Abstract

Permanent changes in group membership may result in detrimental fitness effects on both group residents and immigrants. Factors associated with this form of social instability are rarely documented. We used a 15-year dataset on degus, a social and short-lived species, to test the hypothesis that physical condition and socioecological factors experienced during breeding are associated with social instability in terms of group individual membership (hypothesis 1). We also tested the hypothesis that these factors represent potential cues for individuals to predict social instability conditions during subsequent breeding (i.e., exhibiting autocorrelation) (hypothesis 2). Social instability in degu group membership was ubiquitous. Social instability increased with increasing ectoparasite load but decreased with increasing food abundance, increasing degu density, increasing mean minimum temperature, and increasing number of female group members. Of these conditions, degu density during winter exhibited autocorrelation. Finally, overall predictability of ecological conditions varied from low to high within a 5–6-year period. These findings indicate that socioecological conditions experienced by the breeding adults and their developing offspring predict within-year social instability (hypothesis 1) and provide some limited cues to individuals to predict similar conditions during the subsequent breeding event (hypothesis 2).

Significance statement

Permanent changes in the adult composition of social groups (social instability) can have significant impacts on the fitness of group members. Determining the ecological and social conditions associated with social instability and whether individuals can anticipate social instability in adulthood can inform socioecological theory. In the communally rearing rodent, Octodon degus, social instability during breeding is ubiquitous and impacts the fitness of adult males and females differently. We determined that social instability in degu groups during breeding is associated with local ecological conditions (ambient temperature, ectoparasite loads, abundance of food, population density) and the social environment (number of adult females). Of the ecological variables, only population density exhibited autocorrelation. These results are important because they imply limited ecological cues available for the offspring to anticipate social instability conditions as adults.

中文翻译：

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社会生态条件预测degu社会不稳定，并提供有限的线索来预测随后的繁殖条件

摘要

团体成员身份的永久变化可能会对团体居民和移民产生不利的健康影响。与这种社会不稳定形式有关的因素很少被记录在案。我们使用了degus（一种社会和短命物种）的15年数据集来检验以下假设：就群体个体成员而言，繁殖期间经历的身体状况和社会生态因素与社会不稳定相关（假设1）。我们还检验了以下假设：这些因素代表了个体在随后的育种过程中预测社会不稳定状况的潜在线索（即表现出自相关）（假设2）。degu小组成员的社会不稳定现象普遍存在。社会不稳定性随着外寄生物负荷的增加而增加，但随着食物丰度的增加而减少，增加degu密度，增加平均最低温度和增加女性团体成员的数量。在这些条件下，冬季的degu密度表现出自相关。最后，在5-6年内，生态状况的总体可预测性从低到高不等。这些发现表明，成年成年人及其发育中的后代所经历的社会生态状况可预测年内的社会不稳定性（假设1），并为个体提供一些有限的线索来预测随后的繁殖事件中的类似状况（假设2）。在5-6年内，生态状况的总体可预测性从低到高不等。这些发现表明，成年成年人及其发育中的后代所经历的社会生态状况可预测年内的社会不稳定性（假设1），并为个体提供一些有限的线索来预测随后的繁殖事件中的类似状况（假设2）。在5-6年内，生态状况的总体可预测性从低到高不等。这些发现表明，成年成年人及其发育中的后代所经历的社会生态状况可预测年内的社会不稳定性（假设1），并为个体提供一些有限的线索来预测随后的繁殖事件中的类似状况（假设2）。

重要性声明

社会群体的成年人组成的永久变化（社会不稳定）会严重影响群体成员的身体素质。确定与社会不稳定有关的生态和社会条件，以及个人是否可以预见成年后的社会不稳定，可以为社会生态学理论提供参考。在公共饲养的啮齿动物中，Octodon degus，繁殖过程中的社会不稳定现象普遍存在，并且对成年雄性和雌性的健康产生不同的影响。我们确定，繁殖期间德固族群体的社会不稳定与当地的生态条件（环境温度，体外寄生虫负荷，食物丰富，人口密度）和社会环境（成年雌性数量）有关。在生态变量中，只有人口密度表现出自相关。这些结果之所以重要，是因为它们暗示后代可以利用有限的生态线索来预测成年后的社会不稳定状况。