Spotted
Hyena
Crocuta Crocuta
Mating System
Both
Frank and Holekamp refer to the
spotted hyena's mating system as polygnous, but I think it is more appropriate
to refer to their mating system as Hierarchical Promiscuity. In this mating
system, as defined in our Animal Behavior class, females are found in very large
groups that cannot be controlled by one male. Multiple males associate with
female group and compete for privilege of mating. Polygyny is characterized
by one male plus several females which is not the case in spotted hyenas. The
fact that this species is dominated by the females in every regard sets it apart
from most mammals and makes it harder to fit them into a specific mating system.
Mating
is non-seasonal and can occur at any time of the year (Postanowicz
2003). The annual pattern of births do however show a distinct trough from February
to May (Holekamp et al. 1999). Holekamp, Szykman, Boydston, and Smale's hypothesis
is that seasonal reproduction is affected by the seasonal changes in the availability
of energy or nutrients. Mating consists of a number of relatively short copulations
with the male only showing penile erection only immediately before copulation
and no apparent clitoris erection in the female. Because the females are dominant,
males show signs of fear when trying to mount the females (Applegate 1999).
Frank found that one of the difficulties for
the males is that the female's receptivity is extremely subtle and it only when
she's ready to mate that she will copulate with a male. Until then, she either
ignores the male or threatens them when they come to close. Consequently, the
males' strategy is to regularly approach the female and cautiously sniff their
face, flanks, and hindquarters to determine if they are in oestrus. They will
also sniff the ground where she had been lying. If a female is in oestrus, the
male responds either by following her while she travels awaiting her receptivity
or he will actively court her, called "consortship." Active courtship
consists of the male approaching the female with their head low and bobbing
up and down. His penis is erect and jerking up and down to show high sexual
motivation. If the female is resistant to his advances, "female baiting"
often occurs where he may make a forceful advance to mate with her and when
she whirls to defend herself, he lunges to bite her. Several males may consort
a single female, and this is where the dominant male succeeds in copulation
with her. However, subordinant males have been known to follow the same female
around up to 40 days after she has already mated with the alpha male. The female
doesn't seem to exercise mate choice. She just mates with whoever is with her
when she becomes receptive, leaving the males to sort out the mating rights
(1986). Szykman et al. confirmed this to be a possibility in a study they did
where they researched if males did in fact reflect mate choice. They found that
males can assess the relative reproductive value of individual females and consequently
allocate their own reproductive effort based on this assessment. High and middle
ranking males tended to pursue higher ranking females and lower ranking males
pursued females of any rank especially the higher ranking ones. And in general,
males are most likely to pursue females that are the most likely to be fertile.
This
web site was created by Keeley Roles for an undergraduate class, Animal
Behavior, at Davidson College Spring Semester 2004. Email keroles@davidson.edu
with questions regarding this web page.
Home
• Physical Characteristics •
Female Dominance • Food,
Predation, and Hunting • Social Spacing
• Social Organization •
Mating System • Offspring
• References
