 Subjects -> CONSERVATION (Total: 128 journals)
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- Preliminary pages
Authors: Eileen Rees
Issue No: Vol. 0
- Editorial
Authors: Eileen C. Rees
Issue No: Vol. 0
- Whooper Swans Cygnus cygnus nesting on offshore islands – a new
occurrence or a well-forgotten old phenomenon'
Authors: Sergei A. Kouzov, Anna V. Kravchuk, Evgeny V. Abakumov, Daria M. Afanaseva
Abstract: In recent years, the first cases have been observed of Whooper Swans Cygnus cygnus nesting on the offshore islands and coasts of the eastern Baltic Sea, in Finland and the Leningrad region of Russia. Based both on our own data and a review of the literature, we suggest that the tendency for Whooper Swans to breed on offshore islands was probably the result of the actively growing population having widely colonised the majority of suitable lakes across the continental regions of Finland. This view is supported by Whooper Swans not yet being recorded nesting on Sweden’s numerous coastal islands, where the breeding density of the species is considerably lower. As further supporting evidence, the literature review also found that Whooper Swan nesting in the marine landscape has not been observed anywhere else within its current range. We additionally provide a synthesis of reports made by M.A. Menzbir about Whooper Swans nesting on the northeastern coast of the Caspian Sea in the second half of the 19th century. Based on both historical and current data from other authors, however, we conclude that these claims were in error and that the birds were most likely nesting on coastal freshwater lakes, which were very numerous in the lowlands around the Caspian Sea during the cooler climate conditions of > 100 years ago.
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- Distribution, trends and threats to Eastern Taiga Bean Goose Anser fabalis
middendorffii in the River Lena basin, East Siberia
Authors: Victor G. Degtyarev
Abstract: Recent studies suggest that the Eastern Taiga Bean Goose Anser fabalis middendorffii is showing accelerated declines in abundance over the last 20 years, despite protection from hunting in the River Lena basin, northeast Russia. An understanding of its distribution and current threats throughout its breeding range therefore is required for the effective conservation of this subspecies, some of which is provided here through field research, together with a review of scientific publications and reports from local people. Currently, the geese occupy streams in remote sub-montane and plateau areas, a distribution pattern unlikely to be natural but the result of long-term overhunting. Historically-occupied habitats were associated with lowland, large river valleys which used to form the major part of its breeding grounds, but the improvement and accessibility of weapons and transportation led to increasing fragmentation of the Eastern Taiga Bean Goose’s breeding range, so that the large rivers and more accessible reaches of the streams are no longer used for nesting. Fishing and tourism can also have a negative effect on breeding by geese, factors which may continue to contribute to the decline of the Eastern Taiga Bean Goose to this day. More rigorous enforcement of anti-poaching legislation, and modification to hunting and protected area regulation, should be undertaken to reduce unintentional shooting of Taiga Bean Geese by law-abiding hunters. Recent observations and reports from local people suggest that arrival in autumn of tundra-breeding geese migrating through the Eastern Taiga Bean Goose’s breeding range is now later than in the 20th century. Data therefore are needed to inform adjustments to the hunting regulations, for instance by developing telemetry studies to track the timing and stopovers used by of birds during migration, as well as providing insights into their movements on the breeding and wintering grounds. Under the current flexible protection regime, the most important streams used by Eastern Taiga Bean Geese in protected areas should be closed to any visitors during the summer months, particularly areas important for the geese and other species in the eastern Aldan highlands and on the Vilyuiskoe Plateau in eastern Siberia.
