New blog from trainee Ecologist, Gordon Bryden. He's been out and about looking for hoverflies at Loch Leven.
Hoverflies at RSPB Loch Leven
Hoverflies are one of the most distinctive fly families, and definitely the most popular. They are mostly big and colourful bee and wasp mimics with a distinctive hovering flight around flowers and sunny spots. Many of the species have larvae which eat huge numbers of greenfly, making them very popular with gardeners too and they are vital cogs in ecosystems. A significant number of the UK’s hoverfly species are rare, making the group really important for conservation as well.
I took advantage of a brief break in the weather to head out to RSPB Loch Leven in Kinross to look for hoverflies. Loch Leven has an interesting mix of wetlands, woods, flower patches and hills so there are lots of habitats for a wide variety of species. Flowers are usually the best place for finding hoverflies since the adults will gather around them to stock up on nectar and pollen.
Far and away the most common species on site was Eristalis pertinax, shown above feeding at a flower. As you might guess from the picture, hoverflies are important pollinators since they visit so many flowers. Bizarrely this is one of the species whose larvae are the “rat-tailed maggots” which live in oxygen free sludge filtering out microbes to eat. I think that’s a much more dramatic change than any butterfly.
This is one of the aphid eating hoverflies. It’s hard to be sure from just a picture, but I believe this particular species is Platycheirus albimanus. Like Eristalis, the adults are completely vegetarian and feed on nectar and pollen. The larvae are important predators of greenflies and other aphids. Little flies like this probably eat far more aphids than ladybirds do, but get almost none of the credit.
Although it’s not a hoverfly, I just couldn’t resist taking a (blurry) photo of this Garden Tiger moth. Once a very common species, it’s numbers have dropped massively in recent years to the point that it’s becoming rather rare. It’s good to find one at Loch Leven.
Just to be thorough I climbed all the way up to the top of the hill in the Loch Leven reserve to check for hoverflies. It was much taller than I thought it was (much to the dismay of the volunteer I had shadowing me), but the view of the wetlands was spectacular. Sadly there weren’t any hoverflies up there but I made sure to snap a photo as a souvenir. In the end I found 13 different species of hoverfly on the site in just one day. No rare species this time, but it does give us a clearer picture of the ecology of the reserve.