06/04/2026
Another interesting read!
In the early 1980s, a Pennsylvania bear biologist named Gary Alt carried an orphaned black bear cub into a winter den, placed it beside a sleeping wild mother, and walked out. The mother woke up in the spring raising one more cub than she had given birth to. She never knew the difference.
Then Alt tried it outside the den, in spring, and the mother smelled the strange cub and killed it.
That failure is what led to the Vicks VapoRub.
Alt was the black bear biologist for the Pennsylvania Game Commission for twenty-seven years. During that time, he expanded the state's bear population from roughly three thousand to nearly fifteen thousand animals. He also dealt with a problem that every bear state faces. Orphaned cubs. A mother bear gets hit by a car, gets shot during season, gets killed in a management action, and leaves behind cubs that are too young to survive alone. The standard options were captive rearing or euthanasia. Alt wanted a third option. He wanted to give the orphan to a wild mother who was already raising her own.
The biology said it should not work. A black bear mother identifies her cubs by scent. She licks them after birth, and the chemical signature of her saliva marks them as hers. If she encounters a cub that does not carry her scent, she treats it as a threat or an intruder. Outside the den, in the active season, a mother bear that smells a strange cub will reject it. In some cases, she kills it. Alt learned this the hard way.
Inside the den was different. A hibernating mother is in a reduced metabolic state. Her senses are dampened. Her aggression is lower. Her discrimination between her own cubs and a stranger's is weaker. Alt tested the theory by opening a winter den, placing an orphaned cub beside the sleeping mother's existing litter, and backing away. The mother did not wake. The orphan nestled against her body alongside her biological cubs. When the family emerged in the spring, the mother was raising all of them. The orphan had been absorbed.
The technique worked reliably in the den. But orphaned cubs do not always appear in January. Sometimes they show up in April or May, after the mothers are already active and mobile and operating with full sensory awareness. Alt needed a way to introduce orphans to awake, alert mothers without the mother detecting the scent mismatch that would trigger rejection or killing.
He tested two approaches. In the first, he treed a mother bear and her cubs using dogs, released the orphan into the trees, and kept the mother separated from all the cubs for two to seven hours. The extended contact between the orphan and the biological cubs during the separation appeared to transfer enough shared scent that when the mother returned, she accepted the group without identifying the newcomer. The orphans were accepted.
In the second method, Alt sedated the mother, smeared Vicks VapoRub in her nostrils, and placed the orphan with her while she was unconscious. When the sedation wore off, the menthol overwhelmed her olfactory system. She could not distinguish the orphan's scent from her own cubs' scent because she could not smell anything except eucalyptus and camphor. By the time the Vicks wore off, the orphan had been in contact with the mother and siblings long enough that the scent lines had blurred. The orphans were accepted.
Alt later refined the technique further. He found that simply rubbing Vicks VapoRub on the orphan cub, without sedating the mother, was enough to inhibit aggression during introduction. The menthol on the cub's fur masked the foreign scent long enough for the mother to begin treating it as part of the group.
One Pennsylvania mother that supplemented her diet with garbage raised six cubs through the summer, including two orphans Alt had placed with her. Six cubs from a single sow is an extraordinary litter by any measure. The mother did not distinguish between the four she had birthed and the two that a biologist had carried in from somewhere else and smeared with cold medicine.
Lynn Rogers, the Minnesota bear biologist whose long-term research we referenced in the Bear 56 post, confirmed and expanded on Alt's work. Rogers published a framework in 1985 describing four options for orphaned cubs: returning them to their own mothers, introducing them to foster mothers, leaving them alone or transporting them to favorable areas, and raising them in captivity for later release. He noted that mothers with cubs would readily accept strange cubs in dens and sometimes outside dens under certain conditions. The den introduction, Rogers wrote, was the cleanest option. The mother's reduced state during hibernation made acceptance almost automatic.
The technique is still used today. In February 2020, the Virginia Department of Game and Inland Fisheries placed an orphaned cub, rescued by a dog that had carried it home in its mouth, with a wild foster mother nursing three cubs of her own. Virginia's wildlife center maintains GPS-collared female bears specifically so they can locate denning mothers when an orphan needs placement.
Conservation officers track the collar, listen for cub sounds in the den, assess whether the mother has capacity for an additional cub, and make the placement. The mothering instinct is just very strong in most animals, wildlife biologist Bill Bassinger told reporters. Generally, most females will take the young back, even after it has been handled by humans.
A black bear mother that would kill a strange cub on sight in May will adopt it without question in February if you put it beside her while she is sleeping. A black bear mother that would kill a strange cub on sight in May will adopt it without question in May if you rub enough Vicks VapoRub on the cub to overwhelm her nose for an hour. The difference between a dead orphan and a living one is timing, temperature, and a two-dollar tube of menthol ointment from a drugstore.
Gary Alt figured that out in the mountains of northeastern Pennsylvania with a sedated bear, a jar of Vicks, and an orphaned cub that had nowhere else to go. The technique he developed has been used in bear states across the country for forty years. Every spring, somewhere in the Appalachians or the Rockies or the North Woods, a wildlife officer opens a den, places a cub beside a sleeping mother, and walks away knowing that the mother will wake up in April and count one more mouth to feed without ever questioning where it came from.
Source: Alt, G.L. (1984). "Cub Adoption in the Black Bear." Journal of Mammalogy 65(3). / Rogers, L.L. (1985). "Aiding the Wild Survival of Orphaned Bear Cubs." Wildlife Society Bulletin. / North American Bear Center / Virginia Department of Wildlife Resources.
