Bats and barbed wire
Flying foxes are by far the animals most often caught on barbed wire fences. We are aware of many thousands dying every year in Australia, but there are probably tens of thousands when you allow for those in relatively unpopulated areas or away from roads and houses. Of those that are rescued probably about 40% are releasable but this varies across the country. The more extreme the climate the faster they perish on the fence.
Flying foxes are not the only bats to be caught on fences. Microbats, especially yellow-bellied sheath-tails (Saccoliamus flaviventris), and the smaller fruit/nectar bats like tube-nosed (Nyctimene) and blossom bats (Syconycteris and Macoglossus) also come into care.
Please do not try to take a bat off a barbed wire fence unless you are trained for this and vaccinated for rabies. You can do more harm to the bat and yourself. If you are ever bitten or scratched by a bat, wash the wound immediately, treat with iodine and go to a doctor for a rabies vaccination. There is a very small chance that the bat maybe infected with Australian Bat Lyssavirus.
Most rescuers wear armbands and mittens that leave the fingertips free to handle the delicate membrane to avoid further damage. There is a whole range of Personal Protective Equipment for bat handlers, depending on the situation.
(Above) Tolga Bat Hospital rescues many tube-nosed bats (Nyctimene robinsonii) from barb wire fences every year.
(Below) Hotspot fence on top of a ridge line
Bat fencing injuries and treatment:
Not all flying fox carers have access to veterinarians. Many manage the initial first aid but require a vet for euthanasia if the bat is too severely damaged. Sometimes it is not immediately apparent how extensive the die back will be. Many pregnant females abort their babies so it is important to manage their stress as much as possible.
1. Mouth. In desperation many bats will try to bite themselves off the barbs. This can result in severe damage to the roof of the mouth, loss of teeth and even fractures of the jaw. Most of these bats need to be euthanased. Assess carefully for fractures involving the front teeth and punctures to the roof of the mouth.
Treatments: A soft diet is crucial for healing. Monitor closely for juice escaping through the roof of the mouth and out the nose.
2. Wing membrane. Most bats are caught on their wing membranes, causing tearing, puncturing, severe bruising, inflammation and death of tissue. The wing of a bat consists of 2 layers of skin with nerves, blood vessels, musculature and lymphatics in between. The wing is often badly twisted as the bat is spun around on impact, as well as from struggling to free itself.
Treatments: Clean the area with an antiseptic like chlorhexidine and apply hirudoid to bruised areas of the wing once any active bleeding has ceased. Hirudoid is an anticoagulant, helping to avoid clotting in the blood vessels and then die back in the membrane. Some carers like to use aspirin though many prefer hirudoid as a local topical treatment.
Photos right: Upper – Dieback in the wing membrane after being entangled on the barb, and note the swollen veins around it. What began as a hole became a long area of dieback ad will eventually be a tear to the edge of the wing. Lower – note the very swollen wrist joint, as viewed on our left
3. Bones can be broken, or stripped bare. We find dressings, such as Duoderm and Bioclusive that keep the wound moist, to be extremely helpful. Regeneration of wing tissue around the bone can sometimes be miraculous, especially in a young animal.
Treatments: Antibiotics, surgery in some cases.
4. Body. Bats can be entangled by the hair and skin anywhere. The resulting puncture wounds can be of varying severity.
Treatments: Trim hair around wound and clean. Will usually need oral antibiotics, as well as topical treatment.
5. The penis… ouch! Not very often thankfully.
Do not be tempted to rescue the bat and let it go. There is usually a die-back process in the wing that may not be evident initially. The damage may look quite minimal at first, but lack of blood supply to the wing while it is still entangled can lead to a surprising amount of die-back, or loss of wing membrane. Many of these bats may fly away at the time, but then lose the ability to fly over the next few days. Bones are often broken or stripped of wing membrane, and infection may set in. The animal is nearly always stressed and dehydrated, and needs to be kept in care for a minimum of 2 weeks to assess the full effect of the damage.
A typical twisting of the wing membrane around the barbs. This injury will likely result in a hole as the tissue caught in the barb is likely to die. None fo the finger bones are involved so the outcome is good as long as the hole does not break through to the edge of the wing and become a tear.
A good situation with the plain wire mesh underneath, but the finger bones are involved in the entanglement around the barb. An endangered Spectacled flying fox so every life counts.
This Spectacled flying fox is caught on a barbed strand above a mesh fence.