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- Anthropogenically-induced population increases in sympatric breeding
arctic geese incur apparent competition consequences
Authors: Clark Nissley, Christopher K. Williams, Kenneth F. Abraham, Kelly Russo-Petrick
Abstract: Populations of Lesser Snow Geese Anser caerulescens caerulescens and Cackling Geese Branta hutchinsii have increased substantially since the mid-20th century because of their utilisation of agricultural crops as a food resource on their wintering grounds. In contrast, Atlantic Brant Geese Branta bernicla hrota, which specialise in feeding on submerged marine vegetation in winter, have not capitalised on the availability of agricultural crops to the same extent. On the breeding grounds, Atlantic Brant are also adversely affected by multiple forms of competition from other sympatrically-nesting goose species. There has however been little research on apparent competition between these three species. Apparent competition occurs whenever the presence of one species leads to a reduced population density of another species when they share a generalist predator. To determine whether apparent competition stemming from higher goose nest densities might be a functional mechanism in limiting Atlantic Brant Goose reproduction, we monitored artificial nest survival in high, medium, and low goose nest densities at East Bay, Southampton Island, Nunavut, Canada in July 2015. Eggs in artificial nests located in high-density plots had the lowest survival probabilities compared to those in medium- and low-density plots. These results support the hypothesis that the increase in nest densities resulting from anthropogenically-induced population increases of sympatric native competitors could induce decreased breeding success and a cumulative decline in numbers of nesting Atlantic Brant via apparent competition.
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- Estimated size of the Eastern population of the Lesser White-fronted Goose
Anser erythropus revealed from aerial surveys of key moulting sites
Authors: Diana Solovyeva, Sonia Rozenfeld, Daria Barykina, George Kirtaev, Valeria Danilova, Fanjuan Meng, Lei Cao, Guangchun Lei, Qing Zeng
Abstract: The Eastern population of the Lesser White-fronted Goose Anser erythropus (EPLWFG) breeds and moults in Russia and the majority winter in China. Intensive surveys of lakes in the Yangtze River floodplain and in Japan estimated the EPLWFG at 6,600 individuals in 2020 compared to 14,000–19,000 in 2016. Waterfowl are easier to count when concentrated in relatively small areas at key times of the year, and the non-breeding and failed breeding elements of the EPLWFG (an estimated 87% of the population) concentrate at remote moulting sites from early July to mid-August during remigial moult. Locations of GPS-tagged EPLWFG (non-breeding birds and failed breeders), which moulted between 25 June and 17 August, recorded during an earlier study, were plotted on maps of the key moulting region, along the San-Yuryakh and Kyuanekhtyakh Rivers which flow into Omulyakhskaya Bay. An aerial survey undertaken in July 2021 aimed to cover as many locations of the tracked individuals as possible, together with Svyatoy Nos Cape and the New Siberian Islands (where the species was also thought to moult), to count the numbers of geese moulting in these areas. Moulting sites on the delta of the Lena River were also surveyed from the air during the EPLWFG moulting periods in 2019 and 2020. Goose groups were photographed and digitally tagged to GPS coordinates, generating a database which included a date/time stamp to the nearest second, coordinates to the nearest 0.000001 degree, and a picture ID. Photographs were processed using Adobe Photoshop V 21.1.3 software. From detection rates in the survey area, we were able to assess the extent of similar habitat elsewhere in the EPLWFG moulting range, to obtain an estimate of the potential total population size. Moulting EPLWFG were found on Bolshoy Lyakhovaskiy Island in the New Siberian Islands, a new site discovered during this study. A total of 9,373 EPLWFG was counted in moulting flocks at all known and newly discovered moulting sites. The extrapolated estimate for the number of non-breeding and failed breeding birds, on taking the expanded area of suitable habitat into account, was of potentially 24,060 geese. Considering that c. 10% of EPLWFG are successful breeders (i.e. remain on their breeding sites and do not join the moulting flocks), we propose that the overall population size could be as high as 26,733 individuals, excluding offspring of the year.
