scholarly journals Seasonal and regional differences in migration patterns and conservation status of Swan Geese (Anser cygnoides) in the East Asian Flyway

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Iderbat Damba ◽  
Junjian Zhang ◽  
Kunpeng Yi ◽  
Huashan Dou ◽  
Nyambayar Batbayar ◽  
...  

Abstract Background The Swan Goose (Anser cygnoides) breeds across Mongolia and adjacent China and Russia and winters exclusively in China. It is globally threatened, showing long-term major range contractions and declining abundance, linked to habitat loss and degradation. We remain ignorant about the biogeographical subpopulation structure of the species and potential differences in their migration timing, stopovers and schedules, information that could be vital to effective conservation of different elements of the species population, which we address here with results from a telemetry study. Methods In 2017–2018, we attached GPS/GSM telemetry devices to 238 Swan Geese on moulting sites in three discrete parts of their summering area (Dauria International Protected Area, Central Mongolia and Western Mongolia), generating 104 complete spring and autumn migration episodes to compare migration speed and nature between birds of different summer provenances. Results Birds from all three breeding areas used almost completely separate migration routes to winter sympatrically in the Yangtze River floodplain. Although many features of the spring and autumn migrations of the three groups were similar, despite the significantly longer migration routes taken by Western Mongolian tagged birds, birds from Dauria Region arrived significantly later in winter due to prolonged staging in coastal areas and took longer to reach their breeding areas in spring. Among birds of all breeding provenances, spring migration was approximately twice as fast as autumn migration. Areas used by staging Swan Geese (mainly wetlands) in autumn and spring almost never fell within national level protected areas, suggesting major site safeguard is necessary to protect these critical areas. Conclusions This study showed the discreteness of migration routes taken by birds of different summer provenances and differences in their migratory patterns, highlighting key staging areas (Yalu River Estuary in China/North Korea for Dauria Region breeding birds, Daihai Lake for Central Mongolian and Ordos Basin for Western Mongolian birds). Based on this new knowledge of the biogeographical subpopulation structure of the Swan Goose, we need to combine data on subpopulation size, their distribution throughout the annual life cycle and conservation status, to develop more effective conservation strategies and measures to reverse population decline throughout the range.

2008 ◽  
Vol 18 (1) ◽  
pp. 71-86 ◽  
Author(s):  
Holger Schielzeth ◽  
Götz Eichhorn ◽  
Thomas Heinicke ◽  
Johannes Kamp ◽  
Maxim A. Koshkin ◽  
...  

AbstractRealistic population size estimates for waterbirds are crucial for the application of wetland conservation strategies, since the identification of internationally important wetlands is based on local numbers relative to the population size of the respective species. Central Asia is a poorly surveyed region that is situated at the intersection of migration routes that lead waterbirds from Western Siberia to the south-west (South-West Asia, East Africa) and to the south-east (South Asia, India). We calculated waterbird population estimates for the Tengiz–Korgalzhyn region, a large wetland complex in the steppe zone of Central Kazakhstan, based on waterbird surveys conducted between 1999 and 2004. For 20 of 43 species analysed the region supported more than 5% of the relevant flyway populations. Five species occurred with more than 40% of the flyway totals, including the Endangered White-headed Duck Oxyura leucocephala and the Vulnerable Dalmatian Pelican Pelecanus crispus. Peak numbers were recorded in summer and autumn and for most species numbers were more than an order of magnitude lower on spring migration compared with autumn migration. We identified 72 individual sites that held more than 20,000 waterbirds or more than 1% of a particular flyway population at least once. These sites are likely to constitute priorities for conservation. The general conservation status of the region is favourable, since many of the important sites are located within a strict nature reserve. However, outside the reserve hunting, fishing and powerline casualties represent conservation issues that should be monitored more carefully in the future.


