Mammals adjust diel activity across gradients of urbanization

Abstract

Time is a fundamental component of ecological processes. How animal behavior changes over time has been explored through well-known ecological theories like niche partitioning and predator-prey dynamics. Yet, changes in animal behavior within the shorter 24-hour light-dark cycle have largely gone unstudied. Understanding if an animal can adjust their temporal activity to mitigate or adapt to environmental change has become a recent topic of discussion and is important for effective wildlife management and conservation. While spatial habitat is a fundamental consideration in wildlife management and conservation, temporal habitat is often ignored. We formulated a temporal resource selection model to quantify the diel behavior of eight mammal species across ten U.S. cities. We found high variability in diel activity patterns within and among species and species-specific correlations between diel activity and human population density, impervious land cover, available greenspace, vegetation cover, and mean daily temperature. We also found that some species may modulate temporal behaviors to manage both natural and anthropogenic risks. Our results highlight the complexity with which temporal activity patterns interact with local environmental characteristics, and suggest that urban mammals may use time along the 24-hour cycle to reduce risk, adapt, and therefore persist in human-dominated ecosystems.

Rain, recreation and risk: Human activity and ecological disturbance create seasonal risk landscapes for the prey of an ambush predator

“…It is therefore no surprise that fragmentation propagated by ecological disturbance led to similar patterns of increased nocturnality observed in urban areas where human infrastructure drives fragmentation (Figure 4a; Gallo et al, 2021;Gaynor et al, 2018).…”

“…In support of the latter, panthers became more nocturnal during the flooded season, suggestive of temporal antipredator strategies (Figure 4a). Temporal risk minimization in response to humans is well-documented for large carnivores, particularly in cases where habitat fragmentation hinders spatial adaptations (Gallo et al, 2021;Gese et al, 2012;Mills & Harris, 2020;Xiao et al, 2018).…”

“…However, when spatial risk reduction is not possible, antipredator strategies may shift to temporal risk reduction (Kronfeld-Schor & Dayan, 2003;van der Vinne et al, 2019). Consequently, space limitations caused by ecological disturbances and perceived humanassociated mortality risks can increase predator nocturnality (Gallo et al, 2021;Gaynor et al, 2018) and generate 'temporal refuges' for prey corresponding to predictable periods of reduced predator activity (Shores et al, 2019;Tillmann, 2009). Yet, understanding how seasonal risk landscapes, and corresponding antipredator behaviour, generated by ecological disturbances interact with human activity remains elusive.…”