Noonan M.J.,University of Oxford |
Rahman M.A.,University of Oxford |
Rahman M.A.,Cosmos Center |
Newman C.,University of Oxford |
And 2 more authors.
Global Change Biology | Year: 2015
The signal for climate change effects can be abstruse; consequently, interpretations of evidence must avoid verisimilitude, or else misattribution of causality could compromise policy decisions. Examining climatic effects on wild animal population dynamics requires ability to trap, observe or photograph and to recapture study individuals consistently. In this regard, we use 19 years of data (1994-2012), detailing the life histories on 1179 individual European badgers over 3288 (re-) trapping events, to test whether trapping efficiency was associated with season, weather variables (both contemporaneous and time lagged), body-condition index (BCI) and trapping efficiency (TE). PCA factor loadings demonstrated that TE was affected significantly by temperature and precipitation, as well as time lags in these variables. From multi-model inference, BCI was the principal driver of TE, where badgers in good condition were less likely to be trapped. Our analyses exposed that this was enacted mechanistically via weather variables driving BCI, affecting TE. Notably, the very conditions that militated for poor trapping success have been associated with actual survival and population abundance benefits in badgers. Using these findings to parameterize simulations, projecting best-/worst-case scenario weather conditions and BCI resulted in 8.6% ± 4.9 SD difference in seasonal TE, leading to a potential 55.0% population abundance under-estimation under the worst-case scenario; 38.6% over-estimation under the best case. Interestingly, simulations revealed that while any single trapping session might prove misrepresentative of the true population abundance, due to weather effects, prolonging capture-mark-recapture studies under sub-optimal conditions decreased the accuracy of population estimates significantly. We also use these projection scenarios to explore how weather could impact government-led trapping of badgers in the UK, in relation to TB management. We conclude that population monitoring must be calibrated against the likelihood that weather conditions could be altering trap success directly, and therefore biasing model design. © 2015 John Wiley & Sons Ltd.
Jahan I.,Kyoto University |
Hirai Y.,Kyoto University |
Islam M.A.,University of Dhaka |
Islam M.A.,Cosmos Center |
Hirai H.,Kyoto University
Primates | Year: 2013
Hoolock gibbons (genus Hoolock) are a group of very endangered primate species that belong to the small ape family (family Hylobatidae). The entire population that is distributed in the northeast and southeast of Bangladesh is estimated to include only around 350 individuals. A conservation program is thus necessary as soon as possible. Genetic markers are significant tools for planning such programs. In this study, we examined chromosomal characteristics of two western hoolock gibbons that were captured in a Bangladesh forest. During chromosome analysis, we encountered two chromosome variations that were observed for the first time in the wild-born western hoolock gibbons (Hoolock hoolock). The first one was a nonhomologous centromere position in chromosome 8 that was observed in the two examined individuals. The alteration was identical in the two individuals, which were examined by G-band and DAPI-band analyses. Chromosome paint analyses revealed that the difference in the centromere position was due to a single small pericentric inversion. The second variation was a heterozygous elongation in chromosome 9. Analysis by sequential techniques of fluorescence in situ hybridization with 18S rDNA and silver nitrate staining revealed a single and an inverted tandem duplication, respectively, of the nucleolus organizer region in two individuals. These chromosome variations provide useful information for the next steps to consider the evolution and conservation of the hoolock gibbon. © 2013 Japan Monkey Centre and Springer Japan.
Aziz A.,Cosmos Center |
Aziz A.,Jahangirnagar University |
Barlow A.C.D.,Cosmos Center |
Greenwood C.C.,Cosmos Center |
And 2 more authors.
