Nattering Away Again

RSPB Mersehead Blog 19th - 25th April 2025

Someone asked me this week what I find the most exciting species I work with. Although Mersehead is full to the brim of amazing species which change with the seasons, there is one which for myself takes the crown, the humble Natterjack toad.

Mersehead is home to three species of amphibian the common frog, common toad and natterjack toad. The Common Frog is the first to emerge from their winter slumber. They are generally a shade of olive-green or brown, with a dark patch known as a mask behind the eyes but colouration is extremely variable: yellow, pink, red, orange and black individuals are often reported. Second to emerge is the Common Toad with their brilliant bronze eyes. The UK’s rarest amphibian and one we are proud to say calls Mersehead home, the Natterjack Toad, is the last to emerge from hibernation. The bright yellow dorsal strip easily identifies this species, their emerald eyes a stark contrast to the bronze of the common toad.

The Natterjack Toad prefers warmer night air temperatures than the other two amphibians, ideally double figures and with the cold night air and minimal rain throughout March and the beginning of April we have seen a slightly delayed start to the Natterjack Toad breeding season at Mersehead this year. However, it all kicked off over the weekend as we found 29 spawn strings scattered across the pools on Monday morning. Natterjack Toad spawn forms a long line of delicate black eggs, with each spawn comprising two strings. Traditional methods of monitoring the Natterjack Toad were to complete daytime surveys for spawn strings as each female toad will only spawn once each year and so this gives an indication of the number within the population. We complete this survey method twice weekly recording first the number of spawn strings, then tadpole abundance estimates and finally, toadlet emergence. With the conclusion of the second spawn string survey of the week today, the number of spawn strings has quickly risen to 50.

At Mersehead, we also complete nocturnal surveys to monitor the adult population. Each toad is quickly and carefully measured with a ruler to the nearest 5mm. As Natterjack Toads grow bigger with age, this assists with understanding the population dynamics of the colony. At Mersehead, we know that there is currently a wide diversity of ages which indicates that the colony is healthy with new young toads joining the breeding population. 

Other headline news this week is that the first Lapwing chicks have been spotted! The belwo photograph was taken at Mersehead in 2023 by Adam Sutton. Whitethroat has returned to the reserve with it's scratchy song declaring it's arrival. Reed Warbler can be heard singing from the reedbed again and a Whimbrel has been recorded out on the wetlands.

R. Chambers

At Mersehead you will find the RSPB’s only self-catering holiday cottages - Barnacle and Shelduck. Available summer dates are currently going quickly, follow the links to book your next holiday.

*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.