Autumn Juvenile Hedgehogs
What is an Autumn Juvenile Hedgehog?
Autumn juvenile hedgehogs refers to those who have reached maturity and can live independently from their mothers but are likely to be too small to traditionally hibernate successfully. This season typically lasts from September until the end of November, but may vary depending on location and weather conditions. Hedgehogs discovered in March and April may have struggled throughout winter or hibernated at the minimum weight, which can leave them weak upon emergence.
What weight should a Hedgehog be to hibernate?
Whilst there is no guaranteed weight for a hedgehog to survive winter, there is a general consensus that suggests hedgehogs weighing under 450 g have less chances of surviving hibernation than one of 600 g.
Experience has shown that hedgehogs generally hibernate between January - March.. However, recent warmer winters (especially here in Oxfordshire) has shown that some hedgehogs are not even hibernating at all, thus now raising the question as to whether or not the traditional over-wintering of hedgehogs is required.
What is OWR's protocols on Autumn juvenile hedgehogs?
Towards the end of November (usually when the temperatures start to plummet in this area) we generally advise that any hedgehog weighing under 450g is unlikely to survive hibernation (if it does) or die from starvation in freezing weather conditions.
As a result, come the colder months, many juvenile hedgehogs are taken into care and are fed through the winter here with us.
If they reach 600g they are then given the opportunity to hibernate in an outside pen, where they are closely monitored with food and water being made available at all times should they intermittently come out of hibernation. Eventually they are released in April or May.
With that said, there have been many situations through advice, support feeding and regular monitoring that have allowed wild hedgehogs to remain in their natural habitat, undisturbed and have not had any requirement to be subjected to unnecessary captivity. Each and every hedgehog case should always be referred to the professionals and no two scenarios are ever the same.
Whilst this protocol is what we here at OWR currently operate, this doesn't suggest that another way of doing it is wrong. Wildlife rescues tend to sometimes have different views, opinions and approaches. This approach works for us, however should you contact another wildlife rescue , they may choose to do things a little differently, and as long as the hedgehogs are being looked after properly, at the end of the day, we are all doing this work for the same reason/ outcome.
Do all hedgehogs hibernate ?
Hibernation is not always mandatory for a hedgehog, but the truth is, we still do not know exactly what makes a hedgehog want to go into hibernation in the first place. The theory behind hibernation triggers depends on various factors including their overall health, brown fat reserves, natural food availability, and nightly temperatures. These factors differ amongst individual hedgehogs, resulting in varying decisions to hibernate or remain active.
Our data has shown, that due to our recent winters being much warmer, many hedgehogs do not hibernate at all. And, even if they do go into hibernation, they tend to wake up periodically throughout the winter in order to feed.
One thing to bare in mind though is a hedgehog will not suddenly just drop and decide to hibernate in the middle of open ground like a lawn or a pathway. If this is seen, the hedgehog is poorly and should be referred to a suitable rescue immediately.
Instead, they curl themselves up into a ball, tightly weaving the loose nesting material using their spines to create layers of micro climates in the core of the nest itself, which is called a hibernaculum . Usually they will choose dense coverage such as a hedgerow as a nesting site, but other sites may include, underneath sheds, decking, woodland and more worryingly.. bonfires!