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ManyIndividuals – bird field sites in North America and New Zealand


  • Principal investigator: Corina Logan
  • Field sites founded:
    • Santa Barbara, CA great-tailed grackle: December 2013
    • Tempe, AZ great-tailed grackle: December 2017
    • Sacramento, CA great-tailed grackle: December 2020
    • Venus, FL boat-tailed grackle: September 2022
  • Field sites joined via collaboration:
    • Wellington, New Zealand toutouwai collaboration began 2021 (Rachael Shaw)
    • Venus, FL Florida scrub-jay collaboration began: September 2022 (Archbold Biological Station)
    • Auburn, AL blue jay collaboration began: January 2023 (Kelsey McCune)

Site Details

In 2013, I set up a great-tailed grackle field site in Santa Barbara, California as part of my SAGE Junior Research Fellowship at the University of California Santa Barbara. Grackles began colonizing the Santa Barbara area in the 1990s, so it is a relatively recent population. This species is sexually dimorphic in plumage and behavior, and their mating system is polygamous: one to a few males defend a territory, and females build nests on these territories and raise the young. Grackles are generalist foragers and highly associated with human populations: they eat our garbage, crops, and at our outdoor cafes.

With support from the Department of Human Behavior, Ecology and Culture at MPI EVA, I established a second field site in 2017 in Tempe, Arizona to begin population comparisons. Grackles have been in the Tempe area since the 1980s, so this is a slightly older population than the one in Santa Barbara. I established a third field site in 2020 in Woodland and Sacramento, California where grackles have only been present since the 2000s. This site represents the northern edge of their geographic range because it is as far north as I can get while still having a large enough and stable enough population to study. Differences in population ages allow me to investigate what differences are associated with edge populations that might give them an advantage for adapting to new environments.


What is behavioral flexibility and is it a mechanism for surviving in new environments?

Behavioral flexibility, the ability to adapt behavior to new circumstances, is thought to play an important role in a species' ability to successfully adapt to new environments and expand its geographic range. However, flexibility is rarely directly tested in species in a way that would allow us to determine how flexibility works and predict a species' ability to adapt their behavior to new environments. I use great-tailed grackles (an urban bird) as a model to investigate this question because they have rapidly expanded their range into North America over the past 140 years. In Santa Barbara, I found that they are behaviorally flexible and that flexibility is independent from problem solving ability, problem solving speed (Logan 2016a), other behaviors (Logan 2016b), and innovativeness (Logan 2016c), and that grackles can solve some problems with a similar efficiency to New Caledonian crows (Logan et al. 2014).

I am currently investigating how great-tailed grackles are able to rapidly expand their geographic range by testing their behavior, immunity, hormones, parasites, and population genetics in two populations: an older and a newer population. So far, we found that we can manipulate flexibility through serial reversal learning and that this manipulation makes individuals more flexible and more innovative in a new context (a puzzlebox). We also found that reversal learning (a measure of flexibility) positively correlates with performance on the go/no go task (a measure of inhibition), and has no relationship with detour performance (a measure of inhibition) or causal cognition (there was no evidence of causal cognition, though this could be due to our experimental design). Contrary to most bird species studied so far, great-tailed grackles show male-biased dispersal. We discovered the second case of male parental care in great-tailed grackles and are seeing this behavior in multiple locations. The one male-juvenile pair we were able to catch showed that they are not genetically related, indicating that the caring male was not contributing to his direct fitness and instead might perform this behavior as a result of uncertain paternity or as a signal to future mates. 

Does increasing behavioral flexibility increase success in human modified environments? (ManyIndividuals)

I co-founded a global network of researchers with field sites to investigate hypotheses that involve generalizing across many individuals. We conduct the same tests in the same way across species to determine whether the results of particular experiments are generalizable beyond that species. We are manipulating behavioral flexibility in species that are successful in human modified environments (great-tailed grackles and blue jays) and in endangered species (Florida scrub-jays and toutouwai) to determine whether an increase in flexibility improves their success in human modified environments. Follow the link to learn about our open, verifiable, and replicable workflow that makes our research better and faster.

Selected Publications

Summers J, Lukas D, Logan CJ, Chen N (2023). The role of climate change and niche shifts in divergent range dynamics of a sister-species pair. doi: 10.32942/osf.io/879pe

Pacheco MA, Ferreira FC, Logan CJ, McCune KB, MacPherson MP, Albino Miranda S, Santiago-Alarcon D, Escalante AA (2022). Great-tailed grackles (Quiscalus mexicanus) as a tolerant host of avian malaria parasites. doi: 10.1371/journal.pone.0268161

Sevchik A, Logan CJ, McCune KB, Blackwell A, Rowney C, Lukas D (2021). Investigating sex differences in genetic relatedness in great-tailed grackles in Tempe, Arizona to infer potential sex biases in dispersal. doi: 10.26451/abc.

Blaisdell AP, Seitz B, Rowney C, Folsom M, MacPherson M, Deffner D, Logan CJ (2021). Do the more flexible individuals rely more on causal cognition? Observation versus intervention in causal inference in great-tailed grackles. doi: 10.24072/pcjournal.44

Logan CJ, McCune KB, MacPherson M, Johnson-Ulrich Z, Rowney C, Seitz B, Blaisdell AP, Deffner D, Wascher CAF (2021). Are the more flexible individuals also better at inhibition? doi: 10.26451/abc.

Seitz BM, McCune KB, MacPherson M, Bergeron LM, Blaisdell AP, Logan CJ (2021). Using touchscreen equipped operant chambers to study comparative cognition. Benefits, limitations, and advice. doi: 10.1371/journal.pone.0246446

Logan CJ. 2016. Behavioral flexibility and problem solving in an invasive bird. doi:10.7717/peerj.1975

Logan CJ. 2016. Behavioral flexibility in an invasive bird is independent of other behaviors. doi: 10/c598

Logan CJ. 2016. How far will a behaviourally flexible invasive bird go to innovate? doi: 10/c599