Estimating mechanisms and equilibria for offspring begging and parental provisioning.

Evolutionary models for the resolution of family conflicts are sensitive to assumptions regarding the behavioural mechanisms regulating parental resource provisioning and offspring begging. Thus, quantitative empirical estimates of the mechanisms are critical to validate current evolutionary models, but a standardized method is lacking. I present a formalization of Hussell's (1988 Am. Nat. 131, 175-202) original graphical model of mechanisms regulating the effect of begging on provisioning, and of provisioning on begging, based on linear regression equations. The model makes it possible to estimate quantitatively the behavioural mechanisms and the resulting proximate equilibria for begging and provisioning by the use of appropriate experiments and standard linear regression analysis.