Archive for category: News

The winds, rain and winter visitors of autumn have arrived.  I heard and saw my first redwings of the year yesterday (October 15th).  Redwings are small spotty thrushes that look like they have had a nasty accident, as they have two blood red patches just below each wing.  Redwings fly in mainly from Scandinavia in the autumn to spend the winter in parts of western Europe that are kept mild by the Atlantic Conveyor (Gulf Stream).  Redwings prefer to eat insects, but during the winter when insects are scarce, they resort to eating vast amounts of berries, especially hawthorn and rowan.  The soft fruit is digested, but the seeds of these plants pass right through their bodies and are ejected all over the wider countryside where they germinate.  This is an evolved system of seed dispersal which results in open areas of grassland succeeding to become scrub and eventually forest.  This process of succession results in habitats reaching what is called a climax community.  That is a community that cannot develop into anything larger.  In Sussex, the climax community is forest, usually dominated by oak.

There is another bird that disperses the seeds of oak (acorns), this is the jay, often known as the oak jay.  The jay is a species of crow, which in Britain is rather shy.  However, it can often be seen in the autumn collecting acorns from under oak trees, and carrying them in a beak pouch sometimes many miles before burying them in an open area such as a field or clearing.  During the winter, the jay sometimes remembers and sometimes forgets where they are buried.  It will feed on the remembered ones when hungry, and the forgotten ones will become new oak trees, ensuring food for future generations of jays etc.

Interestingly, the word field derives from ‘a felled area of forest’.  At one time, the whole of Sussex would have been high forest, and gradually it has been felled to form fields and other infrastructure for human survival such as houses and roads.  However, nature is constantly trying to reverse this trend, and the redwings and jays are contributing to this with good effect, and some neglected fields are again becoming forested, which is good for absorbing carbon dioxide.
It is interesting to note that a large proportion of hedgerows are now not maintained which has resulted in an increase in strips of woodland.

Many Naturalists spend lots of time watching species so as to understand how they fit in with Nature.  There is a lovely story of two 19th century naturalists, Fritz Müller and Henry Bates.  Both were fascinated by the fact that unrelated species often had similar shapes, colours and/or marking patterns.  They discovered that some species of animal have evolved to mimic others, and by doing so, enhanced their survival probabilities.  To understand this, it is necessary to understand warning signals.  Although many species of animal have camouflaged or cryptic bodies that hide them away from predators (e.g. green or brown frogs hiding from cats and snakes), some animals are brightly coloured (e.g. ladybirds).  It turns out that ladybirds are both toxic and distasteful when eaten, so that predators (usually birds) avoid them.  However, frogs are apparently good to eat, so need the ability to hide from predators.  So, if another species of beetle becomes red, but is also good to eat, predators will tend to avoid it because of its colour, and even though it is good to eat, it is more likely to survive and have offspring.  This is known as Batesian mimicry after Henry Bates.  It also works for flowers where plants that do not provide nectar mimic others that do, so that insects will pollinate them even if they do not provide a reward.

Fritz Müller went to South America and found that many species of butterfly, some closely related, and others not, all had similar shapes and markings, and all were toxic and distasteful.  So why were they all looking similar if they were all toxic or distasteful?  It turns out that even if an animal is bad to eat, it is less likely to be eaten if it looks like another animal that is bad to eat.  It is easier for a predator to learn one warning signal than lots of different signals. So appearances tend to converge over many generations.  So this is known as Müllerian mimicry.

There are many other types of mimicry in nature, such as the peacock butterfly, that has false eyes on its wings.  When its wings are closed it is cryptic and camouflaged.  However, if it moved, it may be spotted by a predator, if this happens, the butterfly suddenly opens its wings and the predator sees 2 huge eyes ‘looking’ at it and should jump back, giving the butterfly time to escape.

Flaming June has arrived at last.  Yesterday (19th June) the temperature rose to 27°C. in the afternoon.  The hottest day of the year so far.  However today there are thunder storms forecast.  At least the old adage that an English summer is “…2 hot days and a thunderstorm.” Seems to still hold true despite the other inconsistencies of our disrupted climate.

The Wrens nesting in our porch fledged today.  I think there were about 5 babies.  The Latin name for Wren is Troglodytes troglodytes meaning cave dweller.  Wrens are insectivorous and love to go inside caves, buildings and other cavities.  They are Britain’s commonest bird, which is surprising as many people rarely see them.  The reasons they are rarely seen are that they are very small, they hide in undergrowth and apart from when they have freshly fledged babies, and they are rarely seen in groups.  However, if a winter is particularly cold, they do sometimes roost in a group inside a cavity to keep warm.  This could be a nest-box, hole in a tree or building.  There are many ways in which Wrens are unique in Britain, for a start, they are apparently the only species of British bird whose ancestors evolved in the New World.  There are many species of Wren in the Americas, but only one in the Old World.

