Mockingbirds can recognize a face among the crowd

The birds are watching. They know who you are. And they will attack.

Not in the movie! This is a scientific fact!

University of California biologists report that mockingbirds can identify and remember those who are thought to threaten their nests. When the gray-white white birds that live throughout these Southeast cities recognize uninvited guests approaching their nests, they will screech, dive and even scratch at the other guests. Meanwhile, they completely ignore other people passing by or standing near that person.

'We tend to treat all mockingbirds equally, but their feelings are not the same,' said Doug Levey, a UF biology teacher. 'The birds mimic of course do not treat anyone as well as anyone.'

The study is described in detail in an article published in the Proceedings of the National Academy of Sciences online.

This study clearly shows that wild animals live in natural environments capable of recognizing individual individuals of other species, Levey said. This may be the answer to the question of why mockingbirds and some birds and other animals have affluent lives in densely populated cities and suburbs - when other species are completely does not exist, or just lives scattered in these places.

'The big question in studying urban ecosystems is why some animals grow and thrive right next to people,' Levey said. 'A hypothesis is that they have the innate ability to innovate and adapt in ways that the other species cannot do.'

Mockingbird is one of the most popular birds living at the Florida University dormitory in Gainesville, where they nest in trees and in bushes close to the ground. In the study, volunteers walked up to the bird's nest, slipped their hands through the foliage and lightly touched the nest, then walked. Three days later, these people repeated their actions on the very bird's nest they touched the first day. On the 5th day, other volunteers changed sessions. A total of 10 volunteers tested on 24 nests, at least 5 times on each during the summer and last spring, the nesting season of the mockingbird.

A mockingbird trying to scratch Devon Duffy, a student at the University of Florida with the aim of chasing her away from her nest at university dormitory on April 19, 2009. It seems that the bird realized she was the one who threatened the safety of the nest in previous times. Student volunteers approached and touched parodies and birds in a study. The results of this study show that mockingbirds recognize, remember and react to people they consider to be threats while completely ignoring others passing by or near the nesting area. (Photo: Lou Guillette / University of Florida)

On the 3rd and 4th days of the experiment, the birds quickly flew from their nest every time a familiar volunteer appeared, even though they went to the bird's nest from the other day and of course. The dress is also different. As the days go by, they fly out faster and emit more warning sounds. Even some belligerent children scratched the scalp's scalp , the scratch is not really dangerous, but annoying, because these birds tend to scratch at the same spot on the skin every day. head, Levey said.

However, on Thursday, when other students approached the nests, the birds hardly moved their wings until they flew out at the last minute. They also emit less warning sounds and less attack than the previous days.

In a dormitory with more than 51,000 students, the road is always full of students going back and forth every day, there are thousands of different people appearing in a radius of several feet around the bird's nest during the breeding season.

However, the mockingbirds in this study are clearly capable of identifying and memorizing individual individuals, based on the characteristics of their two approaches. Levey says this is very different from laboratory tests, where pigeons can only recognize humans after a long period of training. 'It takes only 60 seconds for you to appear that mockingbirds can identify and distinguish you among other students in the dormitory,' Levey said.

For most wildlife, urban development takes away the habitat and brings many enemies. Many species have left or are gradually extinguished, but some species still exist, even some of them thrive. It is clear that such species are better adapted to human habitats. Why?

Very few people disturb the parrot's nest, so it is hard to be the answer. In fact, according to Levey, the ability to recognize people suggests that the bird's ability to recognize it has helped them cope with a complex urban environment - such as the ability to judge which cat can. recognize the bird's nest, and which one merely passes through the nest area.

'We do not believe that mockingbirds have evolved to the ability to distinguish individual individuals in humans. Mockingbirds and people have not lived together long enough for them to do this. ' Levey explained. 'We just assume that these experiments reveal the incredible potential of mockingbirds: the ability to perceive things around them and react appropriately when danger approaches.'

References:
Levey et al.Urban mockingbird quickly learn to identify individual humans.Proceedings of the National Academy of Sciences, 2009;DOI: 10.1073 / pnas.0811827106