The first day of April is notable mostly because that is the time of the year where pranks and deception rule the day. With that theme in mind, there are plenty of instances in nature where animals have evolved to be deceptive as a survival tactic. Here’s a look at bird species that use trickery to get ahead.
The fork-tailed drongo, an African native, likes to hang out with flocks of other birds. This bird typically fills the role of lookout and gives off an alarm call when predators are in the area, which sends the flocks of birds around it scattering into the air to flee. But there is one trick the drongo likes to play to score some easy food, and that is to set off a false alarm call. When the birds around it take off, the drongo goes in and steals their food. If the other birds start to catch on, there’s another trick up the drongo’s sleeve. Researcher Tom Flower of the University of Cape Town and his colleagues determined that the drongo can also mimic the alarm calls of 45 other bird and animal species.
Never underestimate the heroics birds are capable of when it comes to protecting their young. For example, it’s not uncommon to see little birds fly after birds of prey to drive them away from a nest or chicks. Some ground-nesting birds, which are especially vulnerable to being preyed upon, rely on deception to lure predators away from their nests and young. Birds like the killdeer, native to the U.S., Canada and Mexico, protect their nests by feigning injury. The adult killdeer will drag one wing while frantically flapping the other and giving off a distress call. If this doesn’t stop the predator from heading toward the nest, the bird will wobble closer to the predator to get its attention and then flies off when it has distracted the predator. The Northern lapwing employs a similar tactic to protect its young.
Some birds have taken the burden of raising chicks off their shoulders so to speak and instead put that burden on a non-related bird species. Reed warblers are just about the size of a sparrow but they sometimes get tricked into raising a bird four times its size. That larger bird is a cuckoo.
Cuckoo hens are known to fly into a reed warblers’ nest (as well as the nests of dunnocks and meadow pipits), when the parents are away so the cuckoo hen can lay an egg next to those of the reed warbler’s. When the eggs hatch, the unsuspecting reed warbler gets tricked into rearing the cuckoo’s chick. The cuckoo is a brood parasite, which describes an organism that relies on others to raise their young. This behavior is seen in birds, insects and some types of fish.
In a more extreme case of parasitic birds, the North American brown-headed cowbird has been observed “punishing” host birds by destroying their clutches if the host birds reject their eggs. According to Maria Abou Chakra, lead author of a study on the cowbird’s parasitic behavior, “They give the hosts no choice. If they wish to avoid retaliation, they need to keep the foreign egg.”
You can get an up close look at this “mafia-style” parasitic behavior in this Science article, which includes how the cowbird stakes out its target nest and has to get the timing just right to swoop in and leave its egg.