نتایج جستجو برای: foraging periods

تعداد نتایج: 129102  

Journal: :Current Biology 2010
Frederic Bartumeus Luca Giuggioli Maite Louzao Vincent Bretagnolle Daniel Oro Simon A. Levin

Human fishing activities are negatively altering marine ecosystems in many ways [1, 2], but scavenging animals such as seabirds are taking advantage of such activities by exploiting fishery discards [3-5]. Despite the well-known impact of fisheries on seabird population dynamics [6-10], little is known about how discard availability affects seabird movement patterns. Using scenarios with and wi...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2013
Yuuki Y Watanabe Akinori Takahashi

Understanding foraging is important in ecology, as it determines the energy gains and, ultimately, the fitness of animals. However, monitoring prey captures of individual animals is difficult. Direct observations using animal-borne videos have short recording periods, and indirect signals (e.g., stomach temperature) are never validated in the field. We took an integrated approach to monitor pre...

2008
Paolo Lambardi Johann R. E. Lutjeharms Resi Mencacci Graeme C. Hays Paolo Luschi

Leatherback turtles Dermochelys coriacea spend most of their life in oceanic environments, whose physical and biological characteristics are primarily forged by sea current circulation. Water mass movements can mechanically act on swimming turtles, thus determining their routes, and can differentially distribute their planktonic prey. By integrating satellite tracking data with contemporaneous ...

2017
Nicola J. Quick Saana Isojunno Dina Sadykova Matthew Bowers Douglas P. Nowacek Andrew J. Read

Diving behaviour of short-finned pilot whales is often described by two states; deep foraging and shallow, non-foraging dives. However, this simple classification system ignores much of the variation that occurs during subsurface periods. We used multi-state hidden Markov models (HMM) to characterize states of diving behaviour and the transitions between states in short-finned pilot whales. We ...

Journal: :Biology letters 2015
Charmain D Hamilton Christian Lydersen Rolf A Ims Kit M Kovacs

Since the first documentation of climate-warming induced declines in arctic sea-ice, predictions have been made regarding the expected negative consequences for endemic marine mammals. But, several decades later, little hard evidence exists regarding the responses of these animals to the ongoing environmental changes. Herein, we report the first empirical evidence of a dramatic shift in movemen...

2016
Lucy R. Quinn Andrew A. Meharg Jan A. van Franeker Isla M. Graham Paul M. Thompson

Many wildlife studies use chemical analyses to explore spatio-temporal variation in diet, migratory patterns and contaminant exposure. Intrinsic markers are particularly valuable for studying non-breeding marine predators, when direct methods of investigation are rarely feasible. However, any inferences regarding foraging ecology are dependent upon the time scale over which tissues such as feat...

Journal: :Philosophical transactions. Series A, Mathematical, physical, and engineering sciences 2010
Denis Boyer Peter D Walsh

Thanks to recent technological advances, it is now possible to track with an unprecedented precision and for long periods of time the movement patterns of many living organisms in their habitat. The increasing amount of data available on single trajectories offers the possibility of understanding how animals move and of testing basic movement models. Random walks have long represented the main ...

2008
Birgitte I. McDonald Daniel E. Crocker Jennifer M. Burns Daniel P. Costa

Body composition is a direct measure of body condition and as such integrates seasonal variation in foraging success and energy expenditure. In phocids, body condition is a critical determinant of both reproductive effort and ability to survive periods of poor foraging success. We determined body composition in 29 crabeater seals, Lobodon carcinophaga, during austral autumn (April–May 2002) and...

Journal: :Biology letters 2015
T Iwata K Q Sakamoto E W J Edwards I J Staniland P N Trathan Y Goto K Sato Y Naito A Takahashi

The foraging strategy of many animals is thought to be determined by their past experiences. However, few empirical studies have investigated whether this is true in diving animals. We recorded three-dimensional movements and mouth-opening events from three Antarctic fur seals during their foraging trips to examine how they adapt their behaviour based on past experience--continuing to search fo...

Journal: :Ecology Letters 2021

Variation in dietary specialisation stems from fundamental interactions between species and their environment. Consequently, understanding the drivers of this variation is key to ecological evolutionary processes. Dietary wild bees has received attention due close mutualistic dependence on plants, because both groups are threatened by biodiversity loss. Many principles governing pollinator have...

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