For my MSc studies I did a project at the Netherlands Institute of Ecology (NIOO-KNAW), where I studied interference competition in Mallards.
There is a great need for tools to predict the effects of habitat change on wildlife. In case of migratory birds the carrying capacity of a non-breeding site can be defined as the number of bird-days (i.e. the product of the average number of birds per day and the average stopover duration per bird) a site can support. However, in this concept interference competition is disregarded, causing bird-days to be inadequate as a measure when interference competition plays a role. The challenge is to develop more advanced and more accurate methods to calculate carrying capacity that incorporates spatial heterogeneity in resource availability or behavioural aspects of birds, such as interference competition.
Many studies measuring the effects of competition and dominance status have been conducted on a uniform or highly clumped food distribution, while in reality prey distributions are often in-between these two extremes. The few studies that used a more natural food distribution only detected subtle effects of interference and dominance. We therefore conducted an experiment on a natural food distribution with focal mallards Anas platyrhynchos foraging alone and in a group of three, having a dominant, intermediate or subordinate dominance status. This project provided a unique opportunity to test carrying capacity models of varying degrees of complexity.