Rodent Societies: An Ecological & Evolutionary Perspective

(Greg DeLong) #1

intraspecific variation in these behaviors, within some of
the well-characterized species.


Summary


The purpose of this chapter was to examine, in a phylo-
genetic context, components of the breeding system of
Neotomine-Peromyscine rodents from wild populations.
First, using a review of the literature, we describe the pat-
terns in breeding systems within this clade. Second, we ex-
amine the following breeding behaviors to test if there are
any phylogenetic patterns in the observed variation in these
behaviors, and if relationships exist among them: male
spacing, female spacing, relative intersexual home range /
territory size, paternal care, and juvenile dispersal patterns.
Third, we examine whether dietary, physiological, or life-


history characteristics of the taxa explain the observed vari-
ation in these breeding behaviors. In general, we found that
females are solitary and males are roving, and these traits
are ancestral. Male spacing behavior is independent of fe-
male spacing behavior and female spacing behavior is inde-
pendent of male spacing behavior. Paternal care has evolved
multiple times, and there is a trend for monogamously
spaced males to provide care. The ancestral state is for
males to have larger home ranges than females, with very
few taxa demonstrating equitable range sizes. Natal disper-
sal tends to be male biased. We found a positive correlation
between species distribution area and litter size. There was
a trend for nonmonogamous males to have a higher-energy
diet and a higher BMR than monogamous males. Paternal
care was not related to diet or BMR. Female spacing be-
havior was not related to diet but was related to BMR, with
solitary females having a higher BMR than nonsolitary fe-

84 Chapter Six


Figure 6.8 Mirror phylogenies showing the ancestral state reconstruction for male spacing behavior and species distribution area in Neotomine-Peromyscine ro-
dents. Although species distribution area is graphically presented as a binary variable, statistics were performed on continuous data. Binary species distribution area
data are determined as being above or below the average value for all represented species.
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