ACKNOWLEDGEMENT

This is a copy of an article that I have in my possession for years. It was a photocopy and faded at the edges. I am not sure who produced it - Shooting Times or B.A.S.C.,  or the date, as it states at the bottom of each page:

OFFICIAL WEEKLY MAGAZINE: SHOOTING TIMES AND COUNTRY MAGAZINE

FOUNDING MEMBER: COUNCIL FOR COUNTRY SPORTS

          BRITISH SHOOTING SPORTS COUNCIL  

          FEDERATION OF FIELD SPORTS ASSOCIATIONS OF THE E.E.C. (F.A.C.E. U.K.)

  However, as both organisations are interested in furthering field sports I'm sure they will not mind its reproduction here, in the interest of controlling vermin.

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HINTS FOR USING LARSEN TRAPS

The success of Larsen traps

Larsen traps were designed by a Danish gamekeeper in the 1950’s. In Denmark, it has been suggested that this trap alone was responsible for a significant reduction in the national magpie population from 1965.

Larsen traps will catch all corvid pest species (i.e. crows, magpies. jackdaws, jays, rooks) at all  times of year. but their particular value is in catching crows and magpies when these birds set up their breeding territories. The trap mechanism involves a spring door to each catching compartment, which when set is held open by a split perch. In order to enter the trap, birds the size of a magpie or crow inevitably drop onto the perch. The perch gives way, and the birds momentum takes it past the bottom of the door, which flips up - et voila! Because Larsen traps are small, they can easily be moved around. Traps can be moved to deal with specific pairs of crows or magpies, and a few traps can thus be made to cover quite a large area.

Larsens are live-catch traps. Why catch alive? Because of the risk of catching birds other than corvids. Virtually all such non-target birds are protected by law, and must be released alive and unharmed. In today’s countryside, the future of shooting depends on gamekeeping having a responsible image which treasures other aspects of the countryside, arid is sensitive to the feelings of the wider public. Having said this, we have experienced very few captures of non-target species in Larsen traps, another point in their favour. In a survey of over 10,000 birds captured only 1% were of non-target species. Finches and tits often visit them, but are too small to trigger the mechanism, and can in any case escape through the mesh sides. Of course, many legally protected bird species, as well as gamebirds, suffer from corvid predation on their eggs or young, and the Larsen trap is potentially an effective tool in the conservation of these birds too. There is no ‘natural balance’ between corvids and the birds they prey on. because they also feed to a great extent on other foods provided - directly or indirectly - by man.

A second reason to catch corvids alive is that each may in turn be used as a call-bird to attract further captures. In this way, given that you operate several traps, the whole effort quickly grows to an effective scale within a single breeding season.

        When to trap and why.  

We suggest that trapping effort is restricted to spring and early summer, because It Is most efficient and most effective then. In most areas, the overall population of crows and magpies is far greater than the number of breeding pairs. This is apparently because only a limited number of territories with a suitable nest tree at the centre can be fitted into a given landscape. Non-breeding birds usually feed in flocks, roaming over areas much larger than the usual territory. and using different foods from those of territorial birds. Flock birds should be thought of as a reservoir of frustrated would-be breeders. If a territory becomes vacant it will rapidly be claimed by fresh birds from this reservoir. If you trap outside the period March to July, you will have to diminish the reservoir population over a very large area to cause any benefit to your wild gamebird population.  

Operating with call-birds  

Why call-birds work.  

   A call-bird is a previously-caught magpie or crow, which is kept alive in the special compartment of the trap. Uncaught territory holders think a single call-bird is an intruder, and will try to drive it away. They  are very aggressive, and if the trap is left in peace, few are so shy that they will not get caught. In a scientifically conducted experiment by The Game Conservancy in 1989, traps with call-birds were fifteen times more efficient at catching crows, ten times more efficient for magpies.’

Taking care of your call-birds.

