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Wildfowl
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This is an Open Access Journal

Open Access journal
ISSN (Print) 0954-6324 - ISSN (Online) 2052-6458
Published by Wildfowl and Wetlands Trust

[1 journal]

Contents and Dedication
- Authors: Eileen C. Rees
  Issue No: Vol. 72
Editorial
- Authors: Eileen C. Rees
  Issue No: Vol. 72
The International Waterfowl (and Wetlands) Research Bureau: c.
1945–1995
- Authors: David A. Stroud, Jean-Yves Pirot, Mike Smart
  Abstract: The International Waterfowl and Wetlands Research Bureau (IWRB) – an international network of networks co-ordinated by a small Secretariat – was the most important international motivator for wetland conservation of the 20th century. Its legacy includes the International Waterbird Census (IWC) – one of the largest internationally harmonised biodiversity monitoring schemes in the world; advocacy for, and drafting of, the first multilateral environmental agreement – the “Ramsar” Convention on wetlands; the production of multiple contextual data syntheses, including a global series of regional wetland inventories and waterbird flyway atlases; providing mechanisms through which international concerns regarding “unwise use” of wetlands could be highlighted and raised with governments; and the establishment of a wide range of global standards for conservation, notably the selection of protected areas which remains fundamental to contemporary wetland conservation. This is the story of the organisation, from its origins in the 1920s to its eventual merger with other regional wetland conservation organisations in 1995, told in relation to its structures, staffing, activities and achievements. Whilst much has been taken forward since 1995 and continues to this day, through legacy initiatives and successor bodies, much has also been lost – which is regrettable, especially given the biodiversity crisis now facing the world.
  Issue No: Vol. 72
Influence of spatial scale, sex and parental presence on rates of natal
philopatry in non-migratory Canada Geese Branta canadensis
- Authors: Michael R. Conover
  Abstract: Birds often nest in the same area where they were raised (natal philopatry). The level of natal philopatry among non-migratory Canada Geese Branta canadensis in New Haven County, Connecticut, USA, was studied by banding 731 fledglings, then following them over their lives. The proportion of fledglings that returned to New Haven County to nest as adults (i.e. natal return rates) was 0.22 overall: 0.31 for females and 0.12 for males. These rates increased to 0.60 for females and 0.29 for males after correcting for mortality prior to first breeding (i.e. natal homing rates). For 29 fledglings (2 males and 27 females) that hatched in the Maltby Lakes and returned as adults to breed in New Haven County, I knew the location of their natal site, first nesting site, final nesting site, and the identity of their parents and mate. These 29 birds are referred to as “subjects”. During their first nesting year, 28 of 29 subjects (96%) raised their young at their natal brood-rearing site: 17 (59%) nested on their natal lake, 6 (21%) nested on their natal area (often an island within the lake), and 2 (7%) on their natal territory. These percentages were higher than expected if geese were selecting nest sites at random for brood-rearing sites and natal lakes, but not for natal areas or natal territories. Natal philopatry rates were similar during the subjects’ first and last nesting year, and there was also no difference between subjects raised in crèche broods and those raised in two-parent families. Natal philopatry could be mistaken for parental philopatry (i.e. offspring nesting close to their parents). To test this, the location of nesting territories was examined for those subjects that had parents nesting concurrently on a new nesting territory rather than at the subject’s natal territory. Results showed that both natal and parental philopatry occurred; distances to the natal territory and parents’ current territory were similar. Geese that exhibit natal philopatry will complicate efforts to manage geese at large scales, such as states or flyways.
