than all other age classes. The patterns of tooth rake presence and prevalence likely result from sexual coercion of adult females by adult males and intra-sexual male competition. Keywords : intra-specificaggression, female tolerance, sexual coercion, tooth rakes, bot- tlenose dolphins, Tursiops sp
), keep the litter together as an integrated unit. This unit, the pack, in the light of the present study most probably consists of several individuals that differ markedly in behavior or temperament, in social dependency, in intra-specificaggression and in proximity tolerance or spacing patterns. Timid
per unit effort and hence the concentration of the fish remain high, as befits an animal feeding on such a concentrated food supply as the herring and not dispersed by intra-specificaggression. In August or September the cod shoals begin to disperse, ag- gression is intense in the captive cod and the
associated with defense of prey from a conspecific. Certain action patterns may be omitted or reduced in intensity. The vertical head flick of the grey fox with prey is absent during intra-specificaggression, when the lateral head shake (following seizure of opponent's cheek) occurs. Prey catching behavior
. HUNTINGFORD (1976) has reviewed the literature concerning the relationship between inter- and intra-specificaggression and concludes that they are neither invariably linked nor inevitably distinct motivationally. The same in- distinct situation arises if only the causation of intra-specificaggression is
behaviour in the three-spined stickleback, Gasterosteus aculeatus. - Anim. Behav. 32, p. 264-275. HAY, P. A. (1986). Essential behaviour genetics. - Blackwells Scientific Publ., Oxford. HUNTINGFORD, F. A. (1982). Do inter- and intra-specificaggression vary in relation to predation pressure in sticklebacks
- TirrGFORD (1982) argues that a motivational link between anti-predator behaviour and intra-specificaggression provides an economical method of achieving an appropriate behavioural balance. She also suggests (pers. comm.) that manipulations designed to generate short-term variation in schooling tendency
for by variations in the breeding season fecundity of the females caused by yearly variations in the food supply. When groups of females are kept in an enclosed space during the breeding season, they will show intra-specificaggression, and some of the females fail to become sexually mature or do not
day and under similar ambient temperature conditions with no rain and low wind speed for all populations.
Considering lack of evidence that intra-specificaggression in P. muralis can lead to autotomy events (Diego-Rasilla, 2003 ) we used tail break frequencies as rough estimate of inefficient
. - Physiol. Behav. 13, p. 171-173.
199 HUNTINGFORD, F. A. (1976). The relationship between inter- and intra-specificaggression. - Anim. Behav. 24, p. 485-497. JOHNSON, R. N., DE SISTO, M. J. & KOENIG, A. B. (1970). Social experience and interspecies in rats. - Proc. Ann. Conv. Amer. Psychol. Assoc. 5, p