However, all other species of British birds apparently had ancestors that evolved in Europe, Middle East, Africa, Asia and Australia.  Basically everywhere else apart from the Americas.  Wrens are also unusual in as much as it is the male that usually builds the main nest, but the female can sometimes line the inside.  The reason that Wrens are our commonest bird is that they can occupy almost every type of habitat, e.g. coast, hills, forest, garden wetland, and they distribute themselves throughout the land, and the male defends a territory of which there are estimated to be around 7.1 million in Britain.  So the actual population is about double that.  You may not see a Wren very often because of its shy skulking disposition, but you will certainly hear it, it has one of the loudest songs of all British birds, and will also make a very loud tick – tick call that can sometimes be very fast and long such that it sounds a bit like a chain being pulled through a pulley.  Probably the main predator of the Wren is the domestic cat, but maybe the main cause of death is probably cold in the winter.

Summer is on its way at last!  The wind has changed and is now blowing from a more south-westerly direction.  Almost immediately, this change accelerated the swelling of buds on the trees. Also, at last the migrant birds are arriving, such as the Swallows which arrived in Uckfield about the 14th April.  Cuckoos have been heard and Chiffchaffs have started to sing.  As for the resident birds, a pair of Blackbirds has raised 3 chicks in a nest built among the Ivy on the side of our house.  They have been growing in the nest for about 10 days, and left the nest on 19th April.  The timing of this was amazingly lucky as hatching coincided with the change in wind direction. Consequential warming led to the reappearance of Earthworms on which parent Blackbirds rely to feed the chicks.  The Blue Tits have started building their nests, but are doing so about two weeks later than usual.

The (wild and cultivated) Daffodils have had an extended season this year; they seem to like the cold.  However, the Honeybees have not been able to get out and collect nectar and pollen until recently.  There may be a shortage of honey this year as many colonies have died during the extended winter. The Wood Anemones are flowering in the ancient woodlands now and are carpeting the woodland floor.  Lake Wood is a good place to see them.  By mid-May, they should be all but over, and replaced by Bluebells.  Wood Anemones are usually only found in truly ancient woodlands, that is, woodlands that have existed for at least 400 years, and have probably always existed since the last ice age about 10,000 years ago. They generally spread underground from tubers, and rarely survive if transplanted. Areas of woodland cleared of alien plant invaders such as Rhododendron ponticum which are surrounded by Wood Anemones take decades to be recolonized by Wood Anemones, indicating how slowly this plant spreads.  By late autumn, there will be no sign of the Anemone plants among the leaf litter.  When in flower their petals are mostly white, but some have various amounts of purple tinge on them.  Also, when they are in full flower on a windless day, the sweet aroma from these flowers can pervade the woodland.  The flowers close up at night, and generally open at about mid-day.  Bumble Bees quite like them, but other insects rarely visit them.  I have never seen any evidence of Anemones setting or growing from seed.

I’ve just experienced a real spring-like day on 18th February!  Honeybees are flying around looking for pollen and nectar, and also for people to sting if they get too close to the colony.  The target flowers will be mainly Crocuses and Snowdrops, but there are a few Celandines, Primroses and Violets around as well.

A pair of Buzzards was courting over the South Downs this afternoon, and being shouted at by two Carrion Crows.  These and other raptors are now on the increase as thankfully, they are not persecuted as much as they used to be.  I heard a report of a Goshawk near the Holy Cross Church Centre a few days ago; it was plucking a Pigeon, and eventually flew away with it.  Watch out also for Kestrels hovering as they search for prey, especially by roadsides, and Sparrowhawks either soaring overhead or shooting like an arrow through the trees and along hedgerows ready to pounce on an unwary Sparrow, Bluetit or other small bird.

There is a country rule that all hedgerows should be trimmed by 6th March, in order to avoid disturbing nesting birds and dormice etc.  I have been trimming a hedge at the University Ecology Field Trials Plot today, and was delighted to see that Elder is well into breaking bud, and Hawthorn is just starting.  Soon these hedgerows will be transformed from brown to green, and will provide cover for nesting Chaffinches, Long-Tailed Tits, Blackbirds, Songthrushes, Dunnocks (Hedge-Sparrows), Robins, Wrens and many other birds.  Dormice also will use the hedges as motorways to get between woodlots.  Many birds that nest on the ground such as Yellowhammers, Chiffchaffs, Whitethroats and Blackcaps will use the hedges as singing posts.  If you are awake at about 06:00 hrs. you will be treated to the dawn chorus from Blackbirds, Songthrushes, Dunnocks, Robins and Chaffinches right now.  These will soon be joined by many other birds as we progress through March, but as the days progress, so sunrise will get earlier, until it will be 05:30 by early April that the best chorus will be heard.

There will be other seasonal movements to be seen and heard as the amphibians wake up from their winter sleep, and there will be croaking from the ponds and Frog spawn will soon follow.