Contrasting habitat use and conservation status of Chinese-wintering and other Eurasian Greater White-fronted Goose (Anser albifrons) populations

Background GPS/GSM tracking data were used to contrast use of (i) habitats and (ii) protected areas between three Arctic-nesting Greater White-fronted Geese (Anser albifrons, GWFG) populations throughout the annual cycle. We wished to demonstrate that the East Asian Continental Population (which winters on natural wetlands in the Chinese Yangtze River floodplain and is currently declining) avoids using farmland at multiple wintering sites. We also gathered tracking evidence to support general observations from two increasing population of GWFG, the North Sea-Baltic (which winters in Europe) and the West Pacific (which winter in Korea and Japan) winter mostly within farmland landscapes, using wetlands only for safe night roosts. Methods We tracked 156 GWFG throughout their annual cycle using GPS/GSM transmitters from these three populations to determine migration routes and stopover staging patterns. We used Brownian Bridge Movement Models to generate summer, winter and migration stopover home ranges which we then overlaid in GIS with land cover and protected area boundary at national level to determine habitat use and degree of protection from nature conservation designated areas. Results Data confirmed that 73% of European wintering GWFG homes ranges were from within farmland, compared to 59% in Japan and Korea, but just 5% in China, confirming the heavy winter use of agricultural landscapes by GWFG away from China, and avoidance of farmland at multiple sites within the Yangtze River floodplain. The same GWFG used farmland in northeast China in spring and autumn, confirming their experience of exploiting such habitats at other stages of their annual cycle. Chinese wintering birds showed the greatest overlap with protected areas of all three populations, showing current levels of site safeguard are failing to protect this population. Conclusions Results confirm the need for strategic planning to protect the East Asian Continental GWFG population. While the site protection network in place to protect the species seems adequate, it has failed to stop the declines. Buffalo grazing could serve as one simple strategy to improve the condition of feeding habitats at Dongting Lake and Poyang Lake in the Yangtze, where vast Carex meadows exist. In addition, while we warn against pushing GWFG to winter farmland feeding in China because of the long-term potential to conflict with agricultural interests, we recommend experimental sacrificial, disturbance-free farmland within designated refuge areas adjacent to the Yangtze River floodplain wetland reserves as a manipulative experiment to improve the conservation status of this population in years when natural food sources are limited.

Nanchangia anserum gen. nov., sp. nov., isolated from feces of greater white-fronted geese (Anser albifrons)

Two rod-shaped and Gram-stain-positive bacteria (strains C64T and C62) were isolated in 2020 from faeces of greater white-fronted geese (Anser albifrons) from Poyang Lake, PR China. Their optimal growth conditions were at 37 °C, pH 7.0 and with 0.5 % (w/v) NaCl. The two isolates showed a highest 16S rRNA gene sequence similarity to Bowdeniella nasicola DSM 19116T (92.1 %). Phylogenetic/phylogenomic analyses indicated that strains C64T and C62 clustered independently in the vicinity of the genera Varibaculum , Winkia and Mobiluncus within the family Actinomycetaceae , but could not be classified clearly as members of any of these known genera. The average amino acid identity values between our isolates and available genomes of members of the family Actinomycetaceae were around the genus threshold value (45–65 %). The major cellular fatty acids of the strains were C18 : 1ω9c and C16 : 0. The predominant polar lipids were phosphatidylinositol, phosphatidylglycerol, phosphatidylcholine, diacylglycerol, triacylglycerol and cardiolipin. The amino acid composition of peptidoglycan contained alanine, glutamic acid and glycine. The major respiratory menaquinones were MK-8(H4) and MK-9(H4). The whole cell sugars included galactose, arabinose and glucose. On the basis of the results of the 16S rRNA gene sequences comparison, whole-genome phylogenomic analysis, phenotypic and chemotaxonomic characteristics, we propose that strains C64T and C62 represent a novel species belonging to a novel genus within the family Actinomycetaceae , for which the name Nanchangia anserum gen. nov., sp. nov. is proposed. The type strain is Nanchangia anserum C64T (=CGMCC 1.18410T=GDMCC 1.1969T=KCTC 49511T=KACC 22143T).

Landscape Attributes Best Explain the Population Trend of Wintering Greater White-Fronted Goose (Anser albifrons) in the Yangtze River Floodplain

Biodiversity in the Middle and Lower Yangtze Floodplain has critically decreased during the last several decades, driven by numerous determinants. Hence, identification of primary drivers of animal population decline is a priority for conservation. Analyzing long time-series data is a powerful way to assess drivers of declines, but the data are often missing, hampering effective conservation policymaking. In this study, based on twenty-four years (from 1996 to 2019) of annual maximal count data, we investigated the effects of climate and landscape changes on the increasing population trend of the Greater White-Fronted Goose (Anser albifrons) at a Ramsar site in the Middle and Lower Yangtze Floodplain, China. Our results showed that the availability of a suitable habitat and landscape attributes are the key driving forces affecting the population trend, while the effects of climate factors are weak. Specifically, increasing the area of suitable habitat and alleviating habitat fragmentation through a fishing ban policy may have provided a more suitable habitat to the geese, contributing to the increasing population trend. However, we also observed that the grazing prohibition policy implemented in 2017 at Shengjin Lake may have potentially negatively affected geese abundance, as grazing by larger herbivores may favor smaller geese species by modifying the vegetation community and structure. Based on our results, we suggest several practical countermeasures to improve the habitat suitability for herbivorous goose species wintering in this region.