Look after your call-birds. They will work best for you when in good health, because then they move about more in the trap and catch the attention of territory holders. They also call vocally, but won’t do this if miserable. Visit each call-bird at least once a day to renew food and water. If they are seen by territory holders to be actively feeding, they will arouse special jealousy. (Apart from this, you are bound by animal welfare laws, and are furthermore responsible for the good image of the shooting fraternity.) These birds drink a lot of water - earthenware hamster bowls make very suitable non-tipping receptacles. Various kinds of food are suitable, but we have found ‘sausages’ of brawn-type dog food, fed with bread, to be very convenient. If carrion is fed, make sure it is cut up or at least cut open as magpies can have great difficulty in getting Into an intact carcass. Make sure the call-bird has a proper perch - magpies and crows need them particularly for roasting at night, arid there should be adequate shelter from hot sun, rain or wind.

After a while call-birds get quite tame and phlegmatic. Recently caught territory-holders make the best call-birds. as they are more restless and aggressive, so simply move new captures to act as call-bird In a different territory, and keep a turn over of call-birds.  

Which species to use as call-bird.  

In the wild, crows are dominant to magpies, and drive them from their territories. For this reason, a crow will be attracted best to a call-crow but also to a call-magpie; if you specifically want to catch magpies, use only a call-magpie. On no account should species other than corvids be used as decoys - In particular song-birds should never be used.

Where to put the trap.

If you are familiar with your land, you will know the specific trees that always seem to attract crow or magpie nests. If you are just getting to know the area, look out for nest building activity from the beginning of March. Before bud-burst, magpie nests are very obvious In the trees. Crows, and to a lesser extent magpies, often sit high in the trees near the centre of their territory, literally acting sentinel. You should aim to place a trap in plain view of sentinels, and within 100 yards of the nest site. If you haven’t time to watch out for nests or sentinels, concentrate on small copses and spinneys, thick hedges, and woodland edge - but have you really got time to check the traps every day?

Avoid placing traps too close to rookeries, unless you want a full-time job dispatching or releasing rooks! We suggest that crows and magpies are your main target to improve wild gamebird production.

Place the trap on the ground, especially for crows, which like to approach on the ground However, when trapping magpies amongst bushes, or in a dense hedge, the use of four legs raises the trap above brambles and gives it a better chance of being seen.

How to catch both birds of a pair.

First of all, it isn’t strictly necessary to catch both birds of a pair. They defend their territory together, and to remove one will often prevent the remaining bird defending the area against a specuIating pair of intruders: in this way its breeding effort is disrupted. Furthermore, the male bird feeds the female while she is incubating the eggs - if he doesn’t turn up. the hen bird must leave the nest. If you keep up your use of Larsen traps throughout spring and early summer, the establishment of territories will be continually disrupted and while present, fresh birds will be preoccupied with territorial defence and nest building. Their demand for food is never swollen by the need to feed young, and they have little time to watch the movements of incubating gamebirds when the latter come off the nest to feed.

Crows and magpies learn very quickly, and a bird that witnesses its partner being removed from a trap by a human and killed will subsequently be very shy of traps. If you catch a bird in one compartment of a Larsen trap, leave it disputing its case through the wire with the call-bird. Its partner, which may have been elsewhere up to now, will very often join in and get caught in the other compartment. This is one of the beauties of the three-compartment Larsen trap. However, if you have not caught the other bird by nightfall, you probably never will: take out the first capture. It is inhumane to leave one of these birds overnight without a perch and without food and water for the next morning.

We found no advantage in putting two, paired, magpies In the big compartment as call-birds. 

How to handle call-birds.

