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- Preliminary pages
Authors: Eileen Rees
Abstract: N/A
Issue No: Vol. 0
- Editorial
Authors: Anthony D. Fox
Issue No: Vol. 0
- Status, origin and harvest of increasing numbers of Greylag Geese Anser
anser occurring in Denmark throughout the annual cycle
Authors: Kevin K. Clausen, Henning Heldbjerg, Anthony D. Fox
Abstract: Breeding census data and September counts show that numbers of Greylag Geese Anser anser breeding in Denmark have increased more than six-fold in the period 1990–2020. From around the year 2000, the species has also started wintering in Denmark, where mid-winter counts now exceed 100,000 individuals, supporting a substantial increase in the national harvest (> 50,000 Greylag Geese annually since 2014). Rates of increase for all these measures have, however, declined since 2010. To contribute to the sustainable harvest management of such an important migratory quarry species (comprising Danish-breeding geese as well as those originating outside of Denmark), we need to understand both the origin of birds occurring in Denmark during the hunting season and the winter distribution of Danish-breeding birds, yet we lack contemporary information on either. Resighting and recovery data therefore were used to examine the passage and harvest of birds from other countries and to investigate temporal changes in the winter distribution of geese that bred in Denmark. Norwegian-breeding birds passed through Denmark mainly in early autumn, mostly occurring in western Jutland, whereas Swedish-breeding Greylag Geese peaked in numbers during mid-winter and were most numerous in eastern Denmark. In the last two decades, birds from both Norway and Sweden comprised a larger proportion of the Danish hunting bag than before 2000. Late summer reports of birds marked in Germany and Poland likely reflect moult migrants to Denmark during this period. Although marked breeding Greylag Geese from Denmark traditionally overwintered mostly in Spain, recoveries show they have become increasingly sedentary over seven decades, with many now wintering inside Danish national borders. The Northwest/Southwest (NW/SW) European Greylag Goose population (of which Danish birds form a part) is currently the focus of a developing Adaptive Flyway Management Programme, which requires such knowledge of seasonal movements of birds of different origins to ensure informed decision-making and a knowledge-based approach. Our findings can guide decision-making concerning Danish harvest legislation, by quantifying how birds of different breeding provenance contribute to the Danish hunting bag. This may assist with defining the allocation of harvest to comply with attaining the national breeding favourable reference population values established for individual countries.
Issue No: Vol. 0
- Danish Greylag Goose Anser anser use of the Coto Doñana sand dunes
for gritting
Authors: Anthony D. Fox, Henning Heldbjerg, Kevin K. Clausen, Ole R. Therkildsen, Qingshan Zhao, Juan J. Negro, Andy J. Green
Abstract: Four adult female Greylag Geese Anser anser tagged with GPS/GSM tracking devices in East Jutland, Denmark migrated to spend the winter of 2021/22 in Coto Doñana, southern Spain. Regular 10-min GPS positions confirmed that three out of the four birds visited the famous Cerro de los Ánsares (“Hill of the Geese”) on 1–4 different dates during their time in the study area (total duration = 12–95 days). They almost certainly did so to gather grit to aid digestion (as observed and described in the literature), confirming the persistence of this behaviour reported anecdotally over at least two centuries. The visits of 10–50 min duration were most often immediately after sunrise (although one short visit out of nine total visits occurred in the afternoon) and usually occurred from and to adjacent pools north of the dune system, where the geese feed traditionally on Alkali Bulrush Bolboschoenus maritimus. The relatively infrequent visits to the dunes, together with the lack of visits by the fourth bird and also by a Swedish-tagged bird from another study, imply that the geese can obtain grit from other sources within their feeding areas in the marshes and on rice Oryza sp. fields in the vicinity. The observations, however, also confirm that this part of the dune system remains an important source of grit for birds feeding nearby, although why they do so here and not elsewhere in the 30 km long and 2–4 km wide dunes remains unclear.
