Nest site availability and niche differentiation between two cavity‐nesting birds in time and space

Abstract

Niche differentiation is a key concept in the field of ecology and refers to the process by which competing species within an ecological community partition utilization of environmental resources to achieve coexistence. The existence of niche differentiation is uniquely difficult to prove on account of the fact that historical interaction among species, which plays a key role in elucidating the current state of coexistence among species, is not well known. We created continuous niche gradients in nest‐site resources between two sympatric secondary cavity‐nesting birds, the green‐backed tit (Parus monticolus) and the russet sparrow (Passer cinnamomeus), and investigated whether nesting site is a factor contributing to limiting breeding overlap by regular inspection and 388,160 min of film recording. Our results indicate that although we manipulated nest site availability to be uniformly high along the habitat gradient, the two bird species have little overlap in nest sites and rarely compete for them. Furthermore, the green‐backed tit possessed a wide range of fundamental niche that covered that of the russet sparrow, while their reproductive time was largely segregated. The sparrow was more aggressive and outcompeted the tit in their overlapped range. These results suggest that even though nesting sites are crucial to the reproduction of cavity‐nesting birds, some other factor plays a more important role in limiting niche overlap between sparrows and tits in space and time. Given that these two cavity‐nesting birds continued to use different habitats and breed in segregated time after our manipulation, their relationship is better explained by the ghost of competition past theory.

Effectiveness of using nest boxes as a form of bird protection after building modernization

“…Competition for nest-boxes between species that arrive or breed at different times is a well-known phenomenon (e.g. Slagsvold 1975;Minot and Perrins 1986;Charter et al 2013;Milligan and Dickinson 2016;Goldshtein et al 2018;Ye et al 2019). In several cases, a pair of sparrows shared a nest box with a pair of swifts when their breeding times overlapped.…”

Breeding ecology of the Yellow-bellied Warbler (Abroscopus superciliaris)

“…Detailed information of avian reproduction can be obtained when birds accept and use nest boxes. Artificial nest boxes are convenient for breeding ecology studies but are also useful for other studies such as niche utilization (Ye et al 2019).…”

Specialized morphology, not relatively large head size, facilitates competition between a small‐bodied specialist and large‐bodied generalist competitors

“…Competition between Dasypeltis and facultative bird-eggeating snakes in contemporary systems is potentially present as a consequence of historical competition among ancestral lineages, in line with the theory of the ghost of competition past (Weber et al, 2017;Ye, Yang & Liang, 2019). Before adapting to exclusively feeding on bird eggs, ancestral Dasypeltis likely had a broader dietary niche (de Queiroz & Rodríguez-Robles, 2006) and probably competed with several snake species of varying sizes.…”

“…Sympatric species that are ecologically and morphologically similar to each other are predicted to compete for shared resources (Toft, 1985;Arthur, 1987;Ye, Yang & Liang, 2019). This competition can result in selection for differences in ecology and morphology that act to reduce competition between such species.…”