The Ecological Impact of Animal Nests and Burrows

Abstract

Nest building and burrow construction have costs. These costs are not well known but some attempts have been made to measure them either directly as energy and time consumed, or indirectly as fitness changes. Calculation of the energetic cost of web construction in the spider Araneus diadematus is an example of the former approach (Peakall & Witt 1976), and the cost of nest construction in the Eastern Phoebe (Sayornis phoebe) measured as clutch reduction compared with nest reuse (Weeks 1978), is an example of the latter. In some instances at least it can be seen that the result of these building efforts is a direct transfer of function from some other system to the artefact through evolution; for example, McNab (1966) showed that naked molerats (Heterocephalus glaber) which live permanently in the stable temperature of their burrow system had almost completely lost their power of physiological thermoregulation. Nests and burrows can also reduce the biological hazards of the external environment; for example, the paper carton nest of the tropical polistine wasp Nectarinella championi is surrounded by a field of hairs capped with sticky droplets apparently to repel ants (Schremmer 1977). The purpose of this paper is to present the argument that by their nature nests and burrows can come to exert important influences upon certain habitats and a number of different ways in which they do this can be identified (Fig. 1). These have implications for the understanding of social evolution, species diversity and habitat stability which deserve greater attention.