Autumn juvenile hedgehogs are ones that are old enough to be away from their mothers but too small to hibernate.
The autumn juvenile season can start as early as September and is busiest through until the end of November. However some will struggle on and the occasional one can be found from December through until April. [The season will vary slightly depending whether you live in the south or north and depending on the weather.]
The ones found in March and April may have struggled through the winter or they may have hibernated but at the minimum weight for hibernation so they are weakly once they emerge. Young hedgehogs can and will hibernate at 450gms (1lb) or less but are unlikely to survive. It is preferable for them to weigh at least 650gms (1½ lb) in order to hibernate successfully and be in sufficiently good condition to survive post hibernation.
Giving advice on whether to leave them out in the garden and keep feeding them or whether to bring them indoors and over-winter them can be difficult. Left outside it is more difficult to monitor them and if they start to have problems and hide away they can just die. If they are brought indoors the stress of captivity can also kill them. So the following advice will be correct for some hedgehogs and not for others.
HEDGEHOGS THAT CAN PROBABLY BE LEFT IN THE WILD
If the hedgehog is a regular visitor to your garden, is only seen at night, appears active and you are prepared to feed it every night then it can be left in the wild. See notes on feeding and feeding stations. However if the hedgehog goes off its food, wobbles and staggers or starts coming out in the day or you notice it has green slimy poo especially if there is blood in it, then it needs extra help asap (see basic first aid). Even if you have to bring a hedgehog in do keep putting food outside for at least a few more nights, as there may be siblings or other autumn juveniles making the most of your hospitality. If the food does not go you could still continue to provide dry cat biscuits – these will not go off as quickly as tinned food so are less wasteful. It is helpful if you can weigh your visitor once a week to ensure it is putting on weight and doing well. Any under 200gms are likely to be genuine orphans and should be rescued.
Hedgehogs are nocturnal so those out in the day are displaying odd behaviour. Even though they appear lively and are rushing around these hedgehogs probably need rescuing. Once out in the day they can be days away from death. Even when rescued they can seem OK for a day or so and then suddenly collapse and die. So if out in the day whether rushing about or curled up asleep they need rescuing. Hedgehogs do NOT hibernate in the open. They make a nest of leaves etc and disappear into the depths of the nest and are completely hidden. Hedgehogs under 450gms (1lb) that appear to be hibernating (cold and in a tight ball) are suffering from hypothermia and are in fact dying. These must be rescued if they are to stand any chance of survival.
Towards the end of October or if bad weather is expected those under 350gms (12oz) may best be rescued whether they are out day or night. This can be difficult to determine as the further north you are the earlier winter will appear – if in doubt find a carer near you and seek their advice. In October small ones seen away from your garden e.g. crossing the road at night may also be best rescued as they may not have a ready supply of food as ones regularly visiting your garden.
They can have mashed up, meat based dog or cat food mixed with a little cereal (weetabix, bran or wholemeal bread) to give it some bulk. They can also have meat based cat biscuits, as these are good for the teeth. Other titbits can include sultanas and small pieces of fruit, cooked potato, light fruitcake, plain biscuits, cooked chicken, raw mince etc. They will also need a dish of water, especially if dry biscuits are eaten.
Make a feeding station for the outside hedgehogs. Use either a plastic mushroom box or child’s toy box or similar and cut a 13cm x 13cm (5″x5″) hole in one of the short sides. Place this over the food, like a tunnel, and the hedgehog can get through the hole to the food but not the cats. A brick on top should stop the box being pushed aside. Always make sure there is a little food left in the mornings – if not, you are not feeding them enough.
BASIC FIRST AID
Line a high-sided box (hedgehogs are good climbers) with newspaper and put it in a warm room. Pick the hedgehog up using a towel and place it in the box; use that towel as some bedding for it. If the hedgehog is lethargic, cold, wobbles and staggers then it needs a hot water bottle or similar. These hedgehogs need more intensive care and are best passed on to a hedgehog rehabilitator. Cover the bottle with some towel and place the hedgehog on this but still with its towel covering it. The water in the bottle will need to be changed every few hours to keep it warm. Alternatives to hot water bottles are pop bottles full of warm water, ice cream or margarine tubs full of water with the lid on, wheat bags (cover with a small plastic bag to prevent it becoming soiled) a pet snuggle safe or heat pad or a reptile heat mat. Do not use back warming pads for human use, as they are not designed to be urinated on! Provide food and water and then SEEK ADVICE – telephone us on 01382 541311 or the British Hedgehog Preservation Society on 01584 890 801 for carers.
Many autumn juveniles will have lungworms that in turn can cause breathing difficulties. Those already showing signs of problems i.e. out in the day will be most at risk and are likely to have the highest worm burdens. Symptoms may include lack of appetite, no weight gain even when eating, coughing and rapid breathing. These will need worming and antibiotics so are best passed to a rehabilitator who can arrange veterinary treatment.
If you are going to over-winter the hedgehog yourself it should be weighed daily initially as it can be difficult to tell whether it is eating or just walking through the food. If it stays the same weight over a few days or loses weight then it is best passed on to someone with more experience. Provide the food mentioned above and once it is about 600gms (22oz) it can gradually be introduced to a cooler temperature (a bit like hardening off plants). It can eventually go into a shed or garage but do keep feeding it. Let it decide when it wants to hibernate. If it gets up to around 800gms (28oz) and the weather is mild then it can be released. If it was found in your garden or nearby then you can release it, late one evening into your garden – preferably into a ready-made nest site (see Hedgehog Homes). You will also need to provide food and a feeding station. Otherwise release the hedgehog in the spring. Let the wild hedgehogs be your guide, if they are awake and around it is time for yours to go. However some males may start to become very restless and try to escape from their box. If this happens once they are up to weight release them at the earliest opportunity otherwise they may become very stressed and could die.