Supporting Information

This Click & Learn shows that keystone species exist across a variety of ecosystems and can exert their influence in different ways. It highlights 15 different keystone species around the world from a variety of trophic levels and ecological roles — including predators, herbivores, scavengers, and ecosystem engineers. Additional information can be found on this resource’s webpage.

Select “Explore the Map” to show how the species are distributed around the globe. To learn more about a specific species, select its image on the map or landing page.

For implementation ideas, including a worksheet that provides a more structured student experience, refer to the materials on this resource’s webpage.

This resource is optimized for use on desktops, modern tablets, and smartphones. It is supported by the most recent versions of Google Chrome, Firefox, Microsoft Edge, and Safari web browsers.

This resource has been designed, optimized, and/or tested for accessibility compliance (WCAG Level 2.0 AA Success Criteria).

Submit comments, questions, or feedback about this resource via email to:

Bonachela, Juan A., Robert M. Pringle, Efrat Sheffer, Tyler C. Coverdale, Jennifer A. Guyton, Kelly K. Caylor, Simon A. Levin, and Corina E. Tarnita. “Termite mounds can increase the robustness of dryland ecosystems to climatic change.” Science 347, 6222 (2015): 651–655.

Brashares, Justin S., Laura R. Prugh, Chantal J. Stoner, and Clinton W. Epps. 2010. “Ecological and Conservation Implications of Mesopredator Release.” In Trophic Cascades: Predators, Prey, and the Changing Dynamics of Nature, edited by John Terborgh and James A. Estes, 221–240. Washington, DC: Island Press.

Elbroch, L. Mark, and Heiko U. Wittmer. “Table scraps: inter-trophic food provisioning by pumas.” Biology Letters 8, 5 (2012): 776–779.

Estes, James A., John Terborgh, Justin S. Brashares, Mary E. Power, Joel Berger, William J. Bond, Stephen R. Carpenter, et al. “Trophic Downgrading of Planet Earth.” Science 333, 6040 (2011): 301–306.

Friedlander, Alan M., and Edward E. DeMartini. “Contrasts in density, size, and biomass of reef fishes between the northwestern and the main Hawaiian islands: the effects of fishing down apex predators.” Marine Ecology Progress Series 230 (2002): 253–264.

Janiszewski, Pawel, Vladimír Hanzal, and Wojciech Misiukiewicz. “The Eurasian beaver (Castor fiber) as a keystone species — a literature review.” Baltic Forestry 20, 2 (2014): 277–286.

Markandya, Anil, Tim Taylor, Alberto Longo, M.N. Murty, S. Murty, and K. Dhavala. “Counting the cost of vulture decline—An appraisal of the human health and other benefits of vultures in India.” Ecological Economics 67, 2 (2008): 194–204.

McConkey, Kim R., and Donald R. Drake. “Flying Foxes Cease to Function as Seed Dispersers Long Before They Become Rare.” Ecology 87, 2 (2006): 271–276.

Pringle, Robert M. “Elephants as Agents of Habitat Creation for Small Vertebrates at the Patch Scale.” Ecology 89, 1 (2008): 26–33.

Reisewitz, Shauna E., James A. Estes, and Charles A. Simenstad. “Indirect food web interactions: sea otters and kelp forest fishes in the Aleutian archipelago.” Oecologia 146, 4 (2006): 623–631.

Silliman, Brian R., and Mark D. Bertness. “A trophic cascade regulates salt marsh primary production.” Proceedings of the National Academy of Sciences 99, 16 (2002): 10500–10505.

Wilson, Maxwell C., and Andrew T. Smith. “The pika and the watershed: The impact of small mammal poisoning on the ecohydrology of the Qinghai-Tibetan Plateau.” AMBIO 44, 1 (2015): 16–22.


Mark Nielsen, HHMI


Bridget Conneely, HHMI
Jared Lipworth, HHMI
Laura Bonetta, HHMI

Additional Research, Writing, and Editing

Alex Duckles, HHMI
Aline Waguespack Claytor
Esther Shyu, HHMI

UI/UX Design and Development

kapow, inc.


Clips from BioInteractive:

Flying fox, largemouth bass, and leopard clips from Pond5
All other video clips from Shutterstock


Purple sea star diagrams and sea otter graphs by A3MG


Andean condor (“Cougar”) from Pond5
Cougar Close-up” by Sheila Brown, used under CC0
Lakes (“Largemouth Bass”) by Stephen Carpenter, University of Wisconsin–Madison, WI
Meadows (“Eurasian Beaver”) by Alan Law, University of Stirling, Scotland, UK
Mountain Lion” by James Maxon, used under CC0
Sea Otter” by Michael L. Baird, used under CC BY 2.0
Trees in the Serengeti (“Blue Wildebeest”) by Tony Sinclair, University of British Columbia, Canada
All other photographs from iStock/Getty Images Plus

© 2022 Howard Hughes Medical Institute. Please see the Terms of Use for information on how this resource can be used.

Version 1.1
Updated on June 12, 2023