  Issue No: Vol. 72
Continuous behavioural monitoring reveals increased feeding time during
wing moult in free-ranging Pacific Black Ducks Anas superciliosa
- Authors: Hui Yui, Marcel Klaassen
  Abstract: Many waterfowl species go through a wing moult where all flight feathers are lost simultaneously, rendering the birds flightless while their feathers are regrowing. This puts constraints on the birds during this energetically and nutritiously demanding phase in their annual cycle. Previously, it has been proposed that ducks either decrease activity levels to allocate more resources to wing feather moult, or that they increase feeding activity to match the increased nutritional demands. To study how ducks adjust their time-activity budgets during this challenging life-history stage, we evaluated continuous remotely-sensed time-activity budgets in Pacific Black Ducks Anas superciliosa in southeast Australia, prior to, during and after their annual moult. We tracked three ducks using trackers that recorded one of six different behaviours every 2 sec in addition to hourly GPS locations. Rather than reducing their activity levels, all three ducks increased their daily feeding time and decreased daily resting time. Although the sample size was limited, these data provide support for the hypothesis that moult in ducks is a period of enhanced energy expenditure where they feed more to meet the demands for feather regrowth and possibly also compensate for the potentially reduced foraging efficiency due to flightlessness.
  Issue No: Vol. 72
Movement patterns of diving ducks Aythya sp. in western Europe
- Authors: Adrien Tableau, Marie-Lucile Gourlay-Larour, Christophe Sorin, Jean-François Arcanger, Matthieu Guillemain, Jean-Philippe Rabatel, Thierry George, Alain Caizergues
  Abstract: Millions of birds have been ringed worldwide over the past 100 years to provide a better understanding of their movements and demography. Yet despite this impressive effort, knowledge of migration patterns and strategies, including the location of stopover sites and migratory connectivity, remains incomplete because recapture and ring recovery rates are often extremely low. Using re-encounter records for ringed birds found dead or recaptured, and visual sightings reported for individuals ringed and fitted with nasal saddles, we investigated the patterns of post-nuptial movements of Common Pochard Aythya ferina and Tufted Duck A. fuligula caught in France during the breeding season. So far, most ringing effort for these diving duck species has focussed on populations in northeast Europe, whilst migration patterns for the declining populations which breed in southwest European countries, including France, remain almost entirely unknown. Surprisingly, a large proportion of the individuals re-encountered at least once after capture were eitherresident birds or had initiated post-breeding movements to the north or east, to wintering sites spread over a large area encompassing northern France, Belgium, the Netherlands and Great Britain, as well as to the Alpine lakes (Lake Geneva and Lake Constance). The relatively large proportion of residents and short-distance migrants among the ringed individuals highlights the importance of harvest management schemes being assessed at the local scale, in the same manner as for more sedentary species.
  Issue No: Vol. 72
Review of the distribution and conservation of Far Eastern Curlew Numenius
madagascariensis in the River Lena and River Yana basins, East Siberia
- Authors: Victor G. Degtyarev
  Abstract: The catchments of the River Lena and River Yana are the least known parts of the nesting grounds of the endangered Far Eastern Curlew Numenius madagascariensis, despite accounting for almost half of its known breeding range. This analysis reports on the current distribution of the Far Eastern Curlew, delineates the northern and western extent of its breeding range and describes distribution patterns and threats to the species, based on field research, reports from local people, and a review of historical and most recent publications. The breeding grounds extend to 63°17’N–67°31’N latitude north and 112°27’E–135°11’E longitude west, with the western bow-shaped limit extending to the middle reaches of the River Aldan. The only non-mountainous part of its breeding range within the Lena and Yana River basins is in a 700 × 300 km area west of the Verchoyanskiy Range (63°–66°N), which suggests that the Far Eastern Curlew is a species of mountainous and sub-montane areas. Depending on habitat mosaics, breeding curlews are sparsely distributed in solitary pairs, concentrated in mountains and their foothills. Data are lacking to support the estimation of regional trends in the abundance and distribution of Far Eastern Curlews. Annual hunting of the species does not appear to be critical, and the species is not susceptible to any other obvious threats. The Far Eastern Curlew is able to breed successfully in wetlands subject to human disturbance, but the pristine state of the majority of the breeding grounds and the low-level human activities within its core range suggest predominantly favourable conditions and a general lack of critical direct threats to the species in the River Lena and River Yana catchment areas.
