Brain gymnastics: This is the name of one of the chapters of This is how birds do it By New York physicist and biologist Jennifer Ackerman. This chapter is about bowerbirds, of which there are nineteen species, such as the gray-necked bowerbird which has “a well-deserved reputation for being an extreme figure within a family of extreme birds”.
Researchers in Australia have discovered that a male bowerbird is courting a female by furnishing a gazebo containing 1,300 bones and shells. But it can be done more fanatical: Its cousin, the satin blue bowerbird, fills its ‘theater’ with shiny glass shards, beer can tabs, broken jewelry pieces, and straws. The thrones themselves are not nests, they are “theaters of seduction, a theater used by males as a backdrop for song and dance with which they attempt to please female visitors.”
Ackerman’s book, translated A new look at talking, working, playing, raising and thinking about birds, no less insane than the described birds themselves. The reader must actually perform mental exercises in order to observe some of these species, which occur mainly in Australia but also elsewhere. Names such as the golden-crowned gardener’s bird, the weaver’s weaver, the mask-weaver, the golden ground woodpecker, the ornate fairy, the red-breasted bird, the orange-breasted bird, and the spotted-breasted anteater roll over each other, each more exotic than the other in temptation, building Nest, behavior and raising young.
Those who are somewhat accustomed to reading “classic bird books” will be amazed at every page of Ackermann’s book: they never knew that nest building is linked to “neural networks and the reward system.”
Ackermann rightly quotes one of his fellow ornithologists: “There’s a lot we don’t know.” By this, she seems to justify to herself that her book is an eccentric bird book. Compare this to studying birds sea eagle Written by biologist and science journalist Ninke Bentema: One Book About Only One Bird, our country’s largest bird of prey has made an astonishing return for fifteen years. Highlight of the year 2020: Twenty breeding pairs and twenty-two young ones.
how is that possible? In the last century, the sea eagle (Haliaeetus albicilla) still an outcast, and now every nature lover embraces the golden brown bird with its hooked beak and white tail.
This is the paradox that Bentema illustrates in this classic bird book. Classic in a sense of how it works: After a personal description of sea eagles over the author’s park in Alaska, she saw sudden population growth here after she returned to the Netherlands. At first the birds go into hibernation, and then they come to breed. What is the secret force behind this success in a crowded, densely populated country increasingly deprived of nature and birds? She analyzes this process in a scientific way.
Areas such as Biesbosch and Oostvaardersplassen are of critical importance for population growth, such as IJsseldelta and Weerribben. The white-tailed eagle can be called a “creative bird” of the new nature with a lot of swamps, beavers and roughness. In this respect, Bentema’s book is also a book on the development of contemporary nature, in which opinions conflict head on.
The low point in this whole development is that Oostvaardersplassen was not attached to other nature reserves, and a fence was built around it, in part because Secretary of State Henk Bleker (CDA) “came to fix nature policy with the sharp axe,” says Bentema. .
Everyone knows the consequences of this, including the fence: the great shepherds died, and there was panic among nature lovers. The area appears to be nothing but “interesting nature” or “real nature,” according to nature management professor Frank Berendsey and raptor expert Rob Belsma respectively, who quotes Bentema extensively.
Then there’s the mighty sea eagle soaring above all the partying in Bentema’s book. She watches and tracks sea eagles from Alaska to Amsterdam and Waterladenden, living proof to her that “nature can suddenly come up with surprises at the craziest moments.”
Both books also present big surprises to the reader: whether it is a bowerbird that weighs barely 100 grams or a sea eagle that weighs about 5 kilograms, in the words of Nienke Beintema, there is always a lot of beauty around you. This also expresses concern about the future of nature, a topic that Ackermann is completely lacking. Her field of research covers the seemingly non-threatening animals of Australia.
Two biologists working in completely different ways, from classic scientific to highly imaginative, each time showing a different face to the inexhaustible world of birds.
A version of this article also appeared on NRC on the morning of July 2, 2021