At this time of year, autumn colours are always a race between frosty nights and high wind.  Well, the frosty nights have come and the colours deepened, but now many leaves have blown off in the wind, so walking has become a childhood pleasure, through drifted piles of green, yellow, pink, red, plum and brown, to match the November fireworks.

Some insects are still active.  Ivy flowers provide a valuable food source in November and a late wasp was seen on these (above). A common darter was spotted on a stone wall (right).  Under a rough web, on a fallen leaf, a 3mm bright green spider lurked – Nigma walckenaeri (below).

It is always a surprise to visitors that cattle graze the meadows along the Cam, even in the middle of the city.  Over the last few weeks, they have mostly been housed for the winter, no longer depositing their dung pats across the water meadows.  However, under the pats it is far from dead!  The larvae of dung beetles and dung flies survive over-winter as chrysalises, to emerge as adults in the spring.  Fungi break down the dung, worms and plants invade it, rain and frost contribute to decay and soon the nutrients are returned to the soil.

There are still lots of other fungi around.  In Paradise Local Nature Reserve, a huge willow tree was felled about three years ago, after it became dangerously decayed in the middle.  The logs were piled beside the path and now host various bracket and other fungi.  Altogether, I found 15-20 different species in the wood, including oyster mushrooms.

Olwen Williams, 11 November 2016

After a long and mostly hot summer, temperatures are now dropping, especially at night and we can anticipate some autumn colours in the trees.

Walking through the Paradise Local Nature Reserve, I came upon a kingfisher moving ahead of me. Several times, he perched and then splashed down into the water in search of dinner. Kingfishers are the ultimate specialists, in terms of both diet (fish) and nesting place (a hole excavated in a steep bank, out of reach of rats and other predators). I remember that one year, there was a nest in an old drainpipe in the river wall of Clare College, right in the centre of Cambridge.

My cat brings me a variety of ‘presents’! On one occasion a live kingfisher was handed over unharmed and I was able to take it back to the river, where it flew off with an indignant squawk. This week, I found a Convolvulus Hawk-moth on the mat. A night flyer, I would probably never have seen it resting during the day, its grey speckled wings and pink and black abdomen blending perfectly with tree bark. These large moths are autumn migrants from Africa.

This year has been a spectacular year for snails and slugs. Under a pot in the garden, I found several large Black Slugs, Arion ater (which can be brown, yellow or even white) busy with their autumn egg- laying, after which they will die. Between August and October, each individual may lay multiple batches of up to 150 eggs, so if, as a gardener, you want to reduce next year’s population, clear as many eggs as possible! Otherwise leave slugs as part of the ecosystem, as they clear detritus and even dog mess and provide food for hedgehogs and others. I notice my slugs are parasitised by slug mites, Riccardoella limacum, tiny white creatures which run around the outside of the slug and into the lungs via the pneumostome. It reminds one of the rhyme, “Big fleas have little fleas, upon their backs to bite ’em, And little fleas have lesser fleas, and so on, ad infinitum.”

Olwen

11th October

Even the most urban parts of our city can hold wildlife.  October 10th was warm and sunny. Whilst walking through the underpass and the centre of the roundabout connecting Newmarket Road and Elizabeth Way, I noticed how alive with insects the rosemary was. Although I only definitely identified Honey Bee and Common Wasp, the sheltered nectar was clearly very popular with wildlife, providing a food resource in a somewhat concrete part of town.

Louise Bacon