For over 20 years, Vladimir Pravosudov and his students have made the trek from the University of Nevada – Reno to Sagehen every week (usually, every day) to study the humble Mountain Chickadee. The Pravosudov lab focuses on Animal Behavior and Behavioral Ecology with special emphasis on animal cognition. As non-migratory birds that have to store enough food to survive the winter (and remember where they left it), chickadees are a great model organism for this work.
The team has established…
“an RFID-based method to measure spatial learning directly in the field in large number of individuals and we investigate whether individual variation in spatial learning has fitness consequences to survival and reproduction. We annually band hundreds of chickadees with unique PIT-tags and monitor 200+ nestboxes.“
Recent research and publications explore questions like elevational differences in cognition and memory, memory and problem-solving trade-off, elevation effects on social dominance, and dialects of chickadees from different elevations.
These little birds don't migrate, so they have to cache enough food
to get through the winter.
Each chickadee can remember up to 500,000 individual
seed locations with high spatial precision.
Based at University of Nevada - Reno, Vlad studies chickadee cognition at
Sagehen Creek Field Station. His team bands all the chickadees in the
wild research population, a massive task.
In order to band all the birds in the area, the researchers put out nest boxes to attract the female
Chickadees. The babies are then easy to find and band. But sometimes, tragedy strikes:
though cute, chipmunks are egg-predators.
Vlad's team envisioned and built RFID feeders that read the leg bracelets on each bird. The feeders will
only open for certain bracelets, so the birds have to figure out which door will open for them. so that they
can get a seed. Later, the researchers rotate the arrays to discover how quickly the birds at different
elevations can solve the puzzle again.
Plastic and Flexible As We Thought
Vlad's team is discovering that natural selection may favor larger hippocampi in harsher environments:
high elevations birds are better at memory AND problem solving (to deal with longer winters). But that
extra memory comes with a cost: higher elevation birds can't learn new tasks as quickly as
lower elevation birds that don't need to remember so much.
Unsurprisingly, lots of the other forest residents covet Vlad's seeds, too.
Keeping other animals from ravaging the feeders is a constant battle.
These tiny birds are overwintering food-cachers, too, constantly on the hunt for
seeds. If a food-caching bird sees another bird watching, it will move its current
seed to a new hiding place.
These clever birds also don't migrate, and are always looking for food.
A double threat, they eat eggs and nestlings, too.
Some seed competitors are a bigger problem for the researchers than others.
The team is in the mountains virtually every day.
Working in a wild forest in the winter means just getting to the remote research sites can be
exhausting and difficult. The team uses a truck, a track-wheeled 4x4, snowmobiles,
or skis and snowshoes when the snow is just too deep for the vehicles.
Deep snow is not the only road block.
The deep Sierra snowpack is not just an impediment to travel: the feeders need to be kept dug out.
Each time a bird approaches a feeder, it is recorded for analysis to tease out
what the birds are doing, and how long it takes them to solve problems.
(Ugh! The slider isn’t displaying properly. Swipe to advance–or reverse–the pictures.)
- Sonnenberg, Branch, Pitera, Bridge, Pravosudov. “Natural Selection and Spatial Cognition in Wild Food-Caching Mountain Chickadees.” Current Biology, (2019). https://doi.org/10.1016/j.cub.2019.01.006
- Branch, Carrie L., J. P. Jahner, D. Y. Kozlovsy, T. L. Parchman, and V. V. Pravosudov. “Absence of Population Structure across Elevational Gradients despite Large Phenotypic Variation in Mountain Chickadees (Poecile Gambeli).” R. Soc. Open Sci. 4, no. 170057 (2017). http://dx.doi.org/10.1098/rsos.170057.
- Branch, Carrie L., Dovid Y. Kozlovsky, and Vladimir V. Pravosudov. “Elevation-Related Differences in Female Mate Preference in Mountain Chickadees: Are Smart Chickadees Choosier?” Animal Behaviour 99 (January 2015): 89–94. https://doi.org/10.1016/j.anbehav.2014.10.021.
- Branch, Carrie L., D. Y. Kozlovsy, R. Croston, A. M. Pitera, and V. V. Pravosudov. “Mountain Chickadees Return to Their Post-Natal Dispersal Settlements Following Long-Term Captivity.” Behaviour 153 (2016): 551–67. https://doi.org/10.1163/1568539X-00003363.
- Branch, Carrie L., and Vladimir V. Pravosudov. “Mountain Chickadees from Different Elevations Sing Different Songs: Acoustic Adaptation, Temporal Drift or Signal of Local Adaptation?” Royal Society Open Science 2, no. 4 (April 1, 2015): 150019. https://doi.org/10.1098/rsos.150019.
- Buchanan, Katherine L., Jennifer L. Grindstaff, and Vladimir V. Pravosudov. “Condition Dependence, Developmental Plasticity, and Cognition: Implications for Ecology and Evolution.” Trends in Ecology & Evolution 28, no. 5 (May 2013): 290–96. https://doi.org/10.1016/j.tree.2013.02.004.