ВЛИЯНИЕ ЭКСТРЕМАЛЬНОЙ ЗАСУХИ НА ЧИСЛЕННОСТЬ АРКТИЧЕСКИХ ГУСЕЙ НА МИГРАЦИОННОЙ ОСТАНОВКЕ В ДОЛИНЕ РЕКИ ЗАПАДНЫЙ МАНЫЧ В 2020–2021 гг., "Наука юга России"

Экстремальная засуха без осадков на юго-западе Европейской России в районе Весёловского водохранилища продолжалась 78 дней со 2 августа 2020 г. вплоть до наступления холодов. Сумма осадков за этот период составила 0,8 мм. Максимальные и средние температуры воздуха: в сентябре – 34,6 и 20,1 °C соответственно; в октябре – 25,7 и 14,6 °C соответственно. Основные кормовые стации арктических гусей в районе Весёловского водохранилища – поля озимой пшеницы, доминирующие в структуре растениеводства Ростовской области. К моменту прилета на миграционную стоянку белолобого гуся Anser albifrons (Scopoli, 1769) в середине октября и краснозобой казарки Branta ruficollis (Pallas, 1769) в первой декаде ноября 2020 г. из-за засухи и аномально высоких температур озимые культуры не взошли на обширных территориях. Это стало причиной перемещения гусей на миграционную остановку в район оз. Маныч-Гудило юго-восточнее Весёловского водохранилища, где сохранились степные пастбища. В районе Весёловского водохранилища гуси останавливались лишь на короткий отдых. Крупных скоплений белолобого гуся осенью 2020 г. не было (максимум 9000 особей), тогда как предыдущей осенью численность этого вида в пик миграционной остановки составляла 17500 особей. Максимальная численность краснозобой казарки осенью 2020 г. в районе Весёловского водохранилища составила 1700 особей (5000 особей в 2019 г.). Сократилась продолжительность пребывания двух видов осенью 2020 г. по сравнению с предыдущим годом. Март 2021 г. был морозным, озимая пшеница взошла в начале апреля, когда пролет арктических гусей практически завершился. Белолобые гуси останавливались в районе Весёловского водохранилища так же, как и осенью, лишь для короткого отдыха. Многие стаи следовали транзитом, поскольку здесь отсутствовали кормовые ресурсы, необходимое условие для миграционной остановки. Краснозобая казарка на весеннем пролете также следовала через водохранилище транзитом на стоянку в район оз. Маныч-Гудило. Таким образом, экстремальные погодные условия, такие как продолжительная засуха до и во время осенней миграции арктических гусей, могут приводить к резкому снижению экологической емкости местообитаний на миграционной стоянке. Отсутствие влаги с сочетанием аномально высокими температурами, ранний приход морозов осенью с осадками в виде снега, морозный март – факторы, спровоцировавшие полное отсутствие кормовых ресурсов для арктических гусей в районе водохранилища. Ситуацию усугубило также отсутствие природных пастбищ и практически монокультурность сельскохозяйственного растениеводства на больших территориях. В результате засухи, а также сопутствующих погодных и антропогенных факторов численность гусей на миграционной стоянке снижается, меняется характер использования территории: гуси избегают длительных остановок, зачастую следуя транзитом. Часть мигрирующей группировки использует крупный водоем лишь для кратковременного отдыха, перемещаясь на длительную остановку восточнее Весёловского водохранилища, туда, где сохранились степные пастбища.

Lateralization in monogamous pairs: wild geese prefer to keep their partner in the left hemifield except when disturbed

Behavioural lateralization, which reflects the functional specializations of the two brain hemispheres, is assumed to play an important role in cooperative intraspecific interactions. However, there are few studies focused on the lateralization in cooperative behaviours of individuals, especially in a natural setting. In the present study, we investigated lateralized spatial interactions between the partners in life-long monogamous pairs. The male-female pairs of two geese species (barnacle, Branta leucopsis, and white-fronted, Anser albifrons geese), were observed during different stages of the annual cycle in a variety of conditions. In geese flocks, we recorded which visual hemifield (left/right) the following partner used to monitor the leading partner relevant to the type of behaviour and the disturbance factors. In a significant majority of pairs, the following bird viewed the leading partner with the left eye during routine behaviours such as resting and feeding in undisturbed conditions. This behavioural lateralization, implicating the right hemisphere processing, was consistent across the different aggregation sites and years of the study. In contrast, no significant bias was found in a variety of geese behaviours associated with enhanced disturbance (when alert on water, flying or fleeing away when disturbed, feeding during the hunting period, in urban area feeding and during moulting). We hypothesize that the increased demands for right hemisphere processing to deal with stressful and emergency situations may interfere with the manifestation of lateralization in social interactions.

Lateralization of vigilance in geese: influence of flock size and distance to the source of disturbance

Left-eye preference, implicating right hemisphere advantage, is typical for vigilant behaviour of many vertebrates. Nevertheless, lateralization of vigilance may be manifested in other ways, such as different reactions to the danger viewed with the right and left eye. Here, we studied one-side biases in the orientation of white-fronted geese Anser albifrons feeding in flocks at different distances to the source of anthropogenic disturbance (a road with traffic) and in flocks of different sizes. The birds which used the left eye to monitor the road were at shorter distances to the road than the birds which used the right eye. The tendency to monitor the road with the right eye decreased with increasing flock size. Trade-offs between feeding, social and vigilant behaviour could explain these tendencies.