Predators Past and Present

Rancho La Brea is an exceptionally well preserved late Pleistocene site in southern California that has been excavated for over 100 years, yielding more than 3.5 million specimens representing >600 different animals.  Colloquially termed the La Brea Tar Pits, Rancho La Brea contains "tar"—or rather asphaltum — seeps that trapped herbivorous taxa and subsequently lured and trapped carnivores and scavengers.   Subsequently, ~90% of excavated mammal bones belong to the order Carnivora (e.g. cats, dogs, bears, and other relatives) and these specimens provide the rare opportunity to clarify the paleobiology of carnivorans over the past ~50,000 years, an interval that experienced profound climate change, the arrival of humans, and the extinction of megafauna (i.e. large animals).  The consequences of apex predator extinctions on surviving predators is critical to our understanding of apex predator extinctions, today.    

Beyond Rancho La Brea, we study predators across the globe and through time, including cats (e.g. American lions, American cheetahs, cougars, African lions, cheetahs, tigers, lynxes), hyenas, dogs (e.g. wolves, dingos, dire wolves, bone-crushing dogs, coytoes, foxes), ursids (giant short-faced bears, European cave bears, polar bears, black bears, brown bears, sun bears, spectacle bears, and panda bears), wolverines, and other carnivores outside the order Carnivora (e.g. hyenodonts, marsupial sabertooth cats, marsupial lions, Tasmanian tigers, Tasmanian devils, quolls). We study modern predators to both clarify predator ecology and provide insight into interpreting the dietary ecology and behavior of prehistoric predators.

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Currently, we are involved in a multi-institution NSF grant (PIs include Dr. Larisa DeSantis, Dr. Wendy Binder (lead), Dr. Emily Lindsey, Dr. Julie Meachen, Dr. Robin O’Keefe, and Dr. John Southon, Collaborative Research: The timing and ecology of the Late Pleistocene Megafauna at Rancho La Brea, also known as Project SABER. Our research integrates morphological data with stable isotopes, dental microwear, and radiometric dating to clarify the impacts of changing climates on the dominate taxa at Rancho La Brea (i.e., dire wolves, sabertooth cats, coyotes, bison, and horses).

Logo Credit: Larisa R.G. DeSantis

Learn more about Rancho La Brea from Dr. Larisa DeSantis, as part of Pleistocene Predators of the Tar Pits (Paleo Talks Episode 7), a production developed during the COVID-19 pandemic by paleontologists at East Tennessee State University.

 

The most detailed study to date of ancient predators trapped in the La Brea Tar Pits is helping Americans understand why today we’re dealing with coyotes dumping over garbage cans and not saber-toothed cats ripping our arms off.

Consequences of Extinction

Understanding why sabertooth cats, dire wolves, American lions, and more went extinct is the million dollar question. A critical part of our research program is aimed at understanding not only the potential causes of large animal extinctions (e.g., climate change, human hunting) but also the consequences of those extinctions on middle-sized predators (e.g., coyotes, cougars). After more than a decade of research on Rancho La Brea mammals, we have identified sabertooth cats and American lions as primarily consuming forested prey while dire wolves largely took down open-country prey (e.g. bison, horses), demonstrating that these predators were not competing for the same prey as was previously thought to be the case.

See our work in North & South America: Global Change

See our integrative methods work: Integrative Paleoecology

Scientists examine four different possible future worlds and how each would pose immense challenges to the big cats of today.

Paleobiology of Sabertooth Cats

Sabertooth cats are one of the most iconic predators to have roamed the earth. There is much debate over the ecology and paleobiology of these apex predators and our work uses tools like stable isotopes and dental microwear texture analysis to reveal the types of prey consumed and the degree to which they fully consumed carcasses. Due to the high abundance of sabertooth cats at Rancho La Brea we are also investigating the dietary behavior of injured cats and have learned a lot about these fierce but also compassionate cats. We also study lesser known extinct and extant big cats, including American lions, American cheetahs, and marsupial sabertooth cats with pouches that once lived in South America.

See our work in North & South America: Global Change

See our integrative methods work: Integrative Paleoecology

Check out our work featured on Curiosity Stream.

(Subscription to Curiosity Stream is required to view these videos.)

