August 2017

Cuckoo pint – Sheila Sims

This month, in woodland and along hedgerows, you may see the bright red berries of the Cuckoo pint. (Rhymes with ‘mint’ not ‘pint’ as in milk.) This plant, which is a member of the Arum family, has lots of other common names, Lords and ladies and Robin’s wake being just two. The leaves, sometimes with purpley-black blotches, emerge in the spring followed by the strange flower. This is in the form of a cowl that contains both male and female flowers at the base of a spike. Fertilisation is by insects, especially Owl midges, which are attracted to the rather smelly scent. The male flowers have tendrils that create an insect trap and as the midges struggle to escape they become covered in pollen which gets deposited on the female flowers. Every part of this plant is poisonous and is responsible for many visits to A&E, especially with children who are attracted to the red berries. In Elizabethan days the root was dried and powdered, mixed with liquid and used to starch the linen ruffs and cuffs which were fashionable at the time. The poor laundresses’ hands were sore and blistered from contact with the powder; I wonder if the wearers also suffered or maybe the processing rendered it harmless.

Hoverfly – Sheila Sims

The Cuckoo pint advertises itself in a very visual way and many insects do the same. They want to deter predators and so some imitate ones that are either dangerous or distasteful.  Wasps and bees are black and yellow striped and birds know that this colouration could be dangerous and so usually avoid them. The caterpillars of the Cinnabar moth feed on Ragwort leaves and in doing so absorb toxins from the plant; they are also black and yellow to indicate danger. Many other caterpillars are brightly coloured, an indication that they taste unpleasant. Some hoverflies, although harmless, have evolved to have the same colours of wasps and bees to protect themselves.

Hen Pheasant on nest
Sheila Sims

Not everything in nature wants to be seen and many animals rely on camouflage to hide their identities. With some ground nesting birds, although the male may be brightly coloured, the female is often drab and earthy making her not as vulnerable to predators as she would be if she were like her partner; pheasants and mallards are two examples. The Willow warbler in the photograph blends well with the Fennel plant. Does it know this? Maybe that is why it risked being so unusually close to the house.

Willow warbler
Sheila Sims

The Oak bush cricket, which lives in tree canopies, needs to match its leafy background to surprise the small invertebrates upon which it feeds and so is green in colour, being virtually invisible to its prey.

Oak bush cricket
Sheila Sims

The Large white butterfly in the photo chose to rest on a Chard leaf when I approached the vegetable bed. Not an animal that is usually well camouflaged but in this case not very visible. An accident? Probably, and its babies didn’t leave us many cabbages!

Large white
Sheila Sims

The upper sides of the wings of a Comma butterfly are brightly coloured but the underside resembles a shrivelled, dead leaf, so when this insect is resting or hibernating it will close its wings and so will be easily missed by a predator; the caterpillar of this species is disguised to look very like a bird dropping!

Buff tip moth
Sheila Sims

The Buff tip moth appears for all the world to be a piece of birch twig but the one that must be one of the best examples of adaptation and natural selection, is the Peppered moth. The black variety of this moth, called carbonaria, was hardly ever recorded before 1848. As they are nocturnal and spend the day resting on lichen covered trees and walls, the black ones would have been more visible to birds than the pale, mottled ones, so most would have been eaten meaning that fewer were left to breed and pass on their colouration. Then along came the Industrial Revolution, the trees and walls became covered with soot and the pollution in the air killed the lichen. Now the paler moths became more visible and it was their turn to be dinner. The changed colour of the environment allowed the now well camouflaged black moths to live and breed and they then became the more common variety in industrial areas. The next episode in this story is the ‘Clean Air Act’ which was passed in the middle of the twentieth century. The soot and pollution disappeared and the trees and walls reverted to their original colours. Now, once again, the black moths were more noticeable and the paler ones blended into the background and more survived to breed; they therefore became the dominant variety again. An amazing example of how nature adapts to changes in the world.

Peppered moths,
usual and carbonaria
Chris Manley, author of
‘British Moths
Photographic Guide’

Some of the marine animals that live in and around our Norfolk chalk reef, also rely on camouflage. There are spider crabs found here that use things they find in the environment to decorate their shells, a habit which gives them the name of ‘decorator’ crabs. They will use seaweed, sponges, gravel and whatever is around to help them blend in to the background; stiff hairs on their shells act like Velcro and keep the decorations in place. Some of these crabs will attach distasteful seaweed or stinging anemones to themselves to deter predators. The hard shells of crabs do not grow with their bodies and have to be shed periodically and decorator crabs will quickly transfer the adornments from the old shell to the new one. Experiments, which involved moving the crabs from one environment to another that was visually different, have found that they will discard the old decorations and replace them with ones from the new surroundings. These animals know what they are doing, so does this imply a level of intelligence? It would be interesting to know. It has certainly been proved that they remember experiences, both good and bad.

Things to take part in this month include:

  • Guided Kayak Nature Adventure Trip – 01603 715191 or

strumpshaw@rspb.org.uk

  • Nature walk & sea dipping, both at Holme Dunes.
  • Evening stroll & BBQ – Cley Marshes.

www.norfolkwildlifetrust.org.uk or 01603 625540.

 

©   Sheila Sims 2017.   Email: sheila@norfolknaturediary.uk

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