Abstract

In many brood-rearing species, suitable nesting resources are needed for nest construction. Here, we used males of a small marine fish, the sand goby, Pomatoschistus minutus, to study the associations between the nest owner’s phenotype (i.e. body size), the characteristics of the nesting resource used for nest construction (i.e. resource size and shape) and nest-building behaviour (i.e. eagerness to build a nest and extent of nest elaboration). We found that male body size was associated with nesting resource size and resource architecture in the field, with the smallest males occupying small flat resources and the biggest males occupying large arched resources. In the laboratory, the type of resource occupied in the field had a limited effect on the level of nest elaboration, but not on other nesting behaviours. Large body size, in turn, was associated with preference for larger resources and, in some circumstances, also the level of nest elaboration. Body size did not affect the eagerness to initiate nest building. Furthermore, males chose arched nesting resources more often than those that were flat, and this preference was also reflected under a ’no-choice’ scenario, based on the time taken for males to initiate nest building. Overall, the results indicate that the importance of male size in nest building is context dependent, while nesting behaviours can also be affected by resource size, resource architecture and, under some circumstances, the nest builder’s experience with resource use.