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Do Birds Mate With Other Species (Crossbreeding)?

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Eurasian hoopoe and European bee-eater

Crossbreeding is the formal term for mating two creatures of different species, breeds, or varieties. Crossbreeding is more common in certain animals than others. For example, crossbreeding is relatively common in birds since many species have much of the same DNA. 

In fact, it is estimated that as much as 10% of bird species have mated with another species. Because of this frequent crossbreeding within birds, it can be hard to determine species of a bird since there are so many hybrids out there.

To learn more about bird crossbreeding, read on. In this article, we fully look at the phenomenon of birds mating with species other than their own, resulting in crossbreeding.

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Do Birds Mate with Other Species?

To answer the question bluntly, birds often mate with other species. Around 1000 bird species are known to have mated with another bird species at least once. This hybridization could have happened in the wild or in captivity.

Most often, birds of the same genus will mate since they have similar DNA. Less commonly, two species of different genus will mate too. In birds, certain species are more likely to cross the species line when mating than others.

Hybridization Explained By Scientific Class

Hybridization occurs whenever animals cross the species line when mating. As a result, birds that are a product of crossbreeding are called hybrid birds. If you want to get technical, here is how hybridization occurs based on scientific class and species of birds:

Scientific Classification And DNA

All birds belong to the scientific class called Aves. All animals within this class have feathers, a high metabolic rate, and lay eggs, though there are more similarities than just these three. Within the class of Aves, there are over 20 orders, and many species within each order.

For example, the Anseriformes order has families of ducks and geese while the Psittaciformes order has families of parakeets and parrots. Within the parrot family, there are around 300 species.

Although this information may not seem relevant to the question at hand, it is thoroughly relevant. Whenever animals are the same species, they have shared DNA that makes reproduction more possible. The further away species get on the scientific classification chart, the more difficult it is for them to reproduce simply because their DNA is vastly different.

It is for this reason that many species only reproduce within their own species. For example, a goose will only mate with a goose and a parakeet will only mate with a parakeet.

Occasionally, animals will mate with other species within their same order. These animals will have similar DNA, but the DNA won’t be as similar as same-species DNA. So, a Hummingbird may mate with a Swift, a bird that belongs in the same order as the Hummingbird. Only rarely do birds mate outside of genus since the DNA is even more different than different species mating.

two hybrid parrots flying
Image Credit: Ondrej Prosicky, Shutterstock

Related Read: Do All Birds Have Feathers? Why Do They Have Them?

Is Crossbreeding Healthy in Birds?

Even though crossbreeding is relatively common in birds, it still is not very healthy. Most hybrid birds do not live past their infancy stage. Occasionally, hybrid birds can live into adulthood if their parents’ genes are particularly healthy. Most often, these healthy genes happen whenever the two species are closely related.

From an evolutionary standpoint, mating is only successful if the offspring can reproduce as well. In many hybrid birds, reproduction is not an option because they are sterile. This is a common phenomenon in other animals as well. That is why mules are sterile – they are the crossbreeding between a donkey and a horse.

That is not to say that no cross bred birds are healthy. Certain species are more likely to mate with other species simply because their DNA is so similar, often resulting in healthy hybrids. It is simply uncommon for this to happen, but not impossible.

Most Common Birds That Mate with Other Species 

Interestingly, certain birds are more likely to crossbreed than others. Ducks, gulls, hummingbirds, and birds of paradise often crossbreed on their own, especially with other birds within their own genus.

Hummingbirds are some of the most interesting to study. Today, at least 20 Hummingbird hybrids have been reported. Likewise, it’s not uncommon for a single family of Hummingbirds to have intergenetic hybrids. Many hybrid Hummingbirds are even healthy.

It has been suggested that these bird types mate with other species more frequently because their genetic profile allows them to. This would make sense since there is very little difference between the Hummingbird species, duck species, etc. 

The Problem of Classification

One thing that’s difficult about crossbreeding is the issue of classification. Whenever two species mate, it’s unclear what that means for the current standard of organization. For example, is species inaccurate classification if many Hummingbird species can reproduce with one another?

Although the classification system we currently have is the best option at the moment, there may come a time in the future when the classification is altered to account for species that frequently crossbreed with other species and animals.

Related Read: Do Birds Mate With Their Siblings? What You Need to Know

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Final Thoughts

Even though it may sound weird, birds mate with other species pretty commonly in comparison to other animals. Don’t get us wrong, most birds still prefer mating within their own species, but it’s not out of the question for certain birds to mate with others not within their own species.

If you are interested in learning more about bird hybridization, we recommend taking up serious bird watching. Occasionally, experienced birdwatchers can pick out hybrid hummingbirds and ducks, which can be a very interesting feat.

Featured Image Credit: Bildagentur Zoonar GmbH, Shutterstock

About the Author Robert Sparks

Robert’s obsession with all things optical started early in life, when his optician father would bring home prototypes for Robert to play with. Nowadays, Robert is dedicated to helping others find the right optics for their needs. His hobbies include astronomy, astrophysics, and model building. Originally from Newark, NJ, he resides in Santa Fe, New Mexico, where the nighttime skies are filled with glittering stars.