Parental Age, Inbreeding and Incubation Method Influence Extremely Low Hatching Success in the Ex‐Situ Population of the Extinct in the Wild Sihek Reproductive success rates are a key parameter determining the recovery potential of ex-situ managed threatened species, with high rates often being required to produce offspring for wild releases wh...

So happy to share that after years of hard work our paper on low hatching success in the #ExtinctInTheWild #Sihek has now been published in Animal Conservation! Read more here: zslpublications.onlinelibrary.wiley.com/doi/10.1111/... #Ornithology #ConservationScience 🌍 🦤 🧪

Bird species lost from wild lays first eggs on new island home | The Zoological Society of London Endangered bird recently returned to the wild have laid first eggs on their new Pacific island home, making them the first wild eggs for the species in almost 40 years.

So exciting to see #sihek eggs confirmed in the wild for the first time in nearly 40 years! www.zsl.org/news-and-eve... #ConservationScience 🌍 🦤 🧪 #Ornithology

Participants of Adder Day 2025 pose under a metal sculpture of a dragonfly on Hounslow Heath

A very successful Adder Day 2025! The weather was almost too nice this year, the scaly fellas didn't hang around for long.

Thanks very much!

Manuscript currently in review, with more info coming with publication - watch this space! Acknowledgements to my supervisors: @rnf.bsky.social, John Ewen, Gary Ward & Amanda Trask, co-authors Gina Ferrie, Erica Royer, Suzanne Medina & Scott Newland, and all zoos that kindly provided data.

Our results find that to best support the growth of the human-managed population of sihek so that releases can continue into the wild, younger and less-inbred males should be prioritised for breeding, and eggs should be parent incubated where possible. See shorturl.at/w0OpY to learn more! 6/6

Analysis showed that #sihek overall hatching success is only ~30%, compared to ~83% across birds and ~79% across similarly threatened birds and those under human care (doi.org/10.1111/acv....), with sire inbreeding, sire age and artificial incubation likely the driving factors behind this 5/6

We began by collecting egg outcome data from many of the institutions that care for sihek, then quantified egg viability and hatching success rates before running Bayesian generalised mixed effects models to determine which factors may limit sihek reproductive success 4/6

The #Sihek (Guam kingfisher) is one such EW species, living solely in human care from the 1980s until a successful release into the wild in 2024. This project aims to understand sihek hatching success in order to help the human-managed population to thrive and enable support for future releases 3/6

Unfortunately, highly threatened birds and those under human care often suffer from low hatching success due to population bottlenecks, small population sizes and inbreeding depression amongst other reasons (doi.org/10.1111/brv...., doi.org/10.1111/acv....) 2/6

#ExtinctInTheWild (EW) species are some of the most at risk in the world, existing only in human care. I’m a PhD student at @zslofficial.bsky.social and @ucl-c4ia.bsky.social studying how time spent in human care may affect EW bird recovery #BOU2025 #Ornithology #ConservationScience 🌍 🦤 🧪 1/6

Hi Andrew! I'd be grateful if you could add me to the science feed please: www.zsl.org/about-zsl/ou... Thanks!