Bat fencing injures in Little Red flying foxes
The Little Red flying foxes are entangled on barbed wire fences more than the 3 larger species of flying foxes, presumably as their flight is weaker in windy conditions and their numbers are usually a lot greater. They are also more nomadic and less likely to know the dangers in any one area. It is not uncommon for large numbers of Little Red flying foxes to get caught over a few weeks, especially when the young cannot fly well enough to cope with windy conditions. On the Atherton Tablelands, these mass events usually occur in August to October. In 1994, 442 Little Red flying foxes were caught, mostly along one 10 km stretch of barbed wire. It’s not unusual to rescue 300 Little Reds off barbed wire fences every year.
We have often rescued bats from government-funded fences that are protecting revegetation plantings from cattle. The irony is that one goal of the revegetation plantings is to improve biodiversity, but when bats come to offer their seed dispersal and pollination services, they are caught. As the plantings increase in height, the situation often improves.
Coming home with a basket of Little Reds from a hotspot fence on the Atherton Tablelands. Two of the five have escaped their wraps.
To rescue a flying fox off a barbed wire fence – only for rabies-vaccinated trained bat handlers
1.Get as much information from the caller as you can eg height of fence as it may be industrial fencing, exact location, are they the owner of the fence. Ask them to make sure bat is safe from dogs, cats, irresponsible people or birds of prey, but to keep a respectable distance so that bat does not become more stressed.
2. Once you arrive, assess the safety of the situation for you and the bat eg is there an electric fence, wild cattle? Fit your personal protective equipment and approach the bat slowly while talking to it. With 2 people, only have one person approach the bat. It can be easiest to have a small towel to put over the strand of wire underneath the bat, or at least step on the wire so you do not entangle the rescue towel while trying to secure the bat. Call the second person over once the bat is safely wrapped in a towel, securely enough so that the head cannot move up under the towel. The towel will usually need to be 2-3 layers thick and large enough to extend the wrap about a handspan below the bat’s head. The bigger the bat, the bigger the wrap. Too big a towel is a problem though as it gets caught on the surrounding barbs. It is difficult to wrap the bat if both wings are caught in the outstretched position.
3. Plan your rescue. If both wings are caught, choose the easiest one first to disentangle. Then readjust the towel before disentangling the other wing. If the bat is caught on the belly it can be difficult to see what direction the barbs are going. If it is obvious that the bat needs to be euthanased, have some sharp scissors if necessary to cut the badly damaged wing so the bat is off the fence quickly.
4. With 2 people, one has heavy duty gloves and holds the wrapped bat. The other person has armbands and mittens and together they assess the degree of entanglement. Syringe or spray water onto the wing if it’s dried on the barb so it will more easily slip off.
Choose between cutting the barb or unravelling the barb. Cut barbs with side cutters close to the wing, but there is often a burr on the cut edge that makes it difficult to slip the membrane over. It is often easier to rotate the barbed wire with pliers to unravel the membrane from the barb.
Also leave enough wire to grab in case you decide to unravel the barb. The wing membrane is often twisted between the barbs so unravelling is often a good choice. It can be very difficult to unwind the wing from the barbs and the longer the bat has been there the more difficult it is. The tools in the photo opposite are various designs that can help the unravelling – the tip of the barb goes into the hole of the tool. You may need to unwind the bat, rotating it horizontally or vertically over the fence before attempting to unwind the membrane from the barb.
5. With a one person rescue there are a few aids that can help you. The towel that secures the bat can be secured closed with clips or clamps, freeing up one of your hands. Some people like to use a sling attached to the top wire for the bat to lie in, with the bat’s feet still hanging from the wire. I wear a pouch with all my tools so I can easily access them while the bat is secured.
Once the bat is removed, it will generally settle best if wrapped in closed basket, rather than being allowed to hang in a cage. Done properly, it should almost never be necessary to cut the wing. If tissue is already dead and badly tangled then it is better to cut those bits of the wing and have the bat off the fence quickly. Unless the bat is badly dehydrated and needing subcutaneous fluids first, we will always offer dilute mango and apple juice/ rehydration fluids. Get the bat to an experienced bat carer as soon as possible. S/he can offer pain relief once the bat is rehydrated and provide first aid.
The author has rescued hundreds of animals off fences and never needed to cut the fence. If you do cut the fence, extreme care is needed as the strain will need to be taken up first. Please do your best to get the permission of the landowner first.
Various types of tools to unwind barbed wire.