Saber-Tooth Brawl (English)

Saber-Tooth Brawl (English)

Cougars may have survived the mass extinction that took place about 12,000 years ago because they were not particular about what they ate, unlike their more finicky cousins--the saber-tooth cat and American lion. Both perished along with the woolly mammoth and many of the other supersized mammals that walked the Earth during the late Pleistocene. This work is of direct application to modern conservation.

Ecology of Surviving Predators

Approximately 10,000 years ago, dire wolves, sabertooth cats, giant short-faced bears, American lions, and American cheetahs roamed North America, and that is not even counting the gray wolves, coyotes, cougars, bobcats, and other mesopredators. Further, bison, horses, camels, tapirs, pronhorns, and deer also inhabited North American and what is now Los Angeles. While there is still significant debate regarding the cause of large-animal extinctions across the globe at the end of the Pleistocene (i.e., warming climates, human arrival, or both), the consequences were profound. Smaller cats like cougars survived along with coyotes likely due to their opportunistic feeding behavior - one of the many consequences of megafuanal extinctions on mesopredators. From studying coyotes, we have also learned that their ecology today as an opportunistic species is a consequence of the megafaunal extinction and their ecology during the Pleistocene was dramatically different (e.g., no evidence of scavenging). We are currently expanding the study of coyotes as part of the collaborative Project SABER. In Project SABER we are dating all coyotes in our study, to assess if an how their morphology, ecology, and behavior has changed over time, in response to climate change and megafaunal extinctions at Rancho La Brea.

See our work in North America: Global Change

See our integrative methods work: Integrative Paleoecology

In 1898, two African lions began attacking and consuming railway workers in Tsavo, Kenya. First reports estimated that 135 people fell victim to these "man-eaters," but further research published in 2009 lessened that number to 35 individuals. Over the years, different theories as to what motivated these attacks have varied, and recently we got to talk with two experts who are working towards finding an answer.

Man-eating Lions

If you have ever seen the movie, “The Ghost and the Darkness” or been to the Field Museum of Natural History in Chicago, you will be familiar with the story of the Tsavo lions. Why did these lions turn to people?  As it turns out it was due to dental problems. We employed dental microwear texture analysis to assess the dietary behavior of man-eating lions in Africa. This work, in collaboration with Dr. Bruce Patterson of the Field Museum, demonstrated that the man-eating lions were relegated to eating soft food and likely found the solution to their dental damage by switching prey sources to humans. See the above Brain Scoop (FLMNH) video which discusses our research motivations (above), while the video below (produced by Vanderbilt) provides a discussion of our results.

An analysis of the microscopic wear on the teeth of the legendary “man-eating lions of Tsavo” reveals that it wasn’t desperation that drove them to terrorize a railroad camp in Kenya more than a century ago.

See our work in Africa: Global Change

Polar bears skulls with dental microwear molds from the University of Alaska Museum of the North. Image Credit: Larisa R.G. DeSantis

Polar bears skulls with dental microwear molds from the University of Alaska Museum of the North. Image Credit: Larisa R.G. DeSantis

Arctic Predators

Animals in the arctic are some of the most vulnerable to on-going climate change, with limitations on how far north they can move, with top predators both vulnerable to the availability of prey resources and able to exert top-down pressures on prey populations, yet we have only limited understandings of their adaptability to long-term climate change.  We focus on dietary responses of carnivorous mammals and their prey, assessing the degree to which carnivorans are impacted by megafaunal extinctions, pronounced warming, and changes in the ecology of co-occurring prey and predator species. Both extinction (predominantly megafauna) and climate change are co-occurring today; thus, assessing the synergistic consequences of extinction and warming are critical to understanding how best to address these challenges.  

See our work in North America: Global Change

Skulls and life reconstructions of the marsupial sabertooth Thylacosmilus atrox (left) and the sabertooth cat Smilodon fatalis (right) (Image by Stephan Lautenschlager, co-author of Thylacosmilus study).

Skulls and life reconstructions of the marsupial sabertooth Thylacosmilus atrox (left) and the sabertooth cat Smilodon fatalis (right) (Image by Stephan Lautenschlager, co-author of Thylacosmilus study).

