Friday 23 September 2016

August expedition

Many of the group were away, so a small number came on the August walk. We started by putting up new stickers along the canal path to indicate our collaboration with both Waterways Ireland and the National Biodiversity Data Centre. We followed this with a scent test and the consensus correctly identified a small plant with yellow florets as pineapple weed.

The weather was good, so we were able to enjoy a number of dragonflies and damselflies, with the Amber-winged Hawker (Aeshna grandis) patrolling the canal bank and both the Ruddy Darter (with its conspicuous red body) and the duller-looking Common Darter resting on the warm path. Aeshna grandis used to be called the Brown Hawker but is now commonly named for its distinctive glowing amber wings. The average length is 73mm and its average wingspan is 102mm. Unlike many insects, males and females look similar. It's probably the easiest dragonfly to watch as it doesn't pay much attention to people and flies in short glides over vegetation.




Looking at the grasses, the flowers and the hedge fruit, we observed the early autumn palate of the flora — the darker pink/purple colours replacing the brighter white/yellow colours of the summer. Examples on our walk included devil's-bit scabious and purple loosestrife (its name comes from the ancient belief that if the plant were placed on the necks of yoked oxen, it would prevent them from being quarrelsome!)



We noticed for the first time that bistort (Persicaria bistorta) is growing on the bank. This is a new development.

We discussed how different flower heads can be from one another, contrasting the pure white funnel-shaped bindweed with the domed, tightly-packed cluster flowerheads of devil's-bit scabious (the name comes from the short, bitten-off appearance of the rootstock). Devil's-bit scabious is a favourite of bees and butterflies and it's very encouraging to see that it's spreading along the canal.




We also talked again about the fact that buttercups, for instance, generally have five petals, while the dreaded ragwort, for example, has 13 petals. The smaller Fibonacci numbers (3,5,8,13,21) are common in the design of flowers. We might have a closer look at this subject next year.




Date: 27 August 2016 Time: 12-1
Attendance: 10 (including 4 children)


 


What we observed and talked about —

Bees: Bombus pascuorum
Birds: Blackbird, Swallow
Butterflies: Speckled Wood

Damselflies: Common Blue Damselfly
Dragonflies: Amber-winged Hawker, Common Darter, Ruddy Darter
Macro moths: August Thorn, Canary-shouldered Thorn, Lesser Yellow Underwing, Oblique Carpet
Micro moths: Ringed China-mark, Rush Veneer
Other insects: Common Green Grasshopper, hoverflies

Flowers: Bindweed, Bistort, Bramble, Bulrush, Cleavers, Common Knapweed, Common Nettle, Creeping Cinquefoil, Devil's-bit Scabious, Eyebright, Glaucous Sedge, Lady's Bedstraw, Marsh Woundwort,  Pineapple Weed, Purple Loosestrife, Red Bartsia, Red Clover, Ribwort Plantain, Silverweed, Taraxacum agg., Water Mint, Wild Carrot, Yellow Flag 
Grasses: Yorkshire Fog

Trees: Ash, Hawthorn, Willow