Aythya Ferina Research Articles

Сезонная динамика гидрофильного орнитокомплекса бухты Круглая (Севастополь, Чёрное море)

Актуальность изучения гидрофильных птиц в городских зонах черноморского побережья обусловлена их важной ролью в структуре прибрежных биоценозов и необходимостью сохранения биоразнообразия в условиях антропогенной трансформации береговой зоны Крыма. Исследована динамика видового состава и численности птиц бухты Круглая (Севастополь). Материал собран в 1995 и 2005–2016 гг. В бухте Круглая установлено пребывание 51 вида водных и околоводных птиц из 8 отрядов. Зимний орнитокомплекс наиболее разнообразен и многочислен (32 вида: 14 Anseriformes, 7 Charadriiformes, 5 Podicipediformes, 3 Gruiformes, 2 Pelecaniformes, 1 Gaviiformes). Регулярно зимуют и количественно доминируют 8 видов – Cygnus olor, Anas platyrhynchos, Aythya ferina, Aythya fuligula, Fulica atra, Larus ridibundus, Larus cachinnans и Larus canus. Определены численность всех видов птиц, возрастной состав Cygnus olor и половой состав Anas platyrhynchos, Aythya ferina и Aythya fuligula. Основу орнитокомплекса составляли бентофаги (не менее 13 видов), ихтиофаги (5) и эврифаги (4). Отмечено 30 пролётных и кочующих видов, преимущественно Charadriiformes (11), Anseriformes (7) и Ciconiiformes (5). Гнездовой орнитокомплекс отсутствовал, только в 2016 г. зарегистрировано гнездование Ixobrychus minutus. Весенний пролёт проходил с конца февраля до мая, осенний –– с августа до первой декады ноября. Для сохранения данной бухты как ценного природного и эколого-воспитательного объекта целесообразно придание ей статуса природного парка.

Annual dynamics, nature-conservancy evaluation and an overview of data on the occurrence of waterbirds at Šaleška Lakes (N Slovenia)

Abstract Between September 2014 and August 2015, 32 systematic surveys of waterbirds were carried out in 10-day periods in the area of Šaleška Lakes. The main objectives of the surveys were to establish the birds’species structure and abundance as well as to assess the area’s significance for their breeding, migration and overwintering. A total of 8927 individuals belonging to 53 species were recorded. Most species were observed at the end of March (27), whereas the highest number of individuals were registered in early January (535). The lowest number of individuals were counted in May (73). Mallard Anas platyrhynchos, Great Crested Grebe Podiceps cristatus, Mute Swan Cygnus olor and Grey Heron Ardea cinerea were observed during all counts. An additional 10 species were registered in at least 50% of the 10-day periods. The highest number of individuals (2891) and species (34) were counted at Lake Šoštanj, the highest number of individuals (295) and species (21) in a single 10-day survey period at Lake Gaberke. Most nestlings and nesting species were recorded at Lake Velenje. The majority of species occurred on all lakes within the research area, while some of them frequented certain lakes only exceptionally. The lowest numbers of birds were observed in central parts of all major waterbodies, particularly at Lake Velenje. Distribution of waterbirds at Šaleška Lakes is greatly influenced by the presence and distribution of people along them, as well as by the depth and riparian vegetation of the lakes and number of suitable roosting places. The number of breeding species is higher than in the 1994-2003 period. Little Bittern Ixobrychus minutus, Kingfisher Alcedo atthis and Great Reed Warbler Acrocephalus arundinaceus are new breeders for the area. The most abundant breeder is the Mallard with up to 16 pairs. The area’s breeders of the greatest conservation concern are the Little Bittern, Great Reed Warbler and Reed Warbler Acrocephalus scirpaceus, with the latter boasting the greatest share of the national breeding population (5%) in the area. Generally, most species occur during the migration season, although none of them in the numbers of conservation concern. Among the 33 waterbird species observed during the International Waterbird Censuses, five were recorded in all 18 years. Pochard Aythya ferina and Coot Fulica atra are of the greatest conservation concern, whereas the greatest share of the national population is reached by the Coot and Great Crested Grebe. In spite of the fact that the numbers of overwintering waterbirds in Slovenia are increasing, their numbers are declining at Šaleška Lakes. Among the 13 species recorded during more than ten International Waterbird Counts in the area researched, eight species are experiencing negative trends.

