The series continues on January 28th where we explore the hidden world of reptiles, amphibians, and other wildlife in winter. Discover how frogs, newts, and woodlice survive the cold, and learn about the ferocious behavior of pike in rivers. Whether you're a nature enthusiast or just curious about the outdoors, this article will provide a fascinating look at the winter habits of these creatures.
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Reptiles and Amphibians
Reptiles and amphibians are cold-blooded, meaning that hibernation this month is obligatory. There are rare sightings of frogs in mild winters, but more often now they are encountered in a glass-like state, if their place of hibernation is accidentally disturbed. Large numbers can occasionally be found in this condition near ponds. Others prefer to spend the month buried in mud at the bottom of a pond, although boggy areas and even drains are sometimes preferred.
Newts are more terrestrial altogether and can be encountered in dead vegetation, their limbs now brittle with the cold. Compost heaps are best left undisturbed as these are often the winter quarters of choice for a host of other animals.
Fish
This is the time when pike are at their most ferocious. They will lie in wait among vegetation near shoals of smaller fish such as chubb. Here they will remain, ready to devour any unfortunate that strays too near. They can even be seen in shallow, clear rivers such as the river Derwent as long as the water is not moving too rapidly. The rivers Lea, Mole and Cray are also worth investigating. Quiet bridges over such rivers are good places to look as the pike sometimes lie in full view, motionless except for a slightly moving tail. Here they will remain perfectly camouflaged among the stones, except for that hauntingly large eye. They are olive brown with green mottling and pale lemon spots on their sides. When young they are called jack pike, then pickerels, before becoming pike and finally luce. Pickerels used to be kept as pets in aquaria where they became tame enough to touch.
They were much more highly prized in medieval London where they were worth twice the price of a salmon and ten times that of a turbot. Also called water wolves, they have a famous appetite which has been known to include whole mallards, moorhens, rats and if one famous story is to be believed even a child’s hand. They are said to become only truly voracious when the water temperature rises to 5º centigrade at which point they will almost take anything. In the middle of the nineteenth century one did attack a child at Ascot and the fish was later found dead and brought to Windsor castle. They can reach seventy pounds in weight and a massive seven feet in length, although the largest caught around London are generally in the region of twenty-five pounds. The skull of a fifty-three pound luce is kept in the Natural History Museum collection.
Other coarse fish e.g. roach, may still be active, even occasionally breaking the surface and quite large fish always seem to be present as you look over the bridge at the entrance of Morden Hall garden centre. Carp and tench are likely to be lying, possibly beside each other, in a still, torpid state in the ooze at the bottom of a lake.
Invertebrates
Many land invertebrates are not really seen this month, particularly if they have retreated into deeper soil to get away from the cold. However, you only have to watch gulls following tractors, waders pushing their beaks into mud or even blackbirds lifting leaves in gardens to realise there are quite enough invertebrates about to get all these creatures through the winter. By now many fallen leaves are black and slimy due to the combined action of bacteria and fungi. Rain has also played its part leaching out various unpalatable chemicals such as tannins.
The result is an excellent food source for active invertebrates such as earthworms, slugs and their predators, centipedes and ground beetles. In the soil column itself there are always seething masses of microscopic nematodes, larvae, mites, potworms, springtails and protozoa all busy leading their lives in the thin film of water that surrounds soil particles.
Woodlice are one of the most common invertebrates to be found. Lift any stone, rotting piece of wood or dig into a pile of decaying leaves and you are likely to see them scurrying away even in January. They have a varied diet of dead wood, dead leaves, occasionally animal matter and even each other if they have just moulted. Gardeners dislike them due to their habit of nibbling roots, vegetables and seedlings. Toads and shrews are known to enjoy eating them but many other animals do not, possibly due to their unpleasant secretions. Their numbers can be explained by several broods a year of up to one hundred eggs a time.
In London we tend to see only five different species. The most common is likely to be the Common woodlouse Oniscus asellus which is flat, shiny, mottled grey and has a tendency to remain attached to the surface you find it on. Although woodlice can vary a lot in colour if you do find one that is a deeper slate grey with orange bases to its antennae it is likely to be Porcello scabes. It is equally as common as Oniscus but tends to prefer drier areas. Three other species that are well distributed and can all be found on Bookham Common are Trichoniscus pusillus, Philoscia musconum and Trachelipus rathkei. The first is our most common small woodlouse. It is usually a mottled reddish-brown with the males a little darker than the females. Philoscia is a little slimmer than most with a dark brown head and dark stripe along the length of its body. Trachelipus has three distinct stripes and is usually a yellowish-grey.
The easiest of all to recognise is the pill woodlouse Armadillidium vulgare. It has the habit of immediately curling up into a perfectly round shiny ball when disturbed. It used to be taken as a pill much as we take medicinal pills today. The belief was that it cured liver complaints in both animals and humans. It comes as little surprise that such common harmless creatures have been given over two hundred local names with many amusing ones such as cheesybobs (Surrey), monkey peas (Kent), parson’s pigs (Gloucestershire), fairies pigs (Lancs), coffin cutters (Ireland), chooky pigs (Dorset) and toebiters (London).
