In the Netherlands, 130 kilos of kingfisher flew around
The number of pairs of kingfishers is estimated by Sovon Vogelonderzoek to be more than a thousand. So that’s more than two thousand coincident adult kingfishers. With the bachelors and certainly a new generation, there will be four thousand kingfishers flashing through the Netherlands in late summer. That is much more than fifty years ago. The kingfisher is known as persecuted and successful. That is comparable.
Four thousand kingfishers: that is one kingfisher for every 4500 Dutch people. In terms of biomass, kingfishers are totally assuming. On a full stomach, three go in an ounce. So 130 kilos of kingfisher flew around in the Netherlands. With an average weight of almost 80 kilos, the 18 million Dutch people easily exceed the kingfisher mass, so one does not have to excel in algebra. About 1.4 billion kilos of people live in the Netherlands.
Shy and fast
Kingfisher is actually a strange name for this bird: a week of frost always thins out their ranks, because it is difficult to fish in frozen water. If fish-rich waters remain open, you have a chance of seeing kingfishers there. You have to be alert, because kingfishers are shy and fast. They often see you before you see them and then they flash convinced. Their shrill cries can show you the way.
White cheeks
During that cold week we were recently at the Drentsche Aa and we actually saw a kingfisher twice. There was a layer of ice on the expanse of water behind a beaver dam, but the stream kept mostly open with its cable. A dozen wild ducks bobbed and a heron trotted about. Many fish swim in the Drentsche Aa, including sticklebacks and other grits that are appreciated by kingfishers.
If you keep your cool, you can sometimes spy a fishing kingfisher for a long time. Through binoculars you can see the iridescent blue back and the fiery orange belly in the sun. The male has a black bill, of the female the beginning of the lower bill is orange-red. Both sexes have white cheeks.
Three times a week, biologist Koos Dijksterhuis writes about something that grows or blooms. Read here his earlier nature diaries.