Landscape homogenization due to agricultural intensification disrupts the relationship between reproductive success and main prey abundance in an avian predator

Abstract

Background Selecting high-quality habitat and the optimal time to reproduce can increase individual fitness and is a strong evolutionary factor shaping animal populations. However, few studies have investigated the interplay between land cover heterogeneity, limitation in food resources, individual quality and spatial variation in fitness parameters. Here, we explore how individuals of different quality respond to possible mismatches between a cue for prey availability (land cover heterogeneity) and the actual fluctuating prey abundance. Results We analyse timing of breeding and reproductive success in a migratory population of Eurasian kestrels ( Falco tinnunculus ) breeding in nest-boxes, over a full three-year abundance cycle of main prey (voles), and consider several components of individual quality, including body condition, blood parasite infection, and genetic diversity ( n = 448 adults) that act on different time scales. Older individuals, and kestrel parents in higher body condition started egg-laying earlier than younger birds and those in lower body condition. Additionally, egg-laying was initiated earlier during the increase and decrease phases (2011 and 2012) than during the low phase of the vole cycle (2013). Nestling survival (ratio of eggs that fledged successfully) was higher in early nests and in heterogeneous landscapes (i.e., mosaic of different habitat types), which was evident during the increase and decrease phases of the vole cycle, but not during the low vole year. Conclusions We found a strong positive effect of landscape heterogeneity on nestling survival, but only when voles were relatively abundant, whereas a difference in the timing of breeding related to territory landscape heterogeneity was not evident. Therefore, landscape heterogeneity appeared as the main driver of high reproductive performance under favourable food conditions. Our results show that landscape homogenization linked to agricultural intensification disrupts the expected positive effect of vole abundance on reproductive success of kestrels. Electronic supplementary material The online version of this article (10.1186/s12983-019-0331-z) contains supplementary material, which is available to authorized users.

Weather and agricultural intensification determine the breeding performance of a small generalist predator

“…Unusual weather, particularly during the winter may affect the survival of birds, mammals, and insects, thus reducing food availability for kestrels 59,60 , and affecting their condition in the following breeding season 61 . However, contrary to our prediction, we did not find an effect of the weather in the preceding winter on clutch size.…”

Floristic Composition and Structure in Relation to Elevation in the Togo Plateau Forest Reserve in Ghana

“…Despite their importance, available data suggest a steady decline in biodiversity from these unique ecological units [9], [10], leading to calls for their conservation [4], [6], [12]. Ecologists have also predicted a 0.2% loss of plateau ecosystems each year, particularly in Africa, Amazonia, and parts of South-East Asia, should the current rate of degradation continue [10], [12]. Further, the existing gaps in knowledge concerning the composition and structure of plateau ecosystems [14], [13], make it difficult to comprehend their function, conservation, and transformations, particularly with elevation and climate [12], [13].…”

“…Ecologists have also predicted a 0.2% loss of plateau ecosystems each year, particularly in Africa, Amazonia, and parts of South-East Asia, should the current rate of degradation continue [10], [12]. Further, the existing gaps in knowledge concerning the composition and structure of plateau ecosystems [14], [13], make it difficult to comprehend their function, conservation, and transformations, particularly with elevation and climate [12], [13]. Understanding the composition and structure of these ecosystems and their drivers as well as managing them sustainably require more floristic surveys at a variety of scales [10], [12].…”

“…Further, the existing gaps in knowledge concerning the composition and structure of plateau ecosystems [14], [13], make it difficult to comprehend their function, conservation, and transformations, particularly with elevation and climate [12], [13]. Understanding the composition and structure of these ecosystems and their drivers as well as managing them sustainably require more floristic surveys at a variety of scales [10], [12]. Several factors drive vegetation composition and structure of plateau ecosystems, of which elevation is one of the most well documented [10], [12].…”

“…Understanding the composition and structure of these ecosystems and their drivers as well as managing them sustainably require more floristic surveys at a variety of scales [10], [12]. Several factors drive vegetation composition and structure of plateau ecosystems, of which elevation is one of the most well documented [10], [12]. Elevation plays an important role in controlling the ecological and physiological adaptations of various growth forms of plants [7], [14].…”