27/10/2020

Reviewing the science on the effects of gamebird releasing – same evidence, different conclusions

Woodland Ride Created For Shooting

GWCT Research

Three documents have been published recently that review the ecological effects of pheasant and red-legged partridge releasing:

  • In August, a comprehensive report commissioned by Natural England and the British Association for Shooting and Conservation (Madden & Sage, ‘NE review’).
  • In October, an RSPB report (Mason et al., ‘RSPB review’) that updated and expanded a review undertaken ten years ago by some of the same authors including a new overall synthesis of effects.
  • Also in October, a peer-reviewed paper in the journal Wildlife Biology with primarily GWCT authors (Sage et al., ‘GWCT-led review’) containing a summary and synthesis of the ecological effects.

Overview of reports

The RSPB and Natural England (NE) reviews are discussed in a blog by the RSPB’s Jen Smart comparing the two review reports, which notes that both the evidence base and many of the findings are similar. The GWCT-led review was published at the same time as the RSPB review and blog, provides a summary of effects using a numerical synthesis and is a standard peer-reviewed paper, so is much shorter than the two reports (you can read more on this here).

We welcome many of the sentiments and agree with many of the points in the RSPB blog. The RSPB and NE reviews (and the GWCT-led review) do cover the same literature on the ecological effects of releasing pheasants and partridges, and the majority of detailed interpretations of that literature are similar.

However, the way that the information is interpreted and summarised has been done very differently. This is important because the interpretation of these documents and hence the policy position of organisations can be heavily influenced by the summary findings of such reviews.

In this blog we look at how this happened and, in particular, at how the RSPB has presented and interpreted the data in a way that we disagree with. This is the way that the six main ecological themes that are discussed and illustrated in the synopsis were defined.

Using those themes, the headline finding of the report is that there are five negative and one positive overall effects of releasing. But how were the RSPB review’s main themes defined? They were selected in advance by the authors. There doesn’t appear to be any scientific basis for the selections made, and the reasoning for them is unclear.

Habitat management theme

One of the six themes in the RSPB review is habitat management associated with released game, the benefits of which are recognised by all, being highlighted in all three documents. The NE report considers two main habitat management themes:

  • Preserving, maintaining and expanding semi-natural habitats such as woodlands and hedgerows, which is a common part of managing a lowland pheasant shoot.
  • The planting of game crops, other crops, maintaining field margin habitats, etc, in and around otherwise intensively farmed fields, which are almost universal game management activities.

Each of these two very separate management themes have a wide range of activities within them that have distinct and very different consequences for habitats, birds and other wildlife. The NE report did not use themes or topics to provide a synthesis of effects, but the GWCT-led review used the literature itself to define themes (referred to as topics) and the basis for theirs. Using these topics, the GWCT-led review synthesis found 10 positive effects, 3 neutral effects and 12 negative ones.

We think this approach leads to a more reasonable reflection of the relative number of beneficial management activities. One criticism might be that there has been more research on management benefits of releasing than of other areas. The RSPB’s blog suggests this, saying “a high proportion of the available literature and evidence is associated with positive ecological impacts”.

But this isn’t true. There was a flurry of papers relating to game crops in the 2000s, but a key objective of relevant research by the GWCT (and others) throughout has been to identify and quantify ‘problems’, and as a consequence there has been more work, more published papers and more grey sources on the potential negative effects of releasing than positives.

A key conclusion of the RSPB review synopsis is: “Positive ecological impacts of release are largely restricted to the secondary benefits of gamebird management…” But in reality, they are largely restricted in this report by the way the RSPB had defined the themes. The word ‘secondary’ also seems to have been added here to imply less important, when this has not been looked at or shown in the review.

Predator issue themes

There is also another choice of main theme we disagree with and that is the issue of illegal raptor killing, which has a theme to itself in the RSPB review. We are not diminishing the issue but feel that given the presence of the ‘Predator Issues’ theme, it should have been included as part of that.

Note that the actual review section on illegal raptor killing is also in danger of confusing what is in the spotlight here – releasing gamebirds in lowland habitats. In the main figure in this section (19) most of the data do not relate to releasing, but this is not indicated in the legend. There is further poor clarification of the figure in the text, and it is not true that cases in the south and east of the UK “could not have been associated with other gamebird management”. In research we need to be especially careful with tricky issues and areas where there might be important nuances and scope for confusion.

Discussion and conclusions

This point about what themes are defined, and how the different topics are allocated to the themes is crucial. The overall effect of putting all the positive management benefits into one main theme, and to over-separate the negative themes, is that the balance of positive to negative effects is predetermined and inevitably tipped heavily to the negative in the RSPB report. In the GWCT-led review, which used the evidence base to define topics, there was an overall approximate balance of positive/neutral effects and negative ones.

These differing summary conclusions are very important because the policy position of various organisations will be heavily influenced by the summary findings of scientific reviews. The GWCT recognises the benefits of releasing and its associated management and, as a consequence, takes the view that working with shoot owners and managers to provide and encourage adherence to best practice, and to reduce bad practice, will lead releasing for shooting towards an overall positive effect on the environment. The RSPB and others are using the RSPB review’s theme-based summary of effects to suggest this is a lost cause and that regulation is necessary.

The widespread management benefits of releasing on farmland in the lowlands and in many woodlands are commonly underestimated by commentators, and this story has been repeated in the RSPB review. Consequently, not only have the summary findings of the review been distorted, but a huge amount of privately funded valuable conservation work is in danger of being dismissed by decision makers. The cost of implementing these diverse activities via publicly funded environmental schemes would be enormous.

The fact that an activity has negative ecological effects is important, and it is equally important to understand what these are and if or how they can be mitigated. However, we do need to consider these effects in the context of other economically viable rural land uses, all of which have negative ecological impacts, and some have very few positive ones. It’s not appropriate to compare releasing for shooting directly with modern agriculture, but it is reasonable to consider it in the context of land uses such as farming and commercial forestry that have a dominant effect on the ecological value of our countryside.

In research our goal is to study and report accurately on the topic of releasing for shooting in the lowlands, and to provide context. We don’t agree with the way themes have been defined in the RSPB review, or the way management benefits are treated. But otherwise the various detailed review work in the three documents provides a fair account of where we are.

Between us we have agreed some priorities for further work, some of which are more complex than direct habitat effects, but pooling our efforts will help investigate these complicated issues. Funding permitting, addressing these questions together should be the next positive step.

Please donate to help us continue our vital work during this difficult time

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