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Dixon A.,International Wildlife Consultants Ltd. | Rahman M.L.,International Wildlife Consultants Ltd. | Galtbalt B.,Wildlife Science and Conservation Center | Gunga A.,Wildlife Science and Conservation Center | And 2 more authors.
Journal for Nature Conservation | Year: 2017

Avian electrocution at power lines is a well-documented phenomenon, yet factors influencing the frequency of electrocution events and the efficacy of mitigation techniques remain relatively under-reported. During May-July, we surveyed a 56 km long 15 kV electricity distribution line running across open steppe in Mongolia recording electrocuted birds of prey under the power poles. We recorded high rates of electrocution of several Threatened raptor species, particularly the Endangered Saker Falcon Falco cherrug, which was killed at a monthly rate of 1.6 birds per 10 km during the period of our study. Electrocution frequency at line poles was associated with density of small mammal holes and the deployment of mitigation measures. It is likely that local prey abundance influences the frequency of birds of prey perching on power poles, which is consequently reflected in electrocution rate. We evaluated the efficacy of mitigation measures and found that the use of perch deflector spikes on the crossarms of line poles reduced electrocution rates when 3 or 4 spikes were deployed. Perch deflectors probably worked by reducing the opportunity for birds to perch adjacent to pin insulators rather than by reducing the frequency of birds perching on the crossarm per se. At anchor poles, reconfiguration of jump wires at two phases, so they passed under the crossarm rather than over, significantly reduced electrocution rates. These mitigation measures potentially represent a relatively inexpensive method to reduce the frequency of raptor electrocution events in regions where cost is a key factor for power line managers in determining whether or not any form of mitigation is used. © 2017 Elsevier GmbH


Newman S.H.,EMPRES Wildlife Unit | Hill N.J.,U.S. Geological Survey | Hill N.J.,University of California at Davis | Spragens K.A.,U.S. Geological Survey | And 14 more authors.
PLoS ONE | Year: 2012

A unique pattern of highly pathogenic avian influenza (HPAI) H5N1 outbreaks has emerged along the Central Asia Flyway, where infection of wild birds has been reported with steady frequency since 2005. We assessed the potential for two hosts of HPAI H5N1, the bar-headed goose (Anser indicus) and ruddy shelduck (Tadorna tadorna), to act as agents for virus dispersal along this 'thoroughfare'. We used an eco-virological approach to compare the migration of 141 birds marked with GPS satellite transmitters during 2005-2010 with: 1) the spatio-temporal patterns of poultry and wild bird outbreaks of HPAI H5N1, and 2) the trajectory of the virus in the outbreak region based on phylogeographic mapping. We found that biweekly utilization distributions (UDs) for 19.2% of bar-headed geese and 46.2% of ruddy shelduck were significantly associated with outbreaks. Ruddy shelduck showed highest correlation with poultry outbreaks owing to their wintering distribution in South Asia, where there is considerable opportunity for HPAI H5N1 spillover from poultry. Both species showed correlation with wild bird outbreaks during the spring migration, suggesting they may be involved in the northward movement of the virus. However, phylogeographic mapping of HPAI H5N1 clades 2.2 and 2.3 did not support dissemination of the virus in a northern direction along the migration corridor. In particular, two subclades (2.2.1 and 2.3.2) moved in a strictly southern direction in contrast to our spatio-temporal analysis of bird migration. Our attempt to reconcile the disciplines of wild bird ecology and HPAI H5N1 virology highlights prospects offered by both approaches as well as their limitations. © 2012 Newman et al.


Dixon A.,International Wildlife Consultants Ltd. | Maming R.,Xinjiang Institute of Ecology and Geography | Gunga A.,Wildlife Science and Conservation Center | Purev-Ochir G.,Wildlife Science and Conservation Center | Batbayar N.,Wildlife Science and Conservation Center
Bird Conservation International | Year: 2013

We report a large number of raptors electrocuted on recently erected electricity distribution lines in the open landscapes of the Mongolian steppe and Qinghai-Tibetan plateau, China. Upland Buzzards Buteo hemilasius and Saker Falcons Falco cherrug, characteristic raptors of these bioregions, were among those found to be electrocuted. Raptor electrocution was a consequence of poorly designed hardware configurations on anchor poles along surveyed lines on the Qinghai-Tibetan Plateau and, additionally, on line poles in the Mongolian steppe. The design flaws were upright pin-insulators on earthed crossarms and the use of jump wires that passed over crossarms via pin insulators on anchor poles. Targeted mitigation of anchor poles could significantly reduce the incidence of electrocution on the lines surveyed on the Qinghai-Tibetan Plateau, whilst all poles on the lines surveyed in the Mongolian steppe require remediation to make them safe for raptors. The Mongolian steppe and the Qinghai-Tibetan Plateau are bioregions that hold the largest breeding and wintering populations of the globally threatened Saker Falcon. The existing and growing network of dangerous electricity distribution lines in these regions may potentially impact the Saker Falcon population, thus we suggest that preventative and/or mitigation measures are implemented. © BirdLife International 2013.


