Welcome to my blog

This is where I post various musings about wildlife and ecology, observations of interesting species (often invertebrates)
and bits of research that grab my attention. As well as blogging, I undertake professional ecological & wildlife surveys
covering invertebrates, plants, birds, reptiles, amphibians and some mammals, plus habitat assessment and management
. I don't work on planning applications/for developers. The pages on the right will tell you more about my work,
main interests and key projects, and you can follow my academic work here.

Monday, 29 September 2014

Floodplain meadows are the new amenity

Our local playing fields are, ecologically speaking, not much more than a green desert - heavily 'improved' amenity grassland with barely a 'weed' in sight. Or at least they were until last winter's ongoing storms caused a local river to burst its banks.

February 2014 - playing fields underwater.
The fields are part of a floodplain and are below the level of the surrounding river channels, some of which have been built up and were used as canals decades ago. The floods seem to have surprised a lot of people, though I'm never really sure why the term 'floodplain' isn't seen as self-explanatory. Anyhow, not all the local residents minded...

A colony of black-headed gulls soon moved in to use the unplanned wetland - other species such as mute swans were also regularly seen.
The fields are also a popular dog-walking location - the shallow 'lagoon' soon became a well-used destination for humans-and-canines as well as avians.
The water persisted for some months but of course dried up when warm weather came. After a hot summer, the ground flora was looking very different to the near-monoculture present only a year ago.

Tall herbs such as fleabanes competing with the grasses.
Meadow plants such as butterbur are already abundant.
Now, I appreciate that leisure is a valid use for playing fields, but this wetted area covers a minority of the total area and the site's use for football and rugby continues unaffected. The newly floral patch is not only popular with invertebrates, but also with walkers (with or without dogs) as a path has been mown around the edge. I hope that it will be left to develop as a 'wild' patch rather than being mown back to amenity grassland status as the leisure-wildlife balance seems excellent currently, but time will tell.

Friday, 12 September 2014

What's in a spider-skin?

I often write about the identification of small invertebrates, but every now and again I take a slightly more basic approach - maybe a particular structure, or a close look at a more familiar species. So, when I found a moulted spider-skin, it seemed like a good opportunity to look at some general spider anatomy.

Moulted spider-skin, about 6.5mm long from the jaws to the tip of the abdomen (i.e. not including legs or palps). Note how the jaws are dark as they are the most heavily chitinised part. Also, only one pair of legs points backwards.
Zooming in on the jaws, the fangs are clearly seen as overlapping hooked structures - the hole at the end is even visible where venom is injected. Other mouthparts are also visible - the thicker part the fang is attached to is the 'chelicera'. Underneath the base of this (this is a view from beneath) and towards the side, is the 'endite' to which the palp is attached, and between the bases of these is the 'labium'. Behind each fang, protruding forwards of the labium, the 'maxilla' has a 'scopula' of bristles pointing inwards, and right in the middle is the mouth. Essentially, the fangs stab and are moved by the chelicerae, the maxillae manipulate, and the labium provides a surface for them to work against when feeding.

Close-up of a section of leg. As well as the covering of small hairs, there are a few long, dark bristles. The green bars indicate these and their number and arrangement can be important features for the identification of some spiders.
The skin showing that the spider emerged with a split between the eyes (circled) and the base of the chelicerae. The sternum surrounded by leg-bases (coxae) is clearly visible.
The arrangement of eyes in three pairs. The lines indicate the six eyes, showing that the eyes in the outer pairs are closely connected with a shared base, and the central pair are also very close together. This arrangement suggests it is a member of the family Segestriidae (a juvenile male I think), though this is not certain. The two crosses indicate structures that look like eyes but are not (they are artefacts of the photo and were not visible down the microscope - probably just light reflecting off part of the carapace).
As you can see, I've focused mainly on the head as this is where a number of possibly unfamiliar structures are located that are hardened, and therefore remain in shed skins. There are many other structures of interest, but those in the abdomen are lost as it is soft and shrivelled. Also, this is a static specimen - in a live spider, the eyes are actually more-or-less tubular and moved by small muscles - what you actually see here are just the lenses - and of course the mouthparts would be mobile.

If you want to know more about spider identification in Britain, I've given details of a few books below, and there is a 'UK Spider Identification' facebook group, plus of course the British Arachnological Society.

Further reading

Jones, D. (1989). A Guide to Spiders of Britain and Northern Europe. Hamlyn, London.
Jones-Walters, L.M. (1989). Keys to Families of British Spiders (AIDGAP Guide). Field Studies Council, Preston Montford.
Roberts. M.J. (1987). The Spiders of Great Britain and Ireland (3 vols.). Harley, Colchester. [compact 2-volume paperback edition published in 1993, but still £100+ so maybe only for the truly keen!]
Roberts. M.J. (1995). Spiders of Britain and Northern Europe. HarperCollins, London. [plus later editions]

Wednesday, 3 September 2014

Black beauty - no, not the horse.

I've posted a few times about my stick-insects - Macleay's Spectres (Extatosoma tiaratum) and can report I now have a lot (like, a pint!) of eggs. They were certainly fecund. I'm not currently raising these however, as I have a different species after a friend sent me a batch of eggs of Black Beauty stick-insects (Peruphasma schultei).

Whereas E. tiaratum are fairly common, P. schultei are not, at least not in the wild. They come from northern Peru and are known only from a 5-hectare area at 1200 - 1800 m altitude in the Cordillera del Condor, a mountainous area known as one of the world's biodiversity hotspots. There they feed on pepper-trees (Schinus spp.) but in captivity, are happy with privet, lilac and honeysuckle (and probably some other small shrubby trees too). They prefer drier conditions (40-60% humidity or thereabouts) than species from more humid areas of the tropics and should be fairly straightforward to keep without expensive equipment. They were only discovered and described in 2002 (Conle & Hennemann, 2005) and relatively little is known about them, although tyhey are popular and are cultured and shared around the world without being collected from the wild. 

This means that although there are plenty of care-sheets on the web, they tend to say exactly the same thing based on not-that-much hard evidence - so, amendments and new info is always useful. For example, I have since found out that they are remarkably good at dying. As the hatchlings tend to hide during daylight, they sometimes crawl beneath things, get stuck and starve. So, no more newspaper in the bottom of the hatchery. Some simply failed to thrive, while others were eaten by a larger specimen that turned cannibal despite having plenty of leaves. They are now segregated more carefully and I'm raising a second batch of eggs alongside the original cannibal. Problems aside, they are rather splendid - velvety black except for reddish mouthparts (and when mature, wing-flaps) and yellowish eyes - they are sometimes called golden-eyes stick-insects. Here they are:

New hatchling. Note the white bands near the tips of the antennae.
Side view of about a 3rd instar nymph looking for something to climb onto. The kinked antennae are due to a problem during the most recent moult.

Good view of the reddish mouthparts and yellow eyes.
In 'scorpion' posture. Note the wing-buds.


Conle, O. V. & Hennemann, F. H. (2005). Studies on neotropical Phasmatodea I: A remarkable new species of Peruphasma Conle & Hennemann, 2002 from Northern Peru (Phasmatodea: Pseudophasmatidae: Pseudophasmatinae). Zootaxa 1068: 59-68.