A new paper suggests that alligators, sea otters, and other such predators are starting to re-populate ecosystems in which they were previously killed off by humans.
While it’s become a bit of a trope in the movies as predators start to encroach on areas that they weren’t a part of previously, it seems that real life is following suit with the introduction of alligators into ecosystems that they haven’t been present in for quite some time. However, while movies tend to make out such a situation as a major disaster, the addition of alligators and other predators into these ecosystems is a good thing for both animals and humans – at least according to the authors of the recent study.
The meta-analysis that suggests that these alligators are a benefit to their new ecosystems was published Monday in the journal Current Biology. Within, a team of researchers detailed their work in finding that several large predators such as alligators, mountain lions, and sea otters are starting to re-colonize ecosystems that were once targeted by humans – making a comeback in areas where they were previously hunted into nothingness.
According to the researchers in a Duke University press release, “It’s not an outlier or short-term blip. It’s the old norm, the way it used to be before we pushed these species onto their last legs in hard-to-reach refuges. Now, they are returning.”
While this is a new revelation, it does pull upon previous research – serving as a meta-analysis involving the “synthesis” of previous data from earlier studies and government reports. When they took a look at this data and isolated the similarities in previous findings, the researchers were able to determine that alligators, sea and river otters, mountain lions, orangutans, gray wolves and other predators are starting to appear in “novel” habitats rather than conventional ones.
Brian Silliman, Duke University professor and author of the study, stated that areas where the populations were starting to decline steeply due to hunting activities are starting to repopulate – going against the “tried-and-true large animal ecology principle” where animals choose where they make their home by virtue of being “habitat specialists.” For example, alligators generally choose to live in swamp ecosystems.
“But this is based on studies and observations made while these populations were in sharp decline,” Silliman continued. “Now that they are rebounding, they’re surprising us by demonstrating how adaptable and cosmopolitan they really are.”
As mentioned above, Silliman believes that the reappearance of predators like alligators in ecosystems where they were previously scarce is great for both human and animal populations. For example, Sea otters, which feed on Dungeness crabs, will start to control the population once again. These crabs were starting to eat too many of the sea slugs that were protesting estuarine seagrass beds from being overcome by epiphytic algae. It’s situations like these in which the introduction of alligators to ecosystems where they were absent can re-balance situations in which the populations were being thrown off balance. According to Silliman, initiatives to protect species that the introduction of predators like alligators are protecting would cost “tens of millions of dollars” – which leads to protection of vulnerable species as well as cost savings for human society as we no longer have to worry as much about the balance of these ecosystems which we have dramatically affected. Ecosystems are finely tuned, and the massive reduction of alligators have caused some major issues. It appears as if this phenomenon may be a good thing after all as ecosystems start to regain some of the stability that they have lost.
