May and June saw a series of natural history talks take place at Ludlow Museum Resource Centre. Each event included a display of specimens and a lecture, as well as an optional tour around the Natural History store with a curator. I was lucky to be invited to attend the talks and gain some insight into various areas of Natural History. I hope they happen again in the future and I wanted to take some time to summarise the programme.
Sue McLamb, the Shropshire County Recorder for dragonflies and damselflies, introduced this fascinating order of insects (Odonata) whose ancestors date back over 300 million years. Sue discussed some of the fundamental differences between dragon- and damselflies (before testing our knowledge). These differences include: most dragonflies’ eyes touch each other because they are so big, whereas damselflies’ eyes are separate. Damselflies are usually smaller and more delicate than the more robust dragonflies; the former are wispy and flitty on the wing compared to the latter’s more direct and purposeful flight. We also learned all about their habits as well as which varieties one would be likely to spot in Shropshire. Here are some more interesting facts I learned from Sue.
- Dragonflies’ forewings are narrower than their hindwings compared to damselflies (Anisoptera = “uneven wings”).
- When stationary, damselflies fold their wings against their bodies, unlike dragonflies who hold their wings out.
- Some damselflies oviposit below the surface of water in tandem, i.e. the male stays above and holds the female behind the head in case she gets attacked and he can “airlift” her out of danger.
- Female damselflies use an air bubble to breathe whilst “walking” down submerged plants to oviposit; she floats up using the bubble and the male grabs her through the water’s surface tension.
- Some dragonflies live as larvae for up to five years before emerging as the much shorter-lived but more recognisable adults.
- Larvae of dragonflies respire by taking water in and out through their abdomen and when threatened they can expel that intake of air to jet propel themselves to safety.
- The exuvia is the most valuable biological record in terms of absolute proof of a successful breeding habitat (as opposed to the sighting of an adult).
Pete Boardman, the Invertebrate Challenge Project Officer for the FSC, spoke in detail about those species of shieldbugs found in Shropshire in the hope that we would be able to identify any we see and report back to him. He is seeking to publish a distribution atlas during 2013 to improve our knowledge of the insect. They are an interesting group to study and can be found in some of our most important wildlife habitats to the most urban of gardens. Pete explained that they are a manageable group for anyone new to entomology, with good identification resources available.
What’s good about flying?
John Mackintosh, the Shropshire County Recorder for mammals, gave a fascinating talk about bats, detailing their evolutionary history, life-cycles and the modifications imposed by flying. John discussed how, because most bats fly at night, all aspects of a bat’s existence have to fit in with the needs of life in the air in the dark. Some of the pints discussed included the following.
- All the bats found in the UK eat insects (elsewhere, some bats eat other things, e.g. fruit).
- The bat fossil record is limited since they are light-boned and terrestrial.
- Bats don’t fully flap their entire forelimb: their wings consist of the arm and whole hand and it’s the outstretched digits they flap in flight. (Compared to Pterosaurs whose wings are formed from the forearm and the fourth finger; and birds’ wings which consist of feathers).
- Bats’ wings are much thinner than birds’ allowing them to manoeuvre more quickly and accurately.
- One theory for the evolution of flight in bats is that they began by grabbing prey out of the air whilst climbing and developed larger hands and webbing between the digits.
- Bat wings are covered in touch-sensitive receptors which have a hair in the centre which allow them to detect and collect information about the air flowing over their wings and subsequently fly more efficiently by changing the shape of their wings in response.
- Flight allows bats to exploit a much large area compared to mammals on foot.
- Short and fat wings are good for manoeuvering but bad for speed, whereas long and thin wings are good for speed but bad for manoeuvering.
- John discussed the common bats around Shropshire regarding their various flight and echolocation characteristics.
- Although bat calls are at a frequency outside of our hearing range, some bats’ calls are louder than a pneumatic drill or a rock concert.
- Bats that hover are around 40-60% more efficient than a hummingbird because they flap their wings fewer times thanks to being able to manipulate the entire wing.
The incredible diversity of flies
Unfortunately, Nigel Jones’ talk about flies was cancelled due to lack of interest. I’m not sure how there can be a lack of interest for such a fascinating order of insects. Shame.
How to write a Management Plan
The full title of the above talk was: “How to write a Management Plan for a small tropical forest in West Africa while sitting in Aston on Clun“. John Tucker told us about Farasuto Forest, a small (2.8 ha) relict patch of The Gambia’s formerly widespread gallery forest. The significance of Farasuto Forest was only realised in 2008 and it was clear the site needed a Management Plan in order to secure the resources necessary for its conservation. John took up the challenge and explained the trials and tribulations of the process.
I found this talk relatable and a little surreal as I had visited a nature reserve in The Gambia (Abuko) with two friends after graduating with the intention of completing a monkey research project there. Upon arrival, all was not as it seemed and, despite the reserve being involved with The Darwin Initiative, we were shocked by the way we were treated, the false promises made before we got there and the complete disinterest of the hosts. I want to stress that all negativity came from the two British people living and working there and not the locals who were, on the whole, charming, friendly and hospitable.
Check out John’s website to find out about the project and details of the plan (it’s much more interesting than it might sound). The result of his hard work is, sadly, not much. He described the process as painful and difficult (although rewarding). He has more or less had to abandon the project and put it behind him. Some of the problems he encountered included:
- Communication breakdowns, in person as well as when John was at home in Shropshire;
- Gambians don’t record anything and don’t write anything down; and
Having had a similarly difficult experience when I visited The Gambia, I was fascinated by John’s account of his. In the end it was red tape and the (understandable) lassitude of the residents that finally stalled the project.
Many thanks to all the speakers and tutors for the great talks. Thanks also to Ludlow Museum Resource Center for putting on such an interesting programme of talks. I hope next year will see more engaging natural history themes being discussed.