T of L: Friends and Rivals

Question 1

For whooper swans:
1. Where do they migrate from / to?
2. What is the colonial composition?
3. Who does the fighting and why?
4. What happens when they win a fight?
5. What is the structure after establishment of boundaries?

Answer 1

1. From Iceland to Scotland
2. Composed of unrelated family groups and bachelors.
3. Males do most of the fighting to establish territorial boundaries around their family (territories are clumped and scattered so their shared, but boundaries are established).
4. After winning, the family does an obnoxious “triumph ceremony”.
5. The structure is in accordance with “dear enemies” hypothesis.

Question 2

For lions:
1. What is one of the main benefits to cooperative living?
2. After killing prey, do they fight?
3. How are young cared for?

Answer 2

1. Benefit includes ability to take down very large prey.
2. After killing prey, they won’t fight if it’s big, they’ll just wait their turn. If times are lean, they feed in “pecking order”.
3. Young are nurtured by mother and sisters (sisters act as wet nurses).

Question 3

For Baboons:
1. How many can potentially live in a group?
2. What is the social structure?
3. How do bachelors gain acceptance?
4. Why do males watch babies, even when they are not his own?
5. Does size matter?
6. How do males show subordination?

Answer 3

1. up to 150 members!
2. Mostly mothers and their young.
3. Bachelors will groom and babysit to win favor with the group and females.
4. Males will be ignored by rivals and adored by females.
5. No, alliances outrank size.
6. Males lip-smack to show subordination.

Question 4

For naked mole rats:
1. Who are the members of the caste?
2. How does the queen retain her throne?
3. How does a new queen emerge?

Answer 4

1. Workers / tunnelers, soldiers who strictly defend, and the queen who mates with the senior soldier (when he dies, the next in line takes his place).
2. The queen uses a communal bathroom and secretes a substance in her urine that suppresses ovarian development. The others cover themselves in her urine to maintain their social bond in the colony.
3. When the old queen dies and a new one develops ovaries and mate.