Wednesday, October 5, 2011

On a grassy knoll

Last Thursday I spent the day at Totternhoe Knolls & Totternhoe Quarry nature reserve. I rarely visit wildlife sites around Luton and Dunstable, but a morning slow-worm survey and an afternoon walk round the site with the Wildlife Trust Conservation Manager had me braving the M1. The M1 is never fun, but there were no serious hold ups despite the interminable roadworks, so I took it easy in my little Ford doing backing vocals for The Eagles. 

The new reserve leaflet is just out but my copy is already battered having spent time in my back pocket.

Totternhoe is a complex of a number of different habitats: Totternhoe Knolls SSSI, Totternhoe Chalk Quarry SSSI and Totternhoe Stone Pit SSSI. The National Trust also manage the land around a medieval motte and bailey castle. The exposed chalk and old workings have created a mosaic of rich-chalk grasslands and scrub. The site also boasts populations of green hairstreaks, small blues and Duke of Burgundy butterflies. Well worth a summer visit. I must get over my M1 phobia. 
The Trust has recently acquired more land at the site :-)
Correction: Mea culpa. The berries below are black bryony (Tamus communis) NOT white bryony as I initially thought. They can look similar and I didn't check properly. You can see a shrivelled leaf attached to the vine (bottom left of picture) which clinches the id.  Thanks to Phil Green at White Cliffs Countryside Partnership for pointing out, via email and with great delicacy, my error. The bryony, whether it be black or white, was putting on a dazzling show draped seductively over the kissing gate. Black bryony berries are poisonous (as are white bryony berries). It is also, like white bryony, an irritant purgative and acrid cathartic. Best left for the birds.
The chalky pits are brilliantly white.
On the survey, we found only 2 slow-worms and both were weighed and measured. 
A few little toads put in a warty but cute appearance.
OK, they aren't quite up to White Cliffs of Dover standard, but we do have some chalk cliffs (aka old quarry walls) in Bedfordshire. 
This green lane, an old drover's road, was reinstated after quarrying. 
The views from the lane across (and into the sun unfortunately!) to Dunstable Downs are wonderful. Here is the land where, before the WWII, you would have looked out at extensive plum orchards. The fruit was used for prunes. The prune skins provided a dye used to dye the felt for the once thriving Luton hat industry. Now you can go and listen to live music and theatre at the Hat Factory arts centre in Luton. BTW Eliza Carthy is playing this Friday.
The Whipsnade lion can just be made out on full zoom in the glare. 
Castle Knoll is all that remains of a medieval motte and bailey castle.
The trig point on top of Castle Knoll. 
From Castle Knoll you look down on the flower-rich chalk grassland of the Little Hills part of the reserve. 
Tor grass (Brachypodium pinnatum) is a problem on the hillside. It can dominate and cause a decrease in biodiversity on chalk grassland once it gets a hold. 
This part of the reserve is being grazed by sheep, les moutons français apparemment, but I don't know the breed.
Old man's beard or traveller's joy (Clematis vitalba) is rampant on parts of the reserve, but the sheep seem to like to nibble it. 
On the way back to the car I found some fallen poplar leaves in the lane. They had swollen, curly stems.
On closer inspection these were clearly galls. Once home a quick Google came up with the answer: a spiral poplar gall cased by a little aphid, Pemphigus spyrothecae

The natural history of the wee aphid that lives in this gall is quite fascinating. In the spring, when a young lady aphid hatches, she starts sucking on the sap of a young poplar leaf stem or petiole (Lämke, 2011). The sucking induces the poplar to respond by deforming into spiral gall. The lady aphid is now safe inside her new home. 
This lady, known as the stem mother, foundress female or fundatrix, eschews sex (no males needed here) and she produces an aphid clone asexually. The resulting aphid nymphs act as soldiers to maintain and defend the home gall against other marauding aphids one assumes, and they develop into wingless (apterous) adults.

At the end of the summer sexually active adults are produced and they leave the home gall, which will crack open as it dries in late summer. These adults have sex and the lady aphids lay their eggs on the bark of a poplar tree. The egg overwinters and the cycle beings again next spring (Tyermana & Roitberg 2004). Cool.

On my walk I passed an allotment growing Jerusalem artichokes. Neither an artichoke nor anything to do with Jerusalem, the name is possibly derived from Italian settlers in the US calling this native American sunflower girasole (Italian for sunflower). Raw or steamed, the root's inulin content can cause, ahem, flatulence. 
Perfect weather, gorgeous site and not a breath of wind. Well worth a visit if you are in the area.


Bibliography and further information
Beds Wildlife Trust (actually the Wildlife Trust for Bedfordshire, Cambridgeshire, Northamptonshire & Peterborough...but that is such a mouthful) manage the site. More land could be secured for nature conservation at Totternhoe. Best to join the Trust here......or you could just leave them a legacy here :-)
Totternhoe Chalk Quarry information here.

Poplar Spiral Gall Aphids
Tyermana JG & Roitberg BD (2004) Factors affecting soldier allocation in clonal
aphids: a life-history model and test. Behavioral Ecology, Volume 15, Issue 1
pages 94-101. Full text here.
Lämke, J (2011) The response of poplar to a gall-inducing sucking herbivore, the aphid Pemphigus spirothecae. Link to Max Planck Institute for Chemical Ecology webpage here.

5 comments:

  1. Re. plum/damson orchards and use as dye (about which there is some doubt) – interesting articles at:
    http://www.bnhs.co.uk/main/docs/muntjac155.pdf
    and
    http://www.jennydean.co.uk/wordpress/?p=2078

    Re: Totternhoe/chalk. Totternhoe stone, also known as “clunch”, was mined here and used in local churches etc. - interesting article at:
    http://www.bedfordshire.gov.uk/CommunityAndLiving/ArchivesAndRecordOffice/CommunityArchives/Totternhoe/TotternhoeStoneQuarryAccordingToPehrKalm.aspx

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  2. Hi Kristen. Very cute and actually a legless lizard. Mel

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  3. Oh! I just learned something new. What are the differences if you don't mind explaining?

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  4. Slow-worms are very snakey at first look but they have some key differences to snakes (see here:
    http://www.arkive.org/slow-worm/anguis-fragilis/?gclid=COXxkNeIk6wCFcNP4QodGnuIAw and here: http://www.wildaboutbritain.co.uk/forums/reptile-and-amphibian-forums/21704-why-slow-worm-not-snake.html)
    Key points seem to be
    1. Lizards have eyelids - snakes do not
    2. Lizards can shed their tails to escape a predator
    3. Skin (scale) structure is different
    Thanks for asking - I had to look it up :-)
    Hope that helps!
    Mel

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