Human-Induced Changes in Landscape Configuration Influence Individual Movement Routines: Lessons from a Versatile, Highly Mobile Species

Abstract

Landscape conversion by humans may have detrimental effects on animal populations inhabiting managed ecosystems, but human-altered areas may also provide suitable environments for tolerant species. We investigated the spatial ecology of a highly mobile nocturnal avian species–the red-necked nightjar (Caprimulgus ruficollis)–in two contrastingly managed areas in Southwestern Spain to provide management recommendations for species having multiple habitat requirements. Based on habitat use by radiotagged nightjars, we created maps of functional heterogeneity in both areas so that the movements of breeding individuals could be modeled using least-cost path analyses. In both the natural and the managed area, nightjars used remnants of native shrublands as nesting sites, while pinewood patches (either newly planted or natural mature) and roads were selected as roosting and foraging habitats, respectively. Although the fraction of functional habitat was held relatively constant (60.9% vs. 74.1% in the natural and the managed area, respectively), landscape configuration changed noticeably. As a result, least-cost routes (summed linear distances) from nest locations to the nearest roost and foraging sites were three times larger in the natural than in the managed area (mean ± SE: 1356±76 m vs. 439±32 m). It seems likely that the increased proximity of functional habitats in the managed area relative to the natural one is underlying the significantly higher abundances of nightjars observed therein, where breeders should travel shorter distances to link together essential resources, thus likely reducing their energy expenditure and mortality risks. Our results suggest that landscape configuration, but not habitat availability, is responsible for the observed differences between the natural and the managed area in the abundance and movements of breeding nightjars, although no effect on body condition was detected. Agricultural landscapes could be moderately managed to preserve small native remnants and to favor the juxtaposition of functional habitats to benefit those farm species relying on patchy resources.

Nightjars, rabbits, and foxes interact on unpaved roads: spatial use of a secondary prey in a shared‐predator system

“…Based on the results from this and our previous work (Camacho et al. ), it seems that short‐term changes in the antipredator responses of nightjars are scale‐dependent. Birds preferentially foraged on unpaved roads over the entire study period (Camacho et al.…”

“…, Camacho et al. ). Fox abundance is, indeed, over five times higher along unpaved roads than in contrasting adjacent habitats (Suárez‐Esteban et al.…”

“…Because roads play a critical role as a foraging habitat for nightjars compared with other habitats (Camacho et al. ) and, therefore, their foraging habits involve the sites where red foxes are most frequent at night (Suárez‐Esteban et al. ), the probability of encountering predators, and thus perceived predation risk, should be highest at their foraging sites.…”

Study on the foraging behaviour of the European nightjar Caprimulgus europaeus reveals the need for a change in conservation strategy in Belgium

“…In our study habitat composition influenced nightjars’ home range size, and results of previous studies suggest that food availability determines nightjars’ foraging distance (Sierro et al , Sharps et al ). In cases of landscape heterogeneity (Camacho et al , Godet et al ) or where the distribution and availability of food resources fluctuates (Penteriani et al , Pfeiffer and Meyburg ), home range size can be affected. However, it is unclear how these factors influence nightjars’ foraging behaviour on a northwestern European scale.…”

Where eagles soar: Fine‐resolution tracking reveals the spatiotemporal use of differential soaring modes in a large raptor

“…Given these technological advances and the discrete nature of uplift, we are now in a position to model the spatiotemporal probability of uplift‐induced flight behaviors or availability of uplift as “energy landscapes” for soaring species (Shepard et al., 2013; Wilson et al., 2011). This advance will be important for a number of applications; for example, the ability to predict the distribution and probability of locomotory behaviors will be critical in mitigating anthropogenic risks associated with specific behaviors (Camacho, Palacios, Sáez, Sánchez, & Potti, 2014; Colchero et al., 2011; Péron et al., 2017; Reid, Krüger, Whitfield, & Amar, 2015). Values of thermal uplift potential have been shown to be useful in predicting flight altitude, and thus wind turbine collision risk, for Andean condors Vultur gryphus and griffon vultures Gyos fulvus, which predominately rely on thermal uplift for low‐energy flight and to a lesser extent for golden eagles, which switch between the use of orographic and thermal uplift (Péron et al., 2017).…”