The role of context in elucidating drivers of animal movement

Abstract

Despite its consequences for ecological processes and population dynamics, intra‐specific variability is frequently overlooked in animal movement studies. Consequently, the necessary resolution to reveal drivers of individual movement decisions is often lost as animal movement data are aggregated to infer average or population patterns. Thus, an empirical understanding of why a given movement pattern occurs remains patchy for many taxa, especially in marine systems. Nonetheless, movement is often rationalized as being driven by basic life history requirements, such as acquiring energy (feeding), reproduction, predator‐avoidance, and remaining in suitable environmental conditions. However, these life history requirements are central to every individual within a species and thus do not sufficiently account for the high intra‐specific variability in movement behavior and hence fail to fully explain the occurrence of multiple movement strategies within a species. Animal movement appears highly context dependent as, for example, within the same location, the behavior of both resident and migratory individuals is driven by life history requirements, such as feeding or reproduction, however different movement strategies are utilized to fulfill them. A systematic taxa‐wide approach that, instead of averaging population patterns, incorporates and utilizes intra‐specific variability to enable predictions as to which movement patterns can be expected under a certain context, is needed. Here, we use intra‐specific variability in elasmobranchs as a case study to introduce a stepwise approach for studying animal movement drivers that is based on a context‐dependence framework. We examine relevant literature to illustrate how this context‐focused approach can aid in reliably identifying drivers of a specific movement pattern. Ultimately, incorporating behavioral variability in the study of movement drivers can assist in making predictions about behavioral responses to environmental change, overcoming tagging biases, and establishing more efficient conservation measures.

Individual variation in home‐range across an ocean basin and links to habitat quality and management

“…This finding adds to the growing evidence of the importance of safe resting areas and more generally for the important role of the risk of predation in shaping animal movements, not just with sea turtles (e.g. Christianen et al, 2023;Heithaus et al, 2007) but more broadly across marine taxa (Lubitz et al, 2022).…”

Differentiating spillover: an examination of cross-habitat movement in ecology

“…Additionally, other marking techniques, such as etching and the use of colored paint or powder, is not feasible with microbes. Therefore, molecular techniques that might indirectly infer movement, such as environmental DNA, gut content analyses, genetic testing or stable isotopes [117][118][119][120], hold promise for smaller organisms or those with cryptic behaviours. For example, performing genetic tests to see the relatedness of populations can separate spillover from Peralta et al [80] no Not addressing a change Cannot differentiate from transitory movement behaviour and more permanent or influential movement Afonso et al [115] royalsocietypublishing.org/journal/rspb Proc.…”

The essential habitat role of a unique coastal inlet for a widely distributed apex predator

“…Behaviours suggested to be related to attacking benthic prey from above and marine mammals from below [23,71]. Given N. cepedianus' diverse diet [23,[34][35][36], and the role of context in movement behaviours [41], activity patterns may vary between feeding grounds. The maximum detection probability of male N. cepedianus at high tide in CV suggests they are more active when water levels are higher.…”

“…The high trophic level diet of N. cepedianus includes teleost, chondrichthyans and marine mammals [34][35][36][37]. Annual seasonal movements into discrete coastal habitats, at least in some locations, are driven by N. cepedianus returning to productive foraging grounds [33,[38][39][40][41]. Large-scale (greater than 1000 km) seasonal migratory movements away from and returning to forging grounds [37,42,43] implies these coastal habitats are essential for supporting adult N. cepedianus.…”