This year, even more pages are being added to the Flamingos’ success story at Zoo Basel. Thirty pink chicks have once again hatched in the zoo’s Flamingo enclosure.
Flamingos (Phoenicopterus roseus) are a permanent feature in Zoo Basel, and have been since 1879! The first Flamingo chick hatched there in 1958. Since then, the zoo has successfully bred over 500 Flamingos. Zoo Basel is one of the world’s leading zoos for Flamingo breeding.
This year is a hugely successful one. Of the 120 adult birds at the zoo, approximately 90 participated in the breeding activities. About 30 chicks have already hatched, and there is a good chance that more will still follow.
Visitors to Zoo Basel’s spacious Flamingo enclosure will instantly notice two things about them: they are pink and have long legs. However, if you look closer, you will also notice that their bills are bent. This is an ingenious form of natural evolution that is totally unique to these birds.
If you watch the flamingos when they eat, the reason for their bent bills becomes clear. They are dipped into the water ‘in reverse’ (upper bill first) and swung back and forth. Lamellae with fine hairs, that work somewhat like the whalebones of baleen whales, are found on the lower and upper jaw. As a Flamingo moves its slightly open upper bill back and forth in the water, it also moves its tongue back and forth like a pump. This drives the water, together with the tiny food particles it contains, into the bill. As the tongue presses forwards again, the bill is closed slightly. The water runs along the lamellae out of the bill, and the food particles get stuck on the fine hairs. Fine papillae on the palate and tongue then transport the food on towards the stomach. This process takes place so quickly that all onlookers will see is the splashing of water around the curved bill. The tongue pumps water in and out up to five times per second.
Unlike adult Flamingos, newly hatched chicks have a very straight and small bill. In their first few days of life, the chicks are entirely dependent on their parents’ crop milk, a milky, slightly reddish juice produced in the cells of the upper digestive tract. Both parents produce this milk and feed their chick. At eight days of age, the chicks start to search for food in the water. With their straight bills, however, they are unable to catch a great deal of food and instead pick at the mud or make circular motions in the water. Only at about two months of age do Flamingos’ bills start to bend. The young birds refine their technique and start to search for food independently.
Flamingos’ curved bills are the result of their adaptation to an otherwise inhospitable habitat. They specialize in living in salt-water lakes and lagoons, where they primarily eat saline crabs, mosquito larvae, tiny insects and algae.