What Do Cuckoo Birds Eat?

You may have heard about the cuckoo’s song or their strange nesting habits, but did you know that their eating habits can be every bit as interesting? Cuckoos are not picky when it comes time to feed, and at times, their need for protein can drive some pretty odd behaviors. So, what do cuckoo birds eat? In this article, we’ll answer that question and more.

What Foods Do Cuckoo Birds Eat?

what food does cuckoo eat

Cuckoos are generally considered insectivores, meaning they mostly eat insects. However, when food is scarce, they will eat a variety of things. 

According to Audubon, cuckoos tend to hunt for insects in the branches of trees and shrubs, but they will sometimes catch flying insects in midair.

A cuckoo’s favorite food appears to be caterpillars, especially the plump, fuzzy or hairy varieties. They aren’t particular about which kids they like, as they will often eat caterpillar species that other birds will avoid.

Cuckoos tend to eat insects that are destructive to crops and plant life, such as the cabbage white butterfly and its larva. They will also eat a variety of moths and butterflies, as well as some types of spiders and centipedes.

Some cuckoos eat more than just insects and invertebrates. They may be driven to seek out other food sources during times of drought or famine, or they may simply adapt to eating a wider variety of foods based on what’s available in a given region. 

Some alternate food sources of cuckoos include lizards, snakes,  and small rodents such as mice. Some cuckoo species will even eat fruit and berries.

With so many food options available, cuckoos are rarely threatened with the possibility of starvation.  

What Does a Baby Cuckoo Eat?

Cuckoos are known as brood parasites; this means they lay their eggs in the nests of other birds, which then raise the young cuckoos as their own. Because of this, baby cuckoos eat whatever they are fed by their host parents.

Young cuckoos are often raised by meadowlarks and reed warblers, both of which tend to feed worms and insects to their young. Depending on the species of the host parent, young cuckoos may be fed whole insects or food regurgitated by the parent.

It is possibly at this young stage of life when cuckoos learn to eat a variety of foods, as they may also be fed bits of fruit and many different invertebrates. Like the adults, young cuckoos are generally not picky about what they’re given to eat, as long as they receive a steady supply of it.

Do Cuckoos Eat Other Birds?

do cuckoos eat other birds

We’ve established that cuckoos eat a lot of different things. They may even be considered opportunistic eaters, as they will eat whatever’s available to them if food is scarce.

This begs the question: will they eat other birds?

Most cuckoos do not stoop to this level of semi-cannibalism, but there have been rare occasions when large cuckoos have been spotted eating birds of smaller species or their chicks.

It is fairly common for cuckoos to eat the eggs of other birds, but they rarely eat other adult birds. When laying eggs in another bird’s nest, a cuckoo may steal one of the existing eggs and either eat it or push it over the edge of the nest. 

Sometimes, cuckoos will eat baby birds. While it’s unclear what drives this behavior, it may be due to food shortage or because the cuckoo plans to lay an egg in the nest and feels the need to remove the existing young.

The following video shows a cuckoo attacking and eating a bulbul chick. The video is a little graphic; watch at your own risk.

How Much Do Cuckoo Birds Eat?

There are around 140 different cuckoo species, and they vary widely from about 6 inches long to over 30 inches. Some weigh less than an ounce, while others weigh well over a pound.

With such a wide range of birds and sizes, it’s impossible to say exactly how much a cuckoo eats on a regular basis. It may also be affected by factors such as season, habitat, and the type and quality of food available. 

Generally, smaller birds require more food relative to their body weight. They need to eat more during cold weather because the higher calorie content helps them keep warm.

What’s more, cuckoos tend to eat more of the foods they like when food is plentiful. They may eat less of whatever is available if they don’t have a consistent supply of the caterpillars they enjoy so much.


Cuckoo birds are insectivores that will eat a variety of other foods if need be. They prefer plump, hairy caterpillars, but they also regularly eat butterflies, spiders, grasshoppers, cicadas, centipedes, and many other invertebrates.

Sometimes, they will even eat small rodents, lizards, and other animals, as well as some types of fruit. They have even been known to eat the eggs and young of other birds.

4 thoughts on “What Do Cuckoo Birds Eat?”

  1. They drop their eggs in other Bird’s nests. They kill off the host eggs or babies and often their new foster mother is fooled and feeds them. Their known as nest parasites


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