Longworth Trap

Longworth Trap

Longworth Trap - UK and Ireland : Latest Edit - 10 July - Editing major mix-ups with A. flavicollis and A. sylvaticus I would love to share all of my photos from the Longworth Trap on one page and thanks to the amazing new update, I can! At the beginning I was using a syste

Latest Edit - 10 July - Editing major mix-ups with A. flavicollis and A. sylvaticusI would love to share all of my photos from the Longworth Trap on one page and thanks to the amazing new update, I can!
At the beginning I was using a system where I would clip the fur, so that I could identify the mammal later on. It then became apparent that I was catching way too many individuals to give them each their own pattern, so I stopped.
All of the mammals I've caught were in my back garden, though I did try for Field Voles in Northumberland with little success!
If I tear myself away from all that, I would like to know what other people have been catching with their Longworth Traps.
What actually IS a Longworth Trap (for people who don't know)A Longworth Trap is a humane way of trapping small mammals for scientific purposes or for general interest and is a great way of finding out what visits your garden (mammal wise). It is made up of two parts: the chamber and the tunnel. The mammal comes in through the tunnel to get to bait inside, and at the end of the tunnel there is a trip wire (sort of thing), which closes the door of the tunnel. The mammal will hopefully then go into the chamber, where there will be bedding and food for it to survive the night.
How do you actually set up the trap? (relatively important)Once you've put together the trap (there should be instructions), the next thing to worry about is how and where to put it out. I usually put it where I know there is mammal activity, for instance underneath the feeder or in the mini meadow at the back of the garden, though you can put it literally wherever you want (though a shady spot is preferable)!
Once you've found a place to put the trap, you cover it up with leaves/grass so as to keep the trap warm in winter and cool in summer.
What I've learnt from the Longworth Trap (by myself and iSpot!)1. Small mammals (particularly Bank Voles in my case) sometimes go to the same Longworth Trap, even if its at the other end of your garden for food. Twice I have caught marked Bank Voles from our feeder outside a network of Field Vole burrows in the mini meadow.
2. Small mammals often live cooperatively with a different species, Wood Mice live in Bank and Field Vole burrows and I photographed a Field Vole coming out of the Bank Vole burrows and I have caught a Yellow-Necked Mouse underneath the feeder too.
3. Bank Voles are the easiest mammals to handle for beginners, you might have a bit of trouble trying to get hold of a Wood Mouse (or worse, a Yellow-Neck).
4. Field Voles don't like to go in the traps as much as (trap happy!) Bank Voles, I put the Longworth Trap right outside of a Field Vole burrow (about fifteen metres away from the feeder) and Bank Voles still get there first!
5. Longworth Traps have domestic uses too. We caught a Yellow-Necked Mouse on our first floor landing, so they are a way to catch small mammals. Always remember to release them afterwards though!
Any alternatives to Longworth Traps?When I first became interested in mammal trapping (The New Amateur Naturalist, Nick Baker), I used Nick Baker's idea of a home-made mammal pitfall trap. You get the lid of a pot or something similar and cut it to the size of the top of a glass. You then use a stick etc. to use as a pivot for the lid. You dig a hole near a mammal burrow and then put the glass inside and then the lid with the pivot on top. I would advise not to put it out when you know its going to rain - otherwise you get a wet Wood Mouse! (A tip: try to make it so that the glass has a smooth side!)
Longworth Traps are quite expensive, so a cheaper alternative is a trip-trap. It's made of plastic and Wood Mice have apparently been known to chew through aluminium Longworth Trap so there's a chance that a trip-trap will get damaged quickly. It is very similar to the Longworth Trap (except made from plastic) and is designed for occasional use.
Small Mammal FactsThese facts are arranged in order, with the most likely to be caught first. I should add to this as it goes along.
Bank VoleLatin Name: Myodes glareolus
Why placed at number one: very common and according to Gill Sinclair they often come to the same Longworth Trap on purpose, even if it's far away (in Bank Vole terms)!
Length (approx.): 10 centimetres
Weight (approx.): 15.4 and 36 grams
Habitat: Gardens, Parks, Hedgerows, Woodland.
Description: The fur is more browny-red than Field Vole and longer tail too. Blunt nose distinguishes it from Apodemus sp.
See photo 2.
Habits: Coming to the same Longworth Trap, even if places far away. I have placed my Longworth Trap right outside a Field Vole run (about twenty metres away from a Bank Vole burrow), yet a Bank Vole still gets there first!
Does not hibernate in winter.
Predators: Weasel, Stoat, Rough-Legged Buzzard, Kestrel, Red Fox, American Mink and Tawny Owl. Weasels have been reported to go into Longworth Traps, following the smell of a Vole.
Red List Status: Least Concern :)
Subspecies?: Myodes glareolus skomerensis, found on the Isle of Skomer in Wales, up to 20,000 individuals in summer.
UK distribution: All over England, and most of Scotland. It has been introduced to South-West Ireland. Absent from most of the Outer Hebrides and similar islands, Isle of Man, Shetland and Orkney. Scarce in the North-West Highlands.
Lifespan: Up to 18 months.
Sometimes I think there are more dead rodents on iSpot than not:

Wood MouseLatin Name: Apodemus sylvaticus
Why placed at number 2: More wide-spread than Apodemus flavicollis and relatively common in gardens (and in garages! http://www.ispotnature.org/node/446017)
Length (approx.): 81-103mm (tail 71-95mm)
Weight (approx.): 13-27 grams
Habitat: Gardens and Urban, Grassland, Moorland, Farmland, Woodland, Upland
Description: Light brown fur, getting darker towards the spine and a very long tail. Large eyes and ears and white to light grey underside.
Habits: Often make hoards. In my garden I have watched Wood Mice come out and feed around both Field and Bank Vole holes. They sometimes block the entrances to their burrows with twigs and leaves in winter and late autumn. Twice I have caught a Wood Mouse and held it by the tail and it has shed some of the skin on its tail to escape. Both times it has, I have a photo of a mouse with a newly shed tail, picture seven on the project.
Predators: Foxes, Weasels, Owl sp. and Domestic Cats
Red List status: Least Concern :)
Subspecies?: Apodemus sylvaticus hirtensis, the St Kilda Field Mouse, brought to the island by Viking settlers.
UK Distribution: Throughout, even on smaller islands.
Lifespan: Adults rarely see two summers.

Field VoleLatin Name: Microtus agrestis
Why placed at number 3: They don't like to go in Longworth Traps very much, though are found more or less throughout the UK, unlike Apodemus sylvaticus.
Length (approx.):90-155mm (tail is less than 40% head and body length)
Weight (approx.): 20-40 grams
Habitat: Gardens, grassland, heathland, farmland, sometimes woodland.
Description: Furry ears, small eyes (diurnal rather than nocturnal), grey-cream on the underside, grey-brown on the upper side, shaggier fur so less prominent ears, tail much shorter than Bank Vole.
Habits: Grass is the main food, especially Bents and Fescues. There are thought to be 75 million individuals in Britain!
Predators: Kestrels, Owls, Red Foxes, Weasels, Stoats, Snakes.
Red List Status: Least Concern :)
Subspecies?: Microtus agrestis macgillivrayi is only found on Islay.
Distribution: Throughout England, absent from Ireland, Orkney, most of the Scottish Islands, Most of the Channel Islands and Scilly. A few records from the Isle of Man on NBN.
Life Span: 1 year on average.

Yellow-Necked MouseLatin Name: Apodemus flavicollis
Why placed at number 4: Only caught once in my garden and only found in the south of England.
Length (approx.): 95-120mm
Weight (approx.): 14-45 grams
Habitat: Garden and Woodland, mainly on the woodland verges.
Description: A complete band of yellow fur is the easiest was to separate A. flavicollis from A. sylvaticus. Brown on the back and white on the underside.
Habits: Eats a lot of seeds. Apparently more arboreal than A. sylvaticus, but not much. Does not hibernate. It also shed its tail when it is caught by it.
Predators: Owls, Foxes, Weasels.
Red List Status: Least Concern :)
Subspecies?: No
Distribution: Found in the south of England, but absent from Mid Somerset and Dorset down to Land's End and the Scilly Isles. It is also found in East Wales. Absent from the Isle of Wight.
Life Span: Few survive more than one year.

Orkney VoleLatin Name: Microtus arvalis subsp. orcadensis
I don't think there is enough data on this species to produce a full fact file.
The Orkney Vole is a subspecies of the Common Vole (Microtus arvalis) and can only be found on some Orkney Islands. It is believed to be introduced from mainland populations in Spain or France, and the date of introduction cannot be later than 4,600 years ago as this is the earliest record. In Orkney it can only be found on five islands: The Mainland, Sanday, Westray, Rousay and South Ronaldsay. They are larger than other populations of Common Voles.
DejayM found an Orkney Vole on the 18th June 2013 and its body measured 11.4 centimetres and its tail was 37mm.
Brown fur on the underside and short tail like M. agrestis. It is the only vole found in Orkney, so if you find a large vole running around on one of the five islands, it's almost 100% an Orkney Vole.

WeighingI occasionally have the chance to weigh the small mammals that I catch with the Pesola scale I received for my birthday. It is an interesting and rewarding measurement to take, but only if the mammal doesn't escape first!
These are the weights I have recorded so far:
Bank Vole
25g (Heaviest yet - caught 17th May 2015)
Wood Mouse
If I take any more weights in the near future I will continue to post them here!

I hope you find this useful!

20 Aug 2014