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Full-Text Articles in Life Sciences

Females In Control: Female Sensitivity To Predation Risk Affects Courtship And Reproductive Behaviours, Tin Nok Natalie Cheng Dec 2015

Females In Control: Female Sensitivity To Predation Risk Affects Courtship And Reproductive Behaviours, Tin Nok Natalie Cheng

Electronic Thesis and Dissertation Repository

Even in the absence of direct killing, predators have a pervasive effect on prey populations through costly anti-predator behavioural responses. In high risk environments, animals can reduce conspicuous behaviours such as courtship displays decreasing exposure at the cost of reproduction. Previous studies typically looked at male behaviour immediately following a predator cue, thus, not considering temporal variations in risk or the impact of female receptivity on male courtship. I placed male and female brown-headed cowbirds under chronically elevated predation risk with periods of high and low risk. Under high predation risk, females performed fewer chatter calls and were more likely …


Fear Of Predators Compromises Parental Care And Juvenile Survival In A Songbird, Philip Blair Dudeck Dec 2015

Fear Of Predators Compromises Parental Care And Juvenile Survival In A Songbird, Philip Blair Dudeck

Electronic Thesis and Dissertation Repository

Predators kill, but the risk of being killed is also a powerful force affecting survival because scared prey eat less, thereby increasing the likelihood of starvation. Young of most animals are extremely vulnerable to predators and may alter their behaviour to limit detection. I investigated the previously unexplored effects that predation risk has on the behaviour of newly fledged offspring and their parents, and the impact this has on offspring survival. I manipulated predation risk using sound and found that parent song sparrows reduced their feedings, providing 60% less food overall. Critically, not only did this parental response estimate survival …


Vocalizations, Feeding And Flight Behaviour Of Nectar-Feeding Bats (Glossophaga Soricina And Leptonycteris Yerbabuenae), Meghan A. Murphy Jul 2015

Vocalizations, Feeding And Flight Behaviour Of Nectar-Feeding Bats (Glossophaga Soricina And Leptonycteris Yerbabuenae), Meghan A. Murphy

Electronic Thesis and Dissertation Repository

When nectar-feeding bats converge on a food source, they may use vocal signals to minimize the risk of interference by others and maximize feeding efficiency. I conducted playback experiments with captive Pallas’ long-tongued bats (Glossophaga soricina) and wild lesser long-nosed bats (Leptonycteris yerbabuenae) to investigate the implications of vocalizations on feeding behaviour and assess behavioural responses. I hypothesized that echolocation calls and social calls are used as air traffic signals around a central food source. I found evidence that L. yerbabuenae primarily use echolocation calls as signals to maintain an efficient group feeding system, and detect their conspecifics …


Ecological And Evolutionary Interactions Between Song Sparrows (Melospiza Melodia) And Their Bloodborne Parasites, Yanina Sarquis-Adamson Feb 2015

Ecological And Evolutionary Interactions Between Song Sparrows (Melospiza Melodia) And Their Bloodborne Parasites, Yanina Sarquis-Adamson

Electronic Thesis and Dissertation Repository

Local adaptation is the result of natural selection operating at a local scale, such that trade-offs in fitness across different environments result in individuals having higher fitness in their place of origin than when transported into a foreign environment. Populations may become locally adapted to features of their abiotic environment, or in the case of coevolutionary arms races between hosts and parasites, to other species comprising their biotic environment. If host populations are adapted to their local (sympatric) parasites, or conversely if parasites are adapted to their local hosts, then interactions with local parasite strains may influence the fitness consequences …