Selective harvest focused on sexual signal traits can lead to extinction under directional environmental change

Authored by Carlos Martinez-Ruiz, Robert J Knell

Date Published: 2017

DOI: 10.1098/rspb.2017.1788

Sponsors: United Kingdom Engineering and Physical Sciences Research Council (EPSRC)

Platforms: R

Model Documentation: Other Narrative Mathematical description

Model Code URLs: https://figshare.com/articles/Supplementary_information_for_Knell_and_Mart_nez_2017_from_Selective_harvest_focused_on_sexual_signal_traits_can_lead_to_extinction_under_directional_environmental_change/5607388

Abstract

Humans commonly harvest animals based on their expression of secondary sexual traits such as horns or antlers. This selective harvest is thought to have little effect on harvested populations because offtake rates are low and usually only the males are targeted. These arguments do not, however, take the relationship between secondary sexual trait expression and animal condition into account: there is increasing evidence that in many cases the degree of expression of such traits is correlated with an animal's overall well-being, which is partly determined by their genetic match to the environment. Using an individual-based model, we find that when there is directional environmental change, selective harvest of males with the largest secondary sexual traits can lead to extinction in otherwise resilient populations. When harvest is not selective, the males best suited to a new environment gain the majority of matings and beneficial alleles spread rapidly. When these best-adapted males are removed, however, their beneficial alleles are lost, leading to extinction. Given the current changes happening globally, these results suggest that trophy hunting and other cases of selective harvest (such as certain types of insect collection) should be managed with extreme care whenever populations are faced with changing conditions.

Tags

Adaptation Climate change Evolution Dynamics sexual selection Conservation Populations Plasticity Predators Directional selection Red deer Lek paradox Trophy hunting Insect collecting Antler size