Collected Evidence: Collected Evidence: Control predatory mammals and birds (foxes, crows, stoats and weasels) A total of nine individual studies from France and the UK (including five replicated controlled studies and a systematic review) looked at the effects of removing predators on birds. Three studies found controlling predatory mammals or birds (sometimes alongside other interventions) increased the abundance or population size of some birds. One of these studies from the UK found numbers of nationally declining songbirds increased on a site where predators were controlled, but there was no overall difference in bird abundance, species richness or diversity between predator control and no-control sites. Five studies (two replicated and controlled, two before-and-after trials) from the UK found some evidence for increased productivity, nest or reproductive success or survival of birds following bird or mammal predator control (sometimes alongside other interventions). A randomized, replicated, controlled study found hen harrier breeding success was no different between areas with and without hooded crow removal. A global systematic review including evidence from European farmland found that reproductive success of birds increased with predator removal.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F699https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F699Thu, 20 Dec 2012 13:08:22 +0000Collected Evidence: Collected Evidence: Restore or create peatland Six studies evaluated the effects on butterflies and moths of restoring or creating peatland. Two studies were in each of Finland and the UK, and one was in each of the Netherlands and Ireland. COMMUNITY RESPONSE (3 STUDIES) Community composition (1 study): One replicated, paired, site comparison study in Finland found that mires restored by filling ditches and cutting trees had a moth community which was intermediate between drained and pristine mires. Richness/diversity (2 studies): One replicated, paired, controlled, before-and-after study in Finland found that after mires were restored by raising the water table and removing large trees, they had a higher species richness of mire specialist butterflies than before restoration or than unrestored, drained mires, and a similar species richness to pristine mires. One replicated, paired, site comparison study in Ireland reported that protected bogs re-wetted by blocking drains had a similar species richness of moths to unrestored and unprotected bogs. POPULATION RESPONSE (5 STUDIES) Abundance (4 studies): Two before-and-after studies (including one replicated, paired, controlled study) in the UK and Finland found that bogs re-wetted by blocking drains and mires restored by raising the water table and removing large trees had a higher abundance of rosy marsh moth caterpillars and mire specialist butterflies than before restoration or than unrestored mires, and a similar abundance to pristine mires. Two replicated, paired, site comparison studies in Finland and Ireland found that mires restored by filling ditches and cutting trees and bogs restored by blocking drains (along with legal protection) had mixed effects on moth abundance compared to unrestored sites depending on species. Survival (1 study): One replicated study in the UK found that where water levels had risen due to peatland restoration, large heath butterfly caterpillars had lower winter survival than in areas where water levels had not risen. BEHAVIOUR (1 STUDY) Use (1 study): One replicated, site comparison study in the Netherlands found that wet heathland where water levels had been recently raised were less frequently occupied by Alcon large blue than sites where the water level had not been raised. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3948https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3948Sat, 13 Aug 2022 14:59:56 +0100
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust
For a full list of, and information about, our champions:
All Evidence Champions
About our champions, why and how to become one:
Become an Evidence Champion

This website uses Cookies

We use limited Cookies to run the site and to analyse our traffic (none for site vendors). By using this site, you will be providing your consent to our use of Cookies.

Accept & continue