This is a demonstration version of a program written to examine the outcome of different parental investment strategies. More specifically, we are interested in determining what sort of cognitive decision rules parents can use to efficiently divide their investment among siblings of varying ages under various environmental conditions.
To address these issues we turn to birds. In many species of bird, chicks hatch a day apart from each other. This hatching asynchrony results in significant differences in size and developmental maturity within the nest, and, as a consequence, differences in the energetic demands of the chicks. Parent birds must meet these differing demands by distributing food resources to the chicks in some adaptive manner. This kind of parental investment is relatively easy to quantify in birds, and investment strategies have already been measured in the field for a number of species.
Furthermore, birds are good models for the study of human parental investment. Like birds, and unlike most mammals, humans are faced with the task of simultaneously raising offspring of different ages, and the same basic biological principles that govern investment decisions in humans should govern them in all species faced with similar investment problems. We therefore expect these simulation studies to be applicable to human parental investment decisions in much the same way that they are applicable to birds.
The simulation works by mimicking the hatching, feeding, growth, and nest-leaving (fledging) of Western bluebird (Sialia mexicana) chicks. We chose bluebirds because the metabolic and growth rate information necessary to build an accurate model are available for this species.
Our goal is to find out what sorts of parental investment strategies work well for our simulated bluebird parents trying to raise a nest of chicks under various environmental conditions. For our birds, parental investment is restricted to the amount of food a parent provides to a given chick. Parental success is measured as the total number and weight of chicks that fledge from the nest.
| Introduction | [Why Bluebirds] | Feeding Heuristics | Simulation |