1992), suggesting that philopatry and associated patterns
of kin structure arise due to factors that are extrinsic to
social groups. Breeding structure, in turn, reflects individ-
uals’ efforts to maximize fitness within the framework im-
posed by kin structure and limited opportunities for dis-
persal. For example, the inbreeding avoidance hypothesis
(Wolff 1994a; Pusey and Wolf 1996) argues that animals
that remain in their natal group may refrain from repro-
ducing to avoid incest and the associated cost of inbreed-
ing depression. Accordingly, in species characterized by
female-only natal philopatry (i.e., low probability of father-
daughter or brother-sister matings), most females in a
group reproduce, while in species characterized by philo-
patry by both sexes, typically only one female per group
reproduces. Thus breeding structure appears to vary in re-
sponse to the adaptive consequences of reproducing with
the suite of potential partners (e.g., kin versus nonkin) gen-
erated by patterns of natal philopatry.
Reproductive skew theory (Keller and Reeve 1994; Reeve
1998; Reeve et al. 1998) also suggests that the breeding
structure of social groups will be related to opportunities
for individuals to disperse and to breed outside of their na-
tal group. Concessions models of reproductive skew pre-
dict that, as the difficulty of leaving the natal area increases,
dominant breeding animals will be required to concede
fewer direct fitness benefits to retain subordinates in their
natal group (Reeve and Keller 1995). Thus the degree of
skew and the prevalence of singular breeding should be
positively related to the difficulty of natal dispersal. Tug-of-
war models of reproductive skew (Clutton-Brock 1998a,
1998b) are less explicit concerning expected relationships
between dispersal and biases in direct fitness. If, however,
increased philopatry leads to greater competitive asymme-
tries among group members (e.g., the formation of a larger
number of competitively asymmetric parent-offspring pairs),
then tug-of-war models should also predict that singular
breeding will be more prevalent in species in which philo-
patry is common (Reeve et al. 1998).
These hypotheses assume that philopatry by both sexes
indicates that natal dispersal is more constrained than it is
when only one sex remains in the natal area. As the proba-
bility of successfully leaving the natal area decreases, spe-
cies may shift from female-only to male-and-female philo-
patry. Intraspecific variation in social structure provides a246 Chapter Twenty-One
Table 21.1 List of social rodent species for which data on breeding structure and pattern of philopatry are available
Breeding Philopatric
Family Species structure sex Reference
Muridae:
Arvicolinae Prairie vole (Microtus ochrogaster)a S M, F Getz et al. 1993; McGuire et al. 1993
Pine vole (Microtus pinetorum) S M, F Fitzgerald and Madison 1983; Solomon et al. 1998
Montane vole (Microtus montanus) S F Jannett 1978
Townsend’s vole (Microtus townsendii) P F Lambin and Krebs 1991
Grey-sided vole (Clethrionomys rufocanus) P F (?) Saitoh 1989
Gerbillinae Mongolian gerbil (Meriones unguiculatus)a S M, F Agren et al. 1989b
Great gerbil (Rhombomys opimus)a P F Rogovin et al. 2003
Murinae Fat dormouse (Myoxus glis)a P F Pilastro et al. 1996
Sigmdontinae White-footed mouse (Peromyscus leucopus)a P F Wolff 1994b
Deer mouse (Peromyscus maniculatus) P F Wolff 1994b
California mouse (Peromyscus californicus) S M Ribble 1992; Solomon and Getz 1997
Castoridae Beaver (Castor canadensis)a S M, F Brady and Svendson 1981; Patenaude 1983
Bathyergidae Naked mole-rat (Heterocephalus glaber)a S M, F Sherman et al. 1991; Bennett and Faulkes 2000
Damaraland mole-rat (Cryptomys damarensis)a S M, F Jarvis and Bennett 1993; Bennett and Faulkes 2000
Common mole-rat (Cryptomys hottentotus) S M, F Burda 1990; Jarvis and Bennett 1990
Giant mole-rat (Cryptomys mechowi) S M, F Burda and Kawalika 1993
Masona mole-rat (Cryptomys darlingi) S M, F Gabathuler et al. 1996
Ctenomyidae Colonial tuco-tuco (Ctenomys sociabilis)a P F Lacey et al. 1997; Lacey and Wieczorek 2004
Sciuridae Black-tailed prairie dog (Cynomys ludovicianus)a P F Hoogland 1995
Yellow-bellied marmot (Marmota flaviventris)a P F Armitage 1991
Hoary marmot (Marmota caligata) S M, F Armitage 2000
Olympic marmot (Marmota olympus) S M, F Armitage 2000
Alpine marmot (Marmota marmota) S M, F Arnold 1990; Armitage 2000
Long-tailed marmot (Marmota caudata) S M, F Armitage 2000
NOTES: Taxonomy follows Wilson and Reeder 1993. For murid rodents, subfamilies are indicated. Ssingular breeding (typically one breeding male and one breeding female
per group). Pa plural breeding (multiple breeding females and /or males per group).
Taxa selected for analyses employing only one species per genus. Typically, the best-studied species in each genus was selected for inclusion in these analyses.