In 2015 SNH commissioned a report to assess the nature and use of corvid cage traps in Scotland. The field work, finished earlier this year, was carried out by Science and Advice for Scottish Agriculture (SASA) and the Game and Wildlife Conservation Trust (GWCT). The project was overseen by a steering group of representatives from RSPB, BASC, SNH and Scottish Government.
My main concern was on how the field workers would view the use of Larsen mate traps, often referred to as clam traps, and pod traps. The clam trap is a wire mesh trap that, when set, rather resembles an open clam. The victim is lured inside and the cage springs shut. The pod tap is a square or rectangular wire mesh structure with a gate at either end. The victim is lured in and both gates shut simultaneously.
Having seen these traps in use, plus almost all other designs involved in the trapping of corvids, most are used legally. Unfortunately they have the capability of being used illegally by those who might wish to catch birds of prey. My concern about the clam trap was that a large bird such as a buzzard is likely to be caught with its wings up in the air and sticking out of the top of the trap. A mammal such as a fox or badger might also be caught round the neck if it reached in for the bait. Since the attention of the Scottish Government and SNH was drawn to the illegal use of clam traps they have been restricted to being used with baits of eggs or bread only. The general licence also states that the trap must be securely pegged down so that it cannot be removed either by an animal caught in it or a predator. It also stipulates a maximum size of the trap and that the trap must not shut tightly along the majority of the length of the meeting edges. Stops could be used to good effect in preventing complete closure and the consequent trapping of wings or head.
In relation to the catching of raptors as by-catch during the trial the vast majority were buzzards. Observations found that buzzards were only caught in traps with meat baits and/or decoys. This applied not just to the clam trap but to all of the traps tested. An occasional tawny owl was caught in a trap with eggs or bread, and a sparrowhawk was caught in a trap with a carrion crow as decoy. In this case the raptor, which takes primarily live birds, may have entered to try to catch the crow. It may be that the owls were trying to catch mice at the bread bait.
While I don’t think for a minute that there will be a cessation of the use of all of the varieties of corvid traps for criminal purposes I am more satisfied now that these traps, including the clam trap, can be used relatively humanely by operators that are intending to stay within the law.
For the 2017 general licence the use of meat bait in Larsen mate (clam) and pod traps will be permitted provided that those intending to do so register their intent in advance and provide SNH with a return of non-target captures. I must say I have my doubts that true returns will be made since evidence of heavy non-target catches are likely to result in the return to bread or eggs bait only but it is a good start.
In addition, during 2017, in conjunction with Police Scotland and Scottish Government, a code of practice for corvid trapping is to be developed. Also under consideration during 2017 is a discussion with Police Scotland on a revision of the trap registration system. I would hope that SNH may take ownership of the system and, as in snaring registration, ensure that the register shows the operator of the trap rather than the owner.
None of this will prevent abuse or misuse of corvid traps by those determined to do so. An increase in time allowed for police to investigate trapping offences (or better still an increase in full-time wildlife crime officers) plus more use of the current power of SNH to suspend the use of a general licence would not go amiss.
The report can be found at http://www.snh.gov.uk/publications-data-and-research/publications/search-the-catalogue/publication-detail/?id=2437