I know you, bad guy! Magpies recognize humans

May 13, 2011

Most people who have had the experience of having pet animals in their houses have the gut feeling that the animals can "recognize" us. They seem to recognize our faces, our voices and our smell. One way or another, they respond to us differently from other people.

Actually, this is not just a gut feeling. Numerous studies have shown that domesticated animals, such as honey bees, chickens, , sheep, dogs, llamas, penguins, seals, rabbits, horses, and octopuses, can recognize humans individually. The common thing among these animals is that they are exposed to an environment where they see humans and interact with humans every day. Then the question is, can the recognize people too?

Although there are many anecdotes that wild animals do so, is surprisingly scant. Only very recently, Northern and American crows have been shown to recognize humans who threatened their nests or captured them.

Well, one more species is added on the list, the Black-billed Magpie. Every spring, researchers from Seoul National University (SNU) and Ewha Womans University are conducting a routine, annual survey of the breeding success of a magpie population within the SNU campus. But something was weird in 2009. One of the crew, Mr. Won Young Lee, a PhD student who was always climbing up the nests and taking out the eggs or chicks for the survey, and also the first author of the paper being printed in the journal , started to be followed and scolded by the owners of the nests. "I remember", Mr. Lee says, "when a magpie came down from a nest tree scolding at me. I was with a second researcher at that time, and I tried to fool the magpie by giving my cap to the other person. But this did not work! When I moved away the bird followed me rather than the fellow observer wearing my cap". The owners of the nests that were not accessed by him did not show any response to his presence. Based on this "accidental" finding, the researchers quickly designed a field experiment. A pair of humans, a climber and one non-climber, wearing the same clothing, was presented to magpies to see whether magpies show selective responses to climbers. The result was that all the tested magpies showed aggressive responses to the climbers only.

"It was very unusual thing," says Dr. Sang-im Lee, the leader of the magpie survey team at Seoul National University. "We've been doing exactly the same survey every year for more than 15 years but nobody was followed by birds." Then, what was so special about this one, unfortunate, crew member? "Usually we take turns when we climb up the nests. But in 2009, Mr. Lee always climbed to the nests because he was putting cameras into the nests." So, repeated presentation of the same human as a threat to the nests could have facilitated the learning process of magpies, and could have led to the recognition of this crew member.

Since birds, such like magpies, are not that much sensitive to smell, and the distance between the experimenters and the magpies were more than 10 meters, it is not likely that the birds recognize smell of a person. It is more likely that they use vision. And because the climber and the non-climber wore the same clothing and walked similarly in the experiment, what remains the most different between the two humans is the face. Dr. Piotr Jablonski, who designed the experiment in this study, says "it is amazing that magpies can recognize one individual human out of twenty thousand people present in the campus." As a foreigner living in Korea, he confessed that he has had difficulties discriminating people, especially during the first year or two. "All Asian looked similar to me but probably not to the magpies."

Just as Dr. Jablonski's discriminatory skills get better with time and being exposed to more Korean people, the magpies in university campus could have been able to recognize humans who pose threat to their nests by having a lot of exposure to people. This process, hypothesized by the researchers, does not require high level of cognitive skills, which is indicated by a long list of (some of which does not seem to be really smart) that can recognize individual human.

Researchers call for more species to be tested and for future studies with species of clearly different cognitive abilities tested in a standard manner in two types of habitats: heavily human-populated urban areas and wild natural habitats where exposure to human presence is minimal. If the researchers are right, then the animals living in urban areas would show higher level of discriminatory skills to humans than those living in rural areas. How many different animals can recognize us individually and exactly how they recognize us will be revealed after more data is collected.

Explore further: Male monkey filmed caring for dying mate (w/ Video)

Provided by Seoul National University

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User comments : 27

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Mercury_01
5 / 5 (2) May 13, 2011
"Most people who have had the experience of having pet animals in their houses have the gut feeling that the animals can "recognize" us. They seem to recognize our faces, our voices and our smell. One way or another, they respond to us differently from other people."

Are you Fing serious? Is the assumption here that our pets cant tell the difference between their owners and anyone else? This is written as if people actually would ever think that way. "Hey man, I swear Im not like, a hippie or anything, but sometimes I think my dog like, recognizes me, or something. I dont know, I guess thats just crazy though right?"
Tason
not rated yet May 13, 2011
I say 'why and how they can recognize human?' 'Are we invaders or friends or destructors?' I think the possible roles human playing in their (domesticated or wild animals) eyes and the ways or the features they recognize are important to answear these questions.
Mercury_01
5 / 5 (1) May 14, 2011
I, for one, welcome our new corvid overlords. http://www.youtub...5yIaEzZ4
epsi00
5 / 5 (2) May 14, 2011
Are there still people out there that think that animals in the wild do not use their brain and senses? Apparently yes.
Noumenal
3.7 / 5 (3) May 14, 2011
Are you Fing serious? Is the assumption here that our pets cant tell the difference between their owners and anyone else? This is written as if people actually would ever think that way. "Hey man, I swear Im not like, a hippie or anything, but sometimes I think my dog like, recognizes me, or something. I dont know, I guess thats just crazy though right?"


