Monday, 27 February 2012

Good signs

Having seen a few frogs during the week, I went up to the place where I always see the first spawn, and every ditch and pool was full:

Batches of Frogspawn
The area covered by that shot is perhaps 50 x 100 cm., so there's a lot of spawn already in place.

Surprisingly enough, that location is very near our highest local point, but the much more likely lower areas are still empty, although I've heard plenty of croaking there.

While I was up there I checked out the local mosses and lichens. The first specimen is the foliose lichen Peltigera membranacea, also known as Rabbit Paw lichen:

The foliose lichen Peltigera membranacea
The amazing colour is accurate.

The next shot has many species of moss and lichen including Racomitrium lanuginosum (centre), Polytrichum urnigerum (male, dotted round the Racomitrium), and I can tell that the white stone to the lower centre has been moved quite recently because it is dotted with Trapelia coarctata, which is one of the pioneering lichens and usually appears very briefly before it gives way to secondary and more persistent species:

Lichens and mosses 
Another prominent lichen is Lecidia lithophila, which is recognised by the orange/brown thallus (body) and black fruitbodies:
Lichens and mosses

Notice that the Lecidea is being parasitised (or at least replaced) by the grey Porpidia-type lichen that is encroaching from the left.

Coltsfoot in full flower is a pleasant reminder that spring is almost upon us:


Perhaps a bit more surprising is a colony of Cow Parsley which is in full flower:

Cow Parsley
This is also at fairly high altitude, and not particularly sheltered. Since other nearby specimens are also either in flower or in bud, I have to assume it's an early-flowering sport or strain, because the location isn't any more favourable than many other areas where the plants are just coming into leaf.

Thursday, 23 February 2012

More moths

The rain continues, but there is an occasional gap when it's safe for insects to fly. If it's dry at night, then we have a chance that a few moths will come to light, and I keep my porch lights (which can be seen for at least 5 miles) on just in case. My house sits on a south-facing slope over a river valley, and there's a bit of rough bog about a mile away, so I can attract moths from quite a range of different habitats when timing and conditions are right.

There are perhaps half a dozen different species of moth flying at the moment, with many more to be expected when the Willow catkins open, which should be about 2 weeks away.

This is the Chestnut:

Chestnut moth - Conistra vaccinii
The Chestnut overwinters as an adult, emerging from its hiding place to feed when conditions are favourable. I have seen and photographed this species a number of times, but this specimen is very much paler than I would expect, although it's obviously quite worn. The larvae feed on a wide range of broadleaf trees and also Docks.

Much easier to identify is the Dotted Border, which gets its name from the row of dots on the trailing edge of the wings:

Dotted Border - Agriopis marginaria
The Dotted Border overwinters underground as a pupa, emerging in February, and the larvae feed on a very wide range of trees and shrubs, and also heather. This is another moth where the female is flightless.

The weather has been much warmer than we had in the last two winters, with just a few nights of frost, so the spring is quite early, with a few flowers just beginning to show. The Willow catkins are on the verge of opening, so that will bring out the early bees, hoverflies and Willow-dependent moths including the various Quakers.

Willow catkins about to open

Saturday, 11 February 2012

A moth!

This is the first moth I have been able to photograph since around November.

The Pale Brindled Beauty - Phigalia pilosaria - normally flies from January to March, but early specimens can be found in December.

Pale Brindled Beauty - Phigalia pilosaria

There are two main colour variants: the first - like mine - is mostly pale, but specimens found in the centre of large cities tend to be almost uniformly dark grey. This is a clear example of selective mutation, where species increase their chances of survival by favouring colour forms that best match their surroundings. Evolution is generally thought to take place over many thousands of years, but it's clear that adaptation can take place in a few hundred years where situations demand. Clean air (like mine, which is washed most days) = pale specimens: polluted air (as found in large cities, with associated sooty deposits) = dark specimens. There are quite a few moths where this variation in colour distribution is the norm. In each case, the pale form is found on my patch.

The specimen in my photograph is clearly a male, since the female - in common with many of the winter moths - is flightless.

Sunday, 5 February 2012

Horse Hair fungus

This is a good time of year to find one of my favourite mushrooms: Marasmius hudsonii, which is found solely on Holly. Hunt around beneath a Holly bush, and have a close look at any soft, black and wet fallen leaves. Pink or white dots are the first indication that you've found one of the most interesting mushrooms we have:
Marasmius hudsonii on Holly
This mushroom is tiny: the cap is between 2 and 3 mm in diameter, and the stipe ('stem') is as fine as horse-hair, hence its common name: Horse-hair mushroom. But look even more closely, and you will see that the cap is covered with tiny, purple bristles.

Underneath, the cap has a few, relatively thick, gills:

Underside of Marasmius hudsonii, showing thick gills
I find this mushroom under almost every specimen of Holly I choose to examine, but there has to be a mat of the soft wet leaves for it to be found: too dry and they won't be there.

There's a similar (but unspiked) member of the same mushroom family that's found on wet Ivy leaves: Marasmius epiphylloides.

Thursday, 2 February 2012

More on mosses

Mosses have a complex and very interesting reproductive cycle: individual plant specimens are either male or female (although some have both male and female portions). The male plants produce gametes in the antheridium, which looks rather like a pepper-pot lid:
Antheridium on male moss plant
These male gametes swim towards the female gametes, which are held in the archegonium on the female plants. Fertilisation takes place and the offspring grows upwards, forming the seta ('stem') and eventually the spore-bearing capsule. This sporophyte looks like it is part of the original plant, but is actually parasitic on it, so when you see a spore capsule forming like the one below, it isn't one plant with green leaves and a spore capsule, it's the mother (leaves) and child (spore-producing sporophyte).

Emerging spore capsule on Polytrichum moss
Here's a shot of last year's capsules:

Old capsules of Polytrichum commune
The specimens I used for these photographs are Polytrichum commune, which is one of our larger mosses. The setae regularly reach over 8 cm. long, which makes them an ideal subject to use for initial moss studies, since everything is large enough to be seen with the naked eye.

The fact that the male gametes swim towards the females gives us one reason that mosses flourish in damp places.