Issue No: Vol. 0
- Moult migration, site fidelity and survival of Canada Geese Branta
canadensis caught at Lake Windermere, Cumbria
Authors: Kane Brides, Kevin A. Wood, Kevin R. Leighton, Jude Barbour, Scott W. Petrek, Jonathan Cooper, Stephen H. Vickers, Stephen E. Christmas, Jon Middleton, Adam Grogan
Abstract: Analyses of 2,108 re-encounters made during 2013–2021 of 1,042 Canada Geese Branta canadensis marked at Windermere, Cumbria, in summers 2013–2021 are used to describe their post-moult migration site linkages. Birds moulting at Windermere were subsequently sighted in 34 counties, although post-moult migration was mainly to the counties of Lancashire, Cheshire and Cumbria itself. The proportions of re-encounters in each direction away from Windermere differed statistically from the pattern expected for random dispersal, for seven out of eight directions. Resightings at Windermere showed that the number of marked individuals returning to moult decreased during the study, although numbers moulting on Windermere remained consistent throughout. We also provide new and updated information on the survival and mean dispersal distance for non-breeding Canada Geese. The mean dispersal distance away from Windermere for all marked individuals was 76 km (95% CI = 14.2). Annual mean survival rates ranged between 0.510 and 0.875 over the study period, with a geometric mean of 0.654 ± 0.199 (95% CI = 0.556–0.751). The results significantly improve our knowledge of the demography of the non-native British Canada Goose population.
Issue No: Vol. 0
- Exploring determinants of breeding success in the Greenland Barnacle Goose
Branta leucopsis
Authors: Courtney Redmond, David Cabot, Susan Doyle, Barry J. McMahon
Abstract: In many bird species across a variety of taxa, larger individuals with greater body stores are more likely to breed successfully. The migratory Barnacle Goose Branta leucopsis breeds in arctic regions including Greenland, Svalbard, Russia, and the North and Baltic Seas. Larger body size and metabolic body stores (weight relative to body size) have been linked to increased fitness through larger clutch size, social dominance, better overall health and more efficient feeding for the Svalbard and Baltic subpopulations, but this has not yet been shown for the Greenland subpopulation. In Greenland, the geese breed in remote areas inaccessible for study, but observations made on the wintering grounds in northwest Scotland and Ireland can provide important insight into factors affecting trends in abundance. To determine the influence of larger body stores or physical size on breeding success in the Greenland Barnacle Goose subpopulation, a dataset with 60 years of morphometric measurements and field observations at one of the principal wintering grounds in Ireland was analysed. Both males and females with larger body stores were more likely to breed successfully, and this relationship was significant. Males with larger body size were also more likely to breed successfully, although this relationship was not significant. Similar relationships were not seen with pairing success, suggesting that body stores and size may have more direct influence on the ability to raise offspring than on securing a mate. While all of the Barnacle Goose subpopulations showed a dramatic increase in the past 60 years, they are susceptible to pressures on both breeding and wintering grounds (e.g. human–wildlife conflicts and avian influenza), necessitating an understanding of the factors that contribute to their population dynamics.
Issue No: Vol. 0
- Numbers and distribution of the Red-breasted Goose Branta ruficollis in
southeast Romania
Authors: Emil Todorov, Alexandru Ifrim, Andrei Cotoara, László Ambrus, Ciprian Fântână, Constantin Ion, Cristian Donșa, Dan Bandacu, Daniel Petrescu, Dănuţ Drăgan, Huela G. Dănuţ, Dumitru Murariu, Dorin Damoc, Emanuel Baltag, Eugen Petrescu, Florin Stavarache, Judit Veres-Szászka, Laurenţiu Petrencu, Lucian Fasola-Matasaru, Nándor Veres-Szászka, Pal Lajos, Sandu Cristian, Sebastian Bugariu, Szabó József, Viorel Cuzic, Vitalie Adjer, Vlad Amarghioalei
Abstract: Southeast Romania is one of the most important wintering areas for the IUCN-designated vulnerable Red-breasted Goose Branta ruficollis, where regular monitoring has been undertaken as a contribution to the international Red-breasted Goose monitoring scheme from 2012 to 2022. Simultaneous roost counts were undertaken from November–February, covering 17 key sites for the species in southeast Romania, and all major wetlands in the country were surveyed in mid-January as part of the International Waterbird Census. The species was found wintering entirely near large lakes and wetlands in the lowlands of southeast Romania, exclusively concentrated in two regions: Baragan and coastal Dobrogea. Between 2012 and 2022, national totals were estimated at between 8,660 and 23,783 individuals, with an average of 16,322 birds, which represents almost 30% of the global population. Population trends for the species in Romania over the same period are classified as “uncertain”. At the regional level, the 10-year period trend shows a moderate increase in Baragan region and a strong increase in coastal Dobrogea, but for the last five years the trend in both regions is uncertain. Solitary birds or small groups might be seen also in other wetlands across the western and eastern lowlands of the country for short periods of time, especially during migration. We found that 25% of observations of the geese were registered outside of the borders of the protected areas, in areas which may hold flocks of over 10,000 Red-breasted Geese. The current vulnerability of this population, and the uncertainty regarding its true global abundance and trends, highlights the need for continuous coordinated counts in the country, in order to understand how the species will adapt to the climate changes, which might have an influence on its total population size and distribution.