Unraveling migratory connectivity of two European diving ducks: a stable isotope approach

Quantifying the strength of migratory connectivity or the degree to which breeding and wintering populations are connected is crucial for conservation and management of migratory birds. Using stable hydrogen isotope ratios of secondary flight feathers (δ 2Hf), we assessed the breeding origins/locations of 666 common pochards (Aythya ferina) and 190 tufted ducks (A. fuligula) captured in France during the 2005–2006 and 2008–2009 wintering seasons. Isotopic values of common pochards wintering on Grand-lieu Lake (western France) displayed a marked bimodal spatial distribution supportive of strong contributions of both northern (60–65° of latitude) and central European (45–55° of latitude) origins. According to the temporal distribution of δ 2Hf values, the presence of common pochards of northern origin reached a maximum at the peak of the wintering season (December–January). In contrast, tufted duck did not display a clear bimodal pattern in δ 2Hf, with individuals displaying a more northerly origin (60–70° of latitude), likely of Russian and Scandinavian origin. First-year individuals had more northern origins than adults, suggesting that either isotopic discrimination differed among age groups or, more probably, that some adults may undergo moult at latitudes lower than that of their breeding ground. Tufted ducks with northerly δ 2Hf values were observed early in the season in individuals sampled in eastern France and late in the season in those sampled in western France. The effects of winter severity on the distribution of individuals over the wintering range were supported for the tufted duck with more northerly values recorded during harsh winters. Management implications of these results are discussed.

Possible effects of ingested lead gunshot on populations of ducks wintering in the UK

Although the use of lead ammunition for shooting wildfowl and/or over listed wetlands in the UK has been banned, c. 70% of ducks shot in England (the only UK country with compliance monitoring) are still shot with lead and the proportion of ducks found dead with signs of lead poisoning from ingested gunshot has not declined significantly since the ban. However, there is little quantitative evidence of the impacts of additional mortality from lead poisoning on duck populations. For the eight duck species that winter in freshwater habitats in the UK, we found that inter‐specific variation in mean population growth rate during the period 1990/1991 to 2013/2014 was significantly negatively correlated with two independent measures of the prevalence of ingested lead gunshot in the UK and Europe. This relationship was found for a wide range of different periods over which population growth was estimated, and also for annual growth rates in the period 1966/1967 to 2013/2014, derived from smoothed population trajectories. These findings support the hypothesis that ingested lead gunshot might affect population trend. An alternative hypothesis, that migratory short‐stopping driven by climate change affected trends in numbers of ducks wintering in the UK, was not supported by simple or partial correlation results. The possible impact of ingested lead gunshot on the Common Pochard Aythya ferina, a species listed as globally threatened, is of special concern.

Egg morphology fails to identify nests parasitized by conspecifics in common pochard: a test based on protein fingerprinting and including female relatedness

Conspecific brood parasites lay eggs in nests of other females of the same species. A variety of methods have been developed and used to detect conspecific brood parasitism (CBP). Traditional methods may be inaccurate in detecting CBP and in revealing its true frequency. On the other hand more accurate molecular methods are expensive and time consuming. Eadie developed a method for revealing CBP based on differences in egg morphology. That method is based on Euclidean distances calculated for pairs of eggs within a clutch using standardized egg measurements (length, width and weight). We tested the applicability of this method in the common pochard Aythya ferina using nests that were identified as parasitized (39 nests) or non‐parasitized (16 nests) based on protein fingerprinting of eggs. We also analyzed whether we can distinguish between parasitic and host eggs in the nest. We found that variation in MED can be explained by parasitism but there was a huge overlap in MED between parasitized and non‐parasitized nests. MED also increased with clutch size. Using discriminant function analysis (DFA) we found that only 76.4% of nests were correctly assigned as parasitized or non‐parasitized and only 68.3% of eggs as parasitic or host eggs. Moreover we found that MED in parasitized nests increased with relatedness of the females that laid eggs in the nest. This finding was supported by positive correlation between MED and estimated relatedness in female–female pairs. Although variation in egg morphology is associated with CBP, it does not provide a reliable clue for distinguishing parasitized nests from non‐parasitized nests in common pochard.