Both crows and magpies can give a fairly painful nip, but neither are really capable of breaking the skin of an adult human. So don’t worry about getting hurt; concentrate rather on handling the bird securely but gently. As you put your hand into the trap, a magpie will flutter round the roof, while a crow will be trying to cram itself into a bottom corner. In either case, trap the bird gently against the floor, roof or side of the trap, sliding your first and second fingers round its neck so that they meet at the fingertips. The bird can’t bite you now, and so long as you don’t let it wriggle its head between these two fingers, ft can’t get away from you. Your palm will be over the bird’s back, and you can use your thumb and fourth and fifth fingers to pin the wings against the body as you pick It up. Both species grip with their feet: use your free hand to gently prise them open again. When taking call-birds out of the big compartment of a Larsen trap, you will find you have to bring them tail first through the access hole.

    Birds can be transported humanely to another trap In a dark box with proper ventilation.      Remember it is in your interests to look after the bird.

How to dispatch a captured corvid humanely.  

  If you are right-handed, hold the bird as described above in your left hand. With your right hand, grip the legs, tail, and wing tips together. In one movement draw the bird out of your left hand, so that it doesn’t have time to bite you, and strike the back of Its head very hard against the edge of the trap / Land Rover / etc. It takes a surprising force to kill one of these birds. Do all you can to make death instantaneous.

               Where to get your first call-bird.  

  Please do not telephone us to ask where you can get a call-bird. Ask your gamekeeper friends, or catch your own. Larsen traps work quite effectively with bait alone - see next section. (You may even care to keep a couple of tame birds from year to year to start you off each spring. They are really fascinating creatures, and if you take an interest, you will learn a lot. We don’t advise you to keep magpie and crow in the same cage, or even adjacent cages.)

Operating with bait alone.  

 As mentioned above, Larsen traps do catch crows, magpies, and other corvids. when used with bait and no call-bird. You will need several to be sure of success, and the strategy is rather different from that described above.

Where to put the trap.  

  Although the trap should be obvious, birds will be more wary of it when there is no call-bird. So It Is probably unwise to stand it out in the open. Put it amongst bushes, or at the base of a hedge or tree.  

  In contrast to using call-birds, it may take a while for your bait to be spotted (because it doesn’t move), or for birds to overcome their natural fear of novel objects. So anticipate quite a long effort, but do check your traps daily.  Pre-baiting (with the trap unset) is completely unnecessary - If a bird goes In, you might as well catch It.  

If your trap catches nothing at first, don’t blame the trap. It is probable that no corvids have found your bait. (After all many natural bird nests escape predation.) Perhaps no corvid thought to look just there. After 10-14 days. it rnay be best to move the trap to try another site.

What bait?

The best bait by far is the egg. However, crows and magpies seem to show a distinct seasonal response to eggs, and will only show keen interest when eggs are naturally available. Outside late March to late July, they are rather indifferent

When you use eggs, aim to make the offering look like a depredated nest.  Make a ‘nest’ of dead grass in one (only one) of the catching compartments, and arrange a clutch of five or six eggs in it.  Cracked or oversize gamebird eggs from the laying pen are ideal, but hens’ eggs (brown or white) seem just as attractive. Break two or three eggs around the trap, and leave the eggshells lying about Most important, on the flat board that shelters a call-bird when present, or on the flat stop between the two catching compartments, carefully break an egg so that the contents lie in a tempting puddle. Renew this egg regularIy -  it is the glistening fresh egg that catches the corvid eye.

Of other baits, carrion is second best (open rabbits or squirrels - again it is the freshly glistening viscera that attracts, and both crows and magpies have limited powers of opening carcasses). Even white sIiced bread may be used: it is eye-catching, fairly natural in farmland (!), and they develop a taste for it.  Again, a. scatter of bait is more eye-catching, but don’t overdo it, or the birds will see no reason to enter the trap.

LARSEN TRAP CONSTRUCTION

The basic frame

1.   Make two side frames from parts A and B.

2.   Make carte frame with parts E and F. Note that the two outer struts (F) overlap the ends of E by 25mm, and that the centre recesses in E are to the outside of the frame. Cover with wire netting (V).