Marsupial Predators

Carnivores eat meat. However, there is also a group of mammals called carnivorans - which includes primarily meat eating mammals. Across the globe and in very different groups of mammals (e.g. metatherians), meat eating occurred many times but in different flavors. We are examining the dietary behavior of quolls, Tasmanian devils, Tasmanian tigers, marsupial lions (all in Australia) and the sabertooth marsupial (from South America) to assess their dietary behavior, modes of food acquisition, and responses to European introduction of non-native predators in Australia. Our work also elucidates potential reasons for their extinction and/or tests hypotheses pertaining the similarities between many of the metatherian mammals and carnivorans.

See our work on Australia’s Predators: An Arid World

See our work in South America: Global Change

See our integrative methods work: Integrative Paleoecology

 

Vanderbilt University paleontologist researching history of Nashville Predators namesake

Produced by News Channel Five Nashville.

Relevant Papers & Press (Predators)

(*graduate student, **undergraduate student) Bold = lab members

  • Janis, C.M., Figueirido, B., DeSantis, L.R.G., Lautenschlager, S. 2020. An eye for a tooth: Thylacosmilus was not a marsupial “saber-tooth predator.” Peer J  8:e9346 (https://doi.org/10.7717/peerj.9346)

  • DeSantis, L.R.G. §, Feranec, R.S., Fox-Dobbs, K., **Crites, J.M., Farrell, A.B., Harris, J.M., Takeuchi, G.T., Cerling, T.E. 2020. Reply to Van Valkenburgh et al. The validity of stable isotope data from tooth enamel to interpreting the ecology of ancient predators and their prey. Current Biology 30:R151-R152 (https://doi.org/10.1016/j.cub.2020.01.011)

  • DeSantis, L.R.G. §, **Crites, J.M., Feranec, R.S., Fox-Dobbs, K., Farrell, A.B., Harris, J.M., Takeuchi, G.T., Cerling, T.E. 2019. Pleistocene megafaunal extinctions, climate change, and mesopredator dietary release. Current Biology 29: 2488-2495 (https://doi.org/10.1016/j.cub.2019.06.059)

  • Stydner, D.D.§, DeSantis, L.R.G., *Donohue, S.L., Schubert, B.W., Ungar, P.S. 2018. A Dental Microwear Texture Analysis of the Early Pliocene African Ursid Agrotherium africanum (Mammalia, Carnivora, Ursidae). Journal of Mammalian Evolution 26: 505-515 (https://doi.org/10.1007/s10914-018-9436-y)

  • *Tanis, B.P., DeSantis, L.R.G., Terry, R.C. 2018. Dental microwear textures across cheek teeth in canids: implications for dietary studies of extant and extinct canids. Palaeogeography, Palaeoclimatology, Palaeoecology 508: 129-138 (https://doi.org/10.1016/j.palaeo.2018.07.028)

  • DeSantis, L.R.G. §, Patterson, B.D. 2017. Dietary behaviour of man-eating lions as revealed by dental microwear textures. Scientific Reports 7: 904 (https://www.nature.com/articles/s41598-017-00948-5)

  • DeSantis, L.R.G. §, DeSantis, D.T. 2017. Experimenting with extinction: A multi-disciplinary investigation into ancient cat extinctions. The Science Teacher 84 (2): 49-55

    • Published in the special evolution themed issue in honor of Darwin Day. 

  • DeSantis, L.R.G. §, Tseng, J., Liu, J. **Hurst, A., Schubert, B.W., Jiangzuo, Q. 2017. Assessing niche conservatism using a multi-proxy approach: dietary ecology of extinct and extant spotted hyenas.  Paleobiology 43: 286-303 (https://doi.org/10.1017/pab.2016.45)

  • **Jones, B.D., DeSantis, L.R.G. § 2016. Dietary ecology of the extinct cave bear (Ursus spelaeus): evidence of omnivory as inferred from dental microwear textures. Acta Palaeontologica Polinica 61 (4): 735–741 (http://dx.doi.org/10.4202/app.00253.2016)

  • DeSantis, L.R.G. § 2016. Dental microwear textures: reconstructing diets of fossil mammals. Surface Topography: Metrology and Properties 4: 023002 (http://iopscience.iop.org/article/10.1088/2051-672X/4/2/023002)

    • Invited Review Paper for a special issue titled: Exposing the past: what surfaces and their measurement can teach us about extinct species and the lives of ancient people.

