Title:
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Scent marking with faeces and anal secretion in the European badger
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defend feeding territories, and that the spatinl distribution of 'patches'
of earthworms (their major prey) determines the size of badger territories.
Such a food-based model has been widely accepted, but has a number of
equivocal assumptions which are discussed. Recently Roper, Shepherdson &
Davies (1986) proposed an alternative model of territorial organisation,
based on the seasonal pattern of territory marking with faeces and anal
gland secretion, which suggested that territoriality in badgers may be more
related to defence of oestrus females by resident males than to defence of
food resources. This hypothesis relies on an un-quantified correlation
between seasonal patterns of territory marking, mating and road mortality.
Here, I attempt to test the strength of the association between these
distributions and to test predictions about the relative contribution of
the two sexes to territorial defence. To do this I present further data on
the deposition of faeces and anal secretion at latrines, together with new
data on the seasonality of road mortality and bite-wounding in badgers. In
addition, I report the results of experiments in which latrines were
continually monitored in an attempt to assess the relative contribution of
the two sexes to territory marking and patrolling. Finally, I report the
results of a chemical investigation (using gas chromatography) of the scent
profile of anal gland secretion.
My results confirm the bimodal seasonal pattern of deposition of
faeces and anal secretion at latrines, but whilst the two distributions
were similar, there were differences which suggested that the two
territorial markers may have different functions. The seasonal pattern of
deposition of anal secretion showed essentially the same distribution as
data on mating, testis weight, bite wounding and road mortality and I
concluded that my results were consistent with the anti-kleptogamy
hypothesis. However, the seasonal pattern of deposition of faeces at
latrines could more easily be explained by seasonal changes in food
availability. My results showed that the incidence of bite wounding and of
patrolling at latrines, was higher in males than females, which is
consistent with predictions derived from the anti-kleptogamy model, but not
with food-based models which predict territory defence to be shared equally
amongst group members. Finally, chemical analysis of anal secretion
revealed that whilst it probably did not signal the sex or identity of it's
producer it may carry information about group membership. In addition, the
secretion was found to be of low volatility and composed of long-chain
fatty acids some fifteen of which were identified. These results are
consistent with the idea that anal secretion acts as a long-term territory
marker.
In conclusion I suggest that my results for the deposition of anal
gland secretion at latrines are consistent with the hypothesis proposed by
Roper et al., (1986) that territoriality in badgers may at least be partly
linked to the defence of oestrus females by resident males. By contrast
seasonal variation in defecation at latrines may at least be partly
explained by seasonal changes in food availability. Given that food and
mates are the most important resources for the survival of an animal, in
the short-term and long-term respectively, it is likely that models of the
territorial spacing pattern of badgers would have to take both resources
into account.
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