How do populations stay stable in a changing world? Check out my preprint with @popgenchen where we use the Florida Scrub-Jay life cycle to see how a population @ArchboldStation has remained stable despite increasing isolation!

Overall, we found that the population of Florida Scrub-Jays @ArchboldStation is robust to increased isolation, with changes in immigration balanced by other demographic rates. Our results emphasize the importance of density-dependence in allowing populations to respond to change.

Changes in the levels of inbreeding over time also did not significantly impact the population growth rate, signifying that the magnitude of this increase was not yet sufficient to destabilize the population.

We linked our environmental factors to the variation in population growth and found that any change due to time in immigration was actually compensated for (negative contributions). This compensation came from increased breeder survival over time.

We also found that more related pairs had lower fecundity (lower Offspring # and greater Failure to Breed). Could the increase in inbreeding be impacting population growth too?.

So we went further! We modeled the demographic rates using environmental factors and time to link these underlying factors to growth. Immigration did decline over time even when accounting for all these other factors!

The results: fecundity had the biggest effect on growth, though part of that impact was due to its covariation with survival. Immigration did not contribute very much, though we knew it was changing over time.

We used matrix population models to link the demographic rates (survival, fecundity, etc.) of the Florida Scrub-Jay to its growth rate to see which rates contributed most to the differences between the years with growth and those without.

Despite these challenges, the population has remained remarkably stable! The population growth rate (lambda) fluctuates between growth (>1) and decline (<1), but the long-term rate (green line) is at 1!

The Florida Scrub-Jay is Federally Threatened due to habitat loss and degradation. As a result, the population at Archbold has become more isolated from neighbors, reducing immigration and increasing inbreeding.

How does a population of threatened birds stay stable while becoming isolated?. To find out more, and see a synthesis of beautiful long-term demographic, environmental, and pedigree data, come to my talk @Evol_mtg on Sunday at 10:00AM (Ecology) #Evol2023

We also added an analysis comparing the habitats occupied by either species over time to a null expectation of no change; we found significantly less overlap (lower Warren's I) for great-tailed grackles over time!

See the pre-print thread here for details on our analyses and findings:

Newly published paper by myself and @LoganCorina, @DieterLukas, and @popgenchen on the range expansion of the great-tailed grackle, and range stability of the boat-tailed grackle! #TheGrackleProject.@PeerComJournal.

RT @popgenchen: Also don't miss @SpitzGladiana's talk on indirect genetic effects in Florida Scrub-Jays at 3:15 pm in Room 21 (Social Evolu….

RT @popgenchen: Hi #Evol2022 don't miss grad student @demo_jemo's talk on the role of climate change & niche shifts in range expansions tod….

Along with exciting analyses, I've seen so many good hair buns at #Evol2022 please, share your knowledge fellow scientists!.

A great first day at #Evol2022 tons of interesting talks, and interesting folks! #EvolDEI

RT @popgenchen: Today is a big day for the Chen lab at #Evol2022! Check out these presentations by @fayegromero, @shailee_shah93, myself, a….

This project is part of a larger preregistered study that has passed peer review @PCI_Ecology: