Fieldwork Update from Austria: summer 2024

September 29, 2024

by J. Smout

Fieldwork update:

Summer 2024 saw the start of a new phase of research on our field site in the Gailtal region of Austria. The site hosts a hybrid zone of oviparous (egg laying) and viviparous (live bearing) lineages of common lizards, Zootoca vivipara. Past research by Elmer Lab members and alumni has focussed on understanding the genetic architecture of viviparity and oviparity as well as investigating differences in reproductive investment, and reproductive success of the different lineages and hybrids.

Our new project, funded by a NERC Pushing the Frontiers grant, centres on a controlled breeding experiment to take place in situ at the hybrid zone. By setting up experimental crosses between oviparous, viviparous, and hybrid lizards of both sexes and by keeping the offspring for the duration of the project, we can address gaps in our existing knowledge of the hybrid zone such as differences in the inclusive fitness of male vs. female lizards and how hybridisation effects offspring survival post-hatching/parturition. Common lizards breed in spring, immediately upon emergence from hibernation, so we spent summer 2024 setting up the breeding experiment for 2025: collecting reproductive-aged lizards, genotyping them, building enclosures, and selecting individuals for the crosses. We arrived at the beginning of June to clear skies and a very successful first week, with almost 100 lizards caught. Mountain weather is fickle, however, and we saw plenty of rain and snow before the season was out.

This was our longest - and maybe most challenging - season so far, with lots of new things to learn and do. It was our first season staying in accommodation directly at the hybrid zone, which cut down on daily travel time but also meant working with limited resources, from electricity to drinking water to mobile phone signal. It was also our first experiment involving housing lizards at the hybrid zone for longer than a few months, and we spent the final stretch of our time in the Alps building 18 separate enclosures for our lizards to overwinter, including plenty of substrate to hide out during freezing winter temps, and insulation to protect the enclosures from the worst of wind-chill. It was a lot of work, but next year we should start to get results from this first round of breeding experiments – watch this space!