Greater Flamingo at Tama Zoo have bred again this year. Just like last year, artificial eggs were placed on the nesting platform to encourage breeding behavior, and as a result, egg-laying began in mid-April, with hatching starting one after another in the latter half of May. As of the end of July, 20 chicks have hatched and are growing up healthy and strong.

Actually, something a little unusual happened during this year's flamingo breeding season.

Two flamingos, "White 48" and "White 7," formed a pair last year. Like other flamingos, these two incubated eggs, hatched them, and carefully raised their chicks. While this may seem normal, both of these flamingos are actually male. While same-sex pairing is a common occurrence in many bird species, not just flamingos, no instances of same-sex pairs successfully hatching eggs have been recorded at Tama Zoo over the past 10 years.


Greater Flamingo protect and raise their chicks.
Now, some of you might be wondering, "Can male flamingos lay eggs and raise chicks together?" First of all, regarding eggs, only females can lay eggs. It is likely that this same-sex pair started incubating eggs that another female had laid and abandoned (or perhaps they took the nest and eggs?).

As for what happens after the chicks hatch, males can raise them on their own. Flamingos secrete a red substance called "flamingo milk" from a part of their esophagus called the "crop," and they feed this flamingo milk mouth-to-mouth to the chicks until they start to eat solid food. Since both males and females can secrete this substance, this same-sex pair was able to feed their chicks flamingo milk, just like other heterosexual pairs.

The reason why they form same-sex pairs in this way is not clear, but there have been reports that there is little difference in behavior between same-sex and opposite-sex pairs during incubation and raising of young. The pair we observed this time was two males, but it seems that females can also form pairs, and sometimes even three birds can form a mating pair.

In any case, not just this same-sex pair, but any pair working together to protect their eggs and raise their chicks is always a source of admiration. You can see flamingos raising their young from May to August, when the eggs hatch, so be sure to come and see them at Tama Zoo during this time.

[Tama Zoo North Garden Animal Care and Exhibition Staff, Mimatsu]

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(August 1, 2025)