نتایج جستجو برای: every year a large number of migratory wintering water birds

تعداد نتایج: 23379012  

2013
Robert L. Simmonds Alexander V. Zale David M. Leslie ROBERT L. SIMMONDS

Oklahoma has about 324 ha of surface water in catfish (Ictalurus spp.) production. The state also supports a large number of migrating and wintering piscivorous birds, particularly double-crested cormorants (Phalacrocorax auritus). To address concerns of aquaculture facility operators regarding loss of fish to cormorants, we asked 11 operators to conduct regular counts of piscivorous birds at e...

2009
Raül Ramos Jacob González-Solís John P. Croxall Daniel Oro Xavier Ruiz

Migratory marine vertebrates move annually across remote oceanic water masses crossing international borders. Many anthropogenic threats such as overfishing, bycatch, pollution or global warming put millions of marine migrants at risk especially during their long-distance movements. Therefore, precise knowledge about these migratory movements to understand where and when these animals are more ...

Journal: :The Science of the total environment 2014
Cynthia D Franci Magella Guillemette Emilien Pelletier Olivier Chastel Salomé Bonnefoi Jonathan Verreault

The Deepwater Horizon oil spill caused the death of a large number of seabirds in the Gulf of Mexico in 2010. However, the long term consequences of oil exposure on migratory birds overwintering in this area have received limited attention. The present study aimed to investigate the impact of oil contamination (e.g., polycyclic aromatic hydrocarbons (PAHs)) on the circulating status of prolacti...

Journal: :Molecular ecology 2013
Colin W Rundel Michael B Wunder Allison H Alvarado Kristen C Ruegg Ryan Harrigan Andrew Schuh Jeffrey F Kelly Rodney B Siegel David F DeSante Thomas B Smith John Novembre

Methods for determining patterns of migratory connectivity in animal ecology have historically been limited due to logistical challenges. Recent progress in studying migratory bird connectivity has been made using genetic and stable-isotope markers to assign migratory individuals to their breeding grounds. Here, we present a novel Bayesian approach to jointly leverage genetic and isotopic marke...

Ali Reza Pourkhabbaz, Jeffrey Levengood Mehdi Hassanpour Mohammad Hosein Sinkakarimi, Seyed Mahmoud Ghasempouri

Every year, migratory waterfowl are hunted and consumed by people in Golestan Province of Iran. Due to the heavy metal contamination of wintering habitats, an estimation of the human health risks associated with the consumption of these ducks is necessary. Therefore, this study was conducted to estimate the health risks of exposure to cadmium (Cd), total chromium (Cr), iron (Fe), lead (Pb), and...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده کشاورزی 1388

چکیده به منظور بررسی اثر تنوع گیاهی و نوع منبع تغذیه ای بر تنوع و تراکم علفهای هرز و حشرات، کارایی مصرف نهاده ها ( نور، آب، عناصر غذایی) و عملکرد و خصوصیات کیفی چند گونه زراعی، آزمایشی به صورت کرتهای خردشده بر پایه طرح بلوکهای کامل تصادفی با سه تکرار در دو سال زراعی 1385-1384 و 1386-1385 در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد به اجرا درآمد. تیمارهای مورد بررسی دو منبع کود دامی و...

2017
Nathalie M LeBlanc Donald T Stewart Snaebjörn Pálsson Mark F Elderkin Glen Mittelhauser Stephen Mockford Julie Paquet Gregory J Robertson Ron W Summers Lindsay Tudor Mark L Mallory

The Purple Sandpiper (Calidris maritima) is a medium-sized shorebird that breeds in the Arctic and winters along northern Atlantic coastlines. Migration routes and affiliations between breeding grounds and wintering grounds are incompletely understood. Some populations appear to be declining, and future management policies for this species will benefit from understanding their migration pattern...

پایان نامه :0 1371

the treatment of in completely formed pulpless teeth has presented considrable problems. these teeth have wide open apexes and the walls of the root canal diverge toward the apical tissues. mechanical preparation cannot be done in the normal manner beacause of the large initial size and the taper of apical part of the canal , a mechanical stop cannot be produced at the apex of the canal and , t...

2014
Simone Giavi Marco Moretti Fabio Bontadina Nicola Zambelli Michael Schaub

Migration is adaptive if survival benefits are larger than costs of residency. Many aspects of bat migration ecology such as migratory costs, stopover site use and fidelity are largely unknown. Since many migrating bats are endangered, such information is urgently needed to promote conservation. We selected the migrating Leisler's bat (Nyctalus leisleri) as model species and collected capture-r...

Journal: :Physiological and biochemical zoology : PBZ 2012
Sari Raja-aho Mirella Kanerva Tapio Eeva Esa Lehikoinen Petri Suorsa Kai Gao Dalene Vosloo Mikko Nikinmaa

Little is known of the normal seasonal variation in redox state and biotransformation activities in birds. In long-distance migratory birds, in particular, seasonal changes could be expected to occur because of the demands of migration and reproduction. In this study, we measured several redox parameters in the barn swallow (Hirundo rustica L.) during the annual cycle. We captured the wintering...

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