Territoriality: Costs and conditions

1
Territoriality Costs and conditions

• The decision to take and/or keep a resource is a
  function of
• Cost is in resource defense
• Personal damage and energy loss
• Less time spent in predator vigilance
• Lost foraging time
• Benefits
• Consistently more and better food
• Less effort to maintain a territory then to
  acquire one.

• Yarrows Spiny Lizard
• Territoriality is seasonal
• Controlled by hormone levels

2

• Yarrows Spiny Lizard Elevated Testosterone
  increases
• General activity levels
• Defensive posturing

3

• Yarrows Spiny Lizard Elevated Testosterone in
  non territorial seasons decreased
• Feeding time/effectiveness
• Lifespan due to starvation
• Controls suffered too
• Feeding treated animals corrected for effects

4
Territoriality benefit More food
5

• Territoriality benefit
• More food
• Healthier males
• Able to leave wintering grounds sooner
• Establish ownership of resources at mating
  grounds sooner

6
Territoriality Costs vs benefit

• Conditional strategies
• Male golden winged sunbirds will defend flower
  patches but only if there is a net caloric gain
  in doing so.

7
Territoriality When to defend
Costs per/hour Foraging 1000 calories Resting
400 calories Defense 2000 calories
8
The adaptive value of allowing satellites in your
territory
Pied wagtails are conditionally territorial and
on occasion will defend rich territories in
owner-satellite teams.
9
King of the hill Why its easier to own than to
acquire
10

• King of the hill the Speckled wood butterfly
• Owner always wins territorial conflicts because
  owning the territory has imparted an advantage
  payoff asymetry

• The value of ownership in this case is that
  sunning spots increases muscle tempurature which
  enhances flight capability manuravibility.

11

• King of the hill The more time on top the
  stronger
• Tarantula hawk wasp owners win territorial
  conflicts but conflict duration increases as a
  function of time away