For the Birds

I am ashamed to say that I am not always a strict respecter of rights of way. While I do always follow existing tracks, and I consider myself to be a considerate user of the countryside, sometimes the most interesting discoveries are to be found just off the designated footpaths. Besides it adds a certain frisson to know that at any moment a gun toting farmer might appear and tell me to “get off of my land!” I suppose the trouble with this approach is that you might blunder inadvertently in to something you don’t understand. Perhaps that is exactly what I am about to do now.

In the course of a recent ramble, some way from the nearest footpath and hidden from view of the general public, I encountered a corvid trap containing three large crows. I have long been aware that farmers shoot crows but it was nonetheless quite shocking to be confronted by these clearly agitated birds thrashing around in the cage. Now I am not squeamish about killing animals when the case requires it, nor am I sentimental about nature or farming, but I do start from a position that all species have a right to exist and we should respect that unless there is a sound argument against, so I decided to find out more.

The day I returned with my camera there was a solitary crow.

The site of the trap was in bushy scrub between two large fields filled with sheep and recently born lambs. Shepherds have long accused crows of killing newborn lambs or pecking out the eyes of ewes whilst debilitated in the act of labour. On the other hand there were pheasant chicks being reared in a nearby coppice and again corvids of all descriptions, including magpies and jays are accomplished predators of ground nesting birds, taking both their chicks and eggs. To confuse things even further, the site was barely half a mile from a nearby island bird sanctuary which is an important nesting site for avocets and many other sea birds, managed by the Royal Society for the Protection of Birds (RSPB). Could they have legitimate reasons for wanting to control numbers of crows in the area?

Sheep

To begin with let’s take a look at the issue of lambs. One report I read quoting from the Australian Journal of Experimental Agriculture and Animal Husbandryspoke of vicious attacks on new born lambs by ravens. Although the same article stated that of seven lambs attacked only two, both of which were “comatose” when attacked, showed signs of damage. Furthermore it states that little crows, although happy to eat the placentas, did not chase the lambs.

Another study based on Scottish hill farms published in The Journal of Applied Ecology found that of 297 lambs found dead on the hill only 17% showed signs of crow attack and further concluded that most of these would have been on the point of death before being attacked. It estimated that only one in 850 lambs born might have survived but for crow attack.

I did not find any definitive research to counter this view that carrion crows present an almost insignificant danger to healthy sheep or lambs.

Birds

It seems that DEFRA, the UK’s Department for Environment, Food & Rural Affairs, is currently running a trial cull of crows and magpies in an attempt to stem the decline in songbird numbers. DEFRA’s figures claim that between 2003 and 2008 farmland bird populations fell by 7%, whereas predator numbers including sparrowhawks, magpies and crows have doubled in the past 30 years.

Naturally the cull is controversial. It is supported by an organisation called Songbird Survival, but opposed by the Royal Society for the Protection of Birds (RSPB) which believes that changing farm practices are responsible for the decline. Moreover some people discern clear links between Songbird Survival and the Game & Wildlife Conservation Trust. The GWCT not only sells the Larsen traps used for catching crows, but is allegedly funded by the commercial shooting industry; also it has been a longtime advocate of culling magpies and other corvids which interfere with game bird rearing.

There is no question that magpies, crows and other corvids are ruthless and efficient predators responsible for the death of thousands of birds each year. That is just how nature is. There is also circumstantial evidence that while predator numbers are rising, songbirds and other small species are in long-term decline. However there is no evidence that any of these facts are related.

Just over a year ago, yet another player, the British Trust for Ornithology (BTO) published what it described as “the biggest ever analysis of songbirds and their predators” in the Journal of Applied Ecology. This report concluded that “for the majority of the songbird species examined there is no evidence that increases in common avian predators or Grey Squirrels are associated with large-scale population declines.”

So it seems that while we continue to find all kind of villains in this story, including cats, squirrels, sparrowhawks and corvids, the most likely culprit affecting the decline in small bird populations is still man.

In any case the trap I found clearly has nothing to do with the DEFRA cull, since that is restricted to sites in Hampshire, Warwickshire, Leicestershire, Herefordshire and the Scottish Borders.

The BTO report does agree that “in some situations, predators of nests, chicks and full grown birds do affect the abundance of avian prey species”. Could the island reserve be such a situation? Well I take it from the RSPB’s opposition to the cull that they are not behind the trap I saw. In any case I believe the large numbers of gulls on the island would present a much greater threat to nesting sea birds than any crows venturing across the water.

Conclusion

So where does that leave us? Well it seems there is no evidence to justify killing crows in order to protect either sheep or wild bird populations. Perhaps there is some local benefit to the pheasant chicks, but in any case these are long since flown from the nursery. So I conclude that the farmer is trapping crows simply because it’s what country folk have always done.

While I deplore the cruelty and the pointlessness of it, I doubt if the numbers involved are significant and it is unlikely to have any appreciable effect on the local wildlife one way or another. Two things do bother me however. Country folk often complain that townies don’t understand the countryside and are resentful when for instance they instigate a ban on hunting or seem insensitive to the effect of fuel prices rises on agricultural communities. But the needless killing of beautiful and innocent birds does the countryside lobby no favours. Moreover large corvid traps often catch more than crows. Birds of prey such as marsh harriers are also carrion eaters, and if one of them ends up in a trap it’s a matter for yet another official body, the police.