RSPB Mersehead Blog 8th – 14th March 2025
Amphibians are now galore at RSPB Mersehead. In recent weeks, both Common Frog Rana temporaria and Common Toad Bufo bufo have been sighted, with high activity levels around the reserve.
Two Common Frogs (Rana temporari) in amplexus. Photo taken at RSPB Mersehead in February 2024. Photo credit: F. Sanders
Common Frog
Common Frog spawn was first spotted this year, at Mersehead, on Sunday 9th March. Mersehead is a wetland site composed of large expanses of freshwater, including ditch networks and pools, providing plentiful locations for amphibians to spawn. Spawning is both rainfall and temperature dependent, and eggs can be laid as early as December or as late as the end of April. Incredibly, a female frog can lay as many as 4,000 eggs in one spring, with only around 1 in 50 of these surviving to adulthood.
A few clumps of spawn at Mersehead have already perished in recent days, most likely due to the cold night-time temperatures and resultant frozen surface water. Spawn can survive in cold temperatures unless the water actually freezes. Eggs in contact with the ice will die, whilst eggs underneath can survive. Despite this, if there is a prolonged spell of cold weather, and a pond is completely frozen over for a long time, this will eventually deprive all spawn of oxygen and all eggs will die. In the image below, you can see a few eggs that have turned white and perished at Mersehead.
Common Frog (Rana temporari) spawn at RSPB Mersehead in front of Meida Hide, March 2025. Photo credit: F. Sanders
Common Frogs are predated by a range of species including Grey Heron Ardea cinerea and Eurasian Otter (Lutra Lutra). A few days ago, frog remains were found at the reserve, showing a large number of unlaid eggs (see photo below).
Common Frog remains – eggs visible. Photo credit: F. Sanders
Common Toad
Mating has been observed amongst Common Toads at Mersehead in recent weeks, and individuals have been sighted crossing the main road. Every year, an estimated 20 tonnes of toads are killed on UK roads, so it is worth slowing down when driving to Mersehead.
When spring arrives, Common Toads return to the pond where they were spawned to find a mate. Males use vocalisations to attract a female, before engaging in amplexus where the male climbs onto a females back and tightly grips around her chest, using nuptial pads to maintain a tight grip. Whilst the male is wrapped around the female, she lays her eggs which he then fertilises with his sperm. A double string of fertilised eggs is produced, taking 10 days before tadpoles emerge, and around 16 weeks before they reach the adult stage.
Common Toad (Bufo bufo) in amplexus. Photo taken in March 2025 near Meida Hide, RSPB Mersehead. Photo credit: F. Sanders
Common Toad (Bufo bufo) in amplexus with small male on top. Photo taken in March 2025 near Meida Hide, RSPB Mersehead. Photo credit: F. Sanders
If you are walking around the reserve, it is worth keeping an eye out for these amazing amphibians. In a few weeks time, the first tadpoles will be visible.
Freya Sanders, Assistant Warden
For more information on individual events and to book a place please go to our website:
https://events.rspb.org.uk/mersehead
Forest School: For more information & to book a place on Forest School please email: mersehead@rspb.org.uk
23rd February
9th March
23rd March
*Flooding - Please note that Mersehead nature reserve is prone to flooding during periods of high rainfall and/or strong winds and tidal surges. To avoid disappointment at these times, please contact the reserve in advance of your visit by email in the first instance at mersehead@rspb.org.uk or check the RSPB Dumfries and Galloway Facebook Page for daily updates.