Biodiversity Fact File: Herring Gulls and Heath Beefly
Thursday 12th January 2017
Herring gull. Amy Lewis
Our Island has a brilliant array of biodiversity and the Manx Wildlife Trust works hard to protect it for future generations to enjoy.
Our biodiversity fact files aim to bring often lesser-known but threatened species to our attention and explain the incredible lives that they lead.
A surprising bird on the red list of threatened species is the herring gull. Most people think of them as a bit of a nuisance and as being found everywhere, but there are quite a few different sorts of gulls.
Herring gulls are a large bird, with grey backs, white underside and black wing tips with white patches that give it a checkerboard appearance, they have a slightly hooked beak which is yellow with a red spot.
They are omnivorous and well known for their scavenging habits, frequenting beaches, playing fields and rubbish sites.
Figures from the Joint Nature Conservation Committee show that between 1969-70 and 1985-88, the UK herring gull population decreased by 48%. This decline continued between 1987 and 1990, with a subsequent recovery by 1999, but it dropped further after 2000. Although rapid at the start, this decline has levelled off and stabilised which may in part be due to the birds adapting from nesting primarily on cliffs to adapting to using buildings.
We tend to notice them more because they are such large birds, have adapted to living near to humans and are very raucous too!
Staying on the theme of flying biodiversity we have a very interesting fly called the heath beefly. It is considered to be a vunerable species in the UK, mainly due to the loss of its habitat, the heath. In Britain it is only found in the Isle of Man and a few sites in East Dorset.
The fly looks very like a bee having a furry body with stripes on, but look closely and it only has two wings unlike a bee that has four. It feeds on bell heather nectar and has a long tongue to be able to probe into these flowers.
Most amazing of all is its life cycle: The female bee has a pouch under her body in which dust is carried, she lays her eggs whilst hovering in midair and coats the eggs in this dust. The dusty eggs are then flicked into or near to the burrows of solitary bees.
The beefly eggs hatch into larvae which then become coated in the dust and with this camouflage enter the solitary bee burrows where they either feed on the bee larvae or the food which has been stored for the growing solitary bee. What an incredible life cycle!