15
Apr
14

New research suggests Langholm buzzards not that fussed about eating red grouse

Richard Francksen BOUEarlier this month, the British Ornithologists’ Union held its annual conference at the University of Leicester. The theme of this year’s conference was the Ecology and Conservation of Birds in Upland and Alpine Habitats.

Conferences like these allow research scientists to present their latest findings to their peer group. This particular conference was of great interest to us, given the high levels of illegal raptor persecution associated with upland moors that are managed intensively for grouse shooting.

There were several presentations worthy of note (and you can read the abstracts in the PDF below) but we wanted to highlight one that many of you will probably be interested in. The presenter, Richard Francksen, a PhD student at Newcastle University, won an award for this research: Best poster presentation by an early career researcher.

Research Title: Common buzzard Buteo buteo diet in relation to changes in vole abundance.

Researchers: Richard Francksen, Mark Whittingham and David Baines.

Here’s the abstract:

Predators whose most important prey are field voles Microtus agrestis are often assumed to increase their predation on other prey groups when vole abundances decline. However, this assumption may not be valid for all prey groups and habitats available to predators. In Britain, voles are an important prey item for common buzzards Buteo buteo, and often form a principal component of the diet throughout much of their geographic range. Langholm Moor in south-west Scotland is an area of upland moorland managed for red grouse Lagopus lagopus scoticus, in which vole indices typically cycle over a three to four year period. We studied vole abundance and buzzard diet at Langholm Moor between 2011 and 2013, which encompassed a complete vole cycle. Breeding buzzards on Langholm Moor have previously been shown to eat red grouse in small numbers alongside their preferred vole prey. Buzzard diet was monitored at 13-16 nests each year using motion triggered cameras, analysis of prey remains and pellet content. An Index of Relative Importance was used to assess the importance of various prey groups to buzzard diet and it was found that the proportion of voles in buzzard diet decreased in line with vole indices. We hypothesised that when vole availability diminished, buzzards would switch to increased predation of red grouse and their chicks, However, grouse were less frequent in buzzard diet when vole indices were low. Instead, buzzards switched to eating more lagomorphs, moles, shrews and corvids; prey groups typically associated with moorland fringe and farmland habitats. This may suggest that when provisioning their chicks, buzzards take red grouse only incidentally while hunting for voles within moorland habitats. When assessing diet and investigating predator impact on prey species, knowledge of all resources and habitats that are available to predators is important.

Other presentations of note include:

Weston et al. Prospecting forays inform young golden eagles prior to emigrating from their natal home range. [Page 10, abstracts book).

Amar & Redpath. Hen harriers in the UK: a tale of contrasting fortunes. [Page 11].

Carroll et al. Impacts of drainage and climate change on keystone insects and upland breeding birds. [Page 21].

Baines et al. Grouse moor management: effects on other upland birds in the UK. [Page 25].

Thompson et al. Does intensive grouse moor management benefit the UK uplands? [Page 26].

Roos et al. Predation and upland birds. [Page 28].

Redpath and Young. The role of ecology in addressing conflicts over upland birds. [Page 33].

Downloadable book of abstracts: BOU Uplands Conference 2014 – abstracts

Photos from the conference here

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3 Responses to “New research suggests Langholm buzzards not that fussed about eating red grouse”


  1. 1 nirofo
    April 15, 2014 at 3:49 pm

    It would be interesting to know what the ratio was if the assumption is based on the total number of grouse taken, what was the number of adults taken compared to predation on their young alone. Whilst I don’t doubt that adult grouse are taken by Buzzards when the opportunity arises, I would doubt they are regularly targeted by design given the amount of energy that would be required to catch one regardless of whether their main prey species is available or not.

    I would say the main reason for the switch to grouse young by Buzzards, (not to mention Hen Harriers) is almost entirely the fault of the shooting estates and their gamekeepers obsession with creating the ideal habitat for large overpopulated numbers of grouse regardless of the consequences. This has led to a severe lack of alternative prey species now that the majority of the breeding birds on the grouse moor habitat has been reduced to almost nothing.

    Don’t blame the Buzzards for something you have created yourselves !!!

    • 2 Dave Dick
      April 15, 2014 at 10:43 pm

      Spot on Nirofo…the “balance of nature”, that we are always hearing about when the shooting industry want raptors, ravens and various mammalian predators destroyed, is also upset by the release of millions of pheasants and red-leg partridges every year. Most of our european mainland neighbours banned this years ago – along with damaging and unselective methods of crow control, such as crow cages and Larsen Traps.

  2. 3 John Miles
    April 16, 2014 at 10:30 am

    Finally something good coming out of our £3.5 million [new Langholm project]. 70% of all bracken has been removed causing erosion. White ground for Black Grouse has been destroyed. 10 ravens to be/have been removed due to them eating white rats from the bird tables but they say to help local farmers. Ha Ha. Do you think we are thick!! Beccleuch will have to sell to the local community in the end because the heather is buggered.


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