A happy locked-down World Swallowtail Day!

Monika Böhm

On June 14 2020, we are celebrating the second ever World Swallowtail Day, and while we can’t have a traditional celebration this year, we can still go on a virtual journey to learn more about swallowtails, the flamboyant rockstars of the butterfly world.

This year, in a global pandemic, nature can seem very far away, especially for city dwellers like me. Even more reason to take every opportunity to reconnect with the wonders of the natural world. This Sunday 14th June provides such an opportunity, as we celebrate the second ever World Swallowtail Day, organised by our friends at the Swallowtail and Birdwing Butterfly Trust.

But why celebrate swallowtails? Swallowtail butterflies are magnificent creatures: think bright dazzling colours, intricately shaped and often tailed wings, and in some cases enormous wingspans! The swallowtail butterflies include the world’s largest butterfly, the Queen Alexandra’s birdwing (females can reach a wingspan of 25 cm or more), the crazily flamboyant species of the genus Bhutanitis, and some extremely high-altitude species: the snow apollos.

UK Swallowtail

Unsurprisingly, these amazing critters are also affected by habitat loss around the world, specifically activities which lead to the loss of caterpillar food plants. Use of pesticides, climate change and invasive species can have severe impacts on swallowtails too. In addition, swallowtails always have and still are highly coveted by collectors worldwide, and all birdwing butterflies as well as some other species of swallowtail have been included in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) to ensure their continued survival.

Researchers in ZSL’s Institute of Zoology are currently carrying out a full comprehensive assessment of the extinction risk of the world’s swallowtails for the IUCN Red List of Threatened Species – an exercise that was last carried out in 1985 by Mark Collins and Michael Morris! So far, we have published assessments for 154 species on the Red List, including the large birdwing butterflies, with another 171 species assessments drafted and waiting to flutter onto the IUCN Red List. This would not have been possible without a team of dedicated volunteers which have helped us to pull together all there is to know on these amazing species – thank you!

Tropical Swallowtail
Of these 325 species so far assessed, 27 species have been assessed as threatened - around 8% of the species assessed. Another 6% was assessed as Near Threatened, while nearly three quarters, or 240 species, were assessed as Least Concern, the lowest extinction risk classification on the IUCN Red List. Thirty-seven species have so far been assessed as Data Deficient, a relatively low number given how little we know about some of these species and the threats impacting them!

In short, this important work is far from done and World Swallowtail Day is a good time to reflect on all the work that still lies ahead. But how to celebrate World Swallowtail Day in times of social distancing? You can join us on 14th June on @ZSLScience twitter to discover the wonder of swallowtails and hear about our assessment project. You can also share your swallowtail stories, pictures, swallowtail-shaped cakes, drawings, or swallowtail-themed yoga poses etc. If social media is not your thing, we released a special episode of ZSL’s WildScience podcast in celebration of World Swallowtail Day 2019, featuring bird poo mimicking larvae, whiffy osmeteria, and Mark Collins of SBBT, the brains behind World Swallowtail Day, who talked about the amazing conservation work happening in Indonesia, Papua New Guinea, Jamaica, and even on our very own doorstep, Norfolk! You can also check out SBBT’s website for other virtual ways of celebrating, including swallowtail poetry and photo competitions! Swallowtails are amazing – spread the word!

Happy Swallowtail Day!


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