DIXON A.,UK Environment Agency | LI X.,CAS Institute of Zoology | RAHMAN M.L.,UK Environment Agency | BATBAYAR N.,Wildlife Science and Conservation Center | ZHAN X.,CAS Institute of Zoology
Bird Conservation International | Year: 2016

Between 1998 and 2011 we monitored the winter ranging behaviour of eight female Saker Falcons Falco cherrug fitted with satellite-received transmitters. Our tracking revealed that the winter home range area occupied by individual Saker Falcons varied greatly (median = 166 km2, range = 5-18,469 km2). A random forest model showed that Saker Falcons wintering on the Qinghai-Tibetan Plateau preferentially occupied areas with rich grassland (cover > 50%) on high altitude plateaus (4,000–5,000 m asl) with low levels of anthropogenic influence. Plant biomass in rich grasslands can support high winter densities of plateau pikas Ochotona curzoniae, which likely explains the preference exhibited by Saker Falcons for grassland cover > 50%. Factors influencing the abundance and distribution of this ‘keystone’ prey species are likely to have an effect on Saker Falcons and other predatory species. A key element of rangeland management on the Qinghai-Tibetan plateau has been the establishment of extensive protected areas as part of a strategy to balance economic and social development with the requirement of sustainably managing water resources, maintaining rangelands for pastoralists and conserving biological diversity. Wide ranging predatory species, such as the Saker Falcon, can be useful indicators of biodiversity in protected areas and act as ‘sentinels’ for anthropogenic changes that may impact many different taxa. Copyright © BirdLife International 2016


Rahman M.L.,International Wildlife Consultants Ltd. | Batbayar N.,Wildlife Science and Conservation Center | Purev-Ochir G.,Wildlife Science and Conservation Center | Etheridge M.,Aberystwyth University | Dixon A.,International Wildlife Consultants Ltd.
Ardeola | Year: 2015

We used patagial tags, VHF radio transmitters, and satellite-received transmitters to investigate the movements and survival of juvenile saker falcons fledged from artificial nests in open landscapes and natural nest sites in hilly areas in Mongolia. During the post-fledging dependence period (PFDP) juveniles progressively moved farther from their nest until dispersal from the natal area. natal home ranges were larger for juveniles fledged at artificial than natural sites and the distance moved by juveniles during PFDP was positively related to fledging date and brood size. Duration of the PFDP was estimated as 40 days (range: 31-52 days). Over the PFDP, the best-fitting model to explain juvenile survival incorporated fledging date and nest site type, with juvenile survival being higher in early fledged broods from natural sites. Predation was identified as a major cause of mortality, especially in open landscapes where artificial nests were located. however, because artificial nests produced more fledglings, we found that overall productivity of juveniles to dispersal at artificial and natural nests sites did not differ significantly.


Rahman M.L.,International Wildlife Consultants Ltd | Purev-Ochir G.,Wildlife Science and Conservation Center | Etheridge M.,Wildlife Science and Conservation Center | Etheridge M.,Aberystwyth University | And 2 more authors.
Journal of Ornithology | Year: 2014

Artificial nests are a commonly used management technique to increase the breeding population and/or productivity of birds with nest site limited populations. We compared nest survival of saker falcons breeding in artificial nests erected in a flat steppe landscape with those breeding in natural nests on rocks and cliffs in adjacent hills of central Mongolia. We found no significant difference in daily nest survival during the egg and nestling stages of the breeding cycle. Nest survival varied across years and was higher at artificial than natural nest sites, primarily because of higher survival rates during the egg stage at artificial nests. However, fledgling productivity was not significantly different although artificial nests produced an average of 3.2 fledglings compared to 2.3 at natural nest sites. We found no significant differences in offspring sex ratios and fledgling mass at artificial and natural nest sites. Provision of artificial nests can increase the range, size and productivity of saker falcon breeding populations, a globally endangered species subject to high mortality and trapping for falconry. This management technique can be used for incentive-driven conservation initiatives, whereby sustainable harvest quotas can be generated from demographic models based on parameters derived from a managed and monitored population breeding in artificial nests. © 2014 Dt. Ornithologen-Gesellschaft e.V.


