Dormouse research and recording

My research:

I am currently studying Zoology at the University of Exeter and am passionate about wildlife, in particular birds. Which is how I came across the Hazel dormouse (Muscardinus avellanarius). Whilst gathering data on nesting birds on the Isle of Wight for the British Trust for Ornithology’s Nest Record Scheme I realised that I could increase the number of records to study by asking friends and colleagues for any records they had of birds in dormouse nest boxes.

This led me to thinking about how the different species interact. Consequently, this year I am carrying out my undergraduate research project on the competition and interactions that occur between the Hazel dormouse and nesting birds, mainly various tit species, for the use of dormouse nest boxes.

These boxes are designed for dormice to use during the summer for breeding. However, they are often used by breeding birds earlier in the year and I want to find out what impact, if any, this might have on the dormice.

A dormouse found during the April check that has come out of hibernation early but fallen into a state of torpor on a cold morning. When handling a torpid dormouse it is important to be as quick and efficient as possible with all data collection as not to warm it up and awaken it from its torpor, before it is returned to its box.

About:

Dormouse are currently declining in both range and numbers mainly due to inappropriate management of hedgerows and woodlands and are now classified as at risk of extinction within the United Kingdom. They are mainly nocturnal animals and spend the majority of their time in the trees with their diet varying through the year from tree flowers in Spring to caterpillars and wasp galls in Summer and finally fattening up blackberries and hazel nuts in Autumn. The habitats that they are most commonly found in is successional woodland, often after it has been coppiced but they can also be found in more mature woodlands or even scrub and hedgerows.

Dormouse boxes unlike birds have a hole at the back that faces the tree, but this doesn't stop birds still using them. 

Population monitoring: 

The National Dormouse Monitoring Scheme (NDMP) is run by the Peoples Trust for Endangered Species (PTES) and you are only allowed to check boxes and handle/photograph dormouse under licence from Natural England. These checks run from roughly April to October and are carried out once a month. When a dormouse is found it is weighed and the life stage it is at recorded, this can ranging from 'pinks' when they have just been born to adults that have to have hibernated over winter at least once.

A young dormouse around 2 weeks old. This one would most likely be recorded as GEO (Grey Eyes Open) although of course there is always an element of subjectivity with any biological recording. 

When a nest is found with extremely young dormice in they are left but if they are found to be large GEC (Grey Eyes Closed) young or older they can be weighed to get a measure of their health although all young are weighted together to speed up the process obtaining an average rather than individual weight, if still relatively young.

Weighing the young dormice, average litter size is 4 but can range from just 1 up to 7!

The sex of the dormouse is also recorded as well as its breeding status which is TS (Testes Scrotal) for males and L (Lactating) for females when breeding.

This one a male, can be sexed due to the further distance between the two dots above the base of the tail compared to what would be expected for a female. The slightly enlarged grey area which are the testes, also give away the fact it is a male.

When checking the boxes you have to record the type of dormouse nest present and this can range greatly. 

A typical dormouse nest with strips of Honeysuckle although this can sometimes be tree bark as seen here and often a lot of fresh green Hazel leaves, woven into a neat ball.

A less typical dormouse nest which has been made more from woven grass.

Other species can also be found using the boxes from the more risky Tree bumble bee nest to a birds or even another mammal such a a wood mouse or shrew.

One of the boxes that has a bird occupying it instead, here a blue tits with 8 cold eggs, most likely meaning she will still be laying her clutch and hasn't started to incubate any yet.

A pregnant female wood mouse, which explains why she looks so large.

Shrew species, being examined in a bag before being returned to its box.

What is Torpor?:

In the autumn or early spring dormice can sometimes be found in a state of torpor on a cold morning. Torpor is a state of decreased physiological activity in an animal, which usually includes reduced body temperature and metabolic rate, but only lasts a matter of hours compared to the more extreme version hibernation, which can last months. Dormice do hibernate over the winter however, they actually go below the ground to do this, where the temperature fluctuates less and doesn't drop as low as staying in a box. Both torpor and hibernation are ultimately used to conserve energy during cold and wet conditions or when food availability is scarce.

Sleepy Dormouse.

A dormouse will need to reach a weight of between 15 and 18 grams by late autumn in order to have enough energy reserves to survive the winter, although they have been found to weigh as much as 40 grams in extreme cases.

Get involved: 

If you have ever been lucky enough to see a dormouse or even found one dead, come across a dormouse nest or perhaps picked up a hazelnut that you think has been chewed by a dormouse you can submit a one off record to this to the National Dormouse Database to help improve their understanding of their distribution and abundance via this link:

http://surveydata.ptes.org/dormousemonitoring/inventory.php

For more information on dormice or to find out how to train to monitor them have a look at the links below

https://ptes.org/get-informed/facts-figures/hazel-common-dormouse-muscardinus-avellanarius/

https://ptes.org/campaigns/dormice/dormousetraining/

I will update you with the results of my study when it is completed later in the Spring.

You can find more of my photography on my Facebook page below:

https://www.facebook.com/robbiephillipsphotography/