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Abstract Aspects of the ecology and life history of the little known theraphosid Nesiergus insulanus are determined on Frégate Island in the Seychelles archipelago. The general behaviour of this species is revealed to be comparable to that of other theraphosids, with field and captive observations establishing that they are a generalist and opportunistic species. The defensive behaviour of the species is determined to be based primarily on the avoidance of conflict situations, with overt aggressive behaviour seldom displayed. Although the opportunistic existence that this species has developed is probably obligatory due to their sedentary lifestyle and limited availability of resources, this behaviour nonetheless allows the species to occupy diverse habitats and exploit niches unavailable to more specialized species.

The honeybees Apis cerana and Apis mellifera are derived from the same ancestral base about two million years ago. With speciation and evolution, they have acquired many advanced living skills in common, but have also evolved very different living strategies due to different distributions. This thesis is an intensive study of the biology of the mixed-species colonies of these species, the aims of which were to investigate their behavioural relationships and uncover the evolutionary conserved features of their behaviours subsequent to speciation. The results show that the two species can form a stable society to perform normal tasks. First, workers of both species in the mixed-colonies could form the typical retinue behaviour to hetero-species queens, thus indicating that queen pheromones could be spread to and by both species. Secondly, both species did not show significantly different ovarian activation under hetero-species queens, suggesting that the queen pheromones more likely play a role of ―honest signal‖ rather than a ―repression‖ substance in the honeybee colonies. Thirdly, both species could mutually decode each other‘s waggle dances, with unexpectedly low misunderstanding; revealing that the dance language in a dark environment is quite adaptive for cavity-nesting honeybees. Fourthly, workers of both species could cooperate with each other in comb construction, although the combs they built contain many irregular cells. Interestingly, A. cerana workers could be stimulated by A. mellifera workers to perform this task, thus confirming self-organization theory in the colony. Fifthly, A. mellifera workers behaved more ―defectively‖ in thermoregulation, but perhaps because A. cerana workers are more sensitive to changes in hive temperature. Given these differences in strategy, A. mellifera workers‘ performance might in fact reduce conflicts. Lastly, when faced with threats of predatory wasps, both species engaged in aggressive defence. Although they did not learn from each other‘s responses, species-specific strategies were adopted by each of them so that the defence of the mixed-colonies is very effective. I conclude that the two species can adapt to each other‘s efforts and task allocation is reasonably organized allowing mixed-species colonies to reach stability. These results suggest that all of the social behaviours discussed here were highly conserved following speciation. This thesis could provide some clues for the study of honeybee evolution from open-nesting to the transition of cavity-nesting.

Migratory birds spend most of the year on the over-wintering grounds or traveling between breeding and wintering areas, but research has focused on the relatively short breeding period. As a consequence, we have only a rudimentary understanding of how life histories of long-distance migrants are shaped by events and selective pressures interacting throughout the annual cycle. In this thesis, I examine the association between plumage traits and performance, both during the over-wintering and breeding phases of the annual cycle and how events during one season carry-over to influence behavioural and evolutionary processes in subsequent seasons in a migratory warbler, the American redstart (Setophaga ruticilla). First, I demonstrate that tail feather brightness is correlated with winter habitat quality in Jamaica, suggesting that plumage may act as a status signal during the non-breeding season. Stable-carbon isotopes analyzed from claws of redstarts arriving on the breeding grounds confirm the association between ornamentation and winter territory quality. Second, I demonstrate that redstarts arriving to breed in southern Ontario from high-quality winter habitats arrive earlier, resulting in a lower probability of paternity loss, a higher probability of achieving polygyny, and higher genetic fledging success. Third, I demonstrate that tail feather brightness, associated with winter territory quality, predicts the likelihood of polygyny during the breeding season, indicating that tail brightness is associated with performance during two phases of the annual cycle. Paternity is predicted by both tail and flank colouration. Finally, I demonstrate that reported trade-offs between reproductive effort and plumage ornamentation as manifested by moult-migration in redstarts is likely an artifact of high variation in local stable-hydrogen isotope signatures (δD) and occasional feather loss and re-growth during the over-wintering period. Thus, moult-migration does not appear to be an important carry-over effect in redstarts. This work demonstrates that plumage may be under selection during both stationary phases of the annual cycle. Furthermore, it suggests that carry-over effects from the non-breeding season can influence evolutionary processes such as sexual selection and highlights the importance of considering selective pressures and events occurring throughout the annual cycle in studying the behaviour and ecology of migratory animals. / Thesis (Ph.D, Biology) -- Queen's University, 2008-09-21 17:31:31.419

Diss. Stockholm : Handelshögsk.

Thesis (B.A. (Hons.))--University of Adelaide, Dept. of Psychology, 1979.