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.
Weekly update from RSPB Conservation Manger Stuart Benn.
The Scottish Open golf championship was held just along the road from us at the weekend and, gladly, there was no repeat of last year when torrential rain caused landslides, floods and massive disruption. This year, the weather was OK but still not the best and, since I had started a heavy cold, I didn’t venture any further than the moors near Inverness. It was good to find a pair of Stonechats feeding their young – they took a real hit in the two hard winters of 09/10 and 10/11 and disappeared from this hill but they can produce several broods each year and the numbers soon bounce back. But the main excitement was seeing a Short-eared owl.
In our popular imagination, owls are birds of the night, the familiars of witches, heard but rarely seen but not so the Shortie which doesn’t conform to type and is out and about during the day. It’s always a real treat to see one (when else do we get the chance to get a really good look at an owl?) and admire their languid flight - the authors of The Nature of the Cairngorms put it brilliantly “its shallow wing beats silently patting the air, as if testing a hot stove.”
Short-eared owls have an amazing world distribution – much of the Northern Hemisphere but South America too as well as remarkable outposts in island groups like the Falklands, Hawaii and the Galapagos. Unfortunately, they are becoming a rare sight in the UK with numbers declining for reasons that aren’t yet clear. But let’s hope their decline is reversed so they don’t just become a bird of our imagination.
I think the weekend bird was just passing through because I hadn’t seen them on the moor earlier in the year and don’t believe they nested although they can be surprisingly inconspicuous. So, no repeat of 2011 when I did find a nest and saw that, if anything, the chicks are even more endearing than their parents!
Photo: Andy Stronach
As regular watchers of Springwatch may remember, owl chicks don’t all hatch on the same day so show quite a size difference and, if hunting is poor, the younger ones don’t survive. But this nest did well with the adults keeping them well-fed with a regular supply of voles and at least five of the young flew – brilliant!
Trainee Ecologist Helen Dickinson has been out and about at our Abernethy reserve searching for deadwood beetles.
Abernethy – Deadwood is good wood!
As an Ecologist trainee within the Scottish Reserves Ecology team, I get to spend time in some of the amazing wild spaces that Scotland and the RSPB have to offer. Most recently I have been working from Forest Lodge at the RSPB Abernethy Forest Reserve in the Cairngorms. My work here focuses on deadwood beetles in different areas of the forest, from ancient native Caledonian forests to 1970’s Scot’s pine plantations.
Deadwood is a hugely important habitat for a wide range of invertebrates. Specialised species are often rare due to the absence of good quality deadwood habitat within woodlands. Historically, foresters removed deadwood for silvicutural purposes due to concerns about insect disease and fungal pathogens. In Abernethy Forest a programme of deadwood creation is part of the site management plan to try and address the balance, specifically in old plantation areas with the aim of restoring them to a more natural structure.
Both standing and fallen deadwood have an important role to play in woodland ecosystems and a small proportion of trees have been treated in a number of different ways to increase deadwood volumes. Scot’s pine trees have been chainsawed at various heights, whinched over, ring barked and all left in situ to create an assortment of deadwood habitat. This variety is required to enhance invertebrate diversity as certain species colonise deadwood at varying stages of decay.
Deadwood plays a crucial role in the deadwood beetle lifecycle both as food and accomodation for the larval and pupal forms. Beetles may spend years in the deadwood from egg to adult. Wood is not the most nutritious of food stuffs so development can be a lengthy process. This also means that finding deadwood beetles can be a tricky business. Evidence of larval chambers is a good sign of deadwood beetle activity. Patterns can vary with species, particularly with Bark beetles and some can be surprisingly beautiful.
Another tell tale sign is bark with emergence holes. Once pupation has taken place adults will chew their way out to freedom and head of into the big wide world of the forest.
Although I am looking specifically for deadwood beetles, I have had the pleasure of seeing many other species, not so specialist but still a real treat to find and I wanted to share some images of several of the bigger beetles found at Abernethy.
Carabus glabratus is a really easy beetle to spot and commonly seen at Abernethy this time of year, ambling across tracks and vegetation. One of the larger ground beetles (Carabids), measuring up to 30mm, this species can be found in damp moorland and forest habitats and close family members including the Violet Ground Beetle (Carabus violaceus), which has a fantastic violet sheen, can be found in most gardens.
Another easily spotted species is the Dor beetle (Anoplotrupes stercorosus), one of the UK’s scarab beetles, which feeds on dung and decaying plant matter. This species is out in abundance in the forests of Abernethy at the moment. If you’re lucky enough to see one that has flipped over onto its back (accidently of course) you will discover that despite its dull black upper side its underside is highly metallic blue/purple.