Nest and brood stage association between ducks and small colonial gulls in boreal wetlands

Heterospecific grouping is often associated with reduced predation. One example of this phenomenon is birds breeding in association with more aggressive species. Here we report a study of the association between breeding ducks and small colonial gulls during the nesting and brood-rearing periods in boreal wetlands in Finland. Dabbling duck nests were rarely found within gull colonies, while Tufted Duck (Aythya fuligula) and Pochard (Aythya ferina) nests were exclusively found within gull colonies.During the brood stage, the broods of most duck species were found more often than expected within the colony areas of small gulls, such as the Black-headed Gull (Chroicocephalus ridibundus) and Little Gull (Hydrocoleus minutus). Dabbling duck broods in particular were associated with gulls. In diving ducks, Tufted Duck broods preferred gull defence areas, whereas Common Goldeneye (Bucephala clangula) broods did not. We suggest that colonies of small gulls may be much more important for ducks than previously thought. In recent years, Black-headed Gull populations have decreased in Finland, and the populations of Tufted Duck and Pochard have concurrently decreased.We recommend that the nesting site requirements of small colonial gulls should be taken into account in wetland restoration and when building new wetlands.

Newly demonstrated foraging method of Herring Gulls and Mew Gulls with benthivorous diving ducks during the nonbreeding period

ABSTRACT Niche construction can lead to coevolutionary episodes and greater specialization, and can have implications for the evolution of biological diversity, so understanding how individuals adjust their behavior to conspecifics and heterospecifics over changing social and environmental gradients presents an interesting research problem. The objective of our study was to test the hypothesis that mixed flocks of gulls and diving ducks congregate as a result of interacting over food. Ducks are vectors that carry zebra mussels (Dreissena polymorpha) up from the bottom of a water body, and gulls consume this type of food. We investigated the interactions of 2 gull species with 3 benthivorous duck species—Common Pochard (Aythya ferina), Tufted Duck (A. fuligula), and Greater Scaup (A. marila)—in the Szczecin Lagoon, Poland. We found that the presence of gulls in duck flocks was closely correlated with foraging by ducks. Eighty-four percent of foraging duck flocks (>5% of the flock members were foraging) and...

Population trends of wintering waterbirds in Lombardy between 2002 and 2013

Birds are among the most important biological components of wetlands. They play a key role in their ecology and are an important cultural resource for the public, in part because some species can be legally hunted. The conservation of waterbirds is especially important in terms of land use planning, in light of their ecological, cultural, and economic value. Here we summarize the results of wintering waterbirds censuses carried out in Lombardy between 2002 and 2013, using the standardized International Waterbird Census methodology. Our goals were to identify priority sites for waterbirds; estimate population sizes; define demographic trends; and provide a technical framework for making administrative and legislative decisions on the management and conservation of wetlands and their bird species. Lombardy hosts substantial numbers of wintering waterbirds, and many of its wetlands qualify as areas of conservation interest under Ramsar Convention criteria, as they host >1% of the Italian population of one or more species. Trends for the 20 species of highest conservation or hunting interest showed stable or increasing populations in most cases, with the exception of Black-necked Grebe, Common Pochard, and Eurasian Coot, which instead decreased in 2002-2013. The favourable population trends for most species suggest that the ecological status of Lombardy’s wetlands is essentially stable, but it could be improved by simple measures to improve the natural value of the shorelines and bottoms of major lakes and flooded gravel pits. Hunting was one of the main factors affecting the distribution and abundance of wintering waterbirds, which concentrate in protected areas - over 50% of all birds, rising to over 70% for species of conservation interest concentrate there, despite the fact that protected areas only account for 43% of sites surveyed. Overall, protected areas hosted bird densities that were almost seven times higher than those managed primarily for hunting, while mixed-use areas hosted intermediate densities of birds. The presence of protected and unprotected areas within the same wetland mitigates the effects of hunting on bird populations and species diversity, and may help maintain adequate conditions for their conservation.