2015 ◽  
Vol 47 (3) ◽  
pp. 183-186 ◽  
Author(s):  
Maria Prieto ◽  
Lidia Romera ◽  
Sonia Merinero ◽  
Gregorio Aragón ◽  
Isabel Martínez

AbstractLobarina scrobiculata(better known asLobaria scrobiculata) is a widespread lichen, threatened and Red-Listed in various European countries. Microsatellite markers for the mycobiont ofL. scrobiculatawere developed in order to investigate its genetic diversity in the Iberian Peninsula and Europe and to design effective conservation strategies. A total of 7 polymorphic markers were isolated and characterized. These microsatellites were tested in natural populations found in the Iberian Peninsula. The number of observed alleles ranged from 3 to 8, and the Nei's unbiased gene diversity from 0·26 to 0·59. These microsatellite markers are the first to be developed forL. scrobiculataand they will be useful for population studies and for the assessment of the conservation status of this species.


2019 ◽  
Vol 2 ◽  
Author(s):  
Urška Ratajc ◽  
Andrej Kapla ◽  
Špela Ambrožič Ergaver ◽  
Al Vrezec

In the past few decades, there has been a sharp decline in specialised and rare species of ground beetles (Carabus) throughout Europe. Our aim was to determine the distribution trends of chosen species and their conservation status in Slovenia. Based on historical and recent data over the period from 1850 to 2018, distribution maps for 25 species of genus Carabus have been made. The reduction in distribution area size was used to evaluate the decline of each species in Slovenia and for assigning them to different categories of threat status. Our results show that a significant number of species from genus Carabus are in decline. Open habitat species of ground beetles (C. cancellatus), ground beetles that are dependent on mature, unmanaged forests (C. glabratus, C. croaticus) and species, very sensitive to climate change (C. irregularis) were found to be the most endangered. Currently, only 3 species are on the Red list of threatened species in Slovenia (C. auronitens, C. gigas and C. variolosus nodulosus), and based on our results, at least 10 species of ground beetles should be added to the existing list. Two species of ground beetles, C. kollari and C. montivagus, have already disappeared from Slovenia in the last few decades, therefore intensive ecological studies of the remaining species and immediate effective conservation strategies are essential.


Author(s):  
MUNEHIRO KITAZAWA ◽  
MASAYUKI SENZAKI ◽  
HIROAKI MATSUMIYA ◽  
SEIICHI HARA ◽  
HARUKA MIZUMURA

Summary The Brown Shrike Lanius cristatus breeds across a large portion of eastern Asia. One subspecies, L. c. superciliosus, is primarily endemic to Japan and was historically abundant throughout its breeding range. However, both local- and broad-scale studies documented a drastic population decline between the 1970s and 1990s, and the status of the taxon is currently unavailable in Japan. We conducted a nationwide survey to estimate the current population size and breeding range of this subspecies within Japan. We further compared our findings to the historical breeding ranges through a literature review. The total population size was estimated at 149 breeding pairs, and the current breeding range was estimated at 6,800 km2, indicating a 90.9% range contraction over the past century. Our study highlights the urgency of protecting remaining breeding habitats and establishing effective conservation strategies for L. c. superciliosus.