3.   Make two end frames with parts C and D.

4.   Lay one side frame on floor- Stand centre division in place and fix second side frame to centre division.

5.   Position and fix end frames.

6.   Invert and fix other side frame to centre and end frames.

7.   Fix 2 parts H into frame.

You now have the basic frame complete.

Completing the trap

1.   Fit ply division (Q) between end frame and centre division.  

2.   Construct entrance to decoy compartment from parts L, M and N. Ensure 

rebated edges of parts N are flush with sides of cut-out in part L.

3.   Slide door into position (part M).

4.   Fix completed entrance to basic frame, ensure

a.  that basic frame is square.

b.   that sliding door is captive on underside

c.  that wire netting on centre frame faces into decoy compartment

5.   Cover decoy compartment top, trap ends, sides and bottom with wire netting (Parts R, S & T).

6.   Assemble flap frames from parts J and K (refer to diagram to ensure correct assembly) and cover with wire netting (part U).

7.  Mark and drill 6mm holes and centre top rails of basic frame (see diagram for position).

8.  Mark and drill 5mm holes in flap frames (see diagram for position).

9.  Insert rod through 6mm hole in end frame. Position spring, (make sure that you select correct spring. Use with long arm flush to flap frame. Position flap aligning holes. Drive rod through flap and into hole in centre frame (see diagram).

10. Staple long arm of spring to flap side ( part J )

11. Fix second flap as in 7, 8, 9, 10.

12.      Push doors down into resting position and trap with flap stop (part F). This must be firmly attached. Note the positions of the six screws in the diagram of completed trap.

13. Cut dowelling to 4 pieces at 150 mm long. Two for each split trip perch (see diagram of complete trap showing one compartment set).

  LARSEN TRAP PARTS LIST

NB: IF YOU WISH TO SET THE TRAP IN AN ELEVATED POSITION ON LEGS OR

SIMILAR. USE 12MM WIRE NETTING FOR THE BOTTOM TO AVOID INJURY TO THE

FEET OF EITHER CALL BIRDS OR CAPTIVES.  

BASIC FRAME

 COMPLETE TRAP

PURCHASING READY MADE TRAP 

The National Association of Regional Game Councils  www.nargc.ie, if you are a member,  have a very reasonable deal in operation, at present, (Feb. 2005) whereby one can purchase a complete larsen trap from Dingle Poultry Supplies, http://www.dinglepoultry.com/game1.html

SUBSIDY FROM N.A.R.G.C.
A subsidy of 50% of the total cost will be paid to Regional Game Councils spending up to €700.00 on predator / vermin control equipment. (i.e. Counties spending €200 will receive a subsidy of €100 with a maximum pay out of €350)
In the event of RGC’s not taking up the full allocation, this subsidy may increase but the maximum payout will not exceed €500 per county.

INFO: http://www.nargc.ie/vermin%20scheme%20PRIZES.htm

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printing these instructions

To my knowledge there are two ways:

   1. On menu bar click file - page set up - click landscape - return to file - print preview. This will allow you to see what the pages will print like. 

With this method you will see that pages can be cut, with half instructions on one page and half on another - that is why I prefer to use method 2.

   2. Have the web page open. Open a blank word document. Return to web page and highlight all you want to print. To highlight move the mouse to the end and press the left button. Keeping the left button pressed down move the mouse pointer up through the page to the start and release the button. You will see all the diagrams and text go yellow on a black background. Now click the right button of the mouse. select copy. At the bottom of your screen click the word document icon to open it. Place your mouse pointer at the start of the document, right click the mouse again and select paste. All will appear in the word document after a few seconds. 

The beauty of this method is you can go through the article and move text down to a new page, make font bigger, smaller, make page borders wider, longer, etc. to suit you. This will ensure that all text, diagrams, etc. are on a complete page. This can then be saved in your documents to print when needed, without having to go on-line. 

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MORE INFORMATION ON LARSEN TRAPS