|
|
|
Extinction papers presented at conservation conference in Brazil Annual Meeting of the Society for Conservation Biology July 27, 2005 Below is a sampling of some extinction-related papers submitted for the conference. All descriptions are excepts from the official "Book of Abstracts" from the meeting. More abstracts. COLLEN, BEN. Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK, ben.collen((AT))ioz.ac.uk. The loss of the last remaining individual of a species is almost impossible to detect. Sadly, many species are known from only a small number of chance sightings or a handful of specimens, with only limited data available on their habitat requirements and likely range. Further, when species become rare, they may persist unseen for an unknown period, so time of last sighting may be a poor indicator of actual time of extinction. Using sighting and specimen records however, it may be possible, to infer the likely extinction date of a species. Using a technique called optimal linear estimation, we test in a number of vertebrate taxa, whether you can reliably infer when a species has finally become extinct. We discuss whether it is possible this technique can inform the 'Extinct' category of the IUCN Red List, and if we can infer causes of contemporary and historical extinction patterns, to give us a truer picture of how the current patterns we observe, arose CLIMATE, DUST, AND DISEASE: THE CAUSE OF THE LATE PLEISTOCENE MEGAFAUNAL EXTINCTIONS? LACKEY, JAMES ALDEN. Department of Biology, Oswego State University, Oswego, NY 13126, USA, lackey((AT))oswego.edu. The cause of the mammalian megafaunal extinction occurring at the Pleistocene-Holocene transition (ca. 11,000-9,000 years ago) when the earth's climate shifted from ice age conditions to present conditions continues to elude identification. The "overkill," "climate," and "hyperdisease" proposals to account for that extinction have been championed vigorously for many years but none has achieved general consensus because each, as a single cause, is perceived as having fatal drawbacks. Severe climatic conditions that caused dust storms in which disease organisms were transported are proposed here as the primary cause of much of that megafaunal extinction. Transport of disease organisms by dust storms in modern times is now well documented in the literature. Immense dust storms occurred at the Pleistocene-Holocene transition (and earlier in the Pleistocene), and they occur today although probably are not as severe. Eastern Asia and northern Africa commonly were (and are) origins of dust storms; southern Asia and northern Africa are proposed as primary sources of pertinent disease organisms. The possible reoccurrence of climatic conditions like those of the past, and the associated transport of disease organisms, represents an immediate threat to existing ecosystems. It is imperative that new ideas about extinction events be generated and evaluated A STOCHASTIC MODEL OF SPECIES TURNOVER: THE ROLE OF INVASION AND EXTINCTION IN STRUCTURING DIVERSITY. CASSEY, PHILLIP. School of Biosciences, University of Birmingham, Edgbaston, UK p.cassey((AT))bham.ac.uk. It has been widely documented that the dual processes of human assisted extinction and invasion will leave a long-lasting legacy on the earth's biodiversity. Nevertheless, the exact nature of this legacy is hotly debated, as are the exact causes of current extinction rates and the effects of species invasions. I present a single state stochastic model for determining the shape of functions of species turnover among different nested scales under simple models of biotic homogenisation. When globally rare species are more susceptible to extinction, regional diversity decreases. However, when endemism is high and species distributions aggregated, diversity increases at all scales other than global. These results are compared to empirical patterns from oceanic island bird distributions INTRINSIC AND EXTRINSIC COMPONENTS IN EXTINCTION RISK: A META-ANALYSIS OF PRIMATE RESPONSES TO FRAGMENTATION. ISAAC, NICK J.B.; Pettifor, Richard; Cowlishaw, Guy C. Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK (nick.isaac((AT))ioz.ac.uk). Recent studies have shown that species' risk of extinction is in- fluenced by intrinsic biological traits, as well as extrinsic factors, such as the nature and severity of pervasive threatening processes. However, none has tested the relative importance of intrinsic and extrinsic components of extinction risk. We present results from a meta-analysis of primate populations in fragmented landscapes. Our data include over 3000 presence-absence records for 60 species in 1000 fragments from all over the tropics (30 landscapes in all). We use Generalised Linear Mixed Models to partition the variance in response among landscapes and among species. As expected, primates are more likely to persist in large fragments compared with small ones, but there is no strong effect of isolation distance. Our results also show that species with large and specialised area requirements are more susceptible to fragmentation. Overall, we find that intrinsic and extrinsic factors are equally important in determining responses to fragmentation Society for Conservation Biology - Brasilia 2005 News index | RSS | Add to MyYahoo! Advertisements: Organic Apparel from Patagonia | Insect-repelling clothing |
MONGABAY.COM
T-SHIRTS 
CALENDARS 
CANVAS BAGS 
|
|
|