Issue No: Vol. 0
- Population trends and distribution of the Lesser Snow Goose Anser
caerulescens caerulescens in Japan, based on 50 years of monitoring
Authors: Yutaka Sabano, Yusuke Sawa, Sachiko Uemura, Masayuki Kurechi
Abstract: Populations of the Lesser Snow Goose Anser caerulescens caerulescens, which historically bred and wintered in East Asia, declined from the 1800s and were almost extinct by the 1890s. In 1993, the “Restoration of Lesser Snow Goose to East Asia Project” was implemented, through cooperation by organisations from Japan, Russia and the United States of America. Since initiation of the project, Snow Geese have been regularly recorded in Japan, and numbers staging or wintering in Japan are still growing. Here, we study the population trends and distribution of Snow Geese wintering in Japan from 1971/72 (before the project commenced) to 2023/24. The mean (± s.d.) number of birds recorded in Japan over the last five winters (2019/20–2023/24) was 1,634 ± 196 geese, suggesting that a regular wintering population has become established in the country. We also collated information on colour-marked individuals. Geese marked in Anadyr (Russia) during the restoration project were found in Japan in subsequent years, suggesting that migratory traditions were also re-established. The extent to which the recent population increase recorded for Snow Geese in Japan was derived from the restoration project however remains unclear, because the exact location of the breeding grounds and migration routes of the Japanese-wintering birds are still unknown. Further studies (e.g. GPS tracking) therefore are required for a full evaluation of the success of this conservation initiative.
Issue No: Vol. 0
- First observations in 20 years of Brent Geese Branta bernicla wintering on
the Shandong coast, China
Authors: Xiaotong Lv, Qingshan Zhao, Mengdan Fei, Yusuke Sawa, Toshio Ikeuchi, Guoxu Yu, Jin Zhang, Fanjuan Meng, Jing Zhang, Yong Zhang, Yanbo Xie, Lei Cao, Anthony D. Fox
Abstract: The East Asian Brent Goose Branta bernicla nigricans population is currently estimated at 5,000–8,700 individuals (just c. 1% of all Brent Geese B. bernicla globally) and is designated by the Conservation of Arctic Flora and Fauna (CAFF) as a priority species for conservation on the East Asian-Australasian Flyway (EAAF). Wintering numbers are concentrated in Japan (where c. 2,500 individuals occur, with an increasing trend), but numbers currently in China (estimated at 5,000 two decades ago) are unknown, emphasising the need for an updated assessment of their abundance and distribution there. A Brent Goose caught in Japan was tracked for five months as it wintered on Sanggou Bay in Shandong Province, confirming this area as a wintering site occupied by the population. Coastal and offshore surveys of Sanggou Bay in January 2023 and 2024 found up to 319 Brent Geese in offshore waters (124 in 2023; 319 in 2024), foraging in aquaculture areas > 2 km from the coastline. As these numbers exceed 1% of the East Asian Brent Goose population (i.e. > 65 individuals), Sanggou Bay qualifies as a site of international importance for the species. The Brent Geese were seen feeding on algal growth within Sweet Kelp Saccharina japonica and oyster (Ostreidae) aquaculture infrastructure and were rarely disturbed by kelp and oyster farmers (who are active mainly in summer), so were subject to almost zero human disturbance. A literature review of Brent Goose distribution and abundance during 1912–2024 suggested that the population historically wintered in the coastal waters of Shandong and Jiangsu Provinces, with up to 10,000 individuals recorded (before 2002), but reports were of < 10 birds present during 2002–2012. Despite our observations, and those documented since 2012, we suspect that fewer Brent Geese winter in China now than two decades ago. We recommend that the Sanggou Bay offshore area be protected and a national survey undertaken, both of the geese and their food resources (e.g. subtidal eelgrass Zostera sp. areas in the Yellow and Bohai Seas) to confirm their distribution, with long-term monitoring put in place for sites where they occur. Restoration of natural seagrass habitats around Changdao Island, Shandong Province (where the Bohai Sea and Yellow Sea meet), which supported the largest numbers historically, is also needed to attract Brent Geese to winter there again.
