Capital and Income Breeding as Alternative Tactics of Resource Use in Reproduction

TLDR

Reproduction drives organisms to increase food intake, and the choice of resource‑use tactics—such as foraging strategies—depends on the costs associated with capital and income breeding. The paper examines the two general resource‑use tactics of capital and income breeding. Capital breeding involves acquiring and storing resources before breeding, whereas income breeding synchronizes resource acquisition with breeding. Income breeding outperforms capital breeding in predictable, resource‑abundant settings, but capital breeding confers advantages under unpredictable food, time constraints, or risky foraging, though it incurs higher prebreeding costs.

Abstract

In order to compensate for the resource demands of reproduction, organisms usually increase the amount of total food resources available. This may be achieved by different tactics of resource use that also include foraging decisions. Two such general tactics are discussed in this paper under the concepts of capital and income breeding. These are defined mainly from the temporal distribution of resource acquisition relative to resource use. A capital breeder acquires its resources in advance and store them endogenously or exogenously until they are needed to supply aspects of offspring production. An income breeder, on the other hand, adjusts its food intake concurrently with breeding, without reliance on stores. In a perfectly predictable environment without limited resources, income breeding is the best option since capital breeders may have to pay a number of energetic and demographic costs for their stored resources. However, under unpredictable food conditions, food/time limitations, and risky foraging conditions, capital breeding offers many benefits. The costing systems (pre- or postbreeding costs) induced by capital and income breeding will largely influence the opportunity for these energetic tactics to evolve. While capital and income breeders may potentially experience both pre- and postbreeding costs, capital breeders may be more exposed to prebreeding costs due to predation in connection with acquisition and carriage of stores.