Trainee Ecologist Gordon Bryden is out and about on our reserves searching for flies!
On the other wing
Searching for flies on reserves might seem like a strange activity for an employee of the RSPB, but flies and their maggots are essential to the ecosystems which all birds depend on. They provide food for birds and their young, they pollinate the flowers and break down waste. In the UK we have well over 9000 species (compare this to the 300 or so bird species). It is a massive job to work with them, so I focus on the groups of flies that are ecologically the most important.
Craneflies are a great example of this. Most people are familiar with “daddy long-legs”, the large awkward flies which bumble about and lose their legs at the slightest touch. In fact there are well over 300 species of these flies and, despite the persistent urban myth, none of them have a deadly venom.
Many gardeners will have encountered leatherjackets while digging around. They are the larval stage of some of the most common cranefly species. They live peacefully in the soil eating roots and decaying plants until pulled up and eaten by a hungry bird. Other species have different needs, and their larvae can be found in a huge variety of habitats, from pond silt, under the bark of trees and inside wild mushrooms. They really are hugely important in the environment as well as being a big food source for many birds.
Pictures: Mounted Tipula irrorata and a standing trunk of deadwood at Abernethy
Finding the right species on reserves is a good indicator that things are on the right track. For instance at Abernethy forest I found Tipula irrorata. This species is an early deadwood coloniser, and reflects well on the deadwood creation at the reserve. Later in the year I’ll be looking for rarer and more specialised species on the reserve.
Wetlands too have their own community of specialist species. When a new area of wetland is created on a reserve it takes time for these species to move in and colonise, but once they have we’ll know that the wetland is in good condition with plenty of leatherjackets for the birds to eat.
Over the next few months I’ll be surveying a number of reserves to look for flies and hopefully, with a little luck, I’ll get some good photos to spice up future posts as well.