  Issue No: Vol. 72
Bird diversity at the Adıyaman-Gölbaşı Lakes Important Bird Area
(IBA), in southeast Turkey
- Authors: Gökhan Büyük, Recep Karakaş
  Abstract: The diversity of avian species at three lakes (İnekli, Azaplı and Gölbaşı) in the Adıyaman-Gölbaşı Lakes Important Bird and Biodiversity Area (IBA), a unique karst landscape in southeast Turkey, was studied for the first time during 2018–2019. A total of 73 different bird species were detected, from 34 families in 18 orders, of which c. 30% were waterbirds. Fifty species potentially breed at the IBA, whilst 23 occur only in winter or during migration. One – the European Turtle Dove Streptopelia turtur – is of global conservation concern, classed as Vulnerable by the International Union for Conservation of Nature (IUCN) in its Red List of threatened species, and 14 are threatened at the national level. The results suggest that these natural lakes are of great importance for birds. Although the Adıyaman-Gölbaşı Lakes IBA was declared a Nature Park in 2008, illegal hunting, harvesting and reed burning are still major problems in the area. An innovative management approach is required to the protect the habitat, water quality, avian diversity and water flow dynamics in the catchment, in order to protect these natural wetlands and ensure that human activity does not impinge on the integrity of the site.
  Issue No: Vol. 72
Identification of wetlands of international importance in Porbandar,
Gujarat, western India during 2015–2021
- Authors: Dhaval Vargiya, Bharat Jethva, Devang Pandya
  Abstract: citizen science initiatives in India. Porbandar District has unique low-lying floodplain areas, locally known as “ghed”, which become inundated with rain and flood waters during the monsoon, creating temporary wetlands used by waterbirds in the region. The ghed-facilitated inundation is also important for protecting several villagers from the devastating effects of flash floods during heavy rains. Twenty-three of Porandar’s wetlands were monitored in January each year from 2015–2021 inclusive, as a part of the AWC (following recommended count schedules and procedures), to assess their importance for waterbirds. A total of 101 counts were made across the 23 sites during the study, repeatedly covering an area of 20,192 ha. Seven wetlands supported > 20,000 waterbirds and two wetlands supported > 100,000 waterbirds at least once. Over 100,000 waterbirds were counted at the Mokarsagar Wetland Complex on five occasions. The highest annual total recorded for all wetlands combined was of 496,620 birds in 2016, and the highest number of species observed was 134 in 2020. Thirty-six species exceeded 1% of the total population (a criterion for designating sites for protection under the Ramsar Convention) at one or multiple sites. Mokarsagar alone supported 32 of these species, with Javar and Mendha Creek each receiving internationally important numbers of 11 species. Five species listed as globally threatened by the International Union for the Conservation of Nature (four classed as Vulnerable; one as Endangered) and a further 11 Near Threatened species were recorded at the Porbandar wetlands. Seventeen wetlands qualified for recognition on the basis that they exceeded at least one of the criteria used to identify sites of regional or international importance. Of the 23 wetlands surveyed, 12 faced one or multiple threats.
