Urbanization and the temporal patterns of social networks and group foraging behaviors

Abstract

Urbanization causes dramatic and rapid changes to natural environments, which can lead the animals inhabiting these habitats to adjust their behavioral responses. For social animals, urbanized environments may alter group social dynamics through modification of the external environment (e.g., resource distribution). This might lead to changes in how individuals associate or engage in group behaviors, which could alter the stability and characteristics of social groups. However, the potential impacts of urban habitat use, and of habitat characteristics in general, on the nature and stability of social associations remain poorly understood. Here, we quantify social networks and dynamics of group foraging behaviors of black‐capped chickadees ( N = 82, Poecile atricapillus ), at four urban and four rural sites weekly throughout the nonbreeding season using feeders with radio frequency identification of individual birds. Because anthropogenic food sources in urban habitats (e.g., bird feeders) provide abundant and reliable resources, we predicted that social foraging associations may be of less value in urban groups, and thus would be less consistent than in rural groups. Additionally, decreased variability of food resources in urban habitats could lead to more predictable foraging patterns (group size, foraging duration, and the distribution of foraging events) in contrast to rural habitats. Networks were found to be highly consistent through time in both urban and rural habitats. No significant difference was found in the temporal clumping of foraging events between habitats. However, as predicted, the repeatability of the clumping of foraging events in time was significantly higher in urban than rural habitats. Our results suggest that individuals living in urban areas have more consistent foraging behaviors throughout the nonbreeding season, whereas rural individuals adjust their tactics due to less predictable foraging conditions. This first examination of habitat‐related differences in the characteristics and consistency of social networks along an urbanization gradient suggests that anthropic habitat use results in subtle modifications in social foraging patterns. Future studies should examine potential implications of these differences for variation in predation risk, energy intake, and information flow.

Individual variation in Black-capped chickadee (Poecile atricapillus) foraging behavior in response to a predator model.

“…The feeders were filled with black oil sunflower seeds and kept filled throughout the duration of the study. The feeders were located ∼130 m apart, a distance that made it likely that we were sampling the same chickadee population at both locations (Bartmess-LeVasseur et al, 2010; Book & Freeberg, 2015); black-capped chickadee flock size varies from three to 12 birds (Jones et al, 2017), and flocks are typically stable over the course of a winter (Jones et al, 2019; Krams et al, 2012). Based on the pairs/groups of birds that visited the feeders together, we estimated that at least four flocks were represented in the population sampled, and there was some evidence that flock composition fluctuated near the end of winter.…”

“…However, winter flocks of great tits have been characterized as fusion-fission, with individual birds' associations varying over the course of the winter (Aplin et al, 2013). In contrast, black-capped chickadees form more stable winter associations (Jones et al, 2017(Jones et al, , 2019Krams et al, 2012), with small flocks consisting of three to 12 individuals (Jones et al, 2017), and linear dominance hierarchies (Devost et al, 2016). Personality of black-capped chickadees is not related to social dominance at feeders (Devost et al, 2016) or food neophobia (Prasher et al, 2019), and does not influence social transmission of information (Jones et al, 2017), but in these studies, personality was assessed by behavior in captivity (Prasher et al, 2019) or in an open-field cage trial following capture, which may not have been fully representative (Devost et al, 2016;Jones et al, 2017).…”

Odontocete spatial patterns and temporal drivers of detection at sites in the Hawaiian islands

“…Detailed spatial information about species presence often aids in the definition of new or distinct populations as well as the understanding of habitat use and movement patterns (e.g., Baird et al, 2010; Scofield et al, 2011; Sequeira et al, 2018). Continuous temporal data facilitate description of key patterns in animal activity, which is crucial for understanding foraging strategies and mitigating harmful anthropogenic interactions (Forney et al, 2011; Jones et al, 2019; Soldevilla et al, 2011). Characterization of spatiotemporal patterns in odontocete (toothed whale) species presence may also facilitate the creation and comparison of habitat models (e.g., Kanaji et al, 2017; Seger & Miksis‐Olds, 2020).…”

Group composition of individual personalities alters social network structure in experimental populations of forked fungus beetles

“…Over the last two decades, research across a range of taxa has confirmed that individual social network position has fitness consequences [8][9][10][11][12][13][14][15][16][17][18][19][20]. Position within a network is known to be a repeatable trait both within the same group [21][22][23][24][25] and in some species across social contexts [26][27][28]. Revealing the sources of variation in individual network position has led to a deeper understanding of how and when such traits are expected to evolve [29,30].…”