Rodent Societies: An Ecological & Evolutionary Perspective

Figure 6.5 Relationship between the logarithm of species distribution
area (km^2 ) and litter size for Neotomine-Peromyscine rodents,Sigmodon
andAkodon.

the Onychomysclade does not differ substantially from the

Neotomine-Peromyscine rodents with respect to the evolu-

tion of breeding behaviors and their correlates. In general,

we found that females were solitary and males were not

monogamous, and these traits are ancestral for the clade.

Male spacing behavior was independent of female spacing

behavior, and female spacing behavior was independent

of male spacing behavior. Paternal care appeared to have

evolved multiple times. Monogamous males tended to pro-

vide care to offspring. The ancestral state was for males to

have larger home ranges than females, with very few taxa

demonstrating equitable range sizes. The ancestral state

was for natal dispersal to be male biased. We found a posi-

tive correlation between species distribution area and litter

size. Nonmonogamous males had a higher-energy diet (i.e.,

carnivory and omnivory) and a higher BMR than monoga-

A Phylogenetic Analysis of the Breeding Systems of Neotomine-Peromyscine Rodents 79

Figure 6.4 (continued)

B