  Issue No: Vol. 72
Distinguishing Tundra Bean Goose Anser fabalis subspecies: blind testing
goose experts, using photographs taken in the field
- Authors: Diana Solovyeva, Tomas Aarvak, Vladimir Emelianov, Alexander Kondratiev, Inga Bysykatova-Harmey, Sergey Kharitonov, Denis Kochetkov, Maria Reutova, Sonia Rozenfeld
  Abstract: Two Tundra Bean Goose Anser fabalis subspecies – the western A. f. rossicus (Buturlin, 1935) and eastern A. f. serrirostris (Swinhoe, 1871) – have been described based on morphological and distributional criteria, although identifying these subspecies outside their breeding and wintering ranges can be challenging. In recent years, studies of other goose populations have increasingly used photographs to identify species in the field. An assessment of whether experts can differentiate the two Tundra Bean Goose subspecies from photographs therefore was undertaken, to verify the accuracy of this potentially useful method for this particular species. Here, we analysed the consistency with which experienced goose researchers attributed pictures of Tundra Bean Geese to either subspecies, using 48 photographs of the heads of individual Tundra Bean Geese, taken at five sites where the birds were caught or observed within different parts of the breeding range. Each individual was assigned to subspecies on the basis of its catch location. Photographs were numbered, mixed using a random number generator, and then submitted to four internationally renowned Bean Goose experts (selected on the basis of their publications) as a blind test. Each expert was asked to identify each picture as either rossicus or serrirostris.Three birds were omitted because they were not assigned as rossicus or serrirostris by all four experts. Overall, 17 (37.8%) of the 45 geese were classed as the same subspecies by the four experts, and a further 18 (40.0%) by three experts, indicating that although some individuals could be identified to the subspecies level in this way, they are not well recognised by the photographs taken during our study. The probability of each expert misassigning subspecies ranged from 0.16 to 0.49 (mean ± s.d. = 0.28 ± 0.07), and the mean probability of the experts classing subspecies correctly (i.e. in accordance with the catch site) was 0.72 ± 0.15 across the study area, increasing to 0.79 ± 0.06 on omitting the least “accurate” expert. There was no difference between catch locations in the proportion of photographs assigned correctly. This study reinforces the view that photographs cannot be used for reliable post hoc identification of Tundra Bean Goose subspecies. Thus, photographs taken during aerial surveys in the arctic, during ground surveys in China, and those posted on eBird and other birding platforms should be treated with caution as a means of describing their distribution. Taking detailed morphological measurements is strongly recommended when handling Bean Geese. Genetic analysis of feathers or blood samples would also help to clarify Tundra Bean Goose systematics and distribution, by identifying the markers that permit differentiation of the two forms.
  Issue No: Vol. 72
Internationally important stopover area for the globally-threatened Common
Pochard Aythya ferina in the Volga River delta
- Authors: Alexander Mischenko, Olga Sukhanova, Sauliua Švažas, Natalia Meshcheriakova, Maxim Perkovskii, Vladimir Strelkov, Alexandre Czajkowski, Daiva Vaitkuvienė
  Abstract: The Common Pochard Aythya ferina (hereafter Pochard), is a widespread freshwater diving duck of the Palearctic. A large and rapid decrease in abundance resulted in it being classified as Vulnerable in the International Union for Conservation of Nature’s (IUCN) Red List in 2015 and it is now considered to be a threatened species globally. The objective of this study was to provide reliable data on numbers and habitat use for Pochard in the delta area of the River Volga (southern European Russia) during their autumn migration. The total number of Pochard staging in the River Volga’s avandelta was estimated at c. 346,000–390,000 individuals in mid-November 2020 and c. 153,200–170,000 in mid-November 2021. Several sites with large numbers of staging Pochard were identified within the delta, and the Volga River delta currently holds the most important stopover concentrations of Pochard in the Palearctic. A large-scale monitoring and research programme is required for Pochard in the delta of the River Volga, because such information is essential for the effective conservation of this globally-threatened species.
  Issue No: Vol. 72
Ovarian degeneration resulting in the phenotypic masculinisation of a wild
female Mallard Anas platyrhynchos
- Authors: Philip Lavretsky, Flor Hernandez, Brian Davis
  Abstract: Among dichromatic avian species, the loss of sexual organs can induce reversal of sexual features among females and males. In particular, the phenotypic feminisation or masculinisation of males and females, respectively, has been linked to the presence of testosterone or luteinizing hormones. Specifically, females lacking a functional ovary (e.g. experience an ovariectomy) or males lacking testes have been found to exhibit male breeding plumage in subsequent moult cycles. We conducted post mortem examination on a wild Mallard Anas platyrhynchos, determined genetically as a female but displaying male plumage, and found that the ovary was missing despite the remaining sexual organs being intact. We concluded that this individual provided an example of spontaneous ovarian degeneration, and that its male-like plumage was attributable to a resulting lack of oestrogen in its body. Together, these results further establish that plumage expression is not strictly genetically based, but rather dictated by the ability for the timely expression or suppression of these genes via modifiers, begging the question of why both sexes retain the molecular variation required to express the male plumage.
  Issue No: Vol. 72
Instructions for Authors
- Authors: Eileen C. Rees
  Issue No: Vol. 72