No, you don't understand. If there hasn't been a specific 'scientific' study done then it isn't real. The only place in which you can find any real answers is the journals in which they write this crap down. Why do you even bother spreading your worthless opinions about animals. They are, at best cardboard cut-outs until enough 'studies' have been done to give them properties. I'd even be hesitant to say that they're made of flesh if I hadn't read that study they did on that...
Mercury_01
not rated yet May 14, 2011
I just cant believe scientists still talk and think like this. This isn't the 1600's. The inquisition isn't going to decapitate you for using both hemispheres of your brain. Some things are just obvious, arent they? I mean, Sure I might wonder if a sheep can recognize me. Theyre not exactly the brightest crayons in the box, but a dog or a horse? Use common sense! Its free!
DavidMcC
not rated yet May 16, 2011
What's your problem, Merury? The article says that both pets and many wild species CAN do what every pet owner knows they can do, which is to distinguish between individual humans. The only question is, for each species, which is the primart sense that they use? Sometimes it might be a combination of senses, I suspect.
JVK
1 / 5 (1) May 16, 2011
1. Avian olfaction is quickly dismissed despite current knowledge of pheromones in birds.
http://www.spring...1784t0u/
2. No animal model suggests that birds use vision to recognize human faces, which makes it extremely unlikely!
3. If they can visually recognize the faces of humans, they are probably able to use their same highly developed visual acuity and specificity to recognize the facial features of the most physically attractive potential mates.
4. Retroactively, using a vague model of human visual recognition, even the explanation for conspecific sex identification via colorful plumage may fall by the way to favor face recognition in birds as an aspect of sexual attraction. Next we can discuss face recognition in both the birds and the bees!
5. We could then take comfort in claims that we are more like birds than we are like other mammals or insects that use olfactory acuity and specificity to sniff out the most reproductively fit mate.
6. But first
DavidMcC
not rated yet May 16, 2011
JVK,
2) if animal models don't incorporate face recognition then maybe that's a problem with the model, not the birds!
Corvids might not have the same visual acuity as raptors, but it won't be very poor, especially in combination with UV vision, which might show us up in a different light, who knows?
3) Why would face recognition take precedence over plumage? It doesn't necessarily in humans when there are other parts of the anatomy on display! :)
DavidMcC
not rated yet May 16, 2011
It occurs to me that a simple experiment could show whether facial recognition is important, and that is for the "favoured person" to wear a realistic face-mask of an "unfavoured person", and vice versa. Does that fool the magpie? The bird's UV vision means that the face masks would have to be realistic in the near UV as well as visible, which is a complication, but not an insuperable one.
DavidMcC
not rated yet May 16, 2011
Also, JVK, I assume the bit about bees was a joke, right? Visual acuity in bees is poor, OK. Their eyes are predominantly motion detectors, (and their ocelli are UV polarization detectors).
JVK
1 / 5 (1) May 16, 2011
Yes, the bit about bees was sarcasm, and made more clear by the end of my post which was cut. It read:
6. But first we must ignore any neurophysiological link from olfaction to hormones and behavior in birds, bees, and mammals to then favor some unknown mechanism that links what they see to behavior.
7. Three cheers for the potential revival of the innate releasing mechanism, a dated, bird-brained concept if ever there was one neurophysiologically speaking, of course.

Re: study design. Studies of mammals show that once the response is conditioned by pheromones to occur, visual and or other sensory stimuli will elicit the same changes in hormones and behavior. The mask would not avoid the confound of conditioning. It is this conditioned response that many people fail to consider when they present results that are relatively meaningless if perception develops due to epigenetic effects of environmental stimuli on genetically predisposed behaviors (as has been recently suggested).
Mercury_01
not rated yet May 16, 2011
What's your problem, Merury? The article says that both pets and many wild species CAN do what every pet owner knows they can do, which is to distinguish between individual humans. The only question is, for each species, which is the primart sense that they use? Sometimes it might be a combination of senses, I suspect.


Yes, there's nothing wrong with the article. No doubt, the researchers know full well how intelligent animals are. My problem was with whoever wrote the introduction.
DavidMcC
not rated yet May 17, 2011
The mask would not avoid the confound of conditioning. It is this conditioned response that many people fail to consider when they present results that are relatively meaningless if perception develops due to epigenetic effects of environmental stimuli on genetically predisposed behaviors (as has been recently suggested).

