Studies

Question 1

Bruce Effect in Wild Geladas

Answer 1

• • by Roberts 2012
• studies ethiopian geladas to test for bruce effects using hormonal fecal samples to identify pregnant/abortions
• results: yes geladas terminate pregnancies after male turnovers (43.8% of infants los tto infancide after male replacement)
• inspired by hilda margaret bruce

Question 2

leading hypothesis for bruce effect

Answer 2

1. less costly for female to end pregnancy
2. stress of new male might insight it aggression/infanticide
3. prevent infanticide
4. get rid of ‘weak’ infants
5. maxinimizes female reproductive success/minimizes energy output

Question 3

wild chacma baboons

Answer 3

huchard 2010
studied friendships/associations/coparenting in chacma baboons in nambia
concludes that males formed friendships to:
1. males have genetic ties to friends infants
2. males usually mate with friends
3. relations as a way to attract other females/reduce own paternity uncertaintiy

Question 4

case study for monogamy?

Answer 4

reichard-sommer 1999; white handed gibbons in Thailand

Question 5

baboon sexual swellings

Answer 5

higham 2009; evaluated pagels reliable indicator hypothesis or nunns graded signal hypothesis in olive baboons