Resource variability and multiple life history strategies

1
Resource variability and multiple life history
strategies

• Adi Boon

2
Why do some individuals outperform others in all
aspects of their life history?

• Genetic variation in ability to acquire resources
  may mask costs of reproduction

3
Genotype X Environment interactions

• When resource availability varies, there can be
  multiple life history strategies maintained in a
  population
• Fast strategy could be costly, especially when
  resources are scarce
• e.g. through higher metabolic rates that result
  in high minimum resource requirements

4
Individuals with a fast life history strategy
should have

• Greater investment in reproduction
• Higher activity levels
• Higher DEE (FMR), BMR and Summit MR

than individuals with a slow strategy, and
therefore
greater reproductive success only when resource
availability is high
5
Does this happen in squirrels?

• Are metabolic rates and life history strategies
  heritable?

• Is there an interaction between resource
  availability, metabolic rates and reproductive
  success?

6
Proposed methods

• Dataset
• Reproductive investment/ success data
• Heritability of life history traits?
• Heritability of metabolic rates?

7
Proposed methods

• Field
• 20 food add 20 control females (fewer?)
• FMR in winter, late lactation, cone caching
• Activity indexes from focals
• Basal and summit MR after weaning
• Reproductive success
• Caching effort focals? Territorial cone counts?
  Cached cone counts?

8
Will this work?