Linking nest predation with brood parasitism in captive zebra finches: a multi-pair study

Abstract

Zebra finches (Taeniopygia guttata) are social, colonial nesting birds with moderate levels of intraspecific brood parasitism reported in both wild and captive populations. In a previous study, individually housed, captive zebra finch pairs responded to nest removal during the egglaying period by parasitising simulated active conspecific nests. In the study reported here, we investigated the role of nest loss as a proximate trigger for parasitism in a more naturalistic setting: small groups consisting of three pairs per aviary. In three of ten experimental trials, females responded to nest removal during the egg-laying period by laying eggs in active neighbouring nests. This rate of parasitism was lower than that reported previously for individually housed pairs, and aggressive interactions between hosts and putative parasites were also observed. The results provide further support for the Hamilton-Orians hypothesis for the evolutionary origin of brood parasitism and highlight the influence of social context on the expression of brood parasitic behaviour. Together with qualitative descriptions of several previously unreported behaviours associated with nesting and brood parasitism in captive zebra finches, these experiments provide a functional context and methodology for future studies on zebra finches as a potential new model for the ecology and evolution of brood parasitism.

Nest destruction elicits indiscriminate con‐ versus heterospecific brood parasitism in a captive bird

“…Following experimental nest destruction, zebra finches showed no preference for laying a physiologically committed egg in a nest containing zebra finch eggs versus a nest containing Bengalese finch eggs. These results provide direct support for the Hamilton–Orians hypothesis in that nest destruction can cause facultative brood parasitism of both intraspecific (Feare ; McRae ; Shaw and Hauber , ) and interspecific nests (this study). Thus nest destruction could be an evolutionarily viable pathway toward obligate interspecific brood parasitism in birds.…”

“…For example, Hamilton and Orians () suggested that the laying of physiologically committed eggs in the nests of other birds following nest predation may be a viable pathway to the evolution of intraspecific and obligate interspecific brood parasitism (“Hamilton–Orians” hypothesis). This evolutionary hypothesis has strong support from theoretical modeling studies (Cichoń ; Robert and Sorci ) and has been demonstrated experimentally in an intraspecific parasitism context: captive zebra finches ( Taeniopygia guttata ) preferentially parasitized the active nests of conspecifics, as opposed to empty nests, following the removal of their own nest during the egg laying period (Shaw and Hauber , ). In the field, both starlings ( Sturnus vulgaris ) and moorhens ( Gallinula chloropus ) responded to the experimental removal of partially completed clutches by laying eggs in the active neighboring nests of conspecifics (Feare ; McRae ).…”

“…In this study, all nest structures were identical (enclosed nests lined with hay and wool), which may be biologically plausible if nest predation resulted in preferential or indiscriminate brood parasitism of a conspecific or a closely related heterospecific with similar nest architecture. Additionally, active defense by nest owners is likely to interfere with nest inspection and successful laying of a physiologically committed egg (Shaw and Hauber ). Thus, for females faced with an immediate need for a host nest in which to lay a physiologically committed egg, host presence may indicate nest suitability; however, opportunities for entering the nest and inspecting its contents will likely be limited.…”

“…Birds were color‐banded and pairs ( N = 17) were housed in individual cages (35 × 30 × 45 cm) that were visually, but not acoustically, isolated from one another (see Shaw and Hauber for further husbandry details). All birds had previously paired, built nests and laid eggs while they participated in other experiments assessing the prevalence of intraspecific brood parasitic behaviors (Shaw and Hauber , ). All protocols were approved by the University of Auckland Animal Ethics Committee.…”

A siblicidal origin for avian brood parasitism?

“…Specifically, obligate interspecific brood parasitism (OBP). Nevertheless, not all lineages that display these ecological traits are brood parasites, and some may have had parasitic strategies curtailed by successful host defenses, such as high levels of nest attention and nest defense (e.g., GonzalezMartin and Ruiz 1996;Geffen and Yom-Tov 2001;Shaw and Hauber 2012;Feeney et al 2012). Given the body of research describing evolutionary and ecological similarities between siblicidal and brood parasitic taxa, discussed below, we propose an evolutionary trajectory by which siblicide may be basal to brood parasitism.…”