Species in danger of becoming victims of their own success

Once rare sights in the North-East and North Yorkshire, the likes of buzzard, red kite and otter are much more frequently spotted – and that brings its own problems.

The animals are in danger of becoming victims of their own success as they encounter challenges linked to rising numbers, including increasing persecution because they are deemed in some quarters to be too numerous. Indeed, the region has seen a number of high profile cases in recent months.

The buzzard is typical of a predator that stepped back from the brink. In the early 1800s, it bred throughout Britain but by the beginning of the 20th Century widespread persecution had resulted in the species being confined to western areas of England, Wales and Scotland. The recovery began around 2000 when the Government started to get tough on poison abuse, and they now nest in every English county and are Britain’s most common bird of prey.

Also on the way back are red kite, which were down to just a handful of pairs restricted to central Wales by the mid-1950s. This was largely down to illegal poisoning, egg collecting and shooting. A series of reintroductions commencing in 1989 completely turned around its fortunes and it is now a common and widespread species in England, though persecution continues.

It’s a similar story for peregrine falcon, which experienced low populations due to persecution and the use of organochlorine pesticides such as DDT in the 1950s before recovering.

All good news, many would say, but not everyone agrees, according to Tim Melling, a conservation officer with the RSPB, who says: “You do hear some people say that there are now too many birds of prey but the truth is that successful predators are a sign of a healthy eco-system.

“Predator numbers are governed by the amount of prey. They will only have high numbers if the amount of prey is high.

“One of the reasons for the success of top predators like buzzard and red kite is that they are generalist feeders, which will eat a wide range of prey.

“They are scavengers that are just as likely to eat earthworms as anything else. Indeed, in Shakespeare’s time, red kite lived in the city, cleaning up the streets.

“Left to their own devices, all species will find their natural level. You do not see a predator growing in numbers above its natural level then dropping back. Rather, it will find its natural level then plateau.

“The problem comes when people in some quarters say that there are too many of them and persecution increases, which unbalances the natural order of things.”

One of the species for which perception is a major concern is the otter. It has taken more than 30 years, but the creature’s comeback is now well under way. After disappearing from most of England in the 1950s, 60s and 70s, they have now returned to every English county thanks to protection under the Wildlife and Countryside Act which reduced persecution, the ban on organochlorine pesticides and cleaner water in rivers and streams.

However, that does not mean all is well.

Vivien Kent, conservation officer at Durham Wildlife Trust, says: “The otter is an apex predator and its population will always be regulated by its food resources. That means that its numbers can never balloon, it is biologically impossible.

“Otters are opportunistic feeders. Fish are their main source of food, and they are best adapted to hunt in the water, but they will also take crustaceans, small mammals and even birds to supplement their diet.

“The problem is that for 35 years numbers were very low and during that time we saw a dramatic increase in the number of fisheries opening up. There were no major predators, certainly not the otter, so they did not need to worry about protection.

“However, the past ten to 15 years have seen otters returning to something approaching pre-1960s levels and, for otters, an unprotected fishery is like laying on a picnic.

“Otters are very territorial and tend to stay in their own areas but if you have an unprotected stretch of water packed with fish you may get more than one otter, maybe including females with cubs.

“You do hear voices in some circles suggesting they be culled but the answer is to install protective fencing. Culling is certainly not the answer. If I was a fishery owner faced with spending a few thousand pounds on protective fencing as a one-off investment or continuing to lose thousands of pounds worth of fish, the economics are in favour of the fencing.

“The other problem is that other predators take fish, including herons, cormorants and mink and it is difficult to tell even if you find dead fish remains what killed the animal. If a fishery owner notices that fish are disappearing, they do tend to blame otters in many cases."