ernst Schüz.
Vogelwarte Rossitten was the world’s first institution to undertake the large scale ringing of birds. E. Schüz and O. Weigold published the first atlas of bird migration as early as 1931. World War II interrupted the ornithological studies on the Courish Spit. They did not recommence until 1956 when Professor Lev Belopolsky established at Rybachy the Biological Station of the Zoological Institute, USSR Academy of Sciences. The station was created by a decision of the Board of the Academy of Sciences with the purpose of studying of bird migration and with the continuation of the scientific tradition begun by German researchers.
Under the leadership of Prof. Belopolsky who was enthusiastic about trapping and ringing large numbers of birds, Janis Jakšis built in 1957 the first ‘large Rybachy trap’. It was made on the same principle as the Heligoland trap, but differs from the latter in having a nonrigid body and by its huge size (entrance up to 30 m, height up to 15 m). The large Rybachy trap resembles a huge fishing trawl fixed on the ground and open to migrating birds. Due to the large size of the trap birds do not perceive it as a source of danger. They enter the trap and in most cases reach its end chamber by themselves, from where then they may be extracted by hand. Up to several thousand birds can be trapped by one standard Rybachy trap in a day. Over 3 million individuals have been trapped and ringed since 1957. On average 30 000 – 40 000 birds are trapped and ringed by this method annually.
Songbirds are most commonly caught, e.g. Chaffinches, Siskins, Goldcrests, Willow Warblers, Great Tits, Starlings, etc. The most numerous non-passerines caught are Sparrowhawks, Long-eared Owls, Great Spotted Woodpeckers and Cuckoos. Each year the traps are open 24 hours a day from 1 April till 1 November. This allows a unique monitoring of biodiversity, numbers, timing of migration, as well as sex and age structures, and the physical state of different birds arriving from northern and north-eastern Europe.
Apart from migrating birds, local breeders also get into the traps. Many of them are repeatedly trapped throughout the year or in subsequent years, which permit the regular monitoring of local populations. We have so far obtained 9000 long-distance recoveries and 30 000 recaptures from our birds ringed. Massive trapping and marking of birds still remain of the priorities in the work of the Biological Station Rybachy. Our main aim is the research into various aspects of annual cycle of birds, especially bird migration.
Currently, we are performing scientific investigations funded by the RSF grant #17-14-01147 (2017–2019) “Sensory systems underlying short- and long-distance navigation in birds”.
Summary of the grant project. The question how migratory animals, especially migratory birds, are able to reach distant destinations is one of the most discussed questions in current biology. Some bird species are capable to perform long-distance navigation. Numerous displacement experiments with a growing list of bird species have clearly shown that displaced birds can reach migratory destinations even from unfamiliar regions situated far aside from their migratory routes. The question what natural cues birds use for positioning and navigation remains unanswered. A conceptual approach to explain bird navigation was proposed in the mid-20th (Kramer 1953) and assumes a two-step process by solving navigational task: first, the animal determines its position relative to the goal (a ‘map’ step), and second, the animal chooses and maintains direction leading towards its desired goal (a ‘compass’ step). Whereby the natural cues used for these two steps could be different. In the last 60 years, the nature of compass cues and compass sensory mechanisms have been actively studied. It is now well established that birds can use stars, solar and geomagnetic cues for directions (Wiltschko & Wiltschko 2015; Chernetsov 2016 for reviews). However, the sensory nature of the ‘map’ (or positioning) system remains understudied. Our research will address the sensory nature of the ‘map’ and sensory mechanisms required for navigation in birds. We will build on recent literature and our own achievements in the field of bird navigation. In the recent literature, there are two most discussed and not mutually exclusive hypotheses explaining sensory nature of bird navigation – a magnetic navigation hypothesis and an olfactory navigation hypothesis. Some researchers have assumed that different natural cues may fit best for different geographic scales and/or different ecological groups of birds may have been adapted to perform navigation using appropriate environmental cues. More specifically, studies using some seabirds (e.g., shearwaters and gulls) and homing pigeons (Columba livia f. domestica) have suggested that the sense of smell is important for their navigational abilities supporting the olfactory hypothesis. It remains unclear however whether all or only some birds use olfaction for navigation, what volatile compounds (odours) are used for positioning and what is the geographic scale where such an approach is suitable. In parallel, our recent studies in some songbird species (Eurasian reed warbler, Acrocephalus scirpaceus) have strongly suggested that the geomagnetic field is necessary and sufficient for positioning across large (100s of kilometers) distances. The latter supports the magnetic navigation hypothesis. We will apply an integrated set of approaches to study the role of both magnetic and olfactory senses for bird navigation, and experimentally examine the two hypotheses of navigation across different geographic scales spanning from a just a few kilometers to ≥1,000 km. We will also test the hypothesis that putative magnetoreceptors may co-locolize with olfactory receptors.