Here are Jan Flamank's Nature Notes for November 2020. Click on each photo to see a larger photo on a new page. For downloadable pdf versions of each topic see the links below.
Halichoerus Grypus, from Greek, meaning ‘hook- nosed sea pig’
Whilst the majority of mammals already have their offspring by now, grey seals give birth to their pups between September and December, and November is the favoured month for female grey seals to return to land to give birth. The UK is home to over half of the world population of these lovely creatures, and the Norfolk, Northumberland and west Scottish coasts are really important beaches during the breeding season.
Much larger than the Common Seal, female Grey Seals are up to 2.5 metres in length, with males often 3 metres, weighing up to 440 kg. That is an impressive size, and especially when weaning their pups, we need to respect them and keep a good distance away. Mothers are very protective of their pups until they are weaned, and will attack human intruders if provoked. Rightly so, I reckon.
The pups are born above the high tide mark, and weigh about 14kg at birth. They grow rapidly on the rich milk from their mother, which is 60% fat, enabling them to put on 2kg a day, laying down thick layers of blubber to insulate them from cold seas. They have delightful white fur for the first two to three weeks of life, but are abandoned by their mother at 3 weeks old to fend for themselves.
Weaned pups spend the next few days and weeks resting, without eating or drinking, and are vulnerable to being trampled by the male bulls, washed off rocks in stormy weather, or disturbed by tourist invasions. Rookeries, where all the pups are born and weaned, are very noisy places. Pups cry like babies, mothers howl at each other, and the bulls grunt and whiffle, sounding like steam trains!
Moulting their white fur, pups reveal the mottled grey coat of the adult. Driven by hunger, they take to the offshore sea, rapidly developing their hunting skills and taste for fish, crustaceans, eels and squid. They are protected to some extent by the Grey Seal Protection Act of 1941, after they were hunted almost to extinction; but still they are allowed to be shot in the ‘open season’ by fishermen and fishery owners who compete for the fish they eat.
Once weaning is over, the huge males mate with the females, after often bloody battles with other males for dominance. The female then does this amazing thing of delaying implantation of the fertilized egg, keeping it safe inside her body for months, so that she will give birth at the same time each year, after a pregnancy of about 7 months. Females live for up to 45 years, the males less at 25, as they are battered by their yearly territorial and mating disputes.
If you are lucky enough to see seal colonies and pups at this time of year, make sure you stay at least 20 metres away, keep dogs on a lead, keep quiet and don’t ever play with frisbees ( as if! ) as they cause awful damage to seals when caught round their neck.
Click here for a downloadable pdf version of Grey Seals
We have talked before about this well known and magnificent tree, but this year has been particularly marvellous for the sheer number of acorns that have been produced. When I go for walks in my local Cat Lane Woods, the acorns have formed a thick rubble on the ground, which looks fantastic, but are also a bit slithery to walk on.
Huge production of seeds is called a ‘mast’ year, and it occurs every 2 to 5 years. There are various theories, but good weather in spring, when pollination of the blossom occurs, is the major factor. The very sunny weather we had in spring positively effects all the oak trees in any location, resulting in them all producing excellent acorns now. More seeds means more oak saplings, and the continuation of our most marvellous, common broadleaf tree. The oak supports the widest variety of invertebrates, insect species, lichen and fungi of any tree in the UK, providing a rich habitat for more than 500 species, so it is incredibly important in maintaining biodiversity.
There is a fascinating, symbiotic relationship between fungi and the oak ecosystem. The Oakbug Milkcap has ultrafine filaments, known as mycrorrhiza, which act as extensions to the oaks root system. The fungi collect extra nutrients and moisture from the soil through these fine filaments, which can then be absorbed by the tree, in exchange for constant sugars from the tree, through photosynthesis.
Pedunculate refers to how the acorns grow from the branch, suspended by long, thin stalks - peduncles - often in pairs. The acorns, snug in their tight fitting cups are clearly visible amongst the almost stalkless leaves, and this is a native tree that most people can recognise. Our only other native oak is the Sessile Oak, where the acorns grow tightly against the branch, and these two can hybridise.
Acorns are an important food source for both birds and mammals, and ‘pannage’ is the term still used for the right to turn pigs loose in woods to feast on the acorns.
Jays are also fond of acorns, and do a great job of increasing the chance of new oaks springing up, away from the shading canopy of the parent tree. Like