New birds on the block: new neighbors increase defensive costs for territorial male willow ptarmigan

Abstract

Previous researchers have hypothesized that site-faithful animals may benefit from the presence of familiar neighbors. This study compares the relative costs of territorial defense against new and former neighbors by male willow ptarmigan (Lagopus lagopus). Territorial defense against new neighbors appeared to require a greater expenditure of both time and effort than did defense against former neighbors. Territorial males that had several new neighbors spent a higher proportion of time fighting than did males with fewer new neighbors, and males with both new and former neighbors spent a greater amount of time fighting with their new neighbors, on average, than with their former neighbors. In addition, fights with new neighbors occurred relatively more frequently and were longer than fights with former neighbors. Finally, fights involving new neighbors tended to escalate to higher levels than fights between former neighbors. Reduced defensive costs for site-faithful, territorial males may provide one explanation for the tendency of males to be more site-faithful than females in many species.

Breeding density, not life history, predicts interpopulation differences in territorial aggression in a passerine bird

“…For example, the 'dear enemy' hypothesis predicts that individuals should be less aggressive towards familiar individuals of a known threat to avoid the costs associated with repetitive territorial contests (Fisher 1954;Trivers 1971;Ydenberg et al 1988). Support for the dear enemy hypothesis has been found in studies of many taxa, including insects (Heinze et al 1996), fish (Frostman & Sherman 2004), amphibians (Jaeger 1981), reptiles (Whiting 1999), birds (Eason & Hannon 1994) and mammals (Price et al 1990). Reduced aggression towards familiar individuals can optimize time and energy expenditure for territory defence and maximize shared mutual benefits among neighbours (Wilson 1975).…”

Red squirrels mitigate costs of territory defence through social plasticity

“…However, most evidence 94 in support of this cooperative phenomenon comes from experimental studies where individuals 95 are exposed to a familiar and unfamiliar stimulus and a behavioural response is recorded 96 (Temeles, 1994). We know less about how behavioural time budgets are affected by long-term 97 social relationships under natural conditions when individuals may have to navigate territorial 98 dynamics with multiple neighbours (but see Bebbington et al, 2017;Eason & Hannon, 1994). 99…”

Prior residency advantage for Atlantic salmon in the wild: effects of habitat quality

“…Finally, the hypothesis of value asymmetry (VA) predicts that the territory has a higher value for the owners and therefore makes them more motivated to defend it (Maynard Smith and Parker 1976). The higher ownership value might be due to invested energy in negotiation of territory boundaries (Eason and Hannon 1994) or the achievement of local experience of hiding places or food resources (Davies and Houston 1981). The VA hypothesis has received support by removal-replacement experiments, mainly in birds (e.g.…”