Issue No: Vol. 0
- Wintering geese of northwestern Black Sea coasts: results of coordinated
monitoring 2017–2022
Authors: Mihail Iliev, Emil Todorov, Ivan Russev, Georgi Popgeorgiev, Anthony D. Fox, Nicky Petkov
Abstract: Northwestern Black Sea coasts support globally important numbers of wintering geese, especially Red-breasted Geese (RBG) Branta ruficollis but also large numbers of Greater White-fronted Geese (GWFG) Anser albifrons and regionally important Greylag Geese (GG) Anser anser. Despite good national mid-winter waterbird counts within Bulgaria, Romania and Ukraine, until recently there were no internationally coordinated counts at other times of the winter. Here, we present coordinated monthly count data from November to February in five recent winters (2017/18–2021/22) from the three countries, collected under a LIFE programme project to support RBG conservation. Mean annual maximum winter counts were 385,363 GWFG (range = 207,655–530,100), 20,919 RBG (13,741–26,834) and 9,728 GG (4,059–13,971) from standardised counts at the same sites throughout the region. Romania supported an overall mean of 77.3% of all GWFG from any one total count in all winter months, 65–95% in all years except for the mild winter of 2018/2019. Romania also contributed 66.3% of all RBG (range = 27%–92%) counted during coordinated international counts. Peak numbers of GWFG tended to occur in Romania in December, but corresponding increases in Bulgaria in January 2019 were the only suggestion of within-winter westward movements. Peak numbers of RBG in all winters generally were counted from January onwards, but again there were no clear patterns of consistent between-country movements in the course of the winter. These data provide a vital baseline for assessing the effects of recent warfare in the region on the distribution and abundance of these critical goose populations, and underline the need for long-term coordinated monitoring over as large an area and as many wetlands as possible in future, in order to understand their long-term trends and the factors affecting them. Such data are also essential to support planning of effective conservation measures and better inform planning issues, such as those posed by wind turbine development occurring throughout the region.
Issue No: Vol. 0
- A next-generation sequencing study of arthropods in the diet of Laysan
Teal Anas laysanensis
Authors: Wieteke A. Holthuijzen, Carmen C. Antaky, Elizabeth N. Flint, Jonathan H. Plissner, Coral A. Wolf, Holly P. Jones
Abstract: The critically endangered Laysan Teal Anas laysanensis (known as koloa pōhaka in the Hawaiian language), in the Northwestern Hawaiian Islands has wild populations on Kamole (Laysan Island), Kuaihelani (Midway Atoll NWR) and Hōlanikū (Kure Atoll). The Laysan Teal face a new risk on Sand Island in Kuaihelani: non-target poisoning via a pending House Mouse Mus musculus eradication programme. After mice were observed attacking and depredating Laysan Albatross Phoebastria immutabilis (mōlī) in 2015, plans to eradicate the mice were developed to protect this seabird species. This approach, however, risks poisoning the Laysan Teal. To reduce exposure, teal will be translocated during mouse eradication. Even so, there remains a potential risk of secondary poisoning for teal by ingesting arthropods that feed on mouse bait. We therefore used next-generation sequencing (NGS) to identify which arthropods teal consume. From August 2019 to February 2020, we collected 71 fresh teal faecal samples on Sand Island, and successfully extracted DNA from 21 samples. Via NGS, we found that teal most frequently consumed cockroaches (order: Blattodea), freshwater ostracods (Cyprididae), midges (Chironomidae) and isopods (Porcellionidae). To a lesser degree, teal also ate spiders (Araneae), moths (Lepidoptera), beetles (Coleoptera), springtails (Entomobryomorpha), thrips (Thysanoptera) and crabs (Decapoda). Notably, the teal on Sand Island showed differences in diet from those on Kamole, which mainly eat flies (Diptera) and brine shrimp (Anostraca, Artemia sp.). Our study serves as a model for risk mitigation during invasive rodent eradication.
