A population of Black-capped Chickadees (Parus atricapillus) living in a favourable environment was colour-banded, and its survival was followed, to find out what prevents continual increase in its numbers. A weekly census of the population was made throughout the two years of the study. All nests were found and the young were banded before they flew. Every two weeks throughout both winters checks were also made on an unhanded population in a control area one and a quarter miles from the main population. Nesting success was high in both years, with 5.0 young per pair being fledged in 1964 and 4.5 young per pair in 1965. Juvenile survival until family break-up was almost 100% in both years; juvenile survival until September seemed to be high. The survival rate of the adults was uneven: there were two periods when it was lower than it was during the rest of the year. The less sharply defined period occurred during the post-breeding moult of the adults. The more sharply defined period of two weeks or less was exactly correlated in both years with a change in behaviour from flocking to territorial behaviour. With the exception of one unmated female in each year, every bird which survived this critical period remained to breed or attempt to breed; hence this change in behaviour in the spring evidently removed surplus birds from the area, and thus prevented continual increase in the population. This behaviour may be the common factor that limits the breeding populations of other species with similar ecology. / Science, Faculty of / Zoology, Department of / Graduate

Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes bibliographical references (p. 119-141).

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Thesis (M.S.)--Villanova University, 2007. / Biology Dept. Includes bibliographical references.

No description available.

Thesis (M.S.)--Villanova University, 2008. / Biology Dept. Includes bibliographical references.

There has been a recent paradigm shift in the study of animal communication from examining interactions as dyads to considering interactions as occurring in a communication network. The dawn chorus of songbirds, a striking acoustic phenomenon, provides an ideal opportunity to study network communication because multiple singers are within range of each other, permitting eavesdropping by both males and females. I used a 16-microphone Acoustic Location System (ALS) to simultaneously record and analyse the dawn chorus in a population of black-capped chickadees (Poecile atricapillus) breeding in eastern Ontario. Males frequency-match neighbours 24% of the time at dawn, more often than expected by chance or during daytime singing interactions. The amount of matching between males from different over-wintering flocks is significantly greater than between flockmates. Males of the same winter dominance rank match significantly more than do males of disparate ranks. Male black-capped chickadees are interacting vocally with neighbours at dawn, using the dawn chorus to mediate social relationships in ways that suggest useful information is available to the network of male and female receivers. Matching levels are not related to distance between opponents. However, males with non-fertile mates move over larger areas while chorusing and are further from their nest than males with fertile mates, suggesting dawn mate guarding. Males with non-fertile mates spend more of their chorus near boundaries with fertile neighbours than non-fertile neighbours possibly positioning themselves to facilitate eavesdropping by fertile females. Male chickadees of high and low winter social rank do not differ in either the size of their communication network, or the way they use their songs when interacting with neighbours. Males match multiple neighbours both sequentially and simultaneously. Simultaneous matching is most often the result of a former flockmate joining an interaction between two males who had been in different winter flocks. High-ranked males join the interactions of their lower-ranked flockmates, preferentially when those males are matching other high-ranked males. The dawn chorus is an interactive communication network in which all males participate and is characterized by interactions between multiple senders and receivers with males eavesdropping on interactions in which they are not involved. / Thesis (Ph.D, Biology) -- Queen's University, 2008-09-17 15:07:56.276

Many recent discoveries in animal cognition have shown that species once thought to be relatively simple are in fact capable of complex problem-solving in accordance with their ecological needs. These findings have resulted from experiments designed with the evolutionary history of the focal species in mind. Transitive inference (TI), the abiliy to infer the ordering of non-adjacent objects within a series, is a cognitive skill once thought to be exclusive to humans. Now considered a litmus-test for logical-relational reasoning, TI is thought to have evolved in social species in order to help track dominance relationships. Although recent work has shown that animals can display TI, it has yet to be demonstrated in the natural context in which it evolved. Songbirds may use TI to gain relative dominance information about others during countersinging interactions, through their use of network communication. Here I demonstrate that black-capped chickadees (Poecile atricapillus) use TI to judge the relative rank of unknown territorial intruders during the breeding season using dominance information provided through song contests. Using a multispeaker playback, I provided focal males with the relative ranks of three simulated “males” through two countersinging interactions (A > B, B > C). I predicted that when presented with the non-adjacent pair (A and C) with no relative rank information provided, focal males would choose to defend against the intruder they perceived as the greater threat. Consistent with my predictions, the majority of focal males approached “male” A. Additionally, male responses were influenced by age, with older males (in their second or later breeding season) approaching the dominant intruder more consistently than younger males (in their first breeding season). This is the first instance of TI being demonstrated in a natural population of untrained animals, and has important implications for the understanding of songbird communication networks. Transitive inference may be used in several natural situations by chickadees throughout the breeding season and a number of possible avenues for future TI research are discussed. Additionally, methods are suggested for the examination of TI during the non-breeding season. / Thesis (Master, Biology) -- Queen's University, 2010-09-24 10:45:17.316

No description available.

Social dominance influences many aspects of the life of animals living in social groups, including fitness. Recent work suggests that individuals occupying different positions in a dominance hierarchy may differ in their behavioural and cognitive traits. The first objective of this thesis was to determine whether personality (i.e. consistent behavioural differences between individuals) is correlated with dominance in natural groups of black-capped chickadees (Poecile atricapillus) in the wild. Dominance relationships within these groups were highly asymmetrical and transitive, which is typical of linear dominance hierarchies. None of the measured personality traits (i.e. aggressiveness in hand, exploration, activity and neophilia) were significantly correlated with dominance. These results suggest that personality does not contribute to the formation of black-capped chickadee hierarchies and add to the growing body of evidence that inherent attributes of individuals are not sufficient to explain the structure of linear dominance hierarchies observed in the wild. The second objective of this thesis was to investigate how dominance and correlates of competitive ability (i.e. sex, age and body condition) are related to novel problem-solving performance, which is a proxy for innovativeness, the invention of new behavioural patterns or the modification of an existing behaviour in a novel context. Problem-solving performance was not significantly associated with sex, age or body condition, but dominants were more efficient problem-solvers than subordinates. This finding suggests that efficiency when solving a novel problem might be driven by cognitive capacity instead of the necessity induced by the social position of an individual. Overall, results of this thesis help to better understand dominance hierarchies in wild groups of animals.