Maybe not, JVK, but the point would still be made or denied that it was the visual appearance of the face to the bird that was what determined who was perceived as the "enemy" and who the "friend".
JVK
1 / 5 (1) May 17, 2011
The point has already been made in these study results that it is facial characteristics that determine perception of the enemy, although no known neurophysiological mechanism allows for this. To me that's like saying who needs biology when we can simply decide what stimulus is involved in cause and effect. It doesn't matter how many times you prove it's the facial stimuli. The requirement for biologically /physiologically meaningful results is a gene-cell-tissue-organ-organ system pathway that links the stimulus to the behavior.
DavidMcC
not rated yet May 18, 2011
JVK, I certainly wasn't saying "who needs biology". You only have to look at other threads here that I have contributed to. I was just interested in the sensory aspect of it, that's all, whereas you seemed to get that part of it wrong in this case.
DavidMcC
not rated yet May 18, 2011
... Another point is that if you don't get the sensory part of the model right, you might not get the rest of the model right.
DavidMcC
not rated yet May 18, 2011
... Because interpretation of any experiment might well involve assumptions about the sensory aspects of it, as was the case in the work cited in the OP.
JVK
1 / 5 (1) May 18, 2011
Sorry, DavidMcC, I didn't mean to imply that you were saying "who needs biology." I'm sure we agree that interpretation of any experiment should be based on what is known about animal models of physiology and behavior. In vertebrates, including avian species, the link from the sensory environment to behavior is an olfactory/pheromonal link. Apparently, this fact has been ignored in the interpretation of the study results we are discussion. But see, for example: Pheromones in birds: myth or reality? at http://www.spring...1784t0u/ and the list of related articles.
DavidMcC
not rated yet May 18, 2011
JVK, perhaps the experimenters should have tried blind-folding the poor, tormented magpie. That would at least show unambiguously whether it could use its nose as well as its eyes! If olfaction/pheromone detection were relevant, the bird would still become aggressive, and if it could still tell where the aggressor was, that would be conclusive, wouldn't it?
DavidMcC
not rated yet May 18, 2011
... Of course, this depends on whether a magpie can get used to having a blindfold on. That, I don't know!
JVK
1 / 5 (1) May 18, 2011
The presumption from both non-human animal and from human studies/models of behavior is that their sense of smell allows the discrimination of visual stimuli paired with olfactory/pheromonal input. Over time this discrimination is not possible in animals made anosmic. I'm not sure what results would be conclusive to those who want the results to show the primacy of visual input. Did you read that homing pigeons navigate via their sense of smell? How many years did people presume that their skills were due to something else? Obviously, we're stuck with some incongruity across species whether the birds are blinded or can see the light coming from the different facial characteristics of nest-disturbing researchers.
DavidMcC
not rated yet May 18, 2011
"I'm not sure what results would be conclusive to those who want the results to show the primacy of visual input."
I was thinking it should be possible to devise an objective method, that didn't depend on what anyone wanted the answer to be.

On the issue of pigeon navigation, I think they are flexible about that, because while it has been shown that smell is used when there are no convenient roads to follow, for example (as in the Italian experiment), it has also been noted that they tend to follow motorways for routine "commuting" when that happens to give a good, short route for them.
DavidMcC
not rated yet May 18, 2011
... Also, when they are close to home, they would surely have to find the actual location using their eyes, otherwise they could fly staight into a tree, or something! :)
JVK
1 / 5 (1) May 18, 2011
Of course visual input is important in sighted animals, as is auditory input in animals that can hear. However, three things are required to directly register information about others in the brain and to link that information to vertebrate behavior. The three things are electrophysiological activity, gene expression, and the initiation of a hormone response from neurons in the brain (i.e., a neuroendocrine response).
1. Mammalian social odors chemically act on olfactory receptors to elicit electrical activity in neurons.
2. The electrophysiological transduction of these social odors from chemical signals to electrical signals, allows them to effect gene expression.
3. Social odors effect gene expression in neurons of the brain that initiate the secretion of gonadotropin releasing hormone (GnRH). The change in GnRH secretion is a hormone response that occurs in neurons of the mammalian brain. It is a neuroendocrine response.
The same neurophysiological mechanism is found in birds.
JVK
1 / 5 (1) May 18, 2011
The neurophysiological mechanism allows vertebrates to distinguish self / non-self differences at the level of MHC diversity. That's more than sufficient to associate the social odors of another species with other physical features, like those involved in face recognition. Until someone details the neurophysiological mechanism that would allow a bird to visually distinguish one human face from another, we clearly have an example of olfactory primacy in birds that is misrepresented, as is typical in cross species comparisons.
DavidMcC
not rated yet May 19, 2011
JVK, you may well be right, but it is possible that the two people concerned in the experiment were more easily distinguished from each other in the near UV than in the visible. Sight is important to birds, and that's why I think the blind-folding experiment would help - is it smelling them apart or not?

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