Culling Corvids

[nightshade]

From the Telegraph Magpies and crows to be culled to protect songbirds - Telegraph

[Dogghound]

Hopefully this thread wont turn into another argument like every other thread on WAB seems to do these days.

Corvids like carrion crows and magpies have increased over recent decades thats for sure. However they are not the root cause of declines in song birds (intensive farming) and studies have been carried out to show that birds like magpies dont have a significant impact on song bird numbers. Although in areas with small vulnerable populations in spring culling may be beneficial to some prey species. A lot of prey species have suffered population declines, so high predator numbers can be detrimental in some areas. Corvids are more of an issue for breeding waders and other ground nesters like grey partridge in my opinion.

I worry about this song bird survival groups idea's you would expect them to be backed by scientists/ornithologists. Buzzards dont pose a significant risk to song birds. I get the impression they will eventually want BOP culling and are probably run by pigeon fanciers and gamekeepers.

[RoyW]

A study funded by (surprise surprise) "SongBird Survival" (see their website if you are interested, but basically the details are as below).
It seems that they will be looking at the fledging success on songbirds on four pairs of sites during 2011 & four or eight pairs of sites in 2012. Crows and Magpies will be trapped with Larsen traps, and humanely destroyed, on one farm in each pair, with the other farm left as a control. It will be interesting to see how much we hear about the results if they don't support SS's opinion that predators are the major reason why songbird numbers are declining.

SongBird Survival's website states that "New high quality research is urgently needed", so we can only hope that they have made sure that there is no bias in the research, and that they are willing to release results if they don't support their existing opinion.

A quote from a previous study that SongBird Survival funded (looking at BTO data, “Population changes of avian predators and grey squirrels in England: is there evidence for an impact on avian prey populations?”):
"This robust study found that:
• There were a large number of positive associations between predators and prey, suggesting that predator numbers have largely increased as the amount of prey has increased. This is particularly the case for native avian nest predators (Great Spotted Woodpecker, Magpie, Jay and Carrion Crow).
Although this largely exonerates these predators, as driving declines in the numbers of songbird species at a national level, it does not preclude individual predators having local effects."

If this study also shows that there is no negative effect on songbirds from predation by corvids, will they continue to look until they do find the result they want, or will they start looking for other reasons for declines and stop repeatedly laying the blame on predators?

[RoyW]

Originally Posted by Dogghound

Hopefully this thread wont turn into another argument like every other thread on WAB seems to do these days.

Worth taking note of before posting!

I'm sure that we can debate this issue sensibly!

[htcdude]

So SongBird Survival are backing this, but who is actually driving the idea forward???

Nige

[RoyW]

Originally Posted by htcdude

So SongBird Survival are backing this, but who is actually driving the idea forward???

SongBird Survival.
It's their own study (which will apparently cost £88,000). The fact that they are funding the study doesn't mean that the findings will automatically be biased towards their viewpoint though.

[Ukwildlifeo]

The fact ic omes from the Songbird survival trust says it all. Sadly it looks like people are listening, something I fear wont be helped by the fact many people have rightly or wrongly lost faith in RSPB or can't tell them apart from the RSPCA (possibly Britain's least liked animal charity at the mo!) and so wont listen to their counter arguments. They will thenlook at the Songbird survival trust as a real bird conservation body, which would be extremely ironic...

[Dogghound]

For anyone interested, including the songbird survival trust before they waste £88,000.

A good study by Thompson et al 1998 looked at the effects of predators on prey species (mainly corvids on nests and raptors on adults) over a 30 year period on CBC (common bird census) plots. This was to assess whether the rates of population change in 23 songbird species varied depending on whether or not either magpies or sparrowhawks were present. The results were unequivocal in that out of 46 comparisons (23 songbirds and two predators) in only two cases did the songbird species show a more negative population trend in the presence of predatory species than in its absence.

Thompson, DL, Green, RE, Gregort, RD & Baillie, SR 1998. The widespread declines of songbirds in rural Britain do not correlate with the spread of their avian predators. Proceedings of the Royal Society London. B 265: 2057-2062.

[Acipiter]

Originally Posted by htcdude

So SongBird Survival are backing this, but who is actually driving the idea forward???

Nige

Look up the trustees and spoke person for S/S- Viscount Coke, surprise surprise, the shooting estate, Holkom hall norfolk.

[Wild-Woman]

Originally Posted by Ukwildlifeo

The fact ic omes from the Songbird survival trust says it all. Sadly it looks like people are listening, something I fear wont be helped by the fact many people have rightly or wrongly lost faith in RSPB or can't tell them apart from the RSPCA (possibly Britain's least liked animal charity at the mo!) and so wont listen to their counter arguments. They will thenlook at the Songbird survival trust as a real bird conservation body, which would be extremely ironic...

Unfortunately I think you may be right Neil. If it becomes apparent to people who do not understand some of the rules of basic ecology (eg my neighbour who hates all predators, but who had a bird munching cat for 16 years) and sees SS as the way forward because it's been dressed up to sound like they care deeply about songbirds, then I can see this debate raging on for years.

I've tried explaining to my neighbour that it's good that we have a sparrowhawk because it means that there is a healthy population of garden birds to maintain it, but he just doesn't 'get it' frustratingly.
I bet if he found out that there is a organisation that would like to cull the preds- he'd be estatic. I'm so glad he doesn't 'do' the internet!