Issue No: Vol. 0
- Breeding biology of the Northern Pintail Anas acuta at the edge of its
southwestern Palearctic range
Authors: Fernando Ibáñez, Juan Calderón, Juan A. Amat
Abstract: One of the most southern breeding sites of the Northern Pintail Anas acuta in the SW Palearctic is in the Guadalquivir marshes (southwest Spain), part of which includes Doñana National Park. Breeding was recorded in 45.7% out of 46 years and was more frequent in those seasons in which the preceding autumn/winter was rainy, suggesting that the species behaved as an opportunistic breeder. Egg-laying started in late March–early April, earlier than in more northern sites. Clutch size and nesting success were similar to those of other populations in Europe and North America. There was a tendency for brood desertion of older ducklings by females. As breeding statistics are similar to those at other sites, the breeding population in the Guadalquivir marshes should not be considered as a peripheral population from an ecological point of view. The size of the breeding population in the Guadalquivir marshes decreased throughout the 20th century. Because the Pintail depends on high water levels to breed in the Guadalquivir marshes, and overexploitation of water resources is increasing in the Doñana area, breeding of this species at this site may be compromised over the next decades.
Issue No: Vol. 0
- Conservation status of the endangered Scaly-sided Merganser Mergus
squamatus on the Korean Peninsula
Authors: Nial Moores, Diana V. Solovyeva, Baek Seung-Kwang, Lee Su-Young, Sergey L. Vartanyan
Abstract: The Scaly-sided Merganser Mergus squamatus is assessed as an Endangered migratory species globally. Effectively restricted for most of the year to rivers in eastern and northeast Asia, the global population in the wild is estimated at 3,600–4,800 individuals. This century has seen a substantial increase in research and conservation effort in the riverine forests of far eastern Russia and northeastern China, where the species is known to breed, and in eastern China where coordinated surveys have found a large proportion of the global population wintering. Data from geolocating loggers and ground observations confirms that a substantial, though still unknown, number of Scaly-sided Merganser pass through the Korean Peninsula during southward and northward migration. In the Republic of Korea (RO Korea), surveys during southward migration found 144–198 individuals along the Imjin River in 2021, and a total of 215 during one-day surveys of three rivers in November 2022. Based on national winter surveys between 2012 and 2022, probably 5% or more of the population also overwinters in the RO Korea. Status in the Democratic People’s Republic of Korea (DPR Korea) remains less clear. The species is assessed in the RO Korea as Endangered nationally and in the DPR Korea as Threatened. Yet there are no sites on the Korean Peninsula being managed for the conservation of Scaly-sided Mergansers, and every river known to be important for the species is being negatively affected by infrastructural development or disturbance.
Issue No: Vol. 0
- Differential mapping of ringed bird distributions from live resightings
versus dead recoveries: an illustration using Eurasian Teal Anas crecca
Authors: Matthieu Guillemain, Betty Plaquin, Adrien Tableau
Abstract: Ringing and visual marking have long been used to delineate bird distribution ranges, but neither method is free from biases linked with differential re-encounter probabilities over the landscape, which may also differ among data collection methods. Modern statistical techniques enable two-dimensional smoothing of the capture/re-encounter information compared with earlier raw ring recovery location maps, improving geographical presentation of areas of greater bird encounter density. However, such technological tools do not solve the issue of the potential biases associated with different data collection methods. We used ring recovery and nasal saddle resighting data from over 14,000 Eurasian Teal Anas crecca ringed in France since 2002 to produce flyway-scale kernel distribution maps to highlight differences between distributions dependent on whether they were derived from recoveries or resighting information, despite abundant data in both cases. Results show that neither large datasets nor modern analytical tools are sufficient to overcome re-encounter probability biases, which require serious evaluation and future dedicated research.