- Croston, R., C. L. Branch, A. M. Pitera, D. Y. Kozlovsy, E. S. Bridge, T. L. Parchman, and V. V. Pravosudov. “Predictably Harsh Environment Is Associated with Reduced Cognitive Flexibility in Wild Food-Caching Mountain Chickadees.” Animal Behaviour, 2017, 123, 139–49.
- Croston, Rebecca, Carrie L. Branch, Dovid Y. Kozlovsky, Timothy C. Roth, Lara D. LaDage, Cody A. Freas, and Vladimir V. Pravosudov. “Potential Mechanisms Driving Population Variation in Spatial Memory and the Hippocampus in Food-Caching Chickadees.” Integrative and Comparative Biology, May 11, 2015, icv029. https://doi.org/10.1093/icb/icv029.
- Croston, Rebecca, D. Y. Kozlovsy, C. L. Branch, T. L. Parchman, E. S. Bridge, and V. V. Pravosudov. “Individual Variation in Spatial Memory Performance in Wild Mountain Chickadees from Different Elevations.” Animal Behaviour 111 (2016): 225–34. http://dx.doi.org/10.1016/j.anbehav.2015.10.015.
- Fox, R.A., T.C. Roth, L.D. LaDage, and V.V. Pravosudov. “No Effect of Social Group Composition or Size on Hippocampal Formation Morphology and Neurogenesis in Mountain Chickadees (Poecile Gambeli).” Developmental Neurobiology 70, no. 7 (2010): 538–47.
- Fox, Rebecca A., Lara D. Ladage, Timothy C. Roth II, and Vladimir V. Pravosudov. “Behavioural Profile Predicts Dominance Status in Mountain Chickadees, Poecile Gambeli.” Animal Behaviour 77, no. 6 (June 2009): 1441–48. https://doi.org/10.1016/j.anbehav.2009.02.022.
- Freas, C.A., K. Bingman, L.D. LaDage, and V.V. Pravosudov. “Untangling Elevation-Related Differences in the Hippocampus in Food-Caching Mountain Chickadees: The Effect of a Uniform Captive Environment.” Brain, Behavior and Evolution 82, no. 3 (2013): 199–209.
- Freas, Cody A., Lara D. LaDage, Timothy C. Roth II, and Vladimir V. Pravosudov. “Elevation-Related Differences in Memory and the Hippocampus in Mountain Chickadees, Poecile Gambeli.” Animal Behaviour 84, no. 1 (July 2012): 121–27. https://doi.org/10.1016/j.anbehav.2012.04.018.
- Freas, Cody A., Timothy C. Roth, Lara D. LaDage, and Vladimir V. Pravosudov. “Hippocampal Neuron Soma Size Is Associated with Population Differences in Winter Climate Severity in Food-Caching Chickadees.” Functional Ecology 27, no. 6 (December 1, 2013): 1341–49. https://doi.org/10.1111/1365-2435.12125.
- Kozlovsky, Dovid, Carrie Branch, Cody A. Freas, and Vladimir V. Pravosudov. “Elevation-Related Differences in Novel Environment Exploration and Social Dominance in Food-Caching Mountain Chickadees.” Behavioral Ecology and Sociobiology 68, no. 11 (August 23, 2014): 1871–81. https://doi.org/10.1007/s00265-014-1796-6.
- Kozlovsky, Dovid Y. “The Relationship between Environment, Behavior, Cognition and the Brain in Specialized Food-Caching Chickadees.” Ph.D., UNR, 2017.
- Kozlovsky, Dovid Y., Carrie L. Branch, and Vladimir V. Pravosudov. “Elevation-Related Differences in Parental Risk-Taking Behavior Are Associated with Cognitive Variation in Mountain Chickadees.” Ethology 121, no. 4 (April 1, 2015): 383–94. https://doi.org/10.1111/eth.12350.
- ———. “Problem-Solving Ability and Response to Novelty in Mountain Chickadees (Poecile Gambeli) from Different Elevations.” Behavioral Ecology and Sociobiology 69, no. 4 (February 17, 2015): 635–43. https://doi.org/10.1007/s00265-015-1874-4.
- Kozlovsky, Dovid Y., E.A. Weissgerber, and V.V. Pravosudov. “What Makes Specialized Food-Caching Mountain Chickadees Successful City Slickers?” Proc. R. Soc. B 284, no. 20162613 (2017). http://dx.doi.org/10.1098/rspb.2016.2613.
- LaDage, L.D., T.C. Roth, R.A. Fox, and V.V. Pravosudov. “Effects of Captivity and Memory-Based Experiences on the Hippocampus in Mountain Chickadees.” Behavioral Neuroscience 123, no. 2 (2009): 284.