Issue No: Vol. 0
- Home range and migration of the Red-breasted Goose Branta ruficollis
mapped by satellite telemetry: implications for conservation
Authors: Emil Todorov, Gabriel B. Chisamera, Viorel D. Gavril, Oana C. Vasiliu, Dumitru Murariu, Ioana Cobzaru
Abstract: The Red-breasted Goose Branta ruficollis, classified as Vulnerable by the IUCN Red List of threatened species, is a long-distance migrant which breeds on the Yamal, Gydan and Taymyr Peninsulas of the Russian arctic. Understanding the birds’ breeding ecology and behaviour during migration can contribute to their efficient conservation. In this study, we fitted two male geese with 18 g Argos Solar PTTs and one female with a 9.5 g Solar PTT to provide information about their breeding home range, time spent in key stopover and staging sites, and the duration of migration. One male and one female goose completed one full cycle of migration, breeding in Taymyr Peninsula and returning to their wintering grounds in southeast Romania. The pre-nuptial migration of the male goose was longer in duration and distance than the post-nuptial migration, which was much shorter. The female goose had shorter pre- and post-nuptial migration than the male. Both geese made more stops during spring than autumn which may be explained by a combination of capital breeding (so stopping more frequently to gain energy reserves in preparation for breeding) and arriving in areas yet to thaw during northbound migration. The summer season in the Taymyr Peninsula lasted roughly 85 days. The male goose bred on a small tributary of the Pyasina River, with a core home range of 20 km2. The female goose had a smaller home range, of 6 km2 in the vicinity of the Rarikha River, near the Gulf of Yenisey. Results of this study provide important knowledge about the birds’ home range, days spent at stopover and staging areas and the distance between those sites. These findings can support conservation communities throughout the species’ range in enabling them to carry out essential conservation activities more effectively.
Issue No: Vol. 0
- An alternative approach to evaluating the energetic carrying capacity of
the landscape for Mallard Anas platyrhynchos wintering in the Mississippi
Alluvial Valley, USA
Authors: Melanie R. Boudreau, Joseph D. Lancaster, Daniela F. Adjaye, Jane E. Dentinger, Lacy A. Dolan Todt, Gabrielle N. Ripa, Carlos Ramirez-Reyes, Craig A. Sklarczyk, Bradly S. Thornton, Holly M. Todaro, Richard M. Kaminski, J. Brian Davis
Abstract: Habitat conservation planning for wintering waterfowl in North America uses estimates of waterfowl energy requirements to assess the ability of regional landscapes to support populations. However, because the spatial and temporal configuration of resources can influence an individual animal’s use of the landscape, there may be benefits to considering the availability of energy from food within individual home ranges on developing conservation planning. This possibility was investigated for female Mallard Anas platyrhynchos wintering in the Mississippi Alluvial Valley using: (1) published energy values for different landcover types (quantified as duck energy days; DEDs/ha), (2) maps of landcover and water availability, and (3) winter home range estimates created using location data from 128 birds fitted with VHF radio transmitters. Following current methods used for regional assessments of food resources available for birds, landcover types were first transformed into their corresponding DED values, and the amount of energy considered potentially accessible to Mallard within their home ranges was then limited by accounting for water availability and DED decay rates. Relatively energy-rich landcover types, such as moist-soil wetlands and croplands, were less likely to be accessible given water coverage. Moreover, a large proportion of Mallard locations were in areas that provided no apparent energy value. Most (> 90%), but not all, Mallard home ranges surpassed the birds’ minimum winter energy needs (i.e. 123 DEDs). We suggest that waterfowl habitat conservation planning should consider an individual bird, home-range approach for DED assessments, and use those assessments to: (1) begin examining potential gaps in landscape water coverage, (2) ensure that multiple resource patches are accessible to individual birds, and (3) provide the mixture of landcover types (including those used for other life history needs), required by focal waterfowl species.
