Read on Twitter
When I started my PhD, this paper was what I wanted to do. But I realized that there isn't much demographic data for salamanders out there to build a realistic model. So I built the rest of my dissertation around getting those data. A thread: https://twitter.com/PlethodoNick/status/1295712808806633473
In its simplest form, what defines population dynamics are survival, growth, and reproduction so that's what i focused on measuring 2/n
For survival and growth, I turned to mark recapture. Terrestrial salamanders spend a lot of time underground and there's a lot of them in forest (~1/m^2) So getting enough recaptures can be time consuming. 3/n
Another issue is that individuals can move out of the study area so they are alive but unavailable for , so traditional mark recapture can bias survival lower (called apparent survival). So we accounted for where individuals were each time they were captured 4/n
the paper from this work can be found here: https://esj-journals.onlinelibrary.wiley.com/doi/10.1002/1438-390X.1005 5/n
even with the mark-recapture data, i was still missing some information, especially about reproduction, so I used museum specimens collected over the last 50 years 6/n
So i was able to dissect over 1000 individuals to assess reproductive condition and was even able to age individuals via skeletochronology 7/n
during winter, salamanders don't do much, just hang out underground and reduce their activity. This inactivity shows up in their long bones (like digits and femurs) so you can count them as annual events 8/n
and salamanders can live a long time, many over 10 years and some individuals can take up to 9 years to become mature! So much variation in their life history, it would be interesting to know how that variation contributes to population growth ;) 9/n
This paper can be found here: https://bioone.org/journals/Copeia/volume-107/issue-4/CH-18-145/Museum-Specimens-Reveal-Life-History-Characteristics-in-Plethodon-montanus/10.1643/CH-18-145.short
but gotta take a step back because if we wanted to know how climate can affect population growth, we would need to know if climate affects their demographic rates 10/n
So we designed a reciprocal transplant experiment, where individuals were moved from low/mid/high elevations so that they were represented in each elev (e.g, low individuals in low, mid, and high elev) 11/n
and found that where individuals are raised is a better predictor of demographic rates than where they were. Support that climate influences demography! Paper here: http://www.herpconbio.org/Volume_14/Issue_2/Caruso_etal_2019.pdf
and so that brings me to the end apper, where this thread started. Putting all this info together and understanding how population growth responds to climate 13/n
we found that late fall, winter, and early spring conditions can have a larger effect on population growth (through affecting survival) and survival of large females was the most important to population growth, paper here: https://rdcu.be/b6kyo (end)
