2020 was another banner year for research

Well, Zoo Atlanta had yet another banner year in producing major research publications in 2020! Our staff published 10 peer-reviewed articles on various lines of our research programs and collaborations. This brings our institutional total up to a minimum of 375 publications since 1978. Listed below are the complete citations and, in some cases, links to the publications.

Brief overview of research at Zoo Atlanta

Zoo Atlanta’s contributions to the world of primate behavioral research, especially those of western lowland gorillas and orangutans, is renowned and dates back to the late 1970s. The arrival of giant pandas in 1999 launched our giant panda research program, and in around 2000 our herpetology research program began to formalize. Through efforts of Zoo staff and collaborations with researchers at other institutions and academia, the animal population at Zoo Atlanta continues to further our knowledge of the basic biology of these animals, as well as inform advancements in animal well-being and veterinary care.

Listed below are the complete citations (in some cases, links to the publications are listed).  Also, here are summaries of our published works in 2020. Of special note for 2020 is that our team published in the Journal of Experimental Biology; this journal generally is considered to be among the most prestigious in our field. Also of significance are the handful of undergraduate students from Georgia Tech who co-authored papers with us. It is entirely uncommon for undergraduates to be publishing peer-reviewed papers, so their showing here is a testament to their diligence and also to the innovative research and teaching partnership between Zoo Atlanta and Georgia Tech.

More than anything, I am so happy to see some new Zoo team names among this year’s publications!

We had far too many collaborating institutions to be listed here. But I’ll note that we had a good number of international collaborations and local highlights, include Georgia State University and Georgia Tech.

Our greatest highlight in 2020 was that the Great Ape Heart Project headquartered at Zoo Atlanta was recognized this year with the Association of Zoos and Aquariums’ (AZA) new prestigious Research Award. We won the award in the inaugural year, ahead of formidable competition!

2020 Publications

Kehoe, S., N.I. Stacy, S. Frasca Jr., T. Stokol, C. Wang, S. Debose, K. Leach, L. Luo, and S. Rivera. 2020. Leukocyte characteristics of the giant panda (Ailuropoda melanoleuca): morphological, cytochemical and ultrastructural features. Frontiers in Veterinary Science 7: doi: 10.3389/fvets.2020.00156.

Jared, C., P. L. Mailho-Fontana, J. R. Mendelson III, and M. M. Antoniazzi. 2020. Life history of frogs of the Brazilian semiarid (Caatinga), with emphasis in aestivation. Acta Zoologica 101:302–310. DOI: 10.1111/azo.12295

                        Research Highlights: Nature 568:9 https://www.nature.com/articles/d41586-019-            00975-4

Astley, J. C., J. R. Mendelson III, J. Dai, C. Gong, B. Chong, J. M. Rieser, P. Schiebel, R. Hatton, H. Choset, and D. I. Goldman. 2020. Surprising simplicities and syntheses in self-propelling squamate and synthetic systems in sand. Journal of Experimental Biology 223: jeb103564 doi: 10/1242/jeb103564

Schiebel, P. E., H. C. Astley, J. M. Rieser, S. Agrawal, C. Hubicki, A. M. Hubbard, K. Cruz, J. R. Mendelson III, K. Kamrin, and D. I. Goldman. 2020. Mitigating memory effects during undulatory locomotion on hysteritic materials. eLife 2020;9e51412 doi.org/10/7554/eLife.51412.

Astley, H. C., J. M. Rieser, A. Kaba, V. M. Paez, I. Tomkinson, J. R. Mendelson III, and D. I. Goldman. 2020. Side-impact collision: mechanics of obstacle negotiation in sidewinding snakes. Bioinspiration & Biomimetics 15:065005 https://doi.org/10.1088/1748-3190/abb415

Cooper, T., C. L. Zabinksi, E.J. Adams, S.M. Berry, J. Pardo-Sanchez, E.M. Reinhardt, K.M. Roberts, J. Watzek, S. F. Brosnan, R. L. Hill, E. G. Weigel, and J. R. Mendelson III. 2020. Long-term memory of a complex foraging task in monitor lizards (Reptilia: Squamata: Varanidae). Journal of Herpetology 54:378–383.

Otsuka, N., A. Ramírez-Velázquez, R. L. Hill, and J. R. Mendelson III. 2020. Clutch size in the black beaded lizard (Heloderma alvarezi) and Guatemalan beaded lizard (Heloderma charlesbogerti), with summaries of other species of helodermatids. Herpetological Review 51:761–763.

Snider, S., and N. Miecznikowski. 2020.  Ungulate. In: Vonk, J., Shackleford, T. (eds.) Encyclopedia of Animal Cognition and Behavior. Springer Publishers. [online resource] https://doi.org/10.1007/978-3-319-47829-6_1455-1

Boyd, R., Danforth, M. D., Rapoport, G., Sleeper, M. M., Devlin, W. H., Kutinsky, I., Brainard, B., Murphy, H.W. (2020). Great Ape Heart Project guidelines for the echocardiographic assessment of great apes. Journal of  Zoo Wildlife Medicine 50: 822–836.           doi:10.1638/2018-016

Prétôt, L., J. Mickelberg, J. Carrigan, T. Stoinski, R. Bshary, and S.F. Brosnan. 2020. Comparative performance of orangutans (Pongo spp.), gorillas (Gorilla gorilla gorilla), and drills (Mandrillus leucophaeus), in an ephemeral foraging task. American Journal of Primatology 2020:e23212   d oi:10.1002/ajp.23212

2020 Research Summaries:

Title: Leukocyte characteristics of the giant panda (Ailuropoda melanoleuca): morphological, cytochemical and ultrastructural features. Frontiers in Veterinary Science.

