Sociality and ecology in ground squirrels (tribe Marmotini).

of the Ph.D. thesis Autor: Jan Matějů Name: Sociality and ecology in ground squirrels (tribe Marmotini) Ground-dwelling squirrels are parafyletic group of rodents from the family Sciuridae (tribes Marmotini and Xerini). Ground-dwelling squirrels are semi-fossorial inhabitants of treeless biotopes. They share most aspects of general biology. They usually breed once a year, have exclusively diurnal activity and are omnivorous. On the contrary, ground-dwelling squirrels display different levels of sociality, which makes them an ideal model to study different ecological aspects connected with evolution of sociality. The first part of the Ph.D. thesis is focused on the relationship between sociality and sexual size dimorphism and relative and absolute size of brain. At first, supposing that different levels of sociality are connected with differences in intensity of sexual selection acting on males, we tested association between sociality and sexual size dimorphism as well as association between sexual size dimorphism and body size - so called Rensch rule. Next, we tested correlation between sociality and relative brain size. In agreement with the Social brain hypothesis, we assumed that e.g. solitarily living species should have smaller relative brain size than species living in stable pairs. We found..