Territoriality I



  • It is unlikely that there will be any populations where all individuals are of equal competitve ability
  • What resources might animals fight over?
    • Food
    • Mate
    • Shelter
    • Breeding/rearing young
    • Territory to attract mate

Territory vs Home Range

  • What is a home range and how does it differ from a territory?
  • Home range: Area in which an organism lives
  • Territory: Defended area,  home range

Mouthbrooding cichlid (Tilapia mossambica)

  • No spaces between territories
  • Retain maximum possible space within them

Are territories beneficial?

  • Smith (1978) Rufous - collared Sparrow
  • Territorial Males plus 'floaters'
  • Mapped territories
  • Colour-ringed population
  • Found that when territorial males died, the younger non-territorial males moved in straight away
  • Reproductive advantage to territoriality

Territory Defence

  • How are territories typically defended?
    • Overy Aggression
      • Fighting
      • Threat Displays
    • Keep out signals
      • Scent marking
      • Singing

Is there a cost to territory defence?

  • Territorial behaviour requires the expenditure of time & energy
  • Yarrow's Spiny Lizard (Marler & Moore, 1989; 1991)

Yarrow's Spiny Lizard

  • Testosterone inserted beneath skin, plus control group
    • Measured behaviour over time
  • Gave food supplement to some testosterone lizards
    • Measured survival over time

When should a territory be defended?

  • So, if territory defence is costly, when should it be defended?
  • When it is economically viable to do so
    • When the benefits


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