Trumpeter finches (Bucanetes githagineus) breeding at highlands have higher breeding success but a shorter breeding season

Abstract

One of the responses of arid-land birds to ongoing climate warming is to shift their ranges towards higher altitudes to track species climatic optima. As this can influence their life history traits, more information is needed on breeding output from these border populations. We studied the breeding biology of the Trumpeter finch (Bucanetes githagineus) during three years in the center of the Saharan Atlas (ca. 1400 m a.s.l). Compared to lowland populations, breeding season was shorter and egg hatchability lower, but breeding success higher, as the main difference regarding previous studies was the lack of predation in the 23 nests we monitored. This is an advantage for this arid-land species breeding at the limit of its altitudinal range. However, in the face on future climate warming, predator ranges are also expected to shift towards higher altitudes, thus minimizing this current advantage, while breeding limitations due to harsh weather could prevail, what could compromise population viability.