University:
Amherst College
Course:
BIOL 281 | Animal Behavior with Lab
Academic year:

2011
Views:

145

Pages:

24
Author:

ku1ni334

Territoriality Home range = the area occupied by an animal Territory = an exclusively occupied, defended area Core area = area of highest use (80%) within home range Home range and core area Richardson’s ground squirrel Home range and core area Richardson’s ground squirrel Core areas usually not used by others red = male grey = female Types of territories Feeding, nesting or mating gerenuk Types of territories Seasonal, year-round breeding territory maintains territory during nonbreeding season breeding territory not territorial during nonbreeding season Mobile and ephemeral territories Sunspot territories Sir Nick Davies Costs of being territorial • Increased energetic costs • Increased exposure to predators Sceloporus jarrovi % lizards alive % lizards active Costs of being territorial T implants controls Time of day controls T implants Days after implantation Territorial energetics 1 µL nectar/day* forage 8 hours 2 µL nectar/day* forage 4 hours 3 µL nectar/day* forage 2.7 hours golden-winged sunbird *average per flower Territorial energetics Excluding others raised nectar from 2 µL to 3 µL, reduced foraging time by 1.3 hours Energy saved in foraging time = 754 Energy spent defending territory = 2000 calories Territorial energetics When nectar was abundant, defense increased it from 4 to 6 µL = 30 fewer min foraging When nectar was scarce, defense increased it from 1 to 2 µL = 4 fewer hrs foraging! Conditional territoriality 0.70 unsuccessful 0.16 0.30 wrasse successful 0.84 Probability that successful nest was successful again Decision to defend territory depends on its recent history “Dear enemies” Jacky dragon Foot drumming or push-ups banner-tailed kangaroo rat Control Neighbor Stranger “Dear enemies” white-crowned sparrow Stranger Neighbor Neighbor on wrong side Neighbor “Dear enemies” hooded warbler Neighbor simulated intrusion by S or N At boundary NNNN NSSN Intruding “Dear enemies” NNNN NSSN Territorial males play “tit for tat” Application of “dear enemy” to conservation Stephens’ kangaroo rat endangered with restricted range Translocations • • • Number alive after 11 months = 0 Relocation of animals in effort to establish new population Largely ineffective due to lack of basic biology, experimental design 600 Stephens’ kangaroo rats translocated in 1992 Application of “dear enemy” to conservation Failing to establish a territory No territory (“floaters”), usually no reproduction hermit thrush Resident effect Territory holder has advantage Rule of thumb = “resident always wins” Uncorrelated asymmetry Correlated asymmetries Resident effect Other explanations: differences in potential payoff Duration of fight Probability of resident winning swordtail Time intruder has held territory Rich territory Poor territory

Bio 281 2011 Lecture 9 - Territoriality - Lecture Notes

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