Genevieve Dalley, Trainee Ecologist with RSPB Scotland, is back with a new blog.
The Ugly Duckling
It’s a familiar story: the unassuming youngster undergoes a magical transformation to become a beautiful adult. The most quoted examples from the insect world are butterflies.
However, there are other creatures out there who, after sometimes years of life trapped in their larval skin, burst forth and take flight. The freshwater creatures which do this are possibly the most remarkable examples of such a lifestyle- adapted to life in water when young and life in the sky as adults. Here is a brief introduction to some of these unfamiliar wonders...
Dragonflies & Damselflies
The dragonflies and damselflies are probably the best known freshwater insects which make the incredible transition from water to air. Whilst familiar in the sky, few people are acquainted with the larval forms of these animals. Yet they can be just as beautiful.
Emerald damselfly nymph (Lestes sponsa).
As they grow, the nymphs periodically shed their skins and pump their bodies up as fast as possible before the new one hardens.
Common darters (Sympetrum striolatum): the pale one has recently shed its old skin and is waiting for the new one to harden.
When the time comes, which can take up to 5 years, the nymphs suddenly get the urge to find a suitable spot to emerge. They can travel impressive distances, sometimes crawling over land, in search of the right spot. Then they break through their old skin and heave themselves out, occasionally pausing for rest, before fully emerging. Finally, they must to pump their wings with fluid, warm up and, after years of waiting, take flight!
A blue-tailed damselfly (Ischnura elegans) pausing halfway out of the larval skin.
A golden ringed dragonfly (Cordulegaster boltonii) resting beside his old larval skin (exuvia).
The mayflies are best known for their infamously short life. However, their flying forms are just a small part of the story. To get to that stage they must first live an underwater life. At this stage they can look remarkably unrecognisable.
A mayfly nymph Electrogena lateralis
After up to two years as a nymph, the time comes to emerge into adult life. The mayfly nymph swims to the water surface and breaks free of the old skin. The newly emerged mayfly rests on the water surface waiting for the wings to dry. At this stage, many mayflies are eaten by fish or birds, never developing into full adults.
This first winged stage is known as the sub-imago, a mayfly's teenage years. After a few hours the sub-imago once again sheds its skin and the colourful adult fly emerges.
Part of the lifecycle of a Mayfly: A mayfly sub-imago (Siphlonuridae), a sub-imago exuvia (Ephemeridae), an adult mayfly (Siphlonuridae).
These creatures go largely unnoticed as nymphs and adults but they are no less interesting. A few days before emergence, the nymphs stop eating and make the final changes to their internal bodies needed to start on their adult life.
Unlike the other groups, the stoneflies simply crawl out of the water and find a sheltered spot to emerge, clinging to a piece of wood or rock. Then, the skin splits open and the adult pulls itself out, leaving the old skin behind. Adult stoneflies look pretty similar to the nymphs and are not very good at flying, avoiding it if they can – which may be why they go so unnoticed!
The life cycle of a stonefly: a nymph (Perla bipunctata), a larval exuvia (Perla bipunctata), an adult stonefly (Leuctra).
All these underwater creatures will be going through emergence throughout the summer months, so now is the best time to go looking for them! Look for the old larval exuvae on rocks, banksides and vegetation beside streams, rivers, ponds and pools. And see if you can spot the adults resting on nearby vegetation or making use of their newly unfolded wings.
The larval exuvae (old nymph skins) can be collected and taken home as a memory to the amazing creatures who once owned them. Just ensure the skin is definitely no longer occupied!
Seabird Tracking and Research (STaR) team member, Ruth Brown, gives us an update on her work tagging seabirds on Colonsay.
For the fifth year running the RSPB STaR team has returned to the island of Colonsay for the summer months. This year the team consists of Tessa Cole, who is well known to many local residents after four seasons on the island, and myself, who is new to the project. Colonsay is part of the Inner Hebrides of Scotland, lying north of Islay and south of Mull, and can be reached by a two-hour ferry journey from Oban. The dramatic cliffs on the west coast of the island are home to around 50,000 breeding seabirds, including 26,000 guillemots (1% of the entire UK population), making this an ideal location for studying the habits of these fascinating birds.
Team Colonsay 2014 - Ruth and Tessa looking ‘field chic’, with the seabird cliffs at Pig’s Paradise, Colonsay in the background (photo by Tessa Cole).
The rugged coastline of Colonsay (photo by Ruth Brown).
Tessa and I arrived on Colonsay back in April and, like the other STaR teams, spent our first few weeks setting up and testing the various tracking devices that we will be deploying throughout the summer. As well as GPS tags, which tell us where the birds are going, and TDR tags, which tell us how deep they are diving, this year we will also be deploying accelerometers for a study being conducted by Marianna Chimienta (PhD student, Aberdeen University). These futuristic devices record a 3D map of exactly what a bird is doing when it is underwater, giving us the most detailed picture yet of how these birds find and collect food.
On Colonsay we are focusing on tracking four species – European shags, razorbills, common guillemots and kittiwakes. The data we collect will be added to that from earlier years to help determine where and how these birds are feeding when they are at sea - information that is vital in order to provide long term protection for these species. This year our tracking work got off to a slow start as many birds started breeding later in the season than they have in other years. This may be due to the particularly severe weather conditions of last winter, which caused high mortality among seabirds and left surviving birds in poor condition. However, by early June the seabird cliffs were teeming with birds and breeding was well underway, allowing Tessa and I to get down to work and start recording tracks for the 2014 season.