Issue No: Vol. 0
- Multi-scale landscape effects on incubation behaviours in boreal nesting
ducks
Authors: Ryan P.H. Johnstone, Matthew E. Dyson, Stuart M. Slattery, Bradley C. Fedy
Abstract: Incubation plays a crucial role in embryonic development and influences nest and adult survival in birds. Among most North American duck species, only females incubate eggs and therefore face a trade-off between self-maintenance and incubation. These patterns of attendance represent incubation behaviour and are influenced by various external factors that can affect the overall fitness of females and their offspring, but we lack an understanding of how habitat structure and composition affects incubation behaviour. We measured incubation recess frequency, duration and incubation constancy in four ground-nesting duck species (at five nests of Mallard Anas platyrhynchos, 12 Blue-winged Teal Spatula discors, five Green-winged Teal Anas crecca, and seven American Wigeon Mareca americana) across a gradient of natural resource development in the western boreal forest of Alberta, Canada. To quantify incubation patterns, we developed a behaviour identification method using a combination of observer-mediated changepoint analyses and generalized additive models. We then examined the effects of important land cover (e.g. marsh), land use (e.g. roads) and temperature on incubation behaviour using generalized linear mixed-effect models. Average (± s.e.) daily recess frequency for all species was 2.81 ± 0.251 breaks per day, with an average break duration of 3 h (183.49 ± 29.52 min). Across species, individuals spent on average 67% (0.67 ± 0.038) of their day incubating. Daily recess frequency was positively correlated with secondary roads (e.g. winter roads, trails, unmaintained roads), overhead cover at the nest site, marsh habitat and air temperature. Recess duration was positively correlated with average air temperature; incubation constancy was negatively correlated with average air temperature and overhead cover. The results suggested that incubating females take more recesses per day in response to increased land cover, land use and temperature; and that they adjust the duration of recesses and incubation constancy in response to warmer weather. This research yields baseline information on the incubation behaviour of boreal ducks, and uses a new quantitative approach to describe the effects of habitat structure and composition on the incubation behaviour of ground-nesting ducks in the western boreal forest.
Issue No: Vol. 0
- Winter population estimates and distribution changes of two common East
Asian dabbling duck species: current status and long-term (1990–2020)
trends
Authors: Beixi Zhang, Fanjuan Meng, Yat Tung, Eun-Jung Kim, Dingtuan Zheng, Jin Yang, Yongxiang Han, Yang Liu, Shuyu Zhu, Jing Li, Zhihong Chen, Xiaoning Wang, Zhidong Yang, Yong Zhang, Changhu Lu, Kai Shan, Chengwu Jiao, Fengqin Wang, Lin Xue, Dongsheng Zhang, Quingquan Bai, Aiwu Jiang, Ming Zhang, Taej Mundkur, Tetsuo Shimada, Wenbin Xu, Dali Gao, Lei Cao, Anthony D. Fox
Abstract: Based on survey data from China and Asian Waterbird Census (AWC) data from 14 other countries, the population status and trends of Eurasian Wigeon Mareca penelope and Northern Pintail Anas acuta (hereafter Wigeon and Pintail, respectively) using the East-Asia Australasia Flyway (EAAF) were estimated for the first time for the 1990s–2020s. In contrast to earlier assessments, more than 98% of the EAAF estimated numbers of Wigeon and Pintail were found to be present in East Asia, with very few counted in Southeast Asia. Their winter abundances were estimated at 250,000 and 220,000 (150,000 and 160,000 in Japan; 90,000 and 50,000 in China; 5,000 and 6,000 in South Korea), respectively in the early 2020s. These current totals compare with the Waterbird Population Estimates (WPE5) of Wetlands International of 500,000–1,000,000 for Wigeon and 200,000–300,000 for Pintail. In the past 30 years, total numbers of both species in East Asia initially decreased and then stabilised, during which time the number of internationally important wintering sites (holding more than 1% of the flyway population) decreased. The majority of Wigeon (73%) and Pintail (87%) were formerly found in coastal areas, where both species have showed significant declines in areas such as the Jiangsu coast, China. Wintering numbers of Wigeon inland increased, while those of Pintail declined. At present, the nine internationally important wintering sites for Wigeon are situated between 36°N and 22°N, while the 26 internationally important wintering areas for Pintail occur at 40°N–22°N. Wintering numbers of both species in Japan are mainly distributed in the south of Hokkaido, whereas in China both species mainly occur in the Yellow River estuary, in southern coastal areas, and along the Yangtze River. In Korea, Pintail are largely restricted to Asan Bay. Based on these results, we draw attention to the urgent need for wetland conservation in China and South Korea to protect both species effectively, and for updated estimates of the numbers of Wigeon and Pintail in Southeast Asia, which in both cases are fewer than 1,000 birds rather than the 80,000 and 20,000 previously estimated.