- ———. “Ecologically Relevant Spatial Memory Use Modulates Hippocampal Neurogenesis.” Proceedings of the Royal Society B: Biological Sciences 277, no. 1684 (2010): 1071–79.
- ———. “Flexible Cue Use in Food-Caching Birds.” Animal Cognition 12, no. 3 (2009): 419–26.
- Pravosudov, V. V. “Cold Weather Cognition.” Biosphere, 2017. https://sagehen.ucnrs.org/pubs/2017/Pravosudov Biosphere_Issue 22_2017.pdf.
- ———. “Long-Term Moderate Elevation of Corticosterone Facilitates Avian Food-Caching Behaviour and Enhances Spatial Memory.” Proceedings of the Royal Society of London B: Biological Sciences 270, no. 1533 (December 22, 2003): 2599–2604. https://doi.org/10.1098/rspb.2003.2551.
- ———. “Memory, Learning, Hormones and Behavior.” In Encyclopedia of Animal Behavior, edited by Michael D. Breed and Janice Moore, 429–37. Oxford: Academic Press, 2010. https://doi.org/10.1016/B978-0-08-045337-8.00262-X.
- ———. “Mountain Chickadees Discriminate between Potential Cache Pilferers and Non-Pilferers.” In Proc. of the Royal Society Biological Sciences, 2008.
- Pravosudov, Vladimir V. “On Seasonality in Food-Storing Behaviour in Parids: Do We Know the Whole Story?” Animal Behaviour 71, no. 6 (June 1, 2006): 1455–60. https://doi.org/10.1016/j.anbehav.2006.01.006.
- Pravosudov, Vladimir V., and Nicola S. Clayton. “Effects of Demanding Foraging Conditions on Cache Retrieval Accuracy in Food-Caching Mountain Chickadees (Poecile Gambeli).” Proceedings of the Royal Society of London B: Biological Sciences 268, no. 1465 (February 22, 2001): 363–68. https://doi.org/10.1098/rspb.2000.1401.
- Pravosudov, Vladimir V., Alexander S. Kitaysky, Colin J. Saldanha, John C. Wingfield, and Nicola S. Clayton. “The Effect of Photoperiod on Adrenocortical Stress Response in Mountain Chickadees (Poecile Gambeli).” General and Comparative Endocrinology 126, no. 2 (April 2002): 242–48. https://doi.org/10.1006/gcen.2002.7798.
- Pravosudov, Vladimir V., Alexander S. Kitaysky, John C. Wingfield, and Nicola S. Clayton. “Long-Term Unpredictable Foraging Conditions and Physiological Stress Response in Mountain Chickadees (Poecile Gambeli).” General and Comparative Endocrinology 123, no. 3 (September 2001): 324–31. https://doi.org/10.1006/gcen.2001.7684.
- Pravosudov, Vladimir V, Sally P Mendoza, and Nicola S Clayton. “The Relationship between Dominance, Corticosterone, Memory, and Food Caching in Mountain Chickadees (Poecile Gambeli).” Hormones and Behavior 44, no. 2 (August 2003): 93–102. https://doi.org/10.1016/S0018-506X(03)00119-3.
- Pravosudov, Vladimir V., and Alicja Omanska. “Prolonged Moderate Elevation of Corticosterone Does Not Affect Hippocampal Anatomy or Cell Proliferation Rates in Mountain Chickadees (Poecile Gambeli).” Journal of Neurobiology 62, no. 1 (January 1, 2005): 82–91. https://doi.org/10.1002/neu.20069.
- Pravosudov, Vladimir V., and Timothy C. Roth II. “Cognitive Ecology of Food Hoarding: The Evolution of Spatial Memory and the Hippocampus.” Annual Review of Ecology, Evolution, and Systematics 44, no. 1 (2013): 173–93. https://doi.org/10.1146/annurev-ecolsys-110512-135904.
- Pravosudov, V.V., T.C. Roth, and L.D. LaDage. “Chickadees Are Selfish Group Members When It Comes to Food Caching.” Animal Behaviour 80, no. 2 (2010): 175–80.
- Tello-Ramos, Maria C., Carrie L. Branch, Dovid Y. Kozlovsky, Angela M. Pitera, and Vladimir V. Pravosudov. “Spatial Memory and Cognitive Flexibility Trade-Offs: To Be or Not to Be Flexible, That Is the Question.” Animal Behaviour, March 21, 2018. https://doi.org/10.1016/j.anbehav.2018.02.019.
- Tello-Ramos, Maria C., Carrie L. Branch, Angela M. Pitera, Dovid Y. Kozlovsky, Eli S. Bridge, and Vladimir V. Pravosudov. “Memory in Wild Mountain Chickadees from Different Elevations: Comparing First-Year Birds with Older Survivors.” Animal Behaviour 137 (March 1, 2018): 149–60. https://doi.org/10.1016/j.anbehav.2017.12.019.