Razorbill (photo by Ruth Brown).
A ledge packed with guillemots (photo by Ruth Brown).
European shag (photo by Ruth Brown).
Roped up and ready for action (photo by Ruth Brown).
In recent weeks there has been an explosion of chicks on Colonsay. Walking to our study sights now means running the gauntlet with protective parents, and it feels like we are constantly being scolded by gulls, lapwings and oystercatchers who have chicks hidden nearby. Chicks are appearing on the seabird cliffs as well. We spotted our first razorbill chick on the 17th June and this was closely followed by the first guillemot chicks and then the first kittiwake chicks. The appearance of chicks, as well as prompting the ‘awwww’ response from me and Tessa several times a day, has lent a new sense of urgency to our tracking work. Guillemot and razorbill chicks leave the nest just three weeks after they hatch, and once they are gone we will no longer be able to catch the adult birds to attach and retrieve our tracking devices. Encouraged by calls from their parents the chicks jump from the cliffs where they hatched into the sea below, despite the fact that they cannot yet fly. These ‘jumplings’ then swim out to sea accompanied by their fathers, who stay with the chicks for several weeks until they are able to fly and look after themselves. Tessa and I are therefore spending long hours each day at the cliffs trying to record as many tracks as we can before ‘jump’ day!
Four recently hatched lapwing chicks (photo by Ruth Brown).
An oystercatcher chick pretending to be a rock (photo by Ruth Brown).
A pair of herring gull chicks (photo by Ruth Brown).
A shag with a large chick (photo by Ruth Brown).
Razorbill and chick (photo by Ruth Brown).
Kittiwakes with small chicks (photo by Ruth Brown).
Luckily it is not all work and no play for us on Colonsay, and I have managed to find some time to explore the island and get to know some of its inhabitants. Tessa has introduced me to many of the local residents, and after two months on the island I feel like I am beginning to get a handle on most people’s names (and the names of their pets!). Colonsay is home to a close-knit community of about 130 people, and there is rarely a week that goes by without a community event to which we are invited. As well as the weekly pub quiz we have also squeezed in several ceilidhs, a 21st birthday party and the grand opening of the all new Colonsay ferry terminal waiting room, and event which turned out to be much livelier than you might expect!
Enjoying some live music in Colonsay Community Hall (photo by Ruth Brown).
Finally I’d like to say a big hello to the other STaR teams across Scotland, I hope the remainder of your season goes well! Check out previous blogs from our teams on Orkney, Fair Isle and the west coast and find out what they've been up to.
All the best from Ruth and Tessa!
Summer is the high season for moths so you've got a good chance of spotting a few if you fancy getting the family out into the garden to give it a go as part of moth night! Did you know that moths can be just as colourful and diverse as butterflies? But because they mostly fly at night we don’t notice this quite as much.
There’s plenty of different species to spot but we thought we’d mention a couple you’re likely to see to get you started. First up – the garden tiger moth:
The garden tiger is a stout moth, that’s also pretty hairy. Its fore wings are chocolatey-brown with cream patterns, and its hind wings are orangey-red with black spots. Its bright colours warn predators that it doesn't taste very nice!
The garden tiger is a widespread species and can be found throughout the UK, however numbers have decreased in recent years. Its brown and black exceedingly hairy caterpillar is often called a 'woolly bear'. The hairs cause irritation, protecting it from predators, like birds – so be warned in case you pick one up! Garden tigers are usually found, as the name suggests, in gardens but you can also spot them in parks, grassland, meadows, and scrubby areas.
Next up is the elephant hawk moth – one that’s sure to stand out with its bright pink colouring:
The elephant hawk-moth is a medium-sized hawk-moth, on the wing from May to July and active at dusk. It is commonly found in parks and gardens, as well as woodland edges, rough grassland, and sand dunes. The caterpillars will start appearing next month and you’ll be able to spot those until around September time. They are very characteristic: greyish-green or brown with two enormous, black eyespots towards the head. When disturbed, they swell up to show these spots and scare-off predators.
So now you know what you’re looking for you’ll need to know how to attract the moths too. There are a couple of easy steps you can take to make it more likely they’ll choose your garden. Moths are attracted to light but it’ll have to be a pretty bright light – a dim old torch won’t do the trick. Switch one on outside and if you have one you can move around sit it on top of a white sheet to make the light even brighter.
There’s another method you can try too called ‘treacling’ which is a great one for the kids to get involved with. Moths are attracted to sweet tasty foods, especially in the early evening when the ones you’ll see are typically out looking for something to eat.
All you need to do is whip up a sticky spreadable treat and smear it on a tree or fence post and wait for it to attract some moths. We suggest mixing golden syrup, bananas, and a splash of rum.
If you want to learn a bit more about moth night and enter your sightings then simply follow this link: http://www.mothnight.info/www/
If you get any good photos from your experience of moth night we’d love to see them here at RSPB – share them on our Facebook or Twitter pages or post them in the comments below. Enjoy moth night!