Lecture 6- Cooperative hunting and RDH Flashcards
What is ‘net benefit’?
Function of: energy expended on stalk, chase, catch and kill versus energy gained from food caught
What are net benefits positively associated with?
African hunting dogs
What are the high energetic cost problems with cooperative hunting in African hunting dogs?
Large litters, pups born at early development - making them vulnerable, housed at den, require babysitters
Why do African hunting dogs have to bolt food?
Vulnerable to lions and hyenas, feed other members by regurgitation
Why is stomach size a problem for African hunting dogs?
Hunting dogs carry food to pups in stomach- small stomach size means cannot carry much, small pack sizes kill relatively large prey but cannot consume all so reduces net energy gain
Why are African hunting dogs termed ‘obligatory social’?
Groups are so important
What is the Resource Dispersion Hypothesis?
Explains how groups could arise because of ‘rules’ used to configure territories in relation to spatial and temporal distribution of resources.
What are the 5 key assumptions of RDH?
1) Resources distributed in patches in the environment
2) Each patch varies in term of both:
a) Frequency with which it is available
b) Amount of food it supplies when it is available
3) Food security
4) Critical period
5) Economically defensible
What is the critical period?
The period when food is limiting
What is the word explanation of RDH?
Basic social unit is predicted to defend MINIMUM ECONOMICALLY DEFENSIBLE AREA that provides their BASIC RESOURCE REQUIREMENTS during a CRITICAL LIMITING PERIOD to a given level of SECURITY
Low temporal heterogeneity means..
If resource availability DOES NOT vary greatly with time, then territory holders should be able to defend a territory that consistently CLOSELY matches their basic requirement
High temporal heterogeneity means..
If resource availability DOES vary greatly over time, then territory holders would need to defend territory, where resource availability is more variable from night to night
3 predictions of RDH?
1) territory size and group size are not NECESSERILY related
2) group size related to resource richness- mean availability outside critical period
3) territory size related to resource disperson
Changes outside critical period only affect…
Group size
Changes during critical period…
Potentially effect territory size
