The Fascinating World of Flamingo Filter Feeding: How and Why They Do It

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Flamingoes are fairly large birds with a curvy neck and long legs, and they’re famous for their pink color and how they stand on one leg. There are five different species of flamingo, one of which is the Chilean flamingo (Phoenicopterus chilensis), which is featured in the above video. The clip shows the bird moving its beak from side to side in the water as it filter feeds.

What is filter-feeding and why do flamingoes get nourishment in this way? Watch the video, and then we will explore the science behind this fascinating feeding mechanism.

About Chilean Flamingoes

Chilean flamingoes weigh between 5.5 and 7.75 pounds and can grow to nearly 5 feet tall. Their plumage is pink and white, and their distinctive bent bill is black and white. They are found in temperate climates in South America, spending their time in shallow and muddy alkaline and brackish lakes in areas that have very little vegetation. Because of this, it’s an advantage for them to get their food from the water rather than from the land. This partly explains why they filter feed.

The Basics of Filter Feeding

As the name suggests, filter feeders get their nutrition by filtering food from water. To do this, they need a filtration organ that filters out or traps tiny particles. The exact structure of the organ varies between filter-feeding animals.

Filter feeders can also vary greatly in size. For example, baleen whales are filter feeders but so are tiny krill. The food they filter out varies by where they live, but it’s typically made up of tiny organisms like plankton. Flamingoes are unusual in that they are the only true avian filter feeders. Some penguins, petrels, and ducks have filter-feeding abilities but they are primitive.

Research shows that Chilean flamingoes capture and eat hundreds of different kinds of tiny animals by filter feeding. These include Calanoida (a type of zooplankton) and Alitta succinea (pile worms). Therefore, filter-feeding provides Chilean flamingoes with a rich and varied diet.

Filter Feeding Adaptation

Flamingoes filter feed with their head upside down. They sweep their specially adapted bill from side to side through the sediment so that water enters it. Their large tongue also acts like a piston drawing more water in. Filtration is provided by slits on the top of the bill and the comb-like structures lining the bill, which are called lamellae. As water is expelled, the food is filtered out, a process that happens about four times a second and causes ripples on the water.

Why Flamingoes Filter Feed

Filter feeding provides a rich and varied source of nutrition for flamingoes in fairly barren landscapes. We don’t know exactly when the flamingo’s ancestors started to filter feed, but it was probably a gradual adaption. Filter feeders can obtain a large biomass of food without using up a huge amount of energy. Therefore, it makes sense for a bird that had evolved to spend most of its time in the water to adopt this advantageous feeding method. Crucially, the flamingo’s piston-like tongue has now evolved to such a large size that it would be impossible for them to swallow a larger piece of food.