Eagle Reintroduction Wales is an exciting project working on reintroducing both the golden eagle and white-tailed eagle to their historic ranges in Wales. Reintroducing eagles is not a simple task, we cannot release eagles into the Welsh environment free willy nilly! Our research is shaped around the IUCN reintroduction criteria which is a comprehensive, strict and highly regulated process governed by Natural Resources Wales (NRW).

Sophie-lee with a golden eagle (left) and a white-tailed eagle (right)

As part of these assessments we need to provide evidence that the modern-day Welsh environment is still suitable to hold both eagle species. Since 2016, we have been assessing the environmental compatibility of Wales. One of the environmental variables taken into consideration to restore golden eagles is climate change. Understanding the historical, current and future climate of Wales help’s us understand if the climate is and will be suitable for breeding golden eagles. From research conducted at Cardiff University by Masters Student Tabitha Gibbons, many Welsh upland regions have experienced increased spring rainfall (see below) – which could affect the breeding of many vulnerable upland breeding birds.

A graph showing the predictions of increased spring rainfall for all upland zones across Wales between 1910-2020. Note that Zone 11 (Upper Snowdonia National Park) appears to have experienced the greatest increase in spring rainfall, while Zone 6 (Radnor Forests) have not experienced much change in climate.

Change in spring rainfall is a key consideration for golden eagles, as an increase in May rainfall has been correlated to lower prey availability, less food provisioned to chicks and higher chick mortality. Despite many parts of Wales being highly suitable for the golden eagle, if the climate is not compatible then nest productivity may be low and species breeding will not be viable to keep the population sustainable over time. But how do we know if increasing spring rainfall will effect golden eagles, you ask?

Well … we can use an ecologically similar species of course! – The peregrine falcon is a perfect study model for an upland breeding bird of prey, like a golden eagle. Just as the nesting season got underway in spring 2021, three Browning Recon Force Advantage camera traps were installed at peregrine sites in upland Wales by licensed raptor biologist Jimmi Hill from Raptor Aid.

Jimmi from Raptor Aid installing camera traps on peregrine falcon nests.

Peregrine Falcons have similar breeding habitats and breeding phenology (timelines) to golden eagles. Both species lay a clutch of eggs (3-4) in late March or early April and eggs hatch early-mid May. Young stay in the nest for 35-42 days before fledging and stay around the nest until they are pushed away by their parents in early January before the breeding cycle starts again. So, by understanding how peregrine falcons are coping with increases spring rainfall we can get a more comprehensive picture about golden eagles – interesting huh!

Cardiff University is now analysing the data from the three Peregrine Cams installed in 2021, exploring: diet, provisioning rates and nest productivity in relation to spring weather. Last year was the wettest May ever recorded and only one of our upland peregrine nests successfully raised chicks.

We are excited to get started with the breeding season of 2022. We hope to install four camera traps at peregrine nests this year between April and October. Keep an eagle-eye out for any further updates!