“O Sister, Where Art Thou?”—A Review on Rescue of Imperiled Individuals in Ants

Abstract

Altruism is defined as an action that decreases the lifetime direct fitness of an actor and benefits one or more recipients. This phenomenon, which is generally difficult to understand and explain, requires special research attention. The subject of this review, rescue, is a type of altruistic behavior in which the actor puts itself at risk to save another individual, the recipient, that is in danger. The highest numbers of published empirical works have been devoted to rescue behavior in ants and they have enormous potential for further study. We review studies devoted to the subject and group them into four main areas of research on ant rescue actions: (1) variation in rescue behavior activity on a between-individual scale, (2) factors contributing to the evolution of rescue behavior on a between-species scale, (3) rescue behavior releaser signals and (4) rescue behavior benefits and costs. We highlight the progress in research on rescue behavior in ants, indicate that this behavior is probably much more common than previously thought yet thus far demonstrated in only a few species, and uncover research gaps and open questions that remain unexplored. We additionally point out some gaps in knowledge that become evident when research devoted to rescue behavior in rats, the second most studied group of animals in this context, is briefly overviewed. We hope to help navigate among studies on rescue behavior and provide the most up-to-date summary of the relevant literature. Moreover, we hope to encourage and facilitate researchers in behavioral ecology and other subdisciplines to further experimentally analyze rescue behavior, not only in ants but also in other taxa.

Injury shortens life expectancy in ants and affects some risk-related decisions of workers

“…Here, we decided to test the importance of life expectancy in the context of risky rescue behavior, in which individuals act to free a nestmate from danger after it signals distress (Czechowski et al 2002 ; Miler and Kuszewska 2017 ). The literature refers to various contexts where ants show this common behavior (Miler and Turza 2021 ). However, there is a considerable unexplained variation in rescue occurrence on both between-species and between-individuals levels (Miler et al 2017a ; Andras et al 2020 ).…”

Desert Ants Learn to Avoid Pitfall Traps While Foraging

“…The capture of an ant worker falling into such pits is not certain and it depends on several factors, such as the soil type and humidity level, pit size and shape, the predator actions, and the ant worker size [ 27 , 28 , 29 , 30 ]. The capture likelihood of some ant species is further reduced owing to rescuing behavior by their nestmates, probably attracted to a volatile pheromone emitted by the trapped worker [ 31 , 32 ]. When ant workers are recruited, the predator might find itself becoming the prey [ 33 ].…”

Do They Know What They Are Doing? Cognitive Aspects of Rescue Behaviour Directed by Workers of the Red Wood Ant Formica polyctena to Nestmate Victims Entrapped in Artificial Snares

“…Behavioural correlates of a social mode of life include affiliative behaviour, a wide spectrum of non-aggressive (friendly) social contacts and interactions [1,2]. Theoretical and experimental research devoted to that issue involves the use of numerous synonymous notions such as prosocial behaviour (pro-sociality) [3][4][5][6][7][8][9][10][11][12][13][14], cooperative behaviour (cooperation) [11,[15][16][17][18][19][20], altruistic behaviour (altruism) [11,16,17,[19][20][21][22][23][24], helping behaviour [3][4][5][16][17][18]25,26] and rescue behaviour [18][19][20][26][27][28][29][30]. The exact scopes of these notions are not easy to delineate, as they are not always defined in precisely the same way.…”