Brown Skuas Can Recognize Individual Humans, New Study Shows
Ornithologists from South Korea and Poland have shown for the first time that Antarctic brown skuas ( Stercorarius antarcticus ), a species that typically inhabited in human-free areas, are able to recognize individual humans who disturbed their nests.
Brown skuas ( Stercorarius antarcticus ). Image credit: B. Navez / CC BY-SA 3.0.
Dr. Won Young Lee of Korea Polar Research Institute and co-authors report in the journal Animal Cognition that they performed a series of experiments at Narebski Point on King George Island, Antarctica.
“We examine individual human recognition abilities in a wild Antarctic species, the brown skua ( Stercorarius antarcticus ), which lives away from typical human settlements and was only recently exposed to humans due to activities at Antarctic stations,” they said.
The ornithologists checked seven skua nests once a week to monitor the breeding status, and the skuas attacked at closer distances with repeated visits of the team members.
To test if the birds specifically distinguish the scientists who visited the nests from those who did not, a pair of humans consisting of nest intruder and neutral human approached to the nests and walked towards the opposite directions.
All seven skua pairs followed and tried to attack the nest intruder but never followed the neutral human.
“I had to defend myself against the skuas’ attack. When I was with other researchers, the birds flew over me and tried to hit me. Even when I changed my field clothes, they followed me. The birds seemed to know me no matter what I wear,” said co-author Yeong-Deok Han, from Inha University.
“It’s amazing that brown skuas, which evolved and lived in human-free habitats, recognized individual humans just after 3 or 4 visits,” Dr. Lee added.
“It seems that they have very high levels of cognitive abilities.”
The cognitive abilities of Antarctic animals have not been well studied before. Brown skuas have been recorded to steal food from other birds or even steal breast milk of nursing elephant seals.
According to the team, opportunistic feeding habits may make them cleverer with time.
“Since this area has been inhabited by humans only after the Antarctic research stations were installed, we think that the skuas could acquire the discriminatory abilities during a short-term period of living near humans,” Dr. Lee said.