Evaluating protected area coverage for migratory bird species across space and time

Many species of migratory bird are in decline, and one of the issues they face is habitat degradation or loss of at some, or all, of the stages of their annual cycle. For migratory birds, this can be particularly problematic as they rely on different areas at different times of the year. Previous BTO research has shown that protected areas can increase bird occurrence, abundance, persistence and likelihood of colonisation. However, the dynamic nature of migratory birds and their reliance on multiple sites have not been taken into account when designating protected areas or in analysing how effective they are for particular species. 

This study aimed to improve our understanding of how well the protected area network serves migratory species by using data from EuroBirdPortal, which includes outputs from BirdTrack. The distributions of 30 widespread Afro-Palearctic migratory species were mapped for every week of the year, allowing the authors to determine how much of each species’ annual cycle is spent in areas that provide adequate protection at any given time.

The study then analysed these results in relation to the 2020 and 2030 Convention on Biodiversity Targets. For the 2020 target, governments aimed to protect 17% of land in their respective countries by 2020. This was considered achieved and was therefore replaced with the ambitious new target of protecting 30% of land in each country by 2030, or ‘30x30’ for short. 

Overall, only 13 of the 30 migratory species looked at in this study had 17% or more coverage by protected areas for the entire European part of their annual cycle. This is quite concerning considering that all of these widespread species could be expected to have 17% or more cover by protected areas under the 2020 target.

The study also found a bias in the protected area network, with protected areas more likely to be situated in regions with little agricultural and development value – farmland was underprotected. This is particularly notable for Ortolan Bunting, which was the least well protected species examined. This species is threatened by agricultural intensification and would benefit from more protected farmland within its range.

It is hoped that by using this study’s analytical method to identify specific weeks of the year when key migratory species are most vulnerable, due to a lack of protected area cover, conservationists can focus on protecting primary sites at those particular times. For example, seasonal hunting bans have recently been shown to significantly benefit the declining Turtle Dove across areas of Europe.

This approach could guide planning for new protected sites being designated under the 30x30 target. In this way we can help to ensure migratory species are adequately covered by protected areas in the future and hopefully help to halt or reverse their declines.

Notes

This project was funded by NERC grants to the British Trust for Ornithology and the University of Durham (NE/T001070/1, C.H., S.G.W., P.A.S. and NE/T001038/1, J.A.B., S.R.B., C.M.H. and J.W.P.H.), and additionally, generously supported by a gift in Will from Michael Welch, for which the authors are extremely grateful.