As populations of big beasts around the world recover, it turns out they live across a greater variety of habitats than we assumed, says this study.
Large-bodied consumers like alligators, wolves, otters and pumas are recovering from persecution. Where previously their populations were decimated, today they are recolonising their historic ranges.
And as they rebound, it turns out we don’t know as much about them as we thought.
The textbooks say that American alligators live in freshwater wetlands, but people keep finding them on the beach. Similar observations are being made for rebounding sea otters in California, which keep turning up in saltmarsh and seagrass meadows.
Why did we assume they didn’t like these habitats? Probably because by the time we studied them, their numbers and habitats had already been decimated.
Other examples of large consumers recolonising ‘unusual’ places include:
- Harp seals and black-backed jackals on the beach
- Gray wolves and river otters on the coast
- Mountain lions in grasslands
- Orangutans in disturbed forest
This is important for historical baselines of predator diversity, as the authors explain:
“For example, for salt marshes we need to insert alligators, sea otters, coyotes, bobcats and river otters (and likely bears) into the higher trophic levels in the food webs.”
The good news it that if these large consumers are comfortable across a wider range of habitats, then their recovery might be easier than we thought. The flip side to this is that many of the habitats it turns out they need, might not be protected or considered in their recovery strategies.
Are the ghosts of nature’s past haunting ecology today? by Brian R. Silliman, Brent B. Hughes, Leo C. Gaskins, Qiang He, M. Tim Tinker, Andrew Read, James Nifong and Rick Stepp was published in Current Biology on 7 May 2018 (Volume 28, Issue 9, Pages R532–R537).