2010 ◽  
Vol 20 (4) ◽  
pp. 410-431 ◽  
Author(s):  
JUAN F. FREILE ◽  
JUAN LUIS PARRA ◽  
CATHERINE H. GRAHAM

SummaryThe current ranges of many tropical species of conservation concern are poorly known, yet this information is critical for assessing their conservation status against the IUCN Red List criteria and implementing species-level management. Antpittas in the generaGrallariaandGrallariculaare elusive, ground-foraging insectivores, highly susceptible to a range of threats. For these genera, we combine environmental niche modelling with expert knowledge in order to predict species’ geographic distributions, and we use current estimates of deforestation to evaluate their conservation status in Ecuador. We use BIOCLIM to generate a first pass geographic prediction, which was further aided by expert knowledge of their natural history. This methodology allowed us to assess the conservation status of each species, revising previous assessments at the national level and making recommendations for revision of global IUCN Red List categories. Based on inferred rates of population decline, derived from estimates of loss of suitable habitat, we suggest ranking three species as ‘Endangered’ in Ecuador, one as 'Vulnerable', and three as ‘Near Threatened’. Predicted national ranges vary in size from 56.05 km2to 112,745 km2. Patterns of range loss were different for each Andean slope, with higher deforestation on the western slope. The combination of niche modelling and knowledge of habitat loss can be a powerful tool to aid conservation efforts in the face of a poor understanding of population demographics, as is the case for many Neotropical taxa. We hope the methodology and results provided here will increase our understanding, and focus future attention on the conservation of this poorly known avian group.


2020 ◽  
Vol 105 (3) ◽  
pp. 281-299
Author(s):  
Javier Carreño-Barrera ◽  
Luis Alberto Núñez-Avellaneda ◽  
Maria José Sanín ◽  
Artur Campos D. Maia

Solitary, dioecious, and mostly endemic to Andean cloud forests, wax palms (Ceroxylon Bonpl. ex DC. spp.) are currently under worrisome conservation status. The establishment of management plans for their dwindling populations rely on detailed biological data, including their reproductive ecology. As in the case of numerous other Neotropical palm taxa, small beetles are assumed to be selective pollinators of wax palms, but their identity and relevance in successful fruit yield were unknown. During three consecutive reproductive seasons we collected data on population phenology and reproductive and floral biology of three syntopic species of wax palms native to the Colombian Andes. We also determined the composition of the associated flower-visiting entomofauna, quantifying the extent of the role of individual species as effective pollinators through standardized value indexes that take into consideration abundance, constancy, and pollen transport efficiency. The studied populations of C. parvifrons (Engel) H. Wendl., C. ventricosum Burret, and C. vogelianum (Engel) H. Wendl. exhibit seasonal reproductive cycles with marked temporal patterns of flower and fruit production. The composition of the associated flower-visiting entomofauna, comprised by ca. 50 morphotypes, was constant across flowering seasons and differed only marginally among species. Nonetheless, a fraction of the insect species associated with pistillate inflorescences actually carried pollen, and calculated pollinator importance indexes demonstrated that one insect species alone, Mystrops rotundula Sharp, accounted for 94%–99% of the effective pollination services for all three species of wax palms. The sequential asynchronous flowering of C. parvifrons, C. ventricosum, and C. vogelianum provides an abundant and constant supply of pollen, pivotal for the maintenance of large populations of their shared pollinators, a cooperative strategy proven effective by high fruit yield rates (up to 79%). Reproductive success might be compromised for all species by the population decline of one of them, as it would tamper with the temporal orchestration of pollen offer.


2020 ◽  
Vol 7 (1) ◽  
pp. 19-26
Author(s):  
Clayton D Delancey ◽  
Kamal Islam ◽  
Gunnar R Kramer ◽  
Garrett J MacDonald ◽  
Alexander R Sharp ◽  
...  

AbstractCerulean Warblers (Setophaga cerulea) are among the fastest declining Nearctic-Neotropical migrant wood-warblers (Parulidae) in North America. Despite ongoing conservation efforts, little is known about their non-breeding distribution. In June 2016-2018, we deployed geolocators (n = 30) on adult male Cerulean Warblers in Indiana, USA, to track annual movements of individuals. Recovered geolocators (n = 4) showed that Cerulean Warblers occurred broadly throughout northern South America. Autumn migration lasted 44-71 days (n = 4), whereas spring migration lasted 37-41 days (n = 3). The average migration distance was 5268 km. During autumn migration, Cerulean Warblers made 1-4 stopovers (i.e., ≥2 days; n = 4) and 1-2 stopovers during spring migration (n = 3). When crossing the Gulf of Mexico during autumn migration, two birds stopped over after crossing, but not beforehand. Two others navigated through the Caribbean rather than crossing the Gulf of Mexico. During spring migration, one individual stopped after crossing, one individual stopped before crossing, and one individual stopped before and after crossing the Gulf of Mexico. No birds migrated through the Caribbean Islands during spring migration. These results represent novel information describing annual movements of individual Cerulean Warblers and will inform conservation efforts for this declining species.


