Do Rodenticides Kill Hedgehogs? Is That A Silly Question...

 

Avon Wildlife News (24:26) carries the following:

"Helping Hedgehogs

Isabella Clark is a researcher based at the University of Reading currently recruiting volunteers across the UK for a citizen science project investigating how urban hedgehogs may be exposed to rodenticides (rat poison) in gardens.    One potential route of exposure involves hedgehogs occurring in the same gardens as rats and mice, where rodenticides may be used to treat infestations.    As a result, hedgehogs in these areas may be more likely to encounter these toxins.

Isabella is looking for volunteers with access to a garden and a motion-activated wildlife or security camera.    Participants will be asked to monitor a leaking tin of sardines in their garden for 1–2 weeks.    No prior experience is required, and full instructions will be provided.

The findings from this project may help improve understanding of the risks rodenticides pose to urban hedgehogs and inform more wildlife-friendly pest control practices.

The project is planned to begin in July 2026, with additional surveys taking place in winter 2026/2027. For more information and to apply, please visit https://sites.googlr.com/view/gardenwildlife-org/home and contact isabella.clark@pgr.reading.ac.uk if you have any questions."

I laughed.  Sorry....monitor a leaking can of sardines for two weeks?  How will it be made to leak? 

1.   An open can leaking poses a risk to foxes, badgers (yes hedgehogs and badgers do frequent the same gardens) and while either might carry the can off.

2. what about rats?  If rats are nearby why would you want to attract them to your propperty? I have first hand experience of what just what damage one lonbe rat can do in a fedw minutes. 

3. I can see a few good cat fights over this leaky can. 

Not sure how this will show hedgehogs will be attracted to rodenticides. I found two dead in my garden early last year after rodenticides were used in three adjacent properties and his have been seen for the first time in the last week. 

I ought to point out that no one was interested in carrying out post mortems on my two hogs and, although there is no exact national figure for the total number of UK hedgehogs killed by rodenticide research shows that nearly all (up to 100%) wild British hedgehogs are exposed to anticoagulant rat and mouse poisons, primarily through secondary poisoning from eating contaminated slugs and insects. (The Telegraph  26 08 2009) A Bristol University study by Dr Claire Dowding who stated that:

""This high figure really is of concern and might be one of the reasons why the British hedgehog population is thought to be declining.

"It's difficult to tell exactly how these animals are exposed to the chemicals.

"They may be eating them directly, scavenging on dead rodents that have been killed by the poison or eating their favourite diet of slugs and snails that have fed on the poison bait."

The study provided the following detailed findings:

• Exposure Rate: Out of 120 hedgehog carcasses examined, 67% (80 hedgehogs) showed direct exposure to rat poison.
• Urban Vulnerability: Hedgehogs in urban environments have significantly higher concentrations of toxic chemicals in their systems.
• Lethality: While secondary poisoning can cause fatal internal hemorrhaging, many die from chronic, compounding toxicity rather than immediate acute poisoning. [1, 2, 3, 4, 5]

For context, this threat exacerbates severe population declines. By comparison, human-related hazards like road traffic kill an estimated 100,000 to 335,000 hedgehogs every year in the UK -not to forget the deer5, foxes, badgers, otters and birds. Our roads arte the new "Killing fields".

Well, maybe Ms Clark has not heard of the Bristol study -it was in 2009 after all.  It should also be pointed out that for over 20 years I have stated and challenged rodentiocides available to buy in shops.  There ARE alternatives to rodenticides.

Also, tut tut.... only the public are to blame? In the Bristol Fox Study two of the foxes that were necropsied died due to rodenticide -NOT the one available to the public but second gen as used by Bristol City Council and although the Wildlife Incident Investigation Scheme (WIIS) told us that the report was considered "not for the public" as it covered up misuse of rodenticide and lack of regular checking by Bristol City Council.

You have regular visiting hedgehogs for over 20 years. Rodenticide is put down (by BCC)  and two dead hedgehogs and the rest not seen again. After a gap of almost a year new hogs have appeared. There is your science.