Bianky V.V.,Kandalaksha State Nature Reserve |
Dzerzhinsky F.Ya.,Moscow State University |
Grintsevichene T.I.,Moscow State University
Zoologicheskii Zhurnal | Year: 2013
Smew, as mergansers of the genus Merganser, is a hunter of agile underwater preys. Its trophic niche is close to that of grebes (Podicepediformes), shags (Phalacrocoracidae: Pelecaniformes), and so on. All of these non-anatid birds are characterized by the inclined position of adductor mandibulae externus muscle controlling both jaws together, while pterygoideus muscle only transmits the retraction force generated by the external adductor to the upper jaw. This functional limitation is imposed on the pterygoideus muscle by the special arrangement of quadrato-mandibular articulation, which allows to expand the mandible sideways actively (by bending its branches) to suck in water, which would be otherwise pushed away together with the food particles during the bill closure. On the contrary, in all anatids, the muscular control of the upper and lower jaws is separate, probably because of their ancestral adaptation to detach food (such as leaves). Due to the different structure of their quadrato-mandibular joint, the action of these two muscles is applied to the jaws independently. The external adductor pulls the mandible up, while the pterygoid muscle draws the upper jaw down itself. As anatids, mergansers, including smew, do not have some morpho-functional prerequisites for an automatic force balance between the two jaws, as well as for active expansion of the lower one. However, anatids are used to dive and search for food underwater, and so mergansers and smew have got an opportunity to develop the ability to hunt actively swimming prey. Their jaws are relatively weak, but they are equipped with denticles derived from lamellas of rhamphotheca that help to capture prey, while the water stream is controlled by their large and strong tongue.
Bianki V.V.,Kandalaksha State Nature Reserve
Zoologicheskii Zhurnal | Year: 2012
An appeal to stop illegal extermination has been repeated in publications on birds of the White Sea since the 18th century. As a result, the Kandalaksha Eider Nature Reserve was established. Its researchers mainly studied the biology of common eider and Charadriiformes and Anseriformes and accomplished their monitoring at the White Sea. Passerines received less attention. The investigations were conducted at the station in Kandalaksha Bay and other sites of the White Sea. This paper contains a review of publications on the results of these studies. Expeditions and long-term studies of specialists from the Academy of Sciences and universities were of less importance in studies of the reserve territory. Recently, the number of ornithologists working at the White Sea has increased and the studies of the White Sea became more sophisticated, although the monitoring character of investigating the ecology and fauna continues to prevail.
Koryakin A.S.,Kandalaksha State Nature Reserve
Zoologicheskii Zhurnal | Year: 2012
The paper presents data of the Nature Chronicle of the Kandalaksha State Nature Reserve on nesting seabirds counts (common eider, turnstone, oystercatcher, herring, great black-backed and common gulls) in the reserved areas of the Kandalaksha Bay for 1967-2010. The reserved territory was significantly enlarged in 1967-1977 resulted in the i ncrease of the number of all species. The common eider population had two peaks ofthe numbers (1967 and 1997). In 1960-1980, helminthiasis and disturbance of broods influenced the eider reproduction. Since the early 1990s, the predation during incubational periods was the main factor limiting the eider reproduction. After rising the number of populations of turnstone, oystercatcher, and common gull, there were relatively stable periods followed by a gradual decline in their numbers. In herring and great blackbacked gulls, peaks in their numbers were immediately substituted for a sharp decline. After 1995, the number of nesting pairs in all these species became lower. Presently, the main factor that limits the reproduction success and determines the distribution of nest colonies in seabirds is predation. The main predators are brown bear and white-tailed sea eagle. In the period of increasing the populations of seabird, both species had minimal numbers. In the 1990s, their number quickly increased resulting from ceasing ofhunt (bear) and efficient protection of the species (white-tailed sea-eagle).
Makarova O.L.,RAS A.N. Severtsov Institute of Ecology and Evolution |
Osadtchy A.V.,Kandalaksha State Nature Reserve |
Melnikov M.V.,Kandalaksha State Nature Reserve
Entomological Review | Year: 2010
Examination of 31 nests of 6 common passerine bird species collected on the Seven Islands Archipelago (the Barents Sea) revealed 25 species of gamasid mites. Most of them belonged to the widespread free-living species commonly occurring in the neighboring taiga and southern tundra areas. There were practically no true Arctic forms among the gamasids found; by contrast, the local flora consisted almost by half of Arctic and Hypoarctic species. The findings of only one species, Neoseiulus cf. tobon, appear to be restricted to the Arctic, while the range of the rare parthenogenetic Iphidinychus gaieri may be restricted to Hypoarctic and mountainous regions of Eurasia. No bird parasites were recorded. Host specificity of the mite assemblages of the nests was not observed. © 2010 Pleiades Publishing, Ltd.