Same-sex White Stork pair observed in Czech Republic

Two female White Storks have formed a same-sex pairing in the Czech Republic.

The storks, which are using a nest in the town of Chýnov, both laid eggs in early May. Local ornithologists say it is the first time that they have recorded a same-sex pairing of the species.

The nest is being filmed by a camera, which has allowed researchers to monitor their behaviour since their arrival earlier in the spring.

The two females have been observed preparing the nest together, greeting each other, clapping their beaks and caring for a clutch of eight eggs – such a high number has never been recorded in a single nest for this species and it was this which confirmed beyond all doubt that both birds were females.

The same-sex pairing of White Storks in Chýnov, Czech Republic, in May 2023 (CAM Chýnov).

One of the females is ringed and has been confirmed as one half of a heterosexual pair which used the same nest in 2022 and raised three young to fledging. The male from this pair failed to return to the area in 2023.

Ornithologist Michael Strnad discovered the same-sex pairing. He said: "Although a new male also appeared at the nest and last year's female courted him, he flew away without mating and did not appear again. Later, a new female persistently taunted last year's female until she accepted it and repeated mating occurred. That it was two females was only proven by the laying of eggs."

He added: "It will be very interesting to see if anything hatches from the eggs because storks mate on the nest, rarely elsewhere, so there is a high probability that the eggs are unfertilised."

Meanwhile, some 50 km away in the town of Horní Cerekv, a rare pairing hybrid pairing of Black Stork and White Stork was noted. The male Black Stork mated with the female White Stork, but was later seen being driven off by a male White Stork.

A mixed pair of Black and White Storks was documented mating in the Czech Republic this spring (Jan Ipri / CSO).

Zdeněk Vermouzek, director of the Czech Ornithological Society (CSO), said: "Black and White Stork nesting together is rare, but it does happen occasionally. A similar case has been noted in Germany this year. It will be interesting to watch the further progress of the nesting and whether any storks will hatch from it. For now, we do not know of a documented hybrid of a Black and White Stork."