Study on Metal Concentrations in Tissues of Mallard and Pochard from Two Major Wintering Sites in Southeastern Caspian Sea, Iran.

We examined concentrations of cadmium, chromium, iron, lead and zinc in the kidney, liver, and pectoral muscle of Mallards (Anas platyrhynchos; n = 30) and Pochards (Aythya ferina; n = 30) from two important wintering sites in the southeastern Caspian Sea in the winter of 2012. Mean lead concentrations (µg g(-1) ww) in livers (2.36 ± 1.00) of Pochard and in kidneys (3.43 ± 0.91) of Mallard exceeded the exposure threshold levels in liver (1.5 µg g(-1) ww) and kidney (3 µg g(-1) ww) of waterfowl. Mean cadmium concentrations in livers (1.63 ± 0.66) of Pochards exceeded the background level of this metal in liver (1 µg g(-1) ww) of waterfowl. Chromium, iron and zinc concentrations were within the normal range as reported in other duck studies. Gender-related and inter-specific variation of metal concentrations in analyzed tissues were observed (t test, p < 0.05). Our results indicated that waterfowl using the Miankalah and Gomishan International Wetlands are being exposed to elevated concentrations of cadmium and lead.

Potential human health risk assessment of heavy metals in the flesh of mallard and pochard in the South Eastern Caspian Sea region of Iran

Every year, migratory waterfowl are hunted and consumed by people in Golestan Province of Iran. Due to the heavy metal contamination of wintering habitats, an estimation of the human health risks associated with the consumption of these ducks is necessary. Therefore, this study was conducted to estimate the health risks of exposure to cadmium (Cd), total chromium (Cr), iron (Fe), lead (Pb), and zinc (Zn) due to the consumption of pectoral muscle of mallard (Anas platyrhynchos) and pochard (Aythya ferina) harvested and hunted in the South-Eastern Caspian Sea region of Iran. The mean values of these metals in the pectoral muscle of mallards and pochards were used to calculate estimated daily intake (EDI), estimated weekly intake (EWI), and target hazard quotients (THQ). The EDI (µg/day/70 kg body weight) for Cd, Cr, Fe, Pb, and Zn in mallard were 0.2, 0.04, 58, 1.1, and 12.8, respectively. The EDI (µg/day/70 kg body weight) for Cd, Cr, Fe, Pb, and Zn in pochard were 0.8, 0.1, 69, 0.8, and 13.4, respectively. The estimated total THQ (higher than 1) indicated that heavy metal levels in pochard flesh were unsafe for consumption. The EDI and EWI of the metals examined were below those recommended by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and oral doses suggested by the United States Environmental Protection Agency (USEPA). There appears to be little risk of exposure to metals associated with the consumption of mallard and pochard in this region.

Blood and cloacal swab sampling for avian influenza monitoring has no effect on survival rates of free‐ranging ducks

Concerns about the spread of avian influenza viruses (AIVs) have led to cloacal swab sampling of hundreds of thousands of birds worldwide as part of AIV surveillance schemes, but the effects of cloacal swabbing have not been adequately evaluated. We tested for differences between swabbed, swabbed and bled, and non‐sampled wild ducks in terms of live re‐encounter and dead recoveries for Common Pochard Aythya ferina and Tufted Duck Aythya fuligula, and also determined re‐encounter and recovery rates for Mallard Anas platyrhynchos and Common Teal Anas crecca. No effects of sampling methods were detected, except in Teal. Re‐encounter rates were lower in sampled Teal than in controls, with annual re‐encounter probabilities being 25% and 35% lower in males and females, respectively. Teal possibly left or avoided sampling sites, or sought sites where they were less detectable after sampling. In general, no deleterious effects were found, suggesting that cloacal swabbing and blood sampling are suitable methods for conducting AIV surveillance in ducks.