Bourouiba L.,Massachusetts Institute of Technology | Wu J.,York University | Newman S.,Emergency Center for Transboundary Animal Diseases | Takekawa J.,U.S. Geological Survey | And 6 more authors.
Journal of the Royal Society Interface | Year: 2010

Virulent outbreaks of highly pathogenic avian influenza (HPAI) since 2005 have raised the question about the roles of migratory and wild birds in the transmission of HPAI. Despite increased monitoring, the role of wild waterfowl as the primary source of the highly pathogenic H5N1 has not been clearly established. The impact of outbreaks of HPAI among species of wild birds which are already endangered can nevertheless have devastating consequences for the local and non-local ecology where migratory species are established. Understanding the entangled dynamics of migration and the disease dynamics will be key to prevention and control measures for humans, migratory birds and poultry. Here, we present a spatial dynamic model of seasonal migration derived from first principles and linking the local dynamics during migratory stopovers to the larger scale migratory routes. We discuss the effect of repeated epizootic at specific migratory stopovers for bar-headed geese (Anser indicus). We find that repeated deadly outbreaks of H5N1 on stopovers during the autumn migration of bar-headed geese could lead to a larger reduction in the size of the equilibrium bird population compared with that obtained after repeated outbreaks during the spring migration. However, the opposite is true during the first few years of transition to such an equilibrium. The age-maturation process of juvenile birds which aremore susceptible to H5N1 reinforces this result. © 2010 The Royal Society.


Dixon A.,International Wildlife Consultants Ltd. | Purev-Ochir G.,Wildlife Science and Conservation Center | Galtbalt B.,Wildlife Science and Conservation Center | Batbayar N.,Wildlife Science and Conservation Center
Journal of Raptor Research | Year: 2013

The use of power line support structures as nesting sites enables some raptors and corvids to increase their breeding range and/or density in landscapes where alternative nest sites are limited. We report on the use of power poles for nesting by two nest-building species, Common Raven (Corvus corax) and Upland Buzzard (Buteo hemilasius), and two falcon species, Saker Falcon (Falco cherrug) and Eurasian Kestrel (Falco tinnunculus) in the nest-site-limited steppes of central Mongolia. Various power pole designs differed in their attractiveness to nest-building species, with structures that provided stable support and shelter being significantly favored. Trials of artificial nest barrels to (i) provide alternative nest sites on favored nesting support structures and (ii) provide additional nest sites on unfavored support structures, failed to induce nest-building species to shift their nest location in the first instance or to increase overall breeding density of large raptors and corvids in the second case. However, both trials resulted in large increases in the number of nesting Eurasian Kestrels. © 2013 The Raptor Research Foundation, Inc.


PubMed | Chinese Academy of Sciences, University of Aarhus, Mongolian Academy of science, Wildlife Science and Conservation Center and 2 more.
Type: Journal Article | Journal: The Korean journal of parasitology | Year: 2016

Chewing lice (Phthiraptera) that parasitize the globally threatened swan goose


PubMed | Chinese Academy of Sciences, Wildlife Science and Conservation Center, U.S. Geological Survey, Bombay Natural History Society and 2 more.
Type: Journal Article | Journal: Movement ecology | Year: 2015

Identifying movement routes and stopover sites is necessary for developing effective management and conservation strategies for migratory animals. In the case of migratory birds, a collection of migration routes, known as a flyway, is often hundreds to thousands of kilometers long and can extend across political boundaries. Flyways encompass the entire geographic range between the breeding and non-breeding areas of a population, species, or a group of species, and they provide spatial frameworks for management and conservation across international borders. Existing flyway maps are largely qualitative accounts based on band returns and survey data rather than observed movement routes. In this study, we use satellite and GPS telemetry data and dynamic Brownian bridge movement models to build upon existing maps and describe waterfowl space use probabilistically in the Central Asian and East Asian-Australasian Flyways.Our approach provided new information on migratory routes that was not easily attainable with existing methods to describe flyways. Utilization distributions from dynamic Brownian bridge movement models identified key staging and stopover sites, migration corridors and general flyway outlines in the Central Asian and East Asian-Australasian Flyways. A map of space use from ruddy shelducks depicted two separate movement corridors within the Central Asian Flyway, likely representing two distinct populations that show relatively strong connectivity between breeding and wintering areas. Bar-headed geese marked at seven locations in the Central Asian Flyway showed heaviest use at several stopover sites in the same general region of high-elevation lakes along the eastern Qinghai-Tibetan Plateau. Our analysis of data from multiple Anatidae species marked at sites throughout Asia highlighted major movement corridors across species and confirmed that the Central Asian and East Asian-Australasian Flyways were spatially distinct.The dynamic Brownian bridge movement model improves our understanding of flyways by estimating relative use of regions in the flyway while providing detailed, quantitative information on migration timing and population connectivity including uncertainty between locations. This model effectively quantifies the relative importance of different migration corridors and stopover sites and may help prioritize specific areas in flyways for conservation of waterbird populations.

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