How a corpse freezer benefits the study of natural history

​Inés has shared a fascinating insight into the use of an additional freezer kept at her home, with the purpose of aiding scientific investigation into the health of wildlife.

"I have recently been updating the inventory of my corpse freezer. This sounds a bit gory but I would like to explain that it is all for a good reason. Last year, a chest freezer became available locally on Freecycle.org and I decided to grab the opportunity and set up a freezer that would act as a local hub for the temporary storage of dead animal samples that can contribute to wildlife conservation and research.

The current contents of my corpse freezer include a dead slow worm that I found on the road (but not flattened) a couple of weekends ago. I reported it on the website Garden Wildlife Health and on the Monday after, I received a call from ZSL vets, very interested in doing a post-mortem on my slow worm. I am just waiting for their pre-paid envelope to send it back to them.

One of our members (thanks, Juney!) found a sparrowhawk in their garden, sadly deceased after having crashed against their window. This one is also in my freezer waiting for another dead bird of prey to be found, to fill the pre-paid box that I have from the (Predatory Bird Monitoring Scheme) before sending it. A few months ago I sent them two owls and when they finish their analysis they will let us know the results. Birds of prey often have symptoms of secondary poisoning or their body tissues contain concerning levels of toxic products, all due to the ingestion of prey items which have been poisoned (e.g., rat poison, slug pellets...).

I also have a couple of otters that died in road collisions with cars, which I will deliver to the Cardiff Otter Project this summer. They will ascertain if the otters have any underlying health condition, their sex, their age, their breeding condition, and possibly do some DNA analysis too. The good news from this project is that populations of otters are slowly recovering nationwide from previous minimum numbers. However, their populations are not genetically diverse and are therefore vulnerable. In addition, background river pollution is also detectable in otter body tissues.

Past contents of my corpse freezer include faecal/swab samples from mustelids that were sent to Nottingham University for research on COVID-19 transmission between humans and wild mammals (none tested positive) and bats that were sent to Defra for rabies testing (also negative).

Other animals that are not required for any post-mortem research project, I may skeletonise for archaeological reference collections.

It is sad to find dead animals, particularly when they have died because of us (humans). While some dead animals may be suitable to be left in the wild to serve as food for scavengers, sometimes it is better to remove the animal from the environment to prevent the spread of disease or contribute to the conservation of the species.

The results from many of these analyses projects provide information on a wide range of elements that are useful for conservation research and have the potential to inform on policy (such as regulating the contents of pest-control products).

If you are potentially interested in helping with this research, please have a look at our website section and scroll down to "Dead wildlife" ​ (https://www.tisburynaturalhistory.com/recording.html) to find out what animals are interesting for sampling. Don't hesitate to get in touch if you encounter any animal samples that may be useful, the "corpse freezer" has some space!"