Newt Mortalities On An Urban Cycle Path

Recently a paper I co-authored with a colleague was published in The Herpetological Bulletin, regarding smooth newt (Lissotriton vulgaris) mortalities on an urban cycle path in central Cambridge. It’s well known that roads can be detrimental to amphibian populations due to collisions with cars but this is the first time that amphibian mortalities have been reported due to collisions with bicycles. I thought I’d take the time to explain our findings more and expand on our potential solutions for the future, as things have changed slightly since the initial publication of the short note. I apologise in advance for the morbid and macabre subject of this post.

A little bit of background on the smooth newt for those who are unfamiliar with the species. They grow to about 11cm in length, are common throughout the UK but have declined slightly in recent years due to habitat loss.

Slightly morbid sights such as this one greeted us on evenings when we would be surveying near by

We discovered an area where newts were being struck by bicycles thanks to a group of friends that had spotted them a couple of days previously. I then made an afternoon visit at the soonest opportunity when I was free. On arrival, I found the remains of a couple of dead newts (like the ones below) that had clearly been dead for a short while, which had started to decompose. They had been repeatedly walked or cycled over, so much so that they were almost indistinguishable from the pavement the path was made of. After this initial discovery, I made it my duty to return whenever I could to try to prevent further newts from becoming fatalities on the cycle path. Luckily, with the help of colleagues, I was monitoring the population nearby that the newts belonged to and so we made regular visits to survey the breeding amphibians as well as prevent future deaths. Despite our best efforts the deaths continued and as illustrated in the photo above, some of the newts unfortunately died as a consequence of their wounds relatively recently before our arrival to the site. The individual above isn’t the freshest example we came across, it was disheartening to think that if we’d been there a few moments earlier we could have prevented such a tragedy.

A squished newt that has started to decompose

What about a solution to the problem? As mentioned in our paper, we believe a drift-fence would be the best bet to help prevent such events occurring again. We haven’t observed any fatalities since 2014 which may be due to changes in the weather. Although a drift-fence would be an ideal solution, unfortunately it seems that this solution can’t be implemented. It’s going to be hard to gain permission from the land owner to install the fence, we originally assumed that the land was owned by the local council. Secondly, the ‘impact site’ is right near a residential area and the drift fence is likely to be tampered with. We are currently looking at potential landscaping features that would help to prevent such events in the future – if you’ve got any ideas I’d be welcome to hear them. For more information regarding this post and our methodologies/findings please refer to our publication.


Allain, S. J. R. & Smith, L. T. (2016). Newt mortalities on an urban cycle path. Herpetological Bulletin, 138, 27-28.


Disclaimer: The views expressed in this post are solely this author's and do not necessarily reflect the views of The Wandering Herpetologist website.
Steven Allain

Author: Steven Allain

Steven Allain is from England and has been fascinated with amphibians and reptiles ever since he was a young boy. He is the current chairman of the Cambridgeshire and Peterborough Amphibian & Reptile Group (CPARG). Gotta question or comment for Steven? Email him at steven[at]

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