High interindividual variability in habitat selection and functional habitat relationships in European nightjars over a period of habitat change

Abstract

An animal's choice of foraging habitat reflects its response to environmental cues and is likely to vary among individuals in a population. Analyzing the magnitude of individual habitat selection can indicate how resilient populations may be to anthropogenic habitat change, where individually varying, broadly generalist populations have the potential to adjust their behavior. We collected GPS point data from 39 European nightjars (Caprimulgus europaeus) at a UK breeding site where restoration measures have altered large areas of habitat between breeding seasons. We calculated individual habitat selection over four breeding seasons to observe changes that might align with change in habitat. We also analyzed change in home range size in line with change in habitat availability, to examine functional relationships that can represent trade‐offs made by the birds related to performance of the habitat.Individual explained more of the variation in population habitat selection than year for most habitat types. Individuals differed in the magnitude of their selection for different habitat types, which created a generalist population composed of both generalist and specialist individuals. Selection also changed over time but only significantly for scrub habitat (60% decrease in selection over 4 years). Across the population, individual home range size was 2% smaller where availability of cleared habitat within the home range was greater, but size increased by 2% where the amount of open water was higher, indicating the presence of trade‐offs related to habitat availability. These results highlight that using individual resource selection and specialization measures, in conjunction with functional responses to change, can lead to better understanding of the needs of a population. Pooling specialist and generalist individuals for analysis could hide divergent responses to change and consequently obscure information that could be important in developing effective conservation strategies.

Context-dependent foraging habitat selection in a farmland raptor along an agricultural intensification gradient

“…inter-individual variability, despite their potential overarching eco-evolutionary consequences (Leclerc et al, 2016;Mitchell et al, 2020). Here we filled this gap of knowledge by exploring the role of intrinsic and extrinsic drivers affecting inter-individual variability in habitat selection.…”

“…However, natural selection acts on individuals. Understanding the drivers of individual variability in habitat selection is therefore pivotal to answer fundamental eco-evolutionary questions (Leclerc et al, 2016;Mitchell et al, 2020;Muff and Fieberg, 2019). Despite its potential significance, such inter-individual variation in habitat selection patterns has been little explored (Avgar et al, 2020).…”

“…Whenever the individual use/selection of specific habitats varies as a function of the availability of this habitat within the frequented area, a so-called 'functional response' in habitat use/selection occurs (Mysterud and Ims, 1998;Holbrook et al, 2019). Functional responses are relevant to characterize behavioural plasticity, the relative advantages or disadvantages of exploiting different habitats, and the potential for a species or population to respond to spatial and temporal landscape changes (Mitchell et al, 2020).…”

Metabarcoding reveals selective dietary responses to environmental availability in the diet of a nocturnal, aerial insectivore, the European Nightjar (Caprimulgus europaeus)

“…Although some samples may have been taken from the same individual, intraspecific variation in diet is common and can reflect both resource availability and the avoidance of competition through resource partitioning (Kotler & Brown 1988, Maldonado et al 2019, Alberdi et al 2020 or differences in habitat selection. We tracked a number of individuals in this population over the same 4 years of this study, and this tracking work highlighted a lack of overall population preference for any particular habitat type (Mitchell et al 2020). The lack of similarity in diet among samples potentially also indicates a lack of association with a particular habitat for foraging.…”

Sex and Population Drive Interindividual Variations in a Cognitive Task Across Three Populations of Wild Zebrafish

“…Even ecosystem studies in pelagic ecosystems show that habitat variability significantly changes the productivity and resource use efficiency of plankton (Kemp et al, 2001). Nightjars (Caprimulgus europaeus) facing greater habitat change show more variability in behavior over time (Mitchell et al, 2020). Although habitat features themselves might influence behavior and repeatability of behavior, it might be that the variability of the habitat has a much higher impact, which would explain why more dynamic habitats are similar to each other in our study, at least in terms of repeatability.…”