On vacation in Maine in 2013, film actor Christian Slater happened upon an orphaned eider duckling and, playing the part of the good Samaritan, brought it to the Center for Wildlife in York. There, Kristen Lamb, the center’s director, recruited the Hollywood star to help find the orphan a new mom. He joined the wildlife rehabilitators in their boat off the coast of Kittery to search for an eider hen with ducklings. When they spotted one, Slater released the foundling and watched as the eider mom retrieved the peeping baby.

Another successful animal adoption in the wilds of Maine.

While this may have been Maine’s most glamorous wildlife adoption, the situation itself is not unusual. Except in very rare instances, though, such adoptions are forged by humans.

“I’ve only seen it (occur naturally) once, and I’ve seen literally hundreds of litters,” state biologist Randy Cross said about his own area of expertise – black bears.

Young animals can become orphaned when they are fleeing a predator, a parent is struck by a car or killed by another animal, or a nest or den is disturbed and the parents flee. But with a little human cunning, some species can be persuaded to care for offspring not their own.

Wildlife rehabilitators in Maine often add a duckling or gosling to the broods of wild ducks and geese. And each spring, when black bears emerge from their dens, a few mother bears find an extra unrelated cub or two comingled with their own.

BIRDS OF A FEATHER

At the Center for Wildlife in York, Lamb helps facilitate eider duckling and Canada gosling adoptions every few years. She’s done it so often, she has her technique of releasing babies back into the wild down pat.

“You want them close enough so that the adults hear the babies peeping and come to get the baby,” Lamb said. “It’s the coolest thing. Mom will swim out and guide them to the (other ducks) in the ocean.”

Lamb said with common eiders and Canada geese, the adults seem to regard any nearby duckling or gosling as one of their own. With eider ducks, the hens protect and raise the ducklings; with Canada geese, both male and female geese watch over the goslings.

Lamb expedited one memorable adoption with a pair of Canada geese in her backyard last summer. After spending several days in her kayak scouring a beaver pond for suitable adoptive parents for an orphaned gosling she was caring for, one day two adult geese with goslings wandered into Lamb’s backyard. Lamb seized the moment. She ran and got the orphaned gosling and used her hanging laundry sheets as a bird blind.

“I let the baby go, and immediately either the mom or the dad looked behind and corralled him or her back to the siblings as if to say, ‘Now where did you go?’” Lamb said. “It’s amazing. They don’t miss a beat. They’re on such high alert to keep the babies together.”

Other water birds, such as wood ducks and teals, are too skittish to make this covert operation possible, Lamb said. But when the state finishes its current inventory of bird nesting sites, she hopes to try adoptions with other species, such as bluebirds.

Actor Christian Slater helps the staff of the Center for Wildlife look for a willing eider mom off the coast of Kittery in 2013. The wildlife center staff recruited Slater to help orchestrate the adoption of an orphaned duckling that Slater found. Photo courtesy of the Center for Wildlife

HELPING HAND

Black bear are the most common mammal to be used as adoptive parents, and state biologists in Maine have orchestrated such blended families for more than 40 years. The state’s 44-year radio-collar study, which tracks female adult bears, helps them to do so. Also, after sows give birth in early January, they slumber through the cubs’ first three to four months of life, and when they wake up, they don’t seem to notice an extra baby or two.

In his 37 years with the Maine Department of Inland Fisheries and Wildlife, Cross has handled close to 90 orphaned cubs, adopting out from one to three at a time. Biologists never place more than a few extra cubs with a sow, as they want to be sure she can rear her litter successfully. Female black bear produce a litter of up to five cubs every two years.

Cross often goes out on his own time to place the cubs – usually they’re moved to remote areas, often by snowmobile. Although saving a few cubs a year has no measurable impact on the state’s population of 36,000 bears, he believes the venture is meaningful. “We think it’s what the public would want us to do,” Cross said. “Most of our orphaned cubs are caused by some type of human activity. They deserve a second chance.”

Bears recognize their cubs by smell. So biologists “disable” the sleeping mother’s sense of smell by rubbing Vicks VapoRub on her nose. When a cub is dropped near the den entrance, the sow will hear it cry and instinctively pull it into the den and under her. Cross said past experience has shown that the new cub soon smells like its step-siblings, so the mother bear doesn’t reject it. Biologists know this because they check the 85 dens with radio-collared sows every year.

For the last 20 years, four specific radio-collared sows have been tasked with the job of “foster mom.” The biologists use this foursome because they are outside the radio-collar study area, so the data from their partially adopted litters – the result of human interference – won’t taint study results. Since black bears can reproduce until age 25, those four moms may raise many foster cubs.

“They are feeding their cubs through the winter. The maternal instinct is high,” Cross said. “They have no reason to suspect any of the cubs aren’t their own, that one simply fell out of the sky.”

Maine state bear biologist Randy Cross holds a cub he relocated to a den in 2009. For 20 years, biologists with the Maine Department of Inland Fisheries and Wildlife have placed orphaned cubs in the dens of bear sows for “adoption.” Photo courtesy of Randy Cross

A RARE OCCURRENCE

Biologists orchestrating adoptions of orphaned bear cubs is a common practice in other states. But Cross knows of only one time an adoption by a black bear occurred naturally in the wild.

In 2009, Cross visited the den of a radio-collared bear that had three cubs. In 2010, when he returned to the den, the sow suddenly had four yearling bears. Somewhere in the litter’s first year, the sow picked up an extra cub, and it wasn’t the work of biologists. Maine biologists keep meticulous records of the dens they visit each winter, and Cross said the fourth cub did not look like the original three.

“It came from another mother and somehow they got mixed up, but we don’t know who the other (mother) bear was,” Cross said.

Such natural adoptions have been recorded in only a few instances in other species. State bird biologist Kelsey Sullivan said common eiders sometimes adopt a duckling or two, but more often, a kind of “babysitting” takes place, where eider hens watch over ducklings that aren’t her own.

A common eider duckling that was orphaned is cared for at the Center for Wildlife in York. The center helps find wild eider hens that may be likely to adopt an orphaned duckling. Photo courtesy of the Center for Wildlife

“I saw a group of 25 eider ducklings with one hen in Portland Back Cove one summer. The hens that take on other ducklings are often referred to as Aunts,” Sullivan said. “They watch over each other’s brood. When you see a hen with a big giant brood, you know they’re not all hers.”

These incidents, called “misdirected parenting,” are very rare, said Noah Perlut, an associate professor of environmental studies at the University of New England. Perlut said the example of natural adoption among common eiders likely is caused by the overwhelming drive within the species to reproduce successfully and prevail over predators.

“Really what’s going on is that it is the time of year that the hormones are driving the birds to breed. It’s so strong they are willing to adopt,” Perlut said. “The cost-benefit is greater. It’s better (to the ducks) to raise one that is not my chick than to not raise chicks.”