On the moult of wild Common Cranes in South-Eastern Ukraine
Journal Title: Бранта: Сборник научных трудов Азово-Черноморской орнитологической станции - Year 2016, Vol 19, Issue
Abstract
In the course of long-term observations of Common Cranes at the southern border of their breeding range (Dnipropetrovsk, Kharkiv, and Luhansk regions, 1989-2013) and further south, in the steppe zone of South-Eastern Ukraine (Kerch Peninsula of the Crimea and Syvash, 1985-1991), a total of 2,676 feathers were collected and identified to study the moult of the species. The reference specimens from the collection of the nursery of rare crane species at Oksky State Nature Biosphere Reserve, Russia were used. During 13 field seasons, a complete moult was recorded in 34 Common Cranes within three permanent study areas (Samarskyi Forest, Dnipropetrovsk Region; Iziumska Luka, Kharkiv Region; and Kreminske Forestry, Luhansk Region). According to the data, collected during the longest period of observations on Iziumska Luka (1989-1991) that included detailed surveys of all social groups of Common Cranes (Winter et al., 1995), it was found out that in 1989-1990 the complete moult was recorded in the second half of April - in June in five and seven breeding individuals, respectively (one of them could be territorial) and in two non-breeding; four cranes moulted later in pre-migration gatherings in July and August. The birds from breeding pairs (1989-1990) with the complete moult comprised 7.2 to 10.1 % of all the individuals inhabiting the area (absolute number of all territorial and non-breeding cranes in two forestry areas of Iziumska Luka in the period between the arrival and hatching of the young in 1990-1991 was 69.3 on the average; (Winter et al., 1995; Winter et al., 1996). The proportion of non-breeding moulting cranes was only 2.9 %. Pre-migration gatherings were formed from the second ten-day period of July; the dynamics of the bird numbers in them highly varied, slowly increasing almost up to the very moment of departure. The average crane number in each of 19 gatherings, recorded between 13 July and 12 September (the date of departure), was 50.3 ± 6.4. Thus, the proportion of individuals with the complete moult in the gatherings made up about 8.0 %. Breeding, territorial, and non-breeding birds losing a part of their feathers still kept their ability to fly for about a month. After that they became flightless because of lack of their flight feathers. This period of “concealed moult” lasted from mid-April to mid-May; this phenomenon has not been known for the species so far. The start of the complete moult of the breeding birds is associated with hatching of their chicks rather than with completion of the clutches. In 16 breeding pairs, the moult started within 57-day period, from the 6–10th days of incubation to the 18-day age of the chicks. The interval between the date of hatching of the last chick and the starting date of the moult extended from minus 30 to plus 27 days, on the average (n = 16) minus 0.75 ± 4.26 days, Cv=55.36 %). The correlation coefficient between these two events was 16 times higher (r=0.275; Fst 0.28 = 49-83-135), than between the dates of laying the last egg and the start of the complete moult (r = 0.017; Fst 0.02 = 9603-16628-27228), but not significant either. Despite such a great variation of the starting dates of the complete moult and its tenuous association with the hatching time of the chicks, the start of the moult in different areas of the breeding range definitely depends on a photoperiod (Markin, 1995; Kashentseva, 1998; Winter & Gorlov, 2003; Keskpaik, Ojaste, 2003; Winter & Gorlov, 2003). The length of primaries (P; n = 44) and rectrices (R; n = 28) of the Common Crane, defined to their pterylia number according to the reference collection, was identified for the first time. The ratio of the P lengths (outside the wing) is as follows (starting from the longest one): 7 > 6 > 8 ≥ 9 > 10 > 5 > 4 > 3 > 2 > 1 >> 11. All rectrices measured from the tip of the quill to the upper edge of the vexillum were almost equal in length. On Churiuk Island (Syvash, Kherson Region, Ukraine; 11.06.1985), 396 feathers of 5–7 non-breeding common cranes with the complete moult were collected within a 50 х 50 m coastal muddy area. Out of 268 largest feathers (P, R, secondaries, tertials, and their greater upper and lower coverts), 105 (39.2%) belonged to the left wing, and 163 (60.8 %) to the right. The use of φ-test for comparison indicated the highest threshold of statistical significance of the differences (Fd = 12.11; F st = 3.9 – 6.8 -11.2; β = 0.999). Why did the moult of the right wing in these birds proceed faster than of the left one? The reason for such difference is unknown; perhaps it is somehow connected with the Earth rotation?
Authors and Affiliations
S. V. Winter, P. I. Gorlov, A. A. Shevtsov
Keywords
Related Articles
- EP ID EP198183
- DOI -
- Views 92
- Downloads 0
Nest sites selection by sympatric Song Thrush (Turdus philomelos) and Blackbird (Turdus merula) in different forests
We studied the nest sites selection by sympatric Song Thrush (Turdus philomelos) and Blackbirds (Turdus merula) in the different types of forests (oak, black alder, spruce, pine and mixed forests). Data was collected in...
Traditions of usage of national species and genus names in scientific works
The article deals with the analysis of using different forms of species and genus national bird names in faunistics issues and special works on nomenclature in Ukrainian, published over the last century and a half. In th...
Waterbirds of ponds and small water reservoirs of Kiev region
The total area of fish ponds and small water reservoirs in Kiev region is about 26 thousand ha, that creates an important network of wetlands for waterbirds. Despite this, avifauna of these wetlands was not studied yet....
Consideration of mentions and records of the Siberian Accentor (Prunella montanella (Pallas, 1776) in Ukraine
In the territory of Ukraine the first indisputable record of the Siberian Accentor (Prunella montanella (Pallas, 1776) was in 1985 when a female of this species was captured near Kyiv. Till 2000 inclusively, another bird...
Grassland waders in the upper Prypiat’ basin: spatial distribution and number dynamics
The paper reviews key breeding sites of grassland waders: Lapwing (Vanellus vanellus), Redshank (Tringa totanus) and Black-tailed Godwit (Limosa limosa) in the basin of upper Prypiat’ river (Volyn and Rivne regions of Uk...