ORYX | Year: 2013
Tigers Panthera tigris face a wide and complex array of threats. Given limited time and resources it is essential to direct conservation actions based on the relative importance of each threat. The Sundarbans Reserve Forest is the last stronghold of tigers in Bangladesh and supports one of the largest populations of tigers in the world. As in other tiger landscapes, the threats faced by the tigers have yet to be assessed. This study follows an approach developed by The Nature Conservancy to identify and prioritize threats and set a time-frame for their reduction. We identified a total of 23 threats; four were linked to tigers, two to prey and 17 to habitat. Of the identified threats, the highest ranked included poaching of tigers, poaching of prey, sea-level rise, upstream water extraction/divergence, wood collection, fishing, and harvesting of other aquatic resources. All threats were then scheduled for reduction, based on the rank and current information base for each threat and the likely time-frame for implementing potential solutions. This study demonstrates how the application of a prioritization framework can greatly improve the focus and likelihood of success of any species- or ecosystem-based conservation programme. © 2013 Fauna & Flora International.
Inskip C.,University of Kent |
Fahad Z.,Cosmos Center |
Tully R.,Cosmos Center |
Roberts T.,University of Kent |
And 2 more authors.
Biological Conservation | Year: 2014
This paper provides the first in-depth exploration of tiger killing behaviour in communities bordering the Sundarbans mangrove forest, Bangladesh. Our findings demonstrate the complexity of carnivore killing behaviour in situations of human-wildlife conflict. We find that killings are not purely retaliatory in nature (i.e. driven by a desire for retribution following livestock depredation or attacks on humans by tigers), and that previous negative experience of tigers is not the sole determinant of villagers' acceptance of killing behaviour. Inter-related socio-psychological factors (risk perceptions, beliefs about tigers and the people that kill tigers, general attitude towards tigers), perceived failings on the part of local authorities whom villagers believe should resolve village tiger incidents, perceived personal rewards (financial rewards, enhanced social status, medicinal or protective value of tiger body parts), and contextual factors (the severity and location of tiger incidents) motivate people to kill tigers when they enter villages and foster the widespread acceptance of this behaviour. The complexity of these factors highlights the need for conservation practitioners to explore and understand people's motivations for killing endangered carnivore species, in order to address better the community-led killing of these animals. For the Sundarbans area, knowledge of these motivational factors can be used to develop conservation actions suitable for developing both communities' capacity and, crucially, desire to co-exist with tigers and to respond with non-lethal action to village tiger incidents. © 2014 Elsevier Ltd.
Bridge E.S.,University of Oklahoma |
Kelly J.F.,University of Oklahoma |
Xiao X.,University of Oklahoma |
Takekawa J.Y.,U.S. Geological Survey |
And 24 more authors.
Ecological Indicators | Year: 2014
Satellite-based tracking of migratory waterfowl is an important tool for understanding the potential role of wild birds in the long-distance transmission of highly pathogenic avian influenza. However, employing this technique on a continental scale is prohibitively expensive. This study explores the utility of stable isotope ratios in feathers in examining both the distances traveled by migratory birds and variation in migration behavior. We compared the satellite-derived movement data of 22 ducks from 8 species captured at wintering areas in Bangladesh, Turkey, and Hong Kong with deuterium ratios (δD) in the feathers of these and other individuals captured at the same locations. We derived likely molting locations from the satellite tracking data and generated expected isotope ratios based on an interpolated map of δD in rainwater. Although δD was correlated with the distance between wintering and molting locations, surprisingly, measured δD values were not correlated with either expected values or latitudes of molting sites. However, population-level parameters derived from the satellite-tracking data, such as mean distance between wintering and molting locations and variation in migration distance, were reflected by means and variation of the stable isotope values. Our findings call into question the relevance of the rainfall isotope map for Asia for linking feather isotopes to molting locations, and underscore the need for extensive ground truthing in the form of feather-based isoscapes. Nevertheless, stable isotopes from feathers could inform disease models by characterizing the degree to which regional breeding populations interact at common wintering locations. Feather isotopes also could aid in surveying wintering locations to determine where high-resolution tracking techniques (e.g. satellite tracking) could most effectively be employed. Moreover, intrinsic markers such as stable isotopes offer the only means of inferring movement information from birds that have died as a result of infection. In the absence of feather based-isoscapes, we recommend a combination of isotope analysis and satellite-tracking as the best means of generating aggregate movement data for informing disease models. © 2014 Published by Elsevier Ltd.