Steve's Herpetological Blog

An insight into the life of Steve, his research and the many books he reads


#SciFri: In search of the marsh frogs of south Essex

This fortnight I thought it would be great to merge #FrogFriday with #SciFri and give you all something a little different. As many of you will know I grew up in south Essex, not far from Southend-On-Sea. In recent years I have lived in Cambridge and Ascot, both some distance away from the coast, which has always caused me some anguish as I miss being able to walk along the beach at any time that suits me to just clear my mind or postulate questions in my head. Enough of the back story, growing up in Essex I used to visit a number of RSPB reserves with my family and my favourite was always Rainham Marshes for the simple fact that it had marsh frogs (Pelophylax ridibundus), a non-native amphibian species. The Marsh itself is just off of the A13, just inside the M25 on the way into London in case you wanted to visit. It’s though that they were introduced to Rainham in around 2004 as this is when the males were first heard calling (it’s quite distinctive). The frogs at Rainham are quite spectacular in that they are your usual brown to green colour but some are also turquoise-blue. Next time you are there, keep an eye out!

One of the marsh frogs seen at Hadleigh Castle Country Park

Recently I got a tip off from a friend that marsh frogs were present at Hadleigh Castle Country Park, a short walk from my hometown of South Benfleet. I hadn’t been back to the site since the 2012 Olympics as the mountain biking was held at the park although before then I did visit quite regularly to photograph the wasp spiders and dragonflies. Its a surprise that I never saw the marsh frogs then, needing to investigate I planned a visit with the great Neil Phillips to head out and search for the frogs. We got to the park at about 7:15 one early Saturday morning and were greeted to the sight of a couple of marsh frogs at the first body of water we found, despite the dry weather we’ve recently experienced. Over the course of the morning we saw over 200 marsh frogs of all life stages (expect eggs), although we did see a pair that was briefly in amplexus. Now we know that the frogs are there, we intend to do some more routine monitoring as not much is known about the frogs and their impact on native amphibians. Keep an eye out for future updates on the subject!

I’m sure this frog was just posing for me

I’m pretty happy at how the photos came out from the day and I’ll be sure to add some to my Flickr in the coming days when I’m a little less busy. Thanks Neil for a great day and I’m so proud at how well the day went, one of the frogs is now also the banner for the Research page here on my website.


  1. I was tipped off in 2003 that there were marsh frogs at Hadleigh Park in the ponds there. One warm June evening we went down there, but heard no calling. We then drove towards Two tree Island behind Leigh on sea station. Just before you go over the bridge there’s a dyke which runs east to west. We parked the car and took a stroll. It wasn’t long and the cackling call was heard and identified. A local dog walker came along and I asked him if he’d heard the calls? He had and in fact had wondered what on earth was making such a racket. He guessed that at peak times there were dozens calling.
    It appears that many of the Thameside dykes now contain ridibundus inc as you mentioned Rainham marshes.


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