Czech scientists reveal why some Prague birds fear humans more than others
A new study by Czech ornithologists reveals why some birds are more scared of humans than others. By examining nearly 70 species in Prague’s parks and cemeteries, researchers found that the key factor shaping a bird’s “fear of humans” is its long-term coexistence with people, not how common the species is in the city.
Why are certain bird species in Prague, such as magpies or thrushes, more afraid of humans than pigeons, blackbirds or sparrows? That’s the question at the heart of a study by ornithologists from the Department of Environmental Studies at the Faculty of Science, Charles University.
To find out, they have been conducting extensive observations in Prague’s parks and cemeteries, measuring a so-called proxy of fear: the distance at which a bird flees from an approaching human. One of the forty locations regularly visited by Peter Mikula from the Faculty of Environmental Sciences at the Czech University of Life Sciences is Prague’s Letná Park.
“Fear in animals can be measured using flight-initiation distance. It’s very important to remember the point you start from and the point at which the bird takes off, so that we can measure that distance,” he explains.
The study brought an unexpected discovery. Surprisingly, how common a species is in the city doesn’t seem to affect its level of fear. Instead, what matters is how long the species has lived side by side with people.
Species that have lived in Prague since before World War II react far less to human disturbance than species that settled in the city more recently. Pigeons, blackbirds, sparrows and nuthatches are less wary of humans because they’ve lived in Prague for decades or even for centuries, says ornithologist Jan Grünwald from Charles University’s Faculty of Science.
“When a species has spent many, many generations exposed to human disturbance, you can expect it to adapt to the very specific environment that cities clearly are.”
On the other hand, species that only began nesting in Prague after World War II tend to be much more fearful. Among the new arrivals that are most skittish are two species of herons: the grey heron and the night heron. And even magpies, although increasingly common, tend to fly away quickly, says Mr. Mikula:
“The magpie is still a rather skittish species. It depends a lot on how you approach it. If you walk straight toward it and it sees that you’re aiming for it, the flight distance is usually quite long. But if you ignore it, the distance is shorter. Magpies are very intelligent birds.”
The research, published in the prestigious journal BMC Biology, took over five years. In total, the researchers carried out 4,500 flight-distance measurements across Prague’s parks and cemeteries, studying 68 bird species.