Issue No: Vol. 0
- Globally threatened Lesser White-fronted Goose Anser erythropus nesting in
association with Peregrine Falcons Falco peregrinus in southern Yamal,
Russia
Authors: Olga Pokrovskaya, Natalia Sokolova, Dorothee Ehrich, Olivier Gilg, Vasiliy Sokolov, Aleksandr Sokolov
Abstract: Knowledge about the breeding biology and potential threats on the breeding grounds is important for conservation of threatened species. The main breeding range of the Lesser White-fronted Goose Anser erythropus (LWFG) forms a belt along the southern part of the Russian arctic and, although their main nesting habitat has been described based on observations of broods or pairs with breeding behaviour, only very few observations of confirmed nests have been reported. Since 2006, we have encountered 36 nests of this rare species in the Erkuta River basin (in the southern part of the Yamal Peninsula), described their nesting habitat and found that 71% of nests were associated with territorial Peregrine Falcons Falco peregrinus. Such a nest association, already described for other Siberian wildfowl, is assumed to increase the nest survival of LWFG in areas with high predation rates, but also raises indirect conservation concerns since the Peregrine Falcon is itself a rare species in many regions of Russia.
Issue No: Vol. 0
- Genetic connectivity between Caucasian and Northern Velvet Scoter
Melanitta fusca populations and its importance for the long-term survival
of the species in the Caucasus
Authors: Nika Paposhvili, Julius Morkunas, Levan Ninua, Tamar Beridze, Niko Kerdikoshvili, Davit Dekanoidze, Marine Murtskhvaladze, Zurab Javakhishvili, Alexander Gavashelishvili
Abstract: Historical data suggest that the Velvet Scoter Melanitta fusca once had a widespread breeding distribution throughout the Caucasus region, but recent studies have revealed that this population has declined significantly and is now restricted to a single small breeding site at Lake Tabatskuri in Georgia. This population was considered a distinct relict group, likely isolated from the continuously distributed population across the northern forest, alpine and arctic regions of western Eurasia because of its geographic isolation. Until now, however, there was no information available about the genetic structure of the potentially isolated Caucasian population and its connectivity to the rest of the more continuously distributed northern Velvet Scoter population. Here, we analysed mitochondrial cytochrome b (hereafter cyt b) sequences and nuclear genotypes at nine microsatellite loci to evaluate: (1) genetic differentiation among the Caucasian and circumpolar populations, and (2) the genetic diversity of the local population. Our analysis revealed no significant genetic differentiation between these two populations based on both genetic markers, indicating that these two regions may represent a single panmictic population. These results are important for planning future conservation measures to maintain the Velvet Scoter population in the Caucasus.
Issue No: Vol. 0
- Year-round movements of female Common Scoter Melanitta nigra nesting in
Scotland; birds of a feather don’t flock together
Authors: Carl Mitchell, Larry R. Griffin, Edward Burrell, Geoff M. Hilton
Abstract: Numbers of breeding Common Scoter Melanitta nigra have declined in Britain and Ireland since the mid-1990s. To investigate little-known aspects of their annual cycle, nine nesting females at four of the main breeding sites in Scotland (in Inverness-shire, Perth and on Islay) were fitted with unique coloured leg rings and global location sensing (GLS) daylight loggers to track their year-round migrations and wintering areas. Unsuccessful breeders (failing at eggs or duckling stage) left the nesting areas and arrived on the sea from 22 July to 7 August (n = 10) with successful breeders (young reared to > 10 days) arriving between 18 and 20 August (n = 2). In December to February, when movements were at a minimum, the birds were widely dispersed at locations including the Moray Firth, (northeastern Scotland), the west and east coast of Ireland, Liverpool Bay (mid-western England) and the west coast of Morocco. The results from GLS deployed on female Common Scoter are the first to link breeding, staging and wintering areas in this species in time and space, showing Scottish-breeding birds wintered at sites from the north to the southerly extent of their known winter distribution. One of the birds wintering off Morocco staged off the Netherlands before returning to Scotland. All birds arrived back on the breeding sites between 13 and 30 April (n = 10). The apparent high survival rate and strong philopatry of female Common Scoters suggest that low reproductive output and/or low first-year survival contribute to the observed decline in breeding numbers, supporting the need for current conservation actions at the Inverness-shire breeding sites to protect the species.
Issue No: Vol. 0
- Instructions for Authors
Authors: Eileen C. Rees
Issue No: Vol. 0
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Open Access journal
