Birds of High-Mountain Daghestan, a Report Based on Two Decades Bird Survey
Total Page：16
File Type：pdf, Size：1020Kb
Journal of Wildlife and Biodiversity 4(2): 73-84 (2020) (http://jwb.araku.ac.ir/) Scientific Report DOI: 10.22120/jwb.2020.115601.1098 Birds of High-mountain Daghestan, A report based on two decades bird survey that include representatives of not only High- Evgeny Ev Vilkov mountain, Intra-mountain, and Piedmont Caspian Institute of Biological Resources, Daghestan but also of the plains of the republic. Daghestan Scientific Centre RAS, M. Gadzhiev However, the formation principle and St. 45, Makhachkala, Russia composition of these communities still have to *Email: [email protected] be revealed. Received: 11 October 2019 / Revised: 26 March 2020 / Accepted: The purpose and objectives of the research were 26 March 2020 / Published online: 15 April 2020. Ministry of Sciences, Research, and Technology, Arak University, Iran. to describe specific features of bird ecology for each of the 11 bird communities forming the Abstract avifauna ecological structure of High-mountain The paper is based on 19 years (1998-2017) of Daghestan. the avifauna monitoring in High-mountain Daghestan. Each of 11 bird communities of the The paper summarizes the results of 19–year study area is characterized by its whole set of (1998–2017) ornithological counts carried out in birds, including the rarely occurred species since 13 key sites, located within 6 administrative the latter promotes the formation of a unique districts of High-mountain Daghestan. Material pattern not only of an individual faunal and methods are fully represented in Report 1. community but also the entire avifauna of the To characterize ecologically different species of region. It is assumed that a specific avifauna birds, the author's classification was used pattern of High-mountain Daghestan is (Vilkov 2010b), distinguishing the birds by their determined not only by resident communities of occurrence in preferred habitats that allowed the typical mountain birds but also by nesting in the identification of 11 bird communities (Vilkov mountains adapted populations of migratory 2020, Fig. 2). The birds, found in the air above birds of the plains. The analysis of the collected the upper boundary of the vegetation (birds of material provides a picture of the species prey, airborne birds), were subdivided into bird diversity and territorial distribution of birds and communities of hoverers and airborne birds, helps to understand the avifauna resource while the air environment, being a feeding place capacities of High-mountain Daghestan. of airborne birds and a location from where the hoverers view the surroundings in search of their Keywords: Avifauna, bird community, victims, is conventionally treated as "habitat". In ecology, High-mountain Daghestan, case of revealing other, not so significant, micropopulaton regularities, the bird communities were segregated into additional groups of birds Introduction depending on their ecological specificity. The High-mountain Province of Daghestan has the most difficult habitat conditions, Findings substantially differing from Piedmont and Proceeding from the avifauna ecological Intra-mountain provinces by the sufficient level structure of High-mountain Daghestan (Vilkov of moisture and contrasting orography 2020, Fig. 2), the species richness of forest bird intensified by intermountain trenches. It is community ranks the first, uniting 45 species occupied by quite complex bird communities 74 | Journal of Wildlife and Biodiversity 4(2): 73-83 (2020) with a total average abundance of 246 ind./km2. searching for food, move in the forest interior The highest taxonomic density and ecological as gender pairs and family groups. During the differentiation of the forest bird community are daytime, differently oriented snow-covered determined by the variety of habitats, high slopes of mountains and groups of shrubs and concentration of forage and diversity of trees between them are exposed to different shelters. In High-mountain Daghestan, being a intensity of light. The slopes located in the bioclimatic province with harsh conditions, insect concentration areas are warmed up at a forest stands still can be found along river different time of the day. As a consequence, valleys, on mountain slopes of northern birds select their routes taking into account the expositions and mainly in the north-western and hours when it is easier to get food in this or that central parts of the highlands, whereas the part of the forest. In the afternoon, when the south-eastern part is dominated by mountain- temperature reaches its peak, birds make up meadow landscapes. The forests are mosaically mixed flocks occupying the forest canopy with fragmented, making such transitional habitats the highest concentration of insects. As a result, as solitary trees, shrubs and small tree-shrub an observer being in the central part of a groves critically important for forest birds. Due mountain forest in the interval between 13 and to their territorial discontinuity, these 15 hours, experiences a minimal presence of transitional