Christina Holm's research while affiliated with Aarhus University and other places

Publications (6)

Article
Sociality in spiders has evolved independently multiple times, resulting in convergently evolved cooperative breeding and prey capture. In all social spiders, prey is captured by only a subset of group members and then shared with other, non-attacking group members. However, spiders' propensity to attack prey may differ among species due to species...
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One of the benefits of cooperative hunting may be that predators can subdue larger prey. In spiders, cooperative, social species can capture prey many times larger than an individual predator. However, we propose that cooperative prey capture does not have to be associated with larger caught prey per se, but with an increase in the ratio of prey to...
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Some semelparous species show terminal investment by suicidal offspring provisioning. This requires internal cellular disintegration for the production of regurgitated food and in preparation for the sacrifice of the female body to the offspring, however, we have limited insights into the extent and costs of such physiological modifications. Extrem...
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Group living animals invariably risk resource competition. Cooperation in foraging, however, may benefit individuals in groups by facilitating an increase in dietary niche. To test this, we performed a comparative study of social and solitary spider species. Three independently derived social species of Stegodyphus (Eresidae) occupy semi-arid savan...
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Division of reproductive behaviour and alloparental care are key aspects of many animal societies. In cooperatively breeding species, variation in helping effort and unequal task participation are frequently observed. However, the extent to which the reproductive state of an individual affects the tasks performed during offspring care remains poorl...

Citations

... For instance, a smaller retreat size might simply enable spiders to emerge quickly and attack the trapped prey faster. Furthermore, communal prey capture behaviour can vary among independently derived social spider species (Grinsted et al. 2022), possibly because of among-species variation in the web phenotype. Such signalling functions of extended phenotypes are known in animals from other taxa (Moreno 2012;Schaedelin and Taborsky 2009). ...
... We found the nests along the side of a minor road in a wheat-growing agricultural area in the northernmost portion of the subtropical ecosystem near the Sonoran Desert and the Gulf of California coast in Mexico (27806 0 N). There is not enough information about the species, except for a few records of its subsocial behavior (Majer et al., 2013;Grinsted et al., 2020), some of its taxonomy, and presence as an endemic species of the southwestern United States and northwestern Mexico (Levi, 1963;World Spider Catalog, 2021). Using nucleotides from seven loci, Luo et al. (2020) found that the species A. analyticus belonged to the same phylogenetic group of Anelosimus as A. studiosus from America. ...
... Mating occurs once a year, after which males die and all female colony members (allo-mothers) cooperate in caring for egg cases and hatchlings. At the end of the allomaternal care stage, juveniles feed on, and kill, the adult females in the colony (gerontophagy) (Seibt & Wickler 1987;Junghanns et al. 2017Junghanns et al. , 2019. This results in a colony structure with no overlapping generations, and all colony members are more or less synchronous with regards to age, developmental stage and body size Grinsted & Lubin 2019). ...
... In Stegodyphus, three species are social while the remaining species are subsocial (Kraus & Kraus 1988). This means that studies aimed at identifying costs, benefits and adaptations to sociality and cooperative behavior tend to view the social Stegodyphus species and their subsocial sister-species as three comparable replicas for the evolutionary transition to sociality (Grinsted et al. 2014;Settepani et al. 2016Settepani et al. , 2017Majer et al. 2018;Grinsted et al. 2020). All social spider species appear to share convergently evolved traits, such as cooperative brood care, cooperative prey capture, inbreeding, and a femalebiased sex ratio (Avilés 1997;, providing an excellent opportunity to perform independent comparative studies aimed at identifying different costs, benefits and adaptations to sociality and cooperative behavior (Grinsted et al. 2014;Settepani et al. 2016Settepani et al. , 2017Majer et al. 2018;Grinsted et al. 2020). ...
... In the campo flicker (Colaptes campestris), male helpers contribute more to nest sanitation than breeders do (Dias and Goedert 2021). In the social spider Stegodyphus dumicola, nonbreeding female group members specialize on prey attack, while breeding females specialize on tending egg sacs ( Junghanns et al. 2017). In saddleback tamarins, adult males specialize on offspring grooming, while adult females specialize on reproduction and lactation (Erb and Porter 2020). ...