2014 ◽  
Vol 64 (4) ◽  
pp. 333-342 ◽  
Author(s):  
Marcos de Miranda Leão Leite ◽  
Cynthia Yuri Ogawa ◽  
Carla Ferreira Rezende ◽  
José Roberto Feitosa Silva

The relationship between weight and size of individuals can be used to evaluate the status of a population, which is particularly useful for natural populations that are being exploited. Ucides cordatus occurs on the Atlantic coast of the American continent, from Florida (USA) to Santa Catarina (Brazil). This species is economically very important, most of all in the Northeastern area of Brazil, as well as in the Dominican Republic and Suriname. The objective of this study was to analyze life phases (‘fattening’, ‘matumba’, ‘milk-crab’, ‘maturation’ and ‘walking’) by use of the weight-length relationships, as well as temporal variations in this condition factor for each sex of U. cordatus. For this purpose, individuals were sampled monthly for twenty-four months at the Jaguaribe River estuary, Ceará State, Northeastern Brazil. The relationship between total weight and cephalothorax width was established using regression analysis, adjusted by a power equation. The dynamics of the condition factor were analyzed for each sex using the variation of its averages related to annual life cycle; this was done for each of the previously-mentioned phases. The relationship between total weight and cephalothorax width showed an isometric growth in males and negative allometric growth in females suggesting that, for the same reference size, males are heavier than females. When considering the average of the female condition factors, these were greater than those for males during the annual life cycle, except during the ‘maturation’ phase, which is the phase with a higher demand of energetic reserves for males. Annual variation of the condition factor in females presented no significant difference.


2016 ◽  
Vol 37 (3) ◽  
pp. 325-330 ◽  
Author(s):  
João Carlos Campos ◽  
Fernando Martínez-Freiría ◽  
Fábio Vieira Sousa ◽  
Frederico Santarém ◽  
José Carlos Brito

The West African crocodile (Crocodylus suchus) is an emblematic species from the Sahara-Sahel with scarce knowledge on distribution and conservation status. This study updated the knowledge on distribution, occupied habitats, population size, and factors that threaten C. suchus and its habitats in Mauritania. Five field expeditions to Mauritania (2011-2016), allowed the detection of 26 new localities, increasing by 27% the current number of all known locations (adding up to ). In most localities less than five individuals were observed, and in all visiting sites the number of observed individuals ranged from one to 23. Eleven threat factors were identified, being droughts and temperature extremes (100% localities affected) and water abstraction for domestic use and nomadic grazing (94%) the most frequent. These findings suggest that crocodiles are apparently vulnerable in Mauritania and that future local conservation strategies are needed to assure the continuity of its fragile populations and preserve their habitats.


1970 ◽  
Vol 36 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Fergan Karaer ◽  
Ferhat Celep

Scorzonera amasiana Hausskn. and Bornm. was described from type specimens collected by J.F.N. Bornmueller in 1889 but it was not collected again until 1993, when it was found near Amasya, Turkey. Populations of S. amasiana were quite small at that limited locations and were vulnerable to human impacts. Therefore, suitable conservation strategies should be developed immediately in order to protect the species from probable extinction. Here, an additional three small populations are reported. Brief history, morphology, habitat and ecology of this endemic species have been discussed. Its current conservation status was reevaluated with respect to the latest IUCN criteria. A key to distinguish it from the other closely related Turkish species is also provided and its distribution map is appended.   Key words: Endangered, Rediscovery, Scorzonera, Turkey DOI = 10.3329/bjb.v36i2.1502 Bangladesh J. Bot. 36(2): 139-144, 2007 (December)


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