Issue No: Vol. 0
- Diet, body condition and seasonal stress in American Black Duck Anas
rubripes and Mallard A. platyrhynchos on Long Island, New York, during
winter
Authors: Aidan J. Flores, Michael L. Schummer
Abstract: Winter habitat for the American Black Duck Anas rubripes (hereon Black Duck) has decreased on the Atlantic coast of North America because of urbanisation and other factors. Human development makes restoration of coastal wetlands for wildlife difficult, but agriculture could increasingly provide food for Black Duck during winter. Diet, body condition and stress indices of Black Duck and Mallard A. platyrhynchos were compared between coastal wetlands and sites with Corn Zea mays fields on Long Island, New York, used by the birds from late-January to late-March. Black Duck and Mallard were captured at Corn sites, whilst only Black Duck were collected in coastal wetlands. Mallard were not available in coastal wetlands for collection during the study. Stable isotope analysis indicated that the Black Duck ate more animal matter (measured by a blood δ15N index) at coastal than Corn sites, whereas Mallard and Black Duck at Corn sites had similar animal diets, although Mallard ate more Corn (determined by blood δ13C levels) than Black Duck. Body mass decreased during the winter for Black Duck at both coastal and Corn sites but increased in Mallard at Corn sites. Stress indices, measured by packed red blood cell volume and heterophil/lymphocyte ratios, suggested less stress for Black Duck when using Corn than when at the coastal sites. Results suggest an endogenous mechanism for weight loss in the Black Duck during winter which differs from Mallards in our study area, although given that Black Duck generally appear to eat less Corn other factors not considered here may also contribute to the weight loss patterns. Overall, Black Ducks appeared to benefit less than Mallards from the availability of Corn. Where feasible, continued protection and restoration to increase quantity and quality of coastal wetlands should be the focus on Long Island and elsewhere where Black Duck and Mallard are sympatric.
Issue No: Vol. 0
- decade of monitoring the Critically Endangered Madagascar Pochard Aythya
innotata: population trends and duckling survival
Authors: Laurence A. Rasoamihaingo, Felix Razafindrajao, Lily-Arison René de Roland, Andrew J. Bamford
Abstract: Factors affecting the breeding success of tropical ducks is an under-researched and poorly understood topic. Here we look at the Critically Endangered Madagascar Pochard Aythya innotata, rediscovered in 2006 at a single location, Bemanevika, in northern Madagascar. Local abundance and duckling survival at the site has been monitored since 2010, during which time numbers increased from 20 to 60 individuals. Timing of breeding was variable between years, but in general most broods hatched in the late dry season (September–November). Duckling survival was low (4%, range = 0.1–18% over the years); however, there were three years of unusually high duckling survival (2017–2019), which seem to have been the driver of the population increase. In contrast to most studies of ducklings, we found higher mortality rates as duckling age increased, peaking at 14 days old. We review the available evidence, for and against five main hypotheses, to explain the low breeding success recorded in this population: predation, food availability, disease, weather and timing of breeding. Predation and timing are not strongly supported as causes of low breeding success. Food availability and weather have evidence in their favour but based, on the evidence currently available, are not able to explain the observed population increase conclusively, suggesting no single overarching cause of the problem. Instead, several of the hypotheses may interact. Future monitoring should focus on collection of more data on disease and food availability.
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- Severe declines in numbers of male American Common Eiders Somateria
mollissima dresseri during spring counts over the past two decades in the
southwestern Bay of Fundy, Canada
Authors: Sarah E. Gutowsky, Mark L. Mallory, Nic R. McLellan, Gregory J. Robertson, Kevin Connor, Scott G. Gilliland
Abstract: The southwestern Bay of Fundy in New Brunswick, Canada, has traditionally provided important habitat year-round for American Common Eider Somateria mollissima dresseri. Numerous anthropogenic stressors from industry and climate change are thought to be having a negative impact on the abundance of dresseri eiders wintering and breeding in this region. We analysed trends in the number of eiders breeding in the Bay of Fundy, recorded during dedicated aerial surveys made to count males attending colonies in spring, flown nearly biannually since 1991. A combination of negative binomial generalized additive models (GAMs) and generalized linear models (GLMs) were used to assess changes in eider numbers over the past 30 years across the entire study region and at the scale of smaller spatial sub-units. We found that the number of eiders breeding in the Bay of Fundy began to decline steeply around the year 2000 in all surveyed areas with an overall regional trend of λ = 0.91 (95% confidence interval = 0.89, 0.92), amounting to a loss of nearly 10% per year over the past two decades. The largest concentrations of nesting eiders continue to be associated with the Grand Manan Archipelago, although numbers have declined there as well. Comparing two years with equal and extensive spatial coverage of surveyed areas, the total number of male eiders counted in the spring in the Bay of Fundy dropped from 8,890 in 1998 to 2,562 in 2017. Altogether, these findings corroborate other evidence that eiders have been declining throughout the Gulf of Maine ecosystem at an alarming rate over the past 20 years, and that distributional shifts are likely occurring across the subspecies’ range.
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- Nesting behaviour and factors affecting reproductive success of Velvet
Scoter Melanitta fusca breeding at Lake Tabatskuri, Georgia
Authors: Sopio Kiknavelidze, Natia Kopaliani, Nika Budagashvili, Nika Melikishvili, Zurab Javakhishvili, Alexander Gavashelishvili, Nika Paposhvili
Abstract: The Velvet Scoter Melanitta fusca is declining globally and the species is classified as vulnerable (VU) on the International Union for Conservation of Nature (IUCN) Red List. Of particular concern is the tiny relict breeding population in the Caucasus, which has been classified as critically endangered. Information on this population remains scarce, and more knowledge of its ecology is required for its effective conservation at its last breeding site in the entire region, Lake Tabatskuri in Georgia. Here, we aim to determine the main drivers of nesting success for the scoters breeding at Lake Tabatskuri, which contribute to the birds’ overall productivity. From 2019–2021, data were collected from all nests on the one breeding island in the lake, during visits made prior to and during incubation, and from camera traps installed by some nests. Results suggested that predator abundance and the frequency of predation attempts had a major impact on nesting success despite the scoters’ defence of their nests. Deploying cameras close to (c. 1 m from) Velvet Scoter nests slightly affected their behaviour, but predation rates appeared to be lower at these nests. In the absence of mammalian predators, Armenian Gulls Larus armenicus (the most numerous breeding bird on the island) and Marsh Harriers Circus aeruginosus predated eggs, which had a significant impact on the outcome of the scoters’ breeding attempts. Predation of nesting females by Marsh Harriers also added to adult mortality and potentially limited production of offspring at Lake Tabatskuri. Continued monitoring of Velvet Scoter abundance and production of offspring at this model site, as well as studying the abundance and impact of the gulls, is essential for determining whether predator control measures are needed to maintain the population.
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- Urban geese discriminate between predators of different sizes
Authors: Friederike Woog, Konrad Schwarz
Abstract: Compared to rural areas, the density of predators such as domestic Dogs Canis lupus familiaris is high in urban areas. Greylag Geese Anser anser recently colonised the city of Stuttgart, southwestern Germany where they frequent large public parks that offer rich grazing for these herbivores. People regularly walk their dogs within the parks, which often disturb the geese and provides an opportunity to study the anti-predator behaviour of Greylag Geese to these potential predators. Goose response distances and strength increased with dog size. Small dogs, people without dogs and vehicles resulted in much shorter response distances. Since large dogs can easily kill geese, it may be adaptive for the geese to fine-tune their behaviour to the real danger from domestic predators.
Issue No: Vol. 0
- Instructions for Authors
Authors: Eileen C. Rees
Issue No: Vol. 0
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