Heron-spotting survey call

The appeal comes from the Wigan-based Canal and River Trust – the charity that cares for 2,000 miles of canals and rivers in England and Wales – as part of the Great Nature Watch, a nationwide survey of wildlife.

Sitting at the top of the food chain, population numbers of grey herons (ardea cinerea) depend on their being able to find enough food – largely fish, frogs and small mammals – and can be negatively affected by poor water quality. The distinctive birds are the second largest in the UK, after only mute swans, and can be seen all over the country.

Trust ecologist Dr Mark Robinson said: “Herons are one of the most majestic sights on our waterways, and they’re also a sign that all is well with the ecosystems they rely on. While we’re constantly monitoring our water quality, with people’s help we can get another insight into the health of wildlife around the waterways.

“As adult birds face no natural predators, they’re the kings of the canals, and take their pick of fish, amphibians and small mammals around the waterways, even gobbling up the odd duckling. Large numbers of herons usually mean healthy, thriving canals and rivers, as they’re natural barometers of water quality, fish stocks and much more – even down to the insect and invertebrate populations that feed their prey. Equally, if there are areas without many sightings, we can have a look into if there are any reasons they might be being put off.”

Sightings can be submitted by downloading the Trust’s free mobile app: eNatureWatch (or search Canal & River Trust in the Apple App Store /Google Play Store). Anyone can take part and record as many sightings as they like between now and the end of September.