formations play a role of short-term birds, since the bulk of them is concentrated at shelters by which part of the forest birds moves its upper boundary. Moreover, the birds, between distant forest areas. These mosaically forming mixed flocks, dramatically shrink their scattered "forest” habitats, located between feeding area, shifting to a strategy of detailed large forest formations, turn a sporadically "combing" of the feeding site moving at high forested area into a conventionally continuous speed and with numerous repeats (probably due woodland massif. Besides, the diffuse to the interspecific competition). This itinerary distribution of forest birds, as a specific method of using the area allows birds to save adaptation, allows them to more effectively their time and energy expenditures when examine the entire forested territory and use exploring new feeding sites in the same area different types of forage and suitable shelters. and increases their feeding efficiency. As an According to the type of their daily movements optimal foraging strategy is formed in the and foraging the mountain forest birds can be course of natural selection and aimed at conventionally subdivided into five groups. increasing the consumption of net energy The first group consists of the species received during feeding (Cowie 1977), this characterized by the extensive range, high method of exploration of the feeding area by speed of movements and the relative this bird group can be attributed to the category permanence of their daily routes (Böhme & of specific adaptations. Banin 2001). It includes the Green Leaf The second group unites birds which diet is Warbler, Caucasian Chiffchaff, Coal Tit, Long- predominated by easily accessible vegetative tailed Tit (9.3 ind./km2), Great Tit (8.4 forage - fruits of the common sea buckthron ind./km2), Blue Tit (2.4 ind./km2), Eurasian Hippophae rhamnoides L., barberry Berberis Treecreeper (5.1 ind./km2) and some others, in vulgaris L., hawthorn Crataegus which diet a significant role is played by insects pseudoheterophylla Pojark, etc. It includes the and sporadically dispersed vegetation forage. Eurasian Jay (6.6 ind./km2), Ring Ouzel (8.4 The Green Leaf Warbler and Caucasian ind./km2), Common Blackbird (11.5 ind./km2) Chiffchaff (31 ind./km2 and 16.2 ind./km2) as and Mistle Thrush (6.4 ind./km2). Feeding of well as the Coal Tit (23 ind./km2) are absolute this bird group is characterized by a small range leaders in abundance. In the morning hours and of movements, lack of permanent routes and under uniform settled weather these species, more full consumption of revealed forage. In 75 | Journal of Wildlife and Biodiversity 4(2): 73-83 (2020) the afternoon they concentrate in areas with fidelity and aggression towards other high abundance of forage resources. When the individuals of the same species, trying to fruits are eaten to such extent that they are penetrate to their territory. found less frequently compared with other The fifth group is composed of diurnal birds of areas, the birds move to other sites (Böhme & prey and owls. It includes the Northern Banin 2001). These two groups cannot be Goshawk (1.3 ind./km2), Eurasian clearly separated since they have species with a Sparrowhawk (1.4 ind./km2), Long-legged transitional type of feeding. Depending on the Buzzard (1.6 ind./km2), Common Buzzard (1.5 environment the foraging strategy of such ind./km2), European Honey Buzzard (0.5 species (for example, Blue Tits) tends to the ind./km2), Saker Falcon (1.7 ind./km2), first or second group. Changes in the forage Eurasian Scops Owl (0.7 ind./km2), resources, depended on the productivity of trees Tengmalm’s Owl (1.2 ind./km2), Long-eared and shrubs, which are the main suppliers of Owl (1.3 ind./km2), and Eurasian Eagle Owl mass forage, have a crucial impact on the (0.4 ind./km2). A distinctive feature of this distribution of birds within their occupied area. group is an increase in the size of their feeding In this regard, none of the above-mentioned area in case of decreasing forage resources or species is a narrow foraging specialist that their availability (Galushin & Golodushko makes them more plastic and resistant to the 1963). They are also characterized by a high forage dynamics in mountains. pronounced fidelity to their nesting area and, in The third group includes birds that less particular, to forests where the same species intensively but quite widely move within (pairs) nest for many years. In fact, during long- extensive forest stands, making prolonged term counts of 2006-2010 in Tlyarosh Village stopovers in particular forest areas with the (Charodinsky District), a pair of Common highest concentration of forage. They are the Buzzards was regularly observed within the Green Woodpecker (3 ind./km2), Greater same coniferous-deciduous forest. A similar Spotted Woodpecker (2.2 ind./km2), Black territorial fidelity is observed for Northern Woodpecker (1 ind./km2), Tree Pipit (4.2 Goshawks, Eurasian Sparrowhawks and owls. ind./km2), Common Chaffinch (9.5 ind./km2), This feature of feathered raptors is traced not Common Bullfinch (4.8 ind./km2), etc.