Trapped between popular fruit and preferred nest location – cafeterias are poor places to raise a family

Abstract

Summary1. Nest-site location is a critical component of habitat preference in birds, reflecting a balance between minimizing the likelihood of nest predation while maximizing access to nutritional resources. While many studies have demonstrated the influence of predators in nest-site selection, few studies have explicitly quantified nutritional resources or considered the interacting effects of predation and food availability in determining nest survival. 2. The painted honeyeater Grantiella picta is a mistletoe-specialist frugivore, with fruit from grey mistletoe Amyema quandang representing the main food source for breeding adults and nestlings. Previous work demonstrated that painted honeyeaters prefer to place their nests within mistletoe substrates. Here, we measured the outcome of 63 nests over two years, relating survival to various structural and resource-based variables to discern whether nests placed in mistletoes were more likely to succeed. 3. Twenty-one nests survived the 33 day nest period, with 35 of the 42 failed nests predated. While few significant differences were discerned between successful and unsuccessful nests in terms of nest tree or surrounding habitat, nest substrate emerged as the most important predictor of nest fate. Survival of nests in mistletoe was 16Á6% across a 33 day active nest period compared with a mean of 43Á1% for nests in other substrates, a difference consistent across both years. 4. Rather than having a positive effect on nest outcome (via access to nutritional resources), proximity to mistletoe had a marked negative effect, with nests in mistletoe suffering a predation rate 2Á6 times higher than nests elsewhere. Rather than predators targeting mistletoe clumps, we suggest that this pattern arises from other species visiting fruiting mistletoe clumps, opportunistically predating the nest contents and disturbing attending parents. We interpret this finding as evidence that the painted honeyeater may be caught in an ecological trap; the cues used to select nesting locations are a poor predictor of success.

Carry‐over effects on reproduction in food‐supplemented wintering great tits

“…Thus, winter feeding may be beneficial under certain conditions, but detrimental in others (Plummer et al 2013a, Catto et al 2021), potentially creating an ‘ecological trap' (Barea and Watson 2013, Hale and Swearer 2016). Although our experiment did not result in an increased breeding density, winter feeding may have population consequences by attracting and improving survival of less‐fit individuals, thereby increasing population density, and reducing average individual condition (Robb et al 2008a).…”

Winter feeding influences the cost of living in boreal passerines

“…However, winter-feeding may have wider physiological and ecological consequences that only recently have started to be studied (Robb et al 2008). For example, increased food availability and predictability may come at the cost of impoverished diet, higher predation risk and pathogen exposure, with negative fitness consequences (Barea & Watson 2013).…”

“…2008). For example, increased food availability and predictability may come at the cost of impoverished diet, higher predation risk and pathogen exposure, with negative fitness consequences (Barea & Watson 2013).…”

Hemiparasites drive heterogeneity in litter arthropods: Implications for woodland insectivorous birds

“…Their bulky structure provides nesting and roosting sites (Cooney et al . ; Barea & Watson ) and their nutritive leaves, fruits, flowers, nectar and litter feed a great diversity of animals (Watson ; Shaw et al . ; Burns and Watson ).…”