Population-Wide Failure to Breed in the Clark's Nutcracker (Nucifraga Columbiana) - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Population-Wide Failure to Breed in the Clark's Nutcracker (Nucifraga Columbiana) write by Taza D. Schaming. This book was released on 2015. Population-Wide Failure to Breed in the Clark's Nutcracker (Nucifraga Columbiana) available in PDF, EPUB and Kindle. In highly variable environments, conditions can be so stressful in some years that entire populations forgo reproduction in favor of higher likelihood of surviving to breed in future years. In two out of five years, Clark's nutcrackers (Nucifraga Columbiana) in the Greater Yellowstone Ecosystem exhibited population-wide failure to breed. Clark's nutcrackers at the study site experienced substantial interannual differences in food availability and weather conditions, and the two nonbreeding years corresponded with low whitebark pine (Pinus albicaulis) cone crops the previous autumn ([less than or equal to] an average of 8 ± 2 cones per tree versus [greater than or equal to] an average of 20 ± 2 cones per tree during breeding years) and high snowpack in early spring ([greater than or equal to] 61.2 ± 5.5 cm versus [less than or equal to] 51.9 ± 4.4 cm during breeding years). The average adult body condition index during the breeding season was significantly lower in 2011 (-1.5 ± 1.1), a nonbreeding year, as compared to 2012 (6.2 ± 2.0), a breeding year. The environmental cues available to the birds prior to breeding, specifically availability of cached whitebark pine seeds, may have allowed them to predict that breeding conditions would be poor, leading to the decision to skip breeding. Alternatively, the Clark's nutcrackers may have had such low body energy stores that they chose not to or were unable to breed. Breeding plasticity would allow Clark's nutcrackers to exploit an unpredictable environment. However, if large-scale mortality of whitebark pines is leading to an increase in the number of nonbreeding years, there could be serious population-level and ecosystem-wide consequences.
Avian Cognition
Avian Cognition - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Avian Cognition write by Carel ten Cate. This book was released on 2017-06-22. Avian Cognition available in PDF, EPUB and Kindle. The cognitive abilities of birds are remarkable: hummingbirds integrate spatial and temporal information about food sources, day-old chicks have a sense of numbers, parrots can make and use tools, and ravens have sophisticated insights in social relationships. This volume describes the full range of avian cognitive abilities, the mechanisms behind such abilities and how they relate to the ecology of the species. Synthesising the latest research in avian cognition, a range of experts in the field provide first-hand insights into experimental procedures, outcomes and theoretical advances, including a discussion of how the findings in birds relate to the cognitive abilities of other species, including humans. The authors cover a range of topics such as spatial cognition, social learning, tool use, perceptual categorization and concept learning, providing the broader context for students and researchers interested in the current state of avian cognition research, its key questions and appropriate experimental approaches.
Clark's Nutcrackers and Whitebark Pine
Clark's Nutcrackers and Whitebark Pine - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Clark's Nutcrackers and Whitebark Pine write by Taza D. Schaming. This book was released on 2016. Clark's Nutcrackers and Whitebark Pine available in PDF, EPUB and Kindle. In the face of widespread environmental change, understanding and promoting resilience and stability of plant-animal seed disperser mutualisms is key to effective conservation strategies. My two primary objectives were to (1) investigate the response of the keystone mutualism between whitebark pine (Pinus albicaulis) and Clark's nutcrackers (Nucifraga columbiana) to declining habitat in the Greater Yellowstone Ecosystem, and (2) suggest management strategies to help ensure persistence of Clark?s nutcrackers, and their important seed dispersal function. Between 2009 and 2016, I studied Clark?s nutcracker demography and behavioral plasticity by evaluating breeding ecology, space use, seasonal habitat selection and use, foraging ecology, and emigration, as a function of habitat quality and abundance. I carried out occupancy surveys, tracked individuals via radio and satellite, conducted behavioral observations, and monitored nests. Clark?s nutcracker demography and behavior was intimately associated with whitebark pine habitat. Population-wide failure to breed followed low whitebark pine cone crops, and in breeding years, fledging success increased with whitebark pine abundance, but decreased in higher mortality stands. Clark?s nutcracker occurrence was associated with both presence of cone-bearing whitebark pines, and landscape-scale abundance of the pines, suggesting conservation strategies should focus efforts at the landscape scale. The birds selected disproportionately high amounts of Douglas-fir (Pseudotsuga menziesii) habitat for their home range, and foraged heavily on Douglas-fir cones, suggesting that whitebark pine should be managed within a habitat mosaic with Douglas-fir. The Clark?s nutcracker-whitebark pine mutualism appears functional in the region because birds were available to disperse seeds. However, it is unclear whether the mutualism is stable. Clark?s nutcrackers are highly mobile facultative migrants, and the majority of radio- and satellite-tagged birds disappeared during both the 2012 high and 2015 moderate whitebark pine cone crops. Managing Clark?s nutcrackers presents a complex conservation challenge, but I suggest promoting stability of Clark?s nutcracker populations, and focusing on the metapopulation in particular, is necessary for effective whitebark pine conservation. In this dissertation, I conclude by outlining recommended management strategies and key research questions that still need to be answered, finishing with important considerations that should be taken into account when designing a conservation plan for plant-animal seed disperser mutualisms.
The Migration Ecology of Birds
The Migration Ecology of Birds - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook The Migration Ecology of Birds write by Ian Newton. This book was released on 2010-08-04. The Migration Ecology of Birds available in PDF, EPUB and Kindle. This book presents an up-to-date, detailed and thorough review of the most fascinating ecological findings of bird migration. It deals with all aspects of this absorbing subject, including the problems of navigation and vagrancy, the timing and physiological control of migration, the factors that limit their populations, and more. Author, Ian Newton, reveals the extraordinary adaptability of birds to the variable and changing conditions across the globe, including current climate change. This adventurous book places emphasis on ecological aspects, which have received only scant attention in previous publications. Overall, the book provides the most thorough and in-depth appraisal of current information available, with abundant tables, maps and diagrams, and many new insights. Written in a clear and readable style, this book appeals not only to migration researchers in the field and Ornithologists, but to anyone with an interest in this fascinating subject.* Hot ecological aspects include: various types of bird movements, including dispersal and nomadism, and how they relate to food supplies and other external conditions* Contains numerous tables, maps and diagrams, a glossary, and a bibliography of more than 2,700 references* Written by an active researcher with a distinguished career in avian ecology, including migration research
The Atlas of Breeding Birds of Alberta
The Atlas of Breeding Birds of Alberta - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook The Atlas of Breeding Birds of Alberta write by Federation of Alberta Naturalists. This book was released on 1992. The Atlas of Breeding Birds of Alberta available in PDF, EPUB and Kindle. This collection of maps of distribution of breeding birds in Alberta is arranged by order and family. Each map shows evidence of nesting (confirmed, probable, possible, observed) with description and illustration of the bird. Extensive bibliography, index of bird names in English, Latin and French, and list of migrants.