Zoo team authors: Spencer Kehoe, Sharon Debose, Kate Leach, Sam Rivera

Despite the giant panda’s importance as a representative species for global wildlife conservation efforts, no studies to date have described normal white-blood cell morphology or constituents using by traditional, readily available, techniques. This study provides novel information on giant panda leukocyte morphology and cellular constituents in health, shows the importance of manual blood film review, has important implications for interpretation in future clinical cases and research, and provides a baseline for future characterization and understanding of changes in blood parameters in response to disease.

Title: Life history of frogs of the Brazilian semiarid Caatinga, with emphasis in aestivation.

Zoo team authors: Joe Mendelson

Frogs in dry habitats, such as deserts, face exceptional challenges with dehydration. Most bury in the soil during the dry season and cover themselves with an impermeable cocoon generated by special skin glands. These Brazilian frogs live in very dry conditions yet have no such specialized skin glands. Their secret is that they select specific spots to bury that have slightly higher soil moisture than the surrounding desert. There, they migrate up and down in the soil during the dry season, tracking the appropriate moisture levels—emerging only during the short rainy season to eat and breed. This study highlights an unexpected behavioral adaptation in frogs living in unforgiving dry environments.

Title: Surprising simplicities and syntheses in self-propelling squamate and synthetic systems in sand.

Zoo team authors: Joe Mendelson

Unlike water, firm ground, or even foliage, sand is a very difficult medium for animals to traverse. This is because it shifts in response to the energy you put into it in order to move forward. Over the last decade, our team has been studying snakes, lizards, and robots to investigate the amazing ways that animals deal with the challenges of sandy substrates. Surprisingly, we have gained insights not only to sand, but to some broader generalities of how animals fundamentally move in nature, and these have important insights into evolution, anatomy, and bio-inspired design of engineered devices.

Title: Mitigating memory effects during undulatory locomotion on hysteritic materials.

Zoo team authors: Joe Mendelson

A particular problem that animals face when moving across or through sand is that when one part of the body deforms the surface of the sand, that can create a minor sandy obstacle for another part of the body—a potentially self-defeating means of locomotion. Using data from animals and mathematical modelling, we investigated and characterized the real problem that animals create for themselves when moving on sand, and now understand why and some snakes completely fail on sandy substrates.

Title: Side-impact collision: mechanics of obstacle negotiation in sidewinding snakes.

Zoo team authors: Joe Mendelson

Field observations of sidewinders in their native habitat indicated even minor obstacles in their intended path of locomotion—for example, even a dried stem of grass emerging from the sand. These are not problems experienced by other snakes. We described the unusual behaviors that sidewinders use to get around these seemingly minor, but actually substantial, obstacles.

Title: Long-term memory of a complex foraging task in monitor lizards (Reptilia: Squamata: Varanidae).

Zoo team authors: Robert Hill, Joe Mendelson

Based on previous work at the Zoo, we revisited a group of lizards that had (mostly) learned to solve a puzzle-feeder device problem. We showed that after a remarkable two-year gap in encountering the device, two species of monitor lizard fully remembered exactly how to solve the problem. This is the first report of long-term complex memory in lizards. Beaded lizards in the same trials were not capable of doing so.

Title: Clutch size in the black beaded lizard (Heloderma alvarezi) and Guatemalan beaded lizard (Heloderma charlesbogerti), with summaries of other species of helodermatids.

Zoo team authors: Robert Hill, Joe Mendelson

Using records from the Zoo and a partnering zoo in Mexico, as well as the scattered published literature, we summarized the basic parameters of the egg clutches of the critically endangered Guatemalan beaded lizard and its relatives. These data are crucial in inform conservation programs as well as husbandry and breeding protocols.

Title: Ungulate [Cognition and Behavior]

Zoo team authors: Sarah Snider, Nadia Miecznikowski.

Encyclopedia reviews are crucial first-references when investigators are exploring new questions or new study species. This account is a thorough review of cognition, migration, and behavior in ungulate (hoofstock) mammals.

Title: Great Ape Heart Project guidelines for the echocardiographic assessment of great apes.

Zoo team authors: Marietta Danforth, Hayley Murphy

One of the most lauded contributions of the award-winning Great Ape Heart Project is how it works across institutions and scientific, medical, and veterinary fields to integrate analyses and conclusions from cardiac studies in all the involved species, including humans. This important paper establishes standard techniques for collecting data, to promote consistency and quality in data collection of cardiac data for great apes globally.

Title: Comparative performance of orangutans (Pongo spp.), gorillas (Gorilla gorilla gorilla), and drills (Mandrillus leucophaeus), in an ephemeral foraging task.

Zoo team authors: Jodi Carrigan, Jennifer Mickelberg
Comparisons of features and behaviors across different species is the basis for how we understand how those features and behaviors, or cognitive abilities in this case, develop in individuals and evolve in species. Replicating previous studies with capuchin monkeys, we expanded to include gorillas, orangutans, and drill monkeys at the Zoo in a complex foraging task. Based on this work, we now understand much better what criteria primates use in making hedge-betting type decisions involving food rewards and discovered important differences among these four species of primates.

Joe Mendelson, PhD
Director of Research