The quality and quantities of an animal's behaviour is related to its energy reserves. I am interested in the relationship between an animal's level of energy reserves and its investment in different behaviours. I have completed many studies that have investigated how incubation behaviour, singing behaviour, and consumption of chemically defended prey are affected by the amount of energetic researves an animal has. I am presently preparing many manuscripts for publication regarding the role of energetic state in behaviour. I am also preparing a short review examining this subject.
Behavioural syndromes
Most studies that examine animal behaviour generally find variation in the expression of the behaviour around a mean. This variation has traditionally been interpreted by biologists as being due to either measurement error or non-adaptive variation around an adaptive mean. Recently, behavioural ecologists have begun to interpret this variation differently and it has been supposed that the observed variation in behaviour between individuals may be the result of differences in personality or temperament between individuals. Behavioural ecologists generally term differrences in temperament between individuals 'behavioural syndromes. Behavioural ecologists define behavioural syndromes as correlations between behavioural traits that are consistent in different situational contexts and over time. For example, it has been found in bird species that aggressive individuals also tend to be bold (i.e., they are quicker to approach novel objects or resume feeding after predator challenge).
My interest lies in quantifying the dynamic realtionships between different behaviours within the same individuals and between individuals between different populations of a free-living bird species. I am also interested in how differences in personality can influence reproductive success of individuals. I am also interested in applying these ideas to conservation of species threatened with the risk of extinction.
Biodiversity and conservation
We are in the midst of a world biodiversity crisis with the 2006 IUCN Red List identifying about 40 per cent of approximately 41,000 species examined being at some risk to extinction. A major cause of this biodiversity crisis is the result of factors that have been mediated by humans (e.g., the introduction of pest species and habitat destruction). The spectre of global warming will exascerbate the problem and it is now probable that we will witness the extinction of many species in the wild within our lifetimes. This includes many flagship species of the conservation movement such as the mountain gorilla and the tiger. I am interested in applying my biological and ecological knowledge to conservation problems. I am especially interested in behavioural conservation (the application of the study of animal behaviour to conservation problems). I am presently developing proposals based on examining how behavioural dynamics in small groups can become abnormal leading to reductions of reproductive output of the entire population.
Predator prey interactions
I am primarily interested in the behavioural and morphological strategies that are involved in predation. Form predators' perspectives, I am interested in the behavioural and morpholgical traits that allow them to exploit prey. For example, I have found that when birds become energetically stressed, that they begin consuming chemically defended more often than when they were not energetically stressed. When birds were first exposed to chemically defended prey, they did not handle the prey any differently than undefended prey. As my experiments progressed, the birds increased the amount of handling that they displayed to the chemically defended prey. The amount of time that the birds devoted to handling prey also varied with the level of chemical defence with more heavily defended prey being handled more than less noxious prey. By handling the prey for longer, the birds might have been attempting to rid the defended prey of their chemical defences. These are among the first results that indicate that generalist predators can develop specialsed behaviours that have only previously been seen in speciallised predators. Similarly, from a prey's perspective, I am interested in similar considerations. For example, in bird species, I am interested in how their masses can change in response to differences in the risk of been captured by avian predators and how these differences can influence morphological evolution.
Life history evolution
I am interested in how differences in life history traits can evolve in animals of different geographical regions. For example, birds in the Sounthern hemisphere tend to lay smaller clutch sizes. This trend has been found even for species that have been introduced from the Northern hemisphere to Southern hemisphere. However, the reasons for this pattern remain elusive.
Sexual selection, mating systems, and and conflicts in reproductive investment
I have many interests in sexual selection, mate choice, and sexual conflict, which I continue to develop. For example, I am interested in the possibility that chemical defences in insects may act as a secondary sexual trait. Chemical defences may also co-vary with with aposematic colour meaning that aposematic colouration could have a sexually selected component as well as functioning to deter predation. There have been studies that have examined the different aspects of this idea, but it has not been examined to its fullest potential in chemically defended invertebrates.