Sexual size dimorphism in ground squirrels (Rodentia: Sciuridae: Marmotini) does not correlate with body size and sociality

Matějů, Jan; Kratochvíl, Lukáš

doi:10.1186/1742-9994-10-27

Cited by 27 publications

(20 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The allometric relationship between SSD and body size, also called Rensch's rule, has been documented in a wide range of animals and in many mammalian orders (Fairbairn, 1997;Fairbairn et al, 2007) but not all (for example rodent sciurids, Matějů and Kratochvíl, 2013). Secondly, the results showed a positive relationship between male-biased SSD and increasing parasite species richness in accordance with the comparative study of Moore and Wilson (2002).…”

Section: Sexual Size Dimorphism and Parasitessupporting

confidence: 75%

Parasite diversity of disease-bearing rodents of Southeast Asia: habitat determinants and effects on sexual size dimorphism and life-traits

Morand

Bordes

2015

Front. Ecol. Evol.

View full text Add to dashboard Cite

We investigated a causal chain of relationships between habitat specialization and parasite species richness in rodent communities in Southeast Asia, and the consequences for variation in immune investment (using spleen size), the degree of sexual competition (using testes) and sexual size dimorphism (SSD). We used data gathered on rodents, their habitat specialization and their parasites (macro-and micro-parasites) in Southeast Asian landscapes. The results supported the hypotheses that parasite diversity drives the evolution of host life-traits and sexual selection. Firstly, host habitat specialization explained the variation in parasite species richness. Secondly, high parasite species richness was linked to host immune investment, using the relative spleen size of rodents. Thirdly, according to the potential costs associated with immune investment, the relative spleen size was found to be negatively correlated with the relative size of testes among rodents. Fourthly, a positive relationship between male-biased SSD and parasite species richness was observed supporting the role of parasitism in sexual selection. Finally, the variation in SSD was positively associated with the degree of habitat specialization. Highest values of female-biased SSD were associated with habitat specialization, whereas highest values of male-biased SSD concerned synanthropic or generalist rodent species. These results, also correlative, will help to facilitate selection of the species that should be thoroughly investigated at the population level to better understand the selective effects of parasites on rodent life-history and behavior.

show abstract

Section: Sexual Size Dimorphism and Parasitessupporting

confidence: 75%

Parasite diversity of disease-bearing rodents of Southeast Asia: habitat determinants and effects on sexual size dimorphism and life-traits

Morand

Bordes

2015

Front. Ecol. Evol.

View full text Add to dashboard Cite

show abstract

“…With respect to rodents, this order has not been thoroughly studied regarding SSD with the exception of squirrels and allies, which show a mixture of male-and female biased SSD (SchulteHostedde, 2007;Hayssen, 2008). A recent study of ground squirrels demonstrates that this group does not follow Rensch's rule (Matějů and Kratochvil, 2013). Tuco-tucos (Ctenomyidae) had been the subject of a SSD study only once (Bidau and Medina, 2013).…”

Section: Discussionmentioning

confidence: 93%

A re-assessment of Rensch's rule in tuco-tucos (Rodentia: Ctenomyidae: Ctenomys) using a phylogenetic approach

Martínez

Bidau

2016

Mammalian Biology

View full text Add to dashboard Cite

Keywords:Body mass Model II regression Phylogenetic reduced major axis Scaling Sexual size dimorphism a b s t r a c t Sexual size dimorphism (SSD) is affected by a large number of factors, mating system being one of the most relevant. Almost 70 species of subterranean rodents of the genus Ctenomys are considered highly polygynic, and polygyny jointly with absence of paternal care of the young, favours high SSD. In this respect, Rensch's rule predicts that SSD scales with body size so that when males are larger than females SSD tends to increase with body size. We studied SSD and Rensch's rule in 28 taxa of Ctenomys using a phylogenetic approach employing the method of phylogenetic reduced major axis (pRMA) to perform reduced major axis (RMA) model II regression in the form of log 10(male mass) on log 10(female mass). The RMA regression slope (ˇ) was statistically tested to accept or reject the null hypothesis that ˇpRMA = 1.0. A slope significantly >1.0 would signal concordance with Rensch's rule. Our results showed that despite a high degree of male-biased SSD as expected from polygynic species, Rensch's rule is not verified in this rodent group. The causes of the non-concordance with Rensch's rule as well as its taxonomic level of application are discussed in terms of current models of SSD.

show abstract

“…Most species exhibit male-biased sexual dimorphism in body mass [29]. The SBH predicts different selection pressures on males and females in species where sociality differs between the sexes [30 -33].…”

Section: Methodsmentioning

confidence: 99%

Absolute, not relative brain size correlates with sociality in ground squirrels

Matějů¹,

Kratochvíl

Pavelková

et al. 2016

Proc. R. Soc. B.

Self Cite

View full text Add to dashboard Cite

The social brain hypothesis (SBH) contends that cognitive demands associated with living in cohesive social groups favour the evolution of large brains. Although the correlation between relative brain size and sociality reported in various groups of birds and mammals provides broad empirical support for this hypothesis, it has never been tested in rodents, the largest mammalian order. Here, we test the predictions of the SBH in the ground squirrels from the tribe Marmotini. These rodents exhibit levels of sociality ranging from solitary and single-family female kin groups to egalitarian polygynous harems but feature similar ecologies and life-history traits. We found little support for the association between increase in sociality and increase in relative brain size. Thus, sociality does not drive the evolution of encephalization in this group of rodents, a finding inconsistent with the SBH. However, body mass and absolute brain size increase with sociality. These findings suggest that increased social complexity in the ground squirrels goes hand in hand with larger body mass and brain size, which are tightly coupled to each other.

show abstract

Sexual size dimorphism in ground squirrels (Rodentia: Sciuridae: Marmotini) does not correlate with body size and sociality

Cited by 27 publications

References 46 publications

Parasite diversity of disease-bearing rodents of Southeast Asia: habitat determinants and effects on sexual size dimorphism and life-traits

Parasite diversity of disease-bearing rodents of Southeast Asia: habitat determinants and effects on sexual size dimorphism and life-traits

A re-assessment of Rensch's rule in tuco-tucos (Rodentia: Ctenomyidae: Ctenomys) using a phylogenetic approach

Absolute, not relative brain size correlates with sociality in ground squirrels

Contact Info

Product

Resources

About