Lecture 6 Flashcards
Blue and coal tits
- Blue tits (Parus caeruleus) favour oak foliage: places insects can be found, places bird can explore
- Coal tits (Parus ater) favour pine tree foliage:
- behavioural differences due to different habitats
- blue tit better at task would find in oak forest
Cultural transmission
=blue tits learning to get cream out of milk bottle through pecking lid off
Poplar Leaf Aphid
- forms galls in which to produce young
- biggest and strongest going to get best spots to lay eggs
-late coming animals must form galls further out on the central rib and so get less sap than first animals gall nearer to the base
Wagtails
- use tails to stir up insects
- food availability makes a difference to how they behave
- tolerant to other animals when there is plenty of food, other animals mean more protection against predators
- however when food tight all satellites get chased away
Food as a reason for territory holding
- bird that doesnt have to chase away is saving energy
- when more food, saving energy as don’t need as much energy
- relationship between food source, chasing away and energy expenditure
Territoriality: great tits
- territory shape changes when remove territory holders
- intruder pressure on size of territory: territory = as big as can be given other animals that are about
Territory size: honeyeaters
Territorial size changes in accordance with food availability or intruder pressure
• As flowers decrease with seasons
• July=lots of flowers=small area
• By sept less animals as driven out due to food shortage
• Need larger territories as need more food
Territoriality: Hummingbirds
- When flower numbers in territory artificially increased (day 3 onwards), foraging time goes down, resting time goes up and weight is rapidly gained
- Territory holding has calorific benefits and costs of defending sites
- When food, don’t need to defend, can keep energy and put on weight
Northern Harriers
- Larger territories have fewer mice but intruder pressure still possible explanation
- Mice mark territory with urine glows in ultraviolet rays for the birds so they see where the mice are
Prior residence effect
who was there first
- White owner, whtie always wins
- Remove white, black becomes owner
- Re release white, black always wins
- If you’re the territory holder defending ability to reproduce and survival
- Intruder have something to gain but not much to lose
- Prior resident will always win
Dispersal: vervet monkeys
• Troop members more likely to disappear in months when they moved into new areas to them
- Important if you know the territory that you are in
- Moving around means going into places they don’t really know=threats
• These monkey move because of food availability ect, when not moving not so many disappearing, moving around more disappearing (attacked by predator)
Dispersal: Belding’s ground squirrels
- Females stay, males go, perhaps to avoid inbreeding.
- Females don’t move far away from where they are born
- Males moving quite a distance
- Theory something to do with inbreeding avoidance
- Other males can come in
Dispersal: serengeti lions
- Infanticide often occurs when new male(s) take over a pride. This brings females back into season again increasing those males’ chances of reproduction
- Females stay, males go, perhaps to avoid mate competition
