Inter-year variation in pup production of Caspian seals Pusa caspica 2005–2012 determined from aerial surveys
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چکیده
منابع مشابه
The Role of Canine Distemper Virus and Persistent Organic Pollutants in Mortality Patterns of Caspian Seals (Pusa caspica)
Persistent organic pollutants are a concern for species occupying high trophic levels since they can cause immunosuppression and impair reproduction. Mass mortalities due to canine distemper virus (CDV) occurred in Caspian seals (Pusa caspica), in spring of 1997, 2000 and 2001, but the potential role of organochlorine exposure in these epizootics remains undetermined. Here we integrate Caspian ...
متن کاملPup production and breeding distribution of the Caspian seal (Phoca caspica) in relation to human impacts.
Aerial surveys of Caspian seals on the winter ice field in Kazakhstan territorial waters were carried out in February 2005 and 2006 to assess the annual pup production for the species and natural predation on newborn pups. Estimated pup production was 21063 in 2005 and 16905 in 2006 (including an estimated figure for pups born in Russian territory in each year). The breeding population size of ...
متن کاملA Histopathology Study of Caspian Seal (Pusa caspica) (Phocidae, Mammalia) Liver Infected with Trematode, Pseudamphistomum truncatum (Rudolphi, 1819) (Opisthorchidae, Trematoda)
BACKGROUND Main objective of this study was to investigate the invasive activity of the liver fluke, Pseudamphistomom truncatum against the Caspian seal (Pusa caspica) and was exemplified at the gross, light microscopy (LM) and electron microscopy (EM) levels. METHODS The study was done on a freshly dead Caspian Seal in the southern coast of Caspian Sea. The checked Caspian seal probably bein...
متن کاملAmphibious hearing in ringed seals (Pusa hispida): underwater audiograms, aerial audiograms and critical ratio measurements.
Ringed seals (Pusa hispida) are semi-aquatic marine mammals with a circumpolar Arctic distribution. In this study, we investigate the amphibious hearing capabilities of ringed seals to provide auditory profiles for this species across the full range of hearing. Using psychophysical methods with two trained ringed seals, detection thresholds for narrowband signals were measured under quiet, care...
متن کاملCollapse of a Marine Mammal Species Driven by Human Impacts
Understanding historical roles of species in ecosystems can be crucial for assessing long term human impacts on environments, providing context for management or restoration objectives, and making conservation evaluations of species status. In most cases limited historical abundance data impedes quantitative investigations, but harvested species may have long-term data accessible from hunting r...
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ژورنال
عنوان ژورنال: Endangered Species Research
سال: 2015
ISSN: 1863-5407,1613-4796
DOI: 10.3354/esr00689