A combination of an inquisitive nature and a scavenging feeding habit make Red Kites potentially vulnerable to a number of man- made problems.
Being scavengers and always on the lookout for food, they are likely to discover poisoned baits which have been placed in the countryside in illegal attempts to control so-called pest species such as foxes and crows. This practice has been illegal in the UK for a long time - not least because of its indiscriminate nature - yet a minority of people still persist in its use. Typically, a dead rabbit, pheasant or pigeon will be dosed with an insecticide and left out in the open. The insecticide will have been formulated and licensed for a particular agricultural or horticultural purpose. It is an offence to use such a substance for any other purpose. Twelve Red Kites are known to have died in Yorkshire through feeding on such baits. Four of the more recent victims were spotted by walkers from public rights of way- begging the question of how many other such victims have gone undetected. Although the actual bait was not found in most of these instances, state of the art analytical procedures and equipment at the Central Science Laboratory at York can establish the nature of the poison and the dosage level, so confirming the probable cause of death. Several other kites have been found dead where the scenario was strongly indicative of them having met a similar fate, but their remains were too decomposed for detailed analysis.
It is highly likely that those kites which died as a result of feeding on poisoned baits were not the intended victims. However, the same cannot be said for those which have been shot, they having obviously been deliberately targeted. Two Yorkshire kites are known to have died after being shot. X-Rays showed that one was riddled with lead shot whilst the other, the male of a new breeding pair which had settled in the Yorkshire Dales and was found dead under its nest, had a pellet lodged against its spine. In 2008, another kite was found on the ground with injuries caused by shooting. It had a broken wing, which fortunately responded to treatment and the bird was subsequently released. A dead kite reported on the YRK website in August 2010 was also found to be shot. It was recovered by YRK from just over the Cumbria border in Dentdale and was identified as one of the Cumbria birds which had been released just three weeks previously in Grizedale Forest.
X-Rays of a number of kites, which had died from other causes, have found them to be carrying lead shot, showing that the above instances are not the only occasions on which kites have been targeted. It is unfortunate that their inquisitive nature – which will often bring them low over the observer – in combination with their size and slow, lazy, flight makes them easy targets.
It is suspected that rats are high on the list of Red Kites' food preference ratings. They often scavenge around farm buildings and analysis has shown that a number of birds which had died from other causes had significant levels of one or more of the more toxic second-generation rat poisons in their systems (Difenacoum, Brodifacoum and Bromadiolone).These substances are known to have caused the deaths of two Yorkshire kites in 2007. They were introduced because first-generation rat poisons (e.g. Warfarin and Coumatetralyl), which are much less toxic to kites and other scavenging species, could no longer be relied upon to control rat numbers. The pesticide industry is aware of the potential side effects of the usage of rat poisons. It has urged users to ensure that:
- they make their storage facilities as rat-proof as possible - prevention being better than cure;
- professional advice is sought, where appropriate;
- they and their staff are properly trained in the handling and application of rat poisons;
- the selection of both the poison and method of application suit the particular situation
- regular checks are made for dead rats, which should be disposed of in a safe manner to stop them getting into the food chain;
The overall objective is to reduce the amount of rat poisons used and to target them more effectively, so reducing the potential for adverse effects on the natural environment.