“It’s bought it! It’s bought it! Oh my goodness, it’s bought the pelican!”
When Sheelagh Halsey of Cheshire, England joined me for a wildlife safari in Level Reyes Nationwide Seashore within the fall of 2022, she and her husband have been hoping to see bobcats and badgers. As a substitute, they ended up being amongst a handful of individuals on the planet to witness a river otter killing a Brown Pelican.
As a full-time wildlife photographer and cinematographer, I’ve additionally spent the previous decade as a nature information at Level Reyes. In a single space of the park that I’ve visited a whole bunch of occasions, I’ve noticed and documented river otters participating in all manners of conduct: mating, elevating their younger, even heading off coyotes. However the first time I witnessed an otter assault and kill a pelican in 2019, I used to be really shocked. Since then, I’ve seen it occur not less than a dozen occasions, with every grisly encounter being equally outstanding.
Because the Halseys and I walked the shoreline that day following a household of river otters feeding within the water, the animals instantly turned their consideration from fish to a floating flock of pelicans bathing in the midst of the lagoon. From my previous observations, I immediately knew what was about to occur: moments later one of many otters torpedoed out of the water, grabbed a pelican by its gular pouch, and held the hen’s head underwater till it drowned.
The Halseys have been as astonished as I used to be that first time. “I couldn’t consider my eyes,” Sheelegh informed me recounting the assault. “It was really unbelievable.”
River otters have a different eating regimen, together with fish, reptiles, amphibians, crayfish, and shrimp. They’re additionally identified to hunt smaller birds resembling coots and gulls—one thing I’ve personally witnessed. However watching them add a hen as massive as a pelican to their meals has been fascinating. Although the conduct has been documented once before in Golden Gate Nationwide Recreation Space in 2006, by all accounts it’s new for the otters of Level Reyes and has far surpassed what was noticed at Golden Gate. Watching and documenting this conduct evolve over the previous few years has been a outstanding expertise for me and some different fortunate photographers, together with my good pal Sarah Killingsworth, whose photos are additionally included on this piece.
Whereas this shift in dietary desire could be shocking, there could possibly be a easy clarification, in accordance with Megan Isadore, govt director of River Otter Ecology Mission. “River otters are opportunistic hunters,” she says. “Level Reyes Nationwide Seashore otters have found that pelicans listed here are a big and comparatively simply caught supply of sustenance.”
They’re additionally plentiful. As soon as listed underneath the Endangered Species Act largely as a result of impacts of DDT, Brown Pelicans have had a outstanding restoration because the banning of the insecticide in 1972. The birds formally shed their endangered label in 2009, and the present world breeding inhabitants is estimated at 370,000. In Level Reyes, numbers have adopted the identical trajectory, in accordance with knowledge from the annual Audubon Christmas Hen Rely. Throughout the Nineteen Seventies, this rely averaged fewer than 150 Brown Pelicans yearly, however tallies in some current years have topped 900.
The birds are most considerable right here within the fall and winter, once they return or move by means of from their breeding grounds in California’s Channel Islands and south alongside the Pacific coast to Mexico. Jutting 10 miles out into the ocean, the Level Reyes peninsula gives various habitat for the pelicans to relaxation and feed with its shoreline, bays, and freshwater lagoons. That is additionally when the otter predation peaks.
The birds congregate in massive numbers within the freshwater lagoons, the place they’re as equally susceptible floating on the water’s floor as they’re standing on the shoreline. When the birds are within the water, the otters swim instantly right into a pod to assault. Sometimes, the entrance pelicans discover the predators simply in time and take to the sky, leaving the others susceptible. On land, I’ve typically seen the otters hunt in teams, with one charging onto the financial institution to flush the pod into the water for the opposite otters to pursue. As soon as they’ve a pelican, they seize its head or gular and maintain the hen underwater till it drowns. Your entire otter household begins feeding on the pelican instantly. This yr, I’ve observed that the otters are taking a number of pelicans throughout a single hunt extra typically than they ever have earlier than.
Regardless of the beforehand recorded otter predation at Golden Gate, this conduct is essentially unknown within the hen world, and what’s taking place at Level Reyes has additionally amazed others once they be taught in regards to the assaults. “The conduct is critical and engaging,” stated Kenn Kaufman, hen skilled and Audubon journal area editor, after seeing the images on this piece. “It appears outstanding {that a} river otter would assault one thing as massive as a Brown Pelican. After all, birds aren’t very heavy for his or her dimension—a Brown Pelican often weighs lower than 10 kilos, whereas a full-grown river otter can weigh greater than 20 kilos.”
Some folks have puzzled whether or not this behavioral change is an indication of a extra critical ecosystem challenge affecting the otters’ typical meals sources. That is actually a chance. Cows graze the lands instantly adjoining to the lagoon. The National Park Service web site warns that streams from surrounding agricultural areas circulation into this lagoon and doubtlessly carry dangerous micro organism. A 2021 media release by In Protection of Animals states water high quality testing at this location exceeded water high quality standards for E.coli and enterococci. In the meantime, the creator of the paper centered on the Golden Gate otter predation posited that eutrophication of the water could possibly be chargeable for killing bigger fish, fueling the dietary shift. However that was only a concept, and till extra rigorous analysis is carried out at Level Reyes, any hyperlinks between habitat well being and this meals shift is theory.
Curiously, what we do know is that this addition to the river otter eating regimen is altering the ecology of the realm itself. Final yr, throughout one stroll alongside the shoreline the place the predation is going down, I counted greater than 25 pelican carcasses. This fall there have been considerably extra because the pelicans have develop into a extra outstanding meals supply for the otters. These carcasses present a straightforward meal for scavengers.
Ornithologist and naturalist David Wimpfheimer has been observing wildlife in Level Reyes for many years, and he’s very accustomed to the realm the place the otter assaults are occurring. “There was a noticeable improve within the variety of coyote sightings on this space with the current improve in pelican predation by river otters,” he says.
River otters typically stash smaller birds resembling gulls among the many rocks and crevices on the lagoon ground, making them tougher for coyotes to find and eat. (The coyotes can and can dive to search out the carcasses.) However the otters don’t do that with the pelicans. They abandon them when performed feeding. Coyotes with their eager sense of scent can detect the corpses and are continuously patrolling the shoreline on the lookout for an opportunistic meal.
A number of species of birds have additionally been noticed consuming the carcasses, together with Turkey Vultures, Widespread Ravens, and Northern Harriers. Although there isn’t a proof but, the bobcats the Halseys had hoped to see may also profit. “This opens up a wholly new meals supply for a lot of animals within the space.” Wimpfheimer says.
As I’ve adopted this astonishing improvement over the previous few years, I’ve typically puzzled if the pelicans acknowledge the carcasses of their species that litter the lagoon’s edge. Do they see them and never perceive? Do they know and easily settle for the chance? How they may adapt to this new predator stays to be seen. Thus far, they’ve proven no indicators of adjusting their conduct. However one factor is evident: The river otters of Level Reyes have discovered a brand new supply of meals—and it doesn’t look to be coming off the menu anytime quickly.
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Watch: Daniel Dietrich created a brief documentary, titled A Style For Birds, that captures cases of otter predation on pelicans. Warning: Some graphic scenes included.
Daniel Dietrich is an award-winning wildlife photographer, filmmaker, and cinematographer dwelling in Inverness, California. His work has been featured on TV, in quite a few publications, and in a number of movies. Dietrich sits on the ethics committee for the North America Nature Images Affiliation (NANPA), he based the nonprofit Conservation Kids, and he owns Point Reyes Safaris, a wildlife images safari firm in Northern California.