  • DeSantis, L.R.G. §, Schubert, B.W., *Schmitt-Linville, E., Ungar, P., *Donohue, S., *Haupt, R.J. 2015. Dental microwear textures of carnivorans from the La Brea Tar Pits, California and potential extinction implications.  Science Series of the Natural History Museum of Los Angeles County 42: 37-52 (https://nhm.org/site/sites/default/files/pdf/contrib_science/lacm-42.pdf)

    • Invited contribution for a special volume titled, La Brea and Beyond: the Paleontology of Asphalt-Preserved Biotas, in commemoration of the 100th anniversary of the Natural History Museum of Los Angeles County's excavations at Rancho La Brea.  Featured in Forbes magazine (Are The Dire Wolves From Game of Thrones Real Animals?).

  • Feranec, R.S. §, DeSantis, L.R.G. 2014. Understanding specifics in generalist diets of carnivorans by analyzing stable carbon isotope values in Pleistocene mammals of Florida.  Paleobiology 40: 477-493 (http://dx.doi.org/10.1666/13055)

  • DeSantis, L.R.G. §, *Haupt, R.J. 2014. Cougars’ key to survival through the late Pleistocene extinction: insights from dental microwear texture analysis.  Biology Letters 10 (4): 20140203 (http://rsbl.royalsocietypublishing.org/content/10/4/20140203)

  • *Donohue, S.L., DeSantis, L.R.G. §, Schubert, B.W., Ungar, P.S. 2013. Was the giant short-faced bear a hyper-scavenger? A new approach to the dietary study of ursids using dental microwear textures. PLoS ONE 8: e77531 (https://doi.org/10.1371/journal.pone.0077531)

  • **Veter, N.M., DeSantis, L.R.G. §, *Yann, L.T., *Donohue, S.L., *Haupt, R.J., **Corapi, S.E., *Fathel, S.L., **Gootee, E.K., **Loffredo, L.F., **Romer, J.L., **Velkovski, S. 2013.  Is Rapoport's rule a recent phenomenon? A deep time perspective on potential causal mechanisms.  Biology Letters 9: 20130398 (http://rsbl.royalsocietypublishing.org/content/roybiolett/9/5/20130398.full.pdf)

  • DeSantis, L.R.G. §, Scott, J.R., Schubert, B.W., *Donohue, S.L., *McCray, B.M., **Van Stolk, C.A., *Winburn, A.A., **Greshko, M.A., **O'Hara, M.C. 2013. Direct comparisons of 2D and 3D dental microwear proxies in extant herbivorous and carnivorous mammals.  PLoS ONE 8: e71428 (https://doi.org/10.1371/journal.pone.0071428)

  • *Haupt, R.J., DeSantis, L.R.G. §, Green, J.L., Ungar, P.S. 2013. Dental microwear texture as a proxy for diet in xenarthrans.  Journal of Mammalogy 94: 856-866 (http://dx.doi.org/10.1644/12-MAMM-A-204.1)

  • DeSantis, L.R.G. §, Schubert, B.W., Scott, J.R., Ungar, P.S. 2012.  Implications of diet for the extinction of saber-toothed cats and American lions.  PLoS ONE 7: e52453 (https://doi.org/10.1371/journal.pone.0052453)

    • Featured in msNBC, in addition to numerous on-line (e.g., Huffington Post, National Geographic), radio (Up all Night, BBC; As it Happens, CBC) and TV media including a National Geographic Wild special called Future Cats.

  • DeSantis, L.R.G. §, *Beavins Tracy, R.A., *Koontz, C.S., *Roseberry, J.C., *Velasco, M.C. 2012.  Mammalian niche conservation through deep time. PLoS ONE 7: e35624 (https://doi.org/10.1371/journal.pone.0035624)

  • Schubert, B.W. §, Ungar, P.S., DeSantis, L.R.G. 2010. Carnassial microwear and dietary behaviour in large carnivorans.  Journal of Zoology 280: 257-263 (http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.2009.00656.x/full)

Check out our book chapters in the following books:

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Smilodon: The Iconic Sabertooth

DeSantis, L.R.G. Dietary Ecology of Smilodon in Smilodon: The Iconic Sabertooth, Johns Hopkins University Press, Baltimore

(ISBN: 9781421425566).

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Dogs: Archaeology Beyond Domestication

Burtt, A., DeSantis, L.R.G. Using Dental Microwear to Understand the Dietary behavior of Domestic Dogs in Precontact North America in Dogs: Archaeology Beyond Domestication, University Press of Florida

(ISBN: 9780813066363)