(Seagulls calling)
[Justin Suraci] Racoons are mesopredators which means they’re medium-sized animals
that will eat almost anything.
Larger apex predators, things like cougars, wolves, and black bears will terrify them.
But what we’re wondering is, what happens when there’s no apex
predators around to scare them?
[Michael Clinchy] They never stop eating on these islands with no predators.
So they’re out day and night, in the intertidal foraging whenever they can
with their head down all the time.
[Justin Suraci] So we’ve got this 200 meter section of shoreline, where we are
effectively simulating predator presence with these vocalization playbacks.
(Dog barking) So here we’ve got two computer speakers
and a small MP3 player in this bottom compartment.
If you’re a racoon, that would be terrifying. So if you’re scared, you have less time to
eat and you spend more time being vigilant or hiding out, and this can lead to lower
impacts on your prey. What we expect to see is that racoons reduce their use of this
200 meter treatment site because we’ve simulated predator presence and they think
it’s scary. We can essentially protect the crabs and fish by scaring the
racoons off of sections of beach.
(Dog barking) [Michael Clinchy] I hear the dog barking
and I ignore it. And there really is a dog, and I’m dead.
And we looked at their responses to cougars and bears, and they don’t
pay any heed to cougar and bear playbacks. But they respond to the dog playbacks.
Cougars and bears have been gone for a century and so they obviously lost their
sensitivity to those cues. We can asses how much of an effect the racoons are having
on the red rock crabs by going out at just after the low tide and looking for crab kills.
So we call it Crab Scene Investigation. And we can identify racoon killed crabs
because they leave the carapace— that’s the shell of the crab—it’s cracked
open, they usually leave bits of flesh, and they leave a pile of appendages,
so they’re very messy eaters.
[Justin Suraci] We’ve got two sets of trail cameras out at each of our treatment sites.
The first set is motion sensitive, and they’re set along the high shoreline
so we get shots of any racoons that are traveling across the high shore that are sort
of set back away from the intertidal. We’ve got another set of cameras that are set to
time lapse and are focused on the intertidal so they’ll get shots of any racoons that are
actually down on the shoreline foraging.
[Michael Clinchy] So there’s three things that tell us convincingly that
these racoons are fearless.
First is that they’re out during the day, which you don’t see elsewhere.
Second is that we see them foraging 100 meters away in the intertidal,
far away from cover, far away from where they could flee from predators.
Third is that when we quantify it, they actually spend less than
one second out of every minute looking up to see what’s around.
[Justin Suraci] Fear is a part of life and it definitely can be good for the
environment, and the racoons in the Gulf Islands, they’re eating so many red
rock crabs, small fish, and other intertidal organisms that they may be having severe
impacts on biodiversity in the islands.
We can’t necessarily reintroduce cougars to instill fear, so we’re looking at other
ways to instill fear in these racoons.
(Seagulls calling)
[Natalie Gray] This is wolf urine.
This is wolf anal gland.