(Solomon and Getz 1997). Female philopatry is prevalent
in rodents and females may benefit by having kin as neigh-
bors through the evolution of nepotistic behaviors (e.g.,
sharing of space; Hoogland 1995; Dalton 2000).
Evolutionary theory predicts that the female reproduc-
tive strategies should be those that result in the greatest
number of offspring in succeeding generations. Among ro-
dents, a female’s reproductive success will be primarily influ-
enced by two factors: whom she mates with and her ability
to rear the offspring after fertilization. In the small percent-
age of rodent species in which males engage in paternal
care of offspring (Gubernick and Alberts 1987; Wang, In-
sel, Rosenblatt, and Snowdon 1996; Gubernick and Teferi
2000; Wynne-Edwards 2003), a female’s reproductive suc-
cess also would depend on the quality of the male as a par-
ent. These factors are not mutually exclusive, since a male’s
genetic contribution will affect the quality and quantity of
the offspring a female produces and his behavior after the
offspring are born may further increase their chances of sur-
vival (e.g., protection from infanticide). In this chapter, we
will focus on precopulatory and postcopulatory behaviors
that affect female reproductive success. We will attempt to
draw conclusions after reviewing the published literature
from field and laboratory studies, and then discuss areas for
future research.
Female Mate Choice
Female choice of mates can occur at various stages: before
copulation, during copulation, after copulation but before
fertilization, and after fertilization (Birkhead and Møller
1993). Most information concerning precopulatory mate
choice by female rodents is derived from laboratory studies
(reviewed in Dewsbury 1988; table 4.1). Although only
measurements of actual copulations are true indications of
mate choice, few studies (25%, N50 studies) report
data on preferential mating. Instead, most studies report
odor preferences (time spent with the odor cues from each
male) or social preferences (time spent with each male) in
settings in which females could not copulate with males
(fig. 4.1). A few studies that have measured odor preferences
(Egid and Brown 1989; Arcaro and Eklund 1998) or social
preferences and mating preferences show that the former in-
deed reveal mating preferences (Pierce and Dewsbury 1991;
Williams et al. 1992), but other studies suggest that a fe-
male’s social preference is not a good indicator for her mat-
ing preference (Gubernick and Addington 1994; Derting
et al. 1999).
Female rodents use many different traits in mate choice,
including mating status (Pierce and Dewsbury 1991), infec-
tion status (Klein et al. 1999), dominance status (Shapiro
and Dewsbury 1986), body size (Solomon 1993a), spatial
ability (Spritzer et al. 2005), genetic compatibility (Lening-
ton et al. 1994; Penn and Potts 1999), relatedness (Barnard
and Fitzsimons 1988; Keane 1990b), and familiarity (Sha-
piro et al. 1986; Salo and Dewsbury 1995; Randall et al.
2002; Zhao et al. 2002; see Andersson 1994 for review).Effects of female choice on reproductive success
One way of determining if female mate preferences are
beneficial would be to test whether females are more likely
to produce litters when paired with preferred males and
whether these matings result in offspring of higher fitness.
Drickamer and colleagues (2000) allowed female house mice
to display social preferences for one of a pair of males that
were selected at random without regard to any particular
phenotypic trait. Half of the females were paired with their
preferred social partner and the other half with the non-
preferred male. A greater proportion of females that mated
with preferred males produced a litter (93% with preferred
mates versus 71% with nonpreferred males). In addition,
sons from preferred matings were dominant to sons from
nonpreferred matings, and adult offspring from preferred
matings built better nests, had larger home ranges, and
survived longer in the laboratory and in field enclosures
than offspring from nonpreferred matings (Drickamer et al.
2000). Although pregnancy rates of daughters from pre-
ferred and nonpreferred matings did not differ statistically,
86% of daughters from preferred matings experienced at
least one pregnancy in field enclosures as compared to only
56% of daughters from nonpreferred matings, suggesting
that there may be significant differences in lifetime repro-
ductive success. These findings suggest that mate choice for
particular males may result in multiple direct and indirect
benefits to females. In the following sections we review the
evidence for benefits from female mate choice in rodents.Mating status of male
When males mate multiple times in quick succession, the
later ejaculates tend to have reduced sperm counts and fer-
tility (Huck and Lisk 1985; Huck et al. 1986; Austin and
Dewsbury 1986). Therefore, the capacity to produce fertile
ejaculates and to impregnate females may be temporarily
limited (Dewsbury 1982b). Thus if females copulate with
previously mated males, they risk the chance that they may
not be impregnated or may have smaller litters.
Pierce and Dewsbury (1991) argued that monogamous
females should be more concerned than polygamous fe-
males about mating with an unmated male because theyReproductive Strategies in Female Rodents 43