Friday, 6 April 2018
The Remarkable Caddisfly And Some Pleasing Statistics
Here, today, you'd be forgiven for thinking spring has sprung. It's not warm, it's windy, but it is sunny. Pop and I have been out running this morning, a rather gentle 4.5 miles. I spent 48 hours after the 18 mile run on Tuesday wavering between eating and yawning. I don't think I've ever eaten so much in 48 hours in my life. M and I went out for a cup of tea and a slice of cake the day after the run and I ended up having a second lunch- an enormous plate of chicken and bacon sandwiches with salad and coleslaw and a bowl of chips. Three hours later, I ate dinner complete with two different puddings, and was still starving for breakfast ten hours later! The hunger and yawning resumed normal proportions at 5pm yesterday. Phew.
You may not have the expense of gym membership with running, but you make up for it in food costs! Still, my VO2 max (the rate at which you transport oxygen to your muscles via blood) has gone up to the top 20% for my age and gender since Tuesday's long run (according to my Garmin), which is rather pleasing. It also tells me the last two runs have been in an aerobic zone, so my heart is doing what it should be :o)
In other news, I'm very involved with our pond. It's that time of year. The newts are back- two boys, two girls as far as I can see, but there are probably more. Smooth newts, the commonest newt in Britain, in fine breeding regalia, all wavy crests and orange spotty tummies. They returned to the pond in March, a little later than normal, but who can blame them with all the ice and snow? And here they'll stay until June, until after they've finished mating and egg laying. Then they disappear into the garden, to sleep beneath log piles by day and emerge at night to hunt insects. You can see one of them in the pic below...
As much as I love watching the newts, it is the caddisflies who've really grabbed my attention this week. There are 12,000 recorded species of caddisfly in the world. They are freshwater insects whose adult stage is terrestrial (they frequently get confused for moths as they fly at night and look a bit moth-like). The larvae absorb my interest because of the intricate cases they construct. Caddisfly larvae are soft-bodied, like caterpillars, and very edible, so they spin a silk thread and attach whatever's to hand to it to protect themselves from predation. Some make heavy cases to help them sink to the bottom of streams where they can hunt for food without being washed downstream, which is so clever. Cases are often species-specific, and all the caddisflies in our pond use the same basic structure for their case. Here's an example I found this morning...
It's a delightful mix of duckweed, buttercup leaf and pond vegetation stalks, neatly cut to size and fixed in a pyramidal structure around the larva in the centre.
Clever, no? But what's even more amazing about these tiny larvae is that each species of caddisfly occupies a niche that is so particular none of the others share it. They are specifically adapted to fit their surroundings based on water flow, mineral and pollutant content and the amount of light the body of water receives. So our caddis are specific to our pond. They are also a great indicator of water purity, because they don't like pollution. There are lots of them in our pond, so I am spending a lot of time watching them grazing on the moss and other vegetation in the water. It's such a brilliant time of year for nature lovers.
I'll leave you with a very funny clip my lovely pal, Sally, sent me about fitbits which made me chuckle... click here
Wishing you all a Top Weekend,