Are there queer animals? Clownfish that change sex, and other species that demonstrate queer behavior

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When you hear about the beauty of everyone under the rainbow, you probably think about humans. But did you know that wildlife around the world also display same-sex sexual behavior, and can change sexes or be a combination of multiple sexes? This is all deeply natural, part of the vibrant world of biodiversity on the planet we call home.

Unfortunately, anti-LGBTQ+ taboos and discrimination throughout history have meant that this topic was rarely studied. Today, research is finally emerging. Here are a few ways that queer behaviors show up in the animal kingdom.

Animals that have same-sex relationships

Same-sex coupling and parenting has been observed in animals for centuries. Over 1,500 animal species engage in same-sex sexual behavior, which can help maintain the health of a species’ population.1 Take a 1910 scientific exploration in Antarctica, where these behaviors were seen in penguins.2 Two penguins of the same sex have been known to adopt abandoned eggs, protecting them and raising the chicks together.3

Elsewhere under the sea, male bottlenose dolphins build relationships with other males. They travel the ocean together, hunting for food and engaging in sexual behavior. And their relationship is deep and lasting – it’s common for these male dolphins to live together for decades!4

Among bonobos, who share almost 99% of their DNA with humans, homosexual encounters are even more common than heterosexual ones. Bonobo societies are led by a group of sexually connected females. Most bonobos are bisexual, and some scientists believe that the purpose of their sexual relationships is not only to reproduce but also to maintain harmony among the group.5

Clownfish swim in an anemone.

Bottlenose dolphins swim in a group. 

Animals that change sex

Often found nestled amid anemones in coral reefs, clownfish are instantly recognizable. But did you know that male clownfish can become female?

Groups of clownfish are led by a female, while the second-in-command fish is male. When the leader dies, the next-in-line male changes into a female in order to become the leader. The tightly maintained hierarchy helps to avoid conflict and facilitate a healthy life.6 And clownfish aren’t the only ones. In fact, around 500 fish species change their sex as adults!7

Animals that are a combination of sexes

Lots of animals have a combination of male and female characteristics.

In butterflies, this phenomenon can show up as distinctly as one wing displaying the pattern typically seen on male butterflies and the other wing displaying the pattern typically seen on a female of the same species. Others are less obvious, such as a body shape that combines aspects of a female and male body.8 Also known as gynandromorphs, intersex butterflies are rare, but special and stunning to ecologists and butterfly lovers alike.

Another example is the bearded dragon, a lizard found in Australia’s arid deserts. When its eggs incubate—the process of growing into an embryo and then hatching into a lizard—at higher temperatures, a genetically male egg could hatch into a female lizard with some male-like characteristics. An intersex bearded dragon’s body resembles the body of a female, but its boldness resembles the behavior of a male.9

Even whales can have both male and female body parts! Belugas, for example, can have reproductive organs from both sexes.10

A pregnant male seahorse. 

A mother bonobo with her child. 

And much more

Animals complicate sexual binaries and show queer behavior in so many more ways. For example, did you know that male seahorses can give birth? The reproductive process starts when males and females court each other in a dance-like ritual. The dance ends with the female putting her eggs in a pouch in the male’s stomach, where he fertilizes them. They will hatch right there in the father seahorse’s pouch, which can carry 2,000 babies at a time! He can even adjust the pouch’s water salinity to create the best possible conditions for his young.11

Many animals are considered sexually monomorphic, which means that it is very difficult to tell males and females apart from one another with our human eyes. So, the next time you see two animals of the same species coupling up, you may want to think twice and check any initial assumptions you have as to who you are observing together.

From butterflies in your backyard to penguins on Antarctic glaciers, animals around the world exhibit a beautiful breadth of sexual fluidity and same-sex relationships. Humans do too, and it deserves celebration.

Special thanks to science writer and New York Times bestselling author Eliot Schrefer for his support with this story.

[1] Monk, J.D., Giglio, E., Kamath, A. et al. An alternative hypothesis for the evolution of same-sex sexual behaviour in animals. Nat Ecol Evol 3, 1622–1631 (2019).
[2] Bawagan, J. (2019, May 2). Scientists explore the evolution of animal homosexuality: Imperial News: Imperial College London. Imperial News.
[3] McKinnell, J. (2018, October 12). Happiest feet: Australia has its first same-sex penguin foster parents. ABC News.
[4] Schrefer, E. (2022). Queer Ducks (And Other Animals). HarperCollins.
[5] Schrefer, E. (2022). Queer Ducks (And Other Animals). HarperCollins.
[6] Vince, G. (2003, July 10). Clownfish turn transsexual to get on in life. New Scientist.
[7] La Trobe University. "Secrets of a sex-changing fish revealed." ScienceDaily. ScienceDaily, 10 July 2019.
[8] Pavid, K. (n.d.). Beauty of the dual-gender butterfly | natural history museum. Natural History Museum.
[9] Li Hong, Holleley Clare E., Elphick Melanie, Georges Arthur and Shine Richard 2016The behavioural consequences of sex reversal in dragonsProc. R. Soc. B.2832016021720160217
[10] De Guise S, Lagacé A, Béland P. True hermaphroditism in a St. Lawrence beluga whale (Delphinapterus leucas). J Wildl Dis. 1994 Apr;30(2):287-90. doi: 10.7589/0090-3558-30.2.287. PMID: 8028121.
[11] National Geographic. (2021, May 4). Seahorse fathers take reins in childbirth.