Article

Cohesion among canids: Insights into social behavior

Three wolves near each other captured on a wildlife camera.
Canid social interactions are responsive to their environment, such as seasonal conditions.

This study explored how animals in social groups, specifically those in the Canis genus (like wolves and coyotes), decide to stay close to each other or not. The researchers tracked 574 individuals from six different Canid species across 15 countries using GPS technology. They wanted to understand what influences the amount of time animals spend together, known as "cohesion." Researchers defined cohesion by determining if animals within the same group were within 100 m of each other during the collection of each GPS location (Figure 1).

A figure showing the world map and location of canids used in the study.
Figure 1. Distribution and sample sizes of social pairs of six Canid species around the world used to investigate factors influencing cohesion and home range overlap within canid social groups, 2003–2019.

Key Findings:

  • Variation in Cohesion: The time spent together varied widely among species and individual pairs within species. Some pairs spent as little as 5% of their time close to each other, while others were close 100% of the time.
  • Wolves vs. Coyotes: Wolves were found to be more cohesive than coyotes. Interestingly, pairs of wolves in larger groups tended to spend less time together, especially when small prey (such as beavers) were abundant. Smaller prey are easier for lone animals to hunt, and can only feed one to a few animals, whereas groups are good for taking down larger prey and more pack members can meet their food requirements while remaining together (Figure 2).
A figure comparing wolves and coyote cohesion.
Figure 2. Cohesion of social pairs of wolves and coyotes during winter and pup-rearing. Pairs are separated as breeding pairs and pairs containing at least one nonbreeder (other pairs).

Black lines in boxes are median values, boxes are bounded by the interquartile range,
error bars include the largest values within 1.5× the interquartile range, and red circles are all data values. Sample sizes are season-pair combinations.

  • Seasonal Changes: Cohesion changed with the seasons, reflecting the animals' cooperative needs during different times of the year. Cohesion was generally higher during the winter when cooperative hunting needs are greatest. Cohesion was lower during the summer because smaller prey are available (young ungulates) and because, during breeding and pup-rearing seasons, pack members often split up so that some could guard pups while others hunted for food to help feed themselves and the pups.
  • Environmental Influence: Factors such as food availability, group size, and the environment (including human impacts and climate change) played significant roles in how cohesive the animals were. For example, cohesion in wolves and coyotes was less during the winter in areas with more human impacts and during times of increased climate variability.

The study highlights the flexibility of social behavior in response to ecological changes and emphasizes the importance of understanding these dynamics, especially for protecting top predators amidst environmental changes. Overall, the research sheds light on the factors that influence cooperation and social interactions in animal groups.

Intrinsic and environmental drivers of pairwise cohesion in wild Canis social groups

Abstract

Animals within social groups respond to costs and benefits of sociality by adjusting the proportion of time they spend in close proximity to other individuals in the group (cohesion). Variation in cohesion between individuals, in turn, shapes important group-level processes such as subgroup formation and fission–fusion dynamics. Although critical to animal sociality, a comprehensive understanding of the factors influencing cohesion remains a gap in our knowledge of cooperative behavior in animals. We tracked 574 individuals from six species within the genus Canis in 15 countries on four continents with GPS telemetry to estimate the time that pairs of individuals within social groups spent in close proximity and test hypotheses regarding drivers of cohesion. Pairs of social canids (Canis spp.) varied widely in the proportion of time they spent together (5%–100%) during seasonal monitoring periods relative to both intrinsic characteristics and environmental conditions. The majority of our data came from three species of wolves (gray wolves, eastern wolves, and red wolves) and coyotes. For these species, cohesion within social groups was greatest between breeding pairs and varied seasonally as the nature of cooperative activities changed relative to annual life history patterns. Across species, wolves were more cohesive than coyotes. For wolves, pairs were less cohesive in larger groups, and when suitable, small prey was present reflecting the constraints of food resources and intragroup competition on social associations. Pair cohesion in wolves declined with increased anthropogenic modification of the landscape and greater climatic variability, underscoring challenges for conserving social top predators in a changing world. We show that pairwise cohesion in social groups varies strongly both within and across Canis species, as individuals respond to changing ecological context defined by resources, competition, and anthropogenic disturbance. Our work highlights that cohesion is a highly plastic component of animal sociality that holds significant promise for elucidating ecological and evolutionary mechanisms underlying cooperative behavior.

Benson, J., D. Keiter, P. Mahoney, B. Allen, L. Allen, B. L. Borg,… K. Joly, … M. Sorum, et al. 2024. Intrinsic and environmental drivers of pairwise cohesion in wild Canis social groups. Ecology: e4492.

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Last updated: December 17, 2024