Integrative taxonomy of central European parasitic flatworms of the family Prosthogonimidae Lühe, 1909 (Trematoda: Plagiorchiida)

Species of the family Prosthogonimidae are considered the most pathogenic poultry trematodes worldwide, affecting particularly low intensity farming in rural areas. Adults of Prosthogonimus occur mainly in the bursa of Fabricius, oviduct and cloaca of ducks, geese, fowl and other birds feeding at least occasionally on dragonflies or damselflies (Odonata). We analyzed the central European species of the Prosthogonimidae, namely Prosthogonimus cuneatus, Prosthogonimus ovatus, Prosthogonimus pellucidus and Prosthogonimus rarus. We sequenced three nuclear (ITS2) and mitochondrial (CO1, ND1) DNA loci of four species isolated from Anas clypeata, Anas strepera, Anas platyrhynchos, Aythya ferina, Passer domesticus and Turdus merula. Intra- and inter-specific sequence variability revealed that all four species represent distinct well-defined entities. Our data, combined with previously published studies, suggest the return of the name Prosthogonimus rarus Braun, 1901 for Schistogonimus rarus (Braun, 1901). The genus name Schistogonimus Lühe, 1909 is considered a junior synonym of Prosthogonimus Lühe, 1899. We identified the existence of two clades, one represented by P. cuneatus and P. pellucidus, and another one formed by P. ovatus and P. rarus. We also provide comparative measurements of these four central European prosthogonimids, and address their tissue specificity, host-specific prevalence (based on the extensive bird cohort examined in years 1962–2014), and for some bird hosts we address also differences in the prevalence of Prosthogonimus spp. in natural and near-natural wetlands in comparison with fishponds utilized for intense carp production. We provide an updated key to European Prosthogonimus spp. based on their morphological characters.

Occurrence of parasitic protozoa in wild waterfowl in southern coastal Caspian sea lagoons

BACKGROUND: Protozoa are common in poultry and otherbirds and can cause mild to severe disease. OBJECTIVES: Thisstudy was concerned with the prevalence of parasitic protozoa inwild waterfowl in Caspian sea lagoons in the North of Iran.METHODS:Atotal of 293 waterfowl belonging to various generaincluding Tadorna tadorna (common shelduck),Aythya fuligula(Tufted duck), Aythya ferina (Common puchard), Spatulaclypeata (Shoveler), Anser anser (greylag goose), CygnusCygnus (Whooper Swan), Anas strepera (Gadwall), AnasPenelope (Eurasian Widgeon), Anas crecca (common teal), andAnas platyrhynchos (mallard) were sampled and tested forintestinal, tracheal, and blood protozoa between winter 2010 andspring 2011. RESULTS: The results showed that 184 birds of 293(62.8%) harbored protozoan parasites. The highest prevalence ofprotozoan contamination belonged to Giardia spp (24.2%) andthe lowest belonged to Haemoproteus spp. (6.1%). Thricomunasgallinea, Plasmodium spp., and Cryptosporidium spp. werefound in 7.2%, 8.2%, and 17% of waterfowl, respectively.Moreover, statistical analyses showed that the highest rate ofgiardiosis was in female Aythya fuligula (43.75%). However,tricomuniasis belonged to Anas crecca (30.5%). On the otherhand, female Cygnus cygnus had the highest rate ofcryptosporidiosis (44.7%), and more infection to Haemoproteusand Plasmodium spp. were observed in Anas platyrhynchos,concurrently. CONCLUSIONS: Migration of various species ofwaterfowl toward the northern parts of Iran has an importantimpact on parasitic diseases in birds and human in these regions.

ИНТЕРЕСНЫЕ ВСТРЕЧИ ПТИЦ В КАЛЕНДАРНЫЕ СРОКИ ЗИМЫ НА МОРСКОМ ПОБЕРЕЖЬЕ ЮЖНОГО ПРИМОРЬЯ

The article presents new data on meeting some bird species in coastal areas of the Southern Primorye in winter. Surveys were conducted at the sea coast in January 2013 and in December-February 2013-2014. In addition, during the winter period 2013/2014 and 2014/2015 surveys were conducted at the lower reaches in the far South-West of Primorye, and in February 2015 – the neighborhood of the village. Pos’et. For the first time in winter there were noted Vanellus vanellus, Tringa ochropus, Anas clypeata, Aythya ferina and Aythya marila. We assume that the warm and snowless winter of 2014/2015 has caused some species of birds to winter here.

Rezultati januarskega štetja vodnih ptic leta 2014 v Sloveniji / Results of the January 2014 waterbird census in Slovenia

Summary In 2014, the International Waterbird Census (IWC) was carried out in Slovenia on 18 and 19 Jan. Waterbirds were counted on all larger rivers, along the entire Slovenian Coastland and on most of the major standing waters in the country. During the census, in which 268 observers took part, 413 sections of the rivers and coastal sea with a total length of 1395.1 km and 226 other localities (178 standing waters and 48 streams) were surveyed. Altogether, 45,346 waterbirds of 62 species were counted. This is the lowest number of waterbirds recorded after the 1997 and 1998 censuses. The greatest numbers of waterbirds were counted in the Drava count area, i.e. 20,217 individuals (44.6% of all waterbirds in Slovenia). By far the most numerous species was Mallard Anas platyrhynchos (43.0% of all waterbirds), followed by Black-headed Gull Chroicocephalus ridibundus (10.1% of all waterbirds), Coot Fulica atra (7.9% of all waterbirds), Yellow-legged Gull Larus michahellis (6.0% of all waterbirds) and Cormorant Phalacrocorax carbo (4.6% of all waterbirds). The number of 1,000 counted individuals was also surpassed by Mute Swan Cygnus olor, Pochard Aythya ferina, Tufted Duck Ay. fuligula and Teal An. crecca. Among the rarer recorded species, the Black Stork Ciconia nigra (registered for the first time during the January Waterbird Censuses; only the second winter record in Slovenia), Cattle Egret Bubulcus ibis and Flamingo Phoenicopterus roseus (both registered only for the second time during the IWC) should be given a special mention. Numbers of the following species were the highest so far recorded during the IWC: Shelduck Tadorna tadorna, Muscovy Duck Cairina moschata, Shoveler An. clypeata, Redthroated Loon Gavia stellata and Pygmy Cormorant Phalacrocorax pygmeus. Also, the total number of C and E category species/taxa was the highest to date, although still quite low with 70 individuals. Numbers of the following species were the lowest so far recorded during the IWC: Cormorant, Little Grebe Tachybaptus ruficollis and Green Sandpiper Tringa ochropus

Letna Dinamika Pojavljanja Vodnih Ptic Na Reki Dravi Med Mariborskim Jezerom In Jezom Melje (Sv Slovenija) / Yearly dynamics of waterbirds’ occurrence on the Drava River between Lake Maribor and Melje Dam (NE Slovenia)

Abstract Between April 2007 and April 2008, 40 systematic waterbird counts were conducted on the Drava River between Lake Maribor and the Melje Dam (length 8.5 km, area 155 ha) to determine the specific composition, abundance and seasonal dynamics of bird occurrence. Between October and May, counts were conducted every week, whereas between June and September they were carried out once every two weeks. In total, 26,803 individuals of 30 species were counted. The number of waterbirds and diversity of species were the highest from late December to late February, when more than 1,000 individuals were regularly present in the area. Waterbirds were distributed along the river unequally, with the highest number of birds present yearround in the city centre and in the first counting sector of Lake Maribor. The Mallard Anas platyrhynchos and Mute Swan Cygnus olor were recorded during every count, while occurrence frequency was greater than 50% in another 10 species. Dominant species in terms of percentage composition were Mallard, Black-headed Gull Chroicocephalus ridibundus, Coot Fulica atra, Mute Swan, Pochard Aythya ferina and Tufted Duck Ay. fuligula. Mute Swan and Mallard were the only breeding waterbirds in the study area. Both the total number of waterbirds and the highest daily total in the first two counting sectors were greater between October and March 1992/93 than in our study. The decline in numbers was the greatest for Mallard, Pochard and Tufted Duck, while an increase was noted in Mute Swan and Yellow-legged / Caspian Gull Larus michahellis / cachinnans. The total number of waterbirds and the number of some species in the study area were significantly higher than expected solely based on its length compared to the length of the lowland Drava in Slovenia (125.7 km). The study area is conservationally important for Pochard, Tufted Duck and Black-headed Gull

A hitherto unrecorded sighting of the Common Pochard Aythya ferina (Linnaeus, 1758) (Aves: Anseriformes: Anatidae) in Vedanthangal Bird Sanctuary, Tamil Nadu, India

The Common Pochard Aythya ferina (Linnaeus, 1758) (Aves: Anseriformes: Anatidae) is recorded for the first time in Vedanthangal Bird Sanctuary, Tamil Nadu, India. As this species is recorded in other parts of Tamil Nadu, a brief sightings and distribution map is also specified.

Species‐specific habitat use of wing‐moulting waterbirds in response to temporary flightlessness

The choice of the moulting habitat is of paramount importance for wing‐moulting waterbirds that have to cope with a flightless period of several weeks. However, some species might have more restricted habitat requirements during moult than others, for example due to a highly specialized feeding ecology. The moult‐related habitat use of five species (Gadwall Anas strepera, Red‐crested Pochard Netta rufina, Common Pochard Aythya ferina, Tufted Duck Aythya fuligula, Coot Fulica atra) was compared at a European inland moulting site that offered a variety of water bodies characterized by different levels of nutrient concentration, water depth, shoreline vegetation density and disturbance. To determine location‐ and species‐specific densities, birds were regularly counted throughout the moulting seasons of 2010 and 2011. In 2011, additional data on Gadwalls were used to assess differences in requirements between the flightless phase of moult and the periods before and after. Furthermore, habitat choice of 38 tagged Gadwalls was compared among two to four successive years. During the moulting season, all species showed clear preferences for specific levels of nutrient content, suggesting an active choice of suitable food sources in both food specialists and generalists. Species showing the strongest attachment to shallow water (Gadwall and Coot) were most sensitive to human disturbance and increasing water depths, and species averse to diving (Gadwall) used ponds with dense shore vegetation while flightless. For Gadwalls, habitat conditions rather than nutrient supply became increasingly important during the flightless phase. Average return rates of 59 and 54% were recorded for male and female Gadwalls, respectively, and the repeated use of familiar locations could be demonstrated in the majority of returning birds (65%). Familiarity with the habitat apparently plays an important role and may enable individuals to compensate for suboptimal conditions at the moulting site.

The complete mitochondrial genome of Aythya ferina (Anatidae: Aythya)

The mitochondrial genome of Aythya ferina (Anatidae: Aythya) is a circular molecule of 16,616 bp in length, containing 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and one control region (D-loop). Overall base composition of the complete mitochondrial DNA was 29.42% A, 22.19% T, 32.83% C and 15.56% G. All the genes in A. ferina were distributed on the H-strand, except for the ND6 subunit gene and eight tRNA genes which were encoded on the L-strand.

Movement patterns in a partial migrant: a multi-event capture-recapture approach.

Partial migration is a pervasive albeit poorly studied phenomenon by which some individuals of a population migrate while others are residents. It has tremendous consequences on seasonal variations of population size/structure and therefore management. Using a multi-event capture-mark-recapture/recovery (CMR) approach, we assessed seasonal site occupancy, survival and site fidelity of a partially migratory diving duck, the Common pochard (Aythya ferina), in an area potentially including both local breeders and winter visitors. The modelling exercise indeed discriminated two different categories of individuals. First, locally breeding females which had a probability of being present in our study area during winter of 0.41. Females of this category were found to be more faithful to their breeding site than males (breeding site fidelity probabilities of 1 and 0.11, respectively). The second category of birds were winter visitors, which included adults of both sexes, whose probability of being present in the study area during the breeding season was nil, and young of both sexes with a 0.11 probability of being present in the area during the breeding season. All wintering individuals, among which there was virtually no locally breeding male, displayed a high fidelity to our study area from one winter to the next (0.41–0.43). Estimated annual survival rates differed according to age (adults 0.69, young 0.56). For both age classes mortality was higher during late winter/early spring than during summer/early winter. Our study is among the first to show how and under which conditions the multi-event approach can be employed for investigating complex movement patterns encountered in partial migrants, providing a convenient tool for overcoming state uncertainty. It also shows why studying patterns of probability of individual presence/movements in partial migrants is a key towards understanding seasonal variations in numbers.