UBC Research Data

Data from: Weak habitat isolation in a threespine stickleback (Gasterosteus spp.) species pair Southcott, Laura; Nagel, Laura; Hatfield, Todd; Schluter, Dolph


Reproductive isolation is central to the study of speciation. Multiple isolating barriers may prevent species from hybridizing, although their individual strength and the interactions between them are rarely measured. We quantified habitat isolation in a recently diverged threespine stickleback species pair (Gasterosteus aculeatus complex) and controlled for any such interactions. Using enclosures in an outdoor pond, we confirm that males of the two species strongly prefer different nesting habitats: limnetic males build nests in open habitats, whereas benthic males nest under vegetation. However, forcing males to nest in their nonpreferred habitat did not reduce the probability of spawning by females. As a result, habitat isolation between the species is estimated to be weak. We compared the strength of habitat isolation estimated in the present study with estimates of other behavioural barriers using previously published data. We discovered that, although total mating isolation between the species is strong, the contributions of differences in body size and male nuptial colour are similarly individually weak. Instead, interactions with other, undetermined species-specific traits were responsible for most of the isolation resulting from differences in body size and, in benthics, colour. This is one of the first attempts to estimate individual isolating barriers at the same time as controlling for interactions.; Usage notes
Habitat-, body size-, and nuptial colour-based isolation in benthic and limnetic sticklebackThree .csv files with associated .txt readme files and an R script file for replication of statistical analyses. The .csv files contain data from (1) a test of nesting habitat preference in male benthic and limnetic threespine stickleback, (2) a test of mate choice by female benthic and limnetic stickleback based on male nest habitat, and (3) mate choice trials between benthics and limnetics measuring the effects of size difference and male nuptial colour on hybridization rate.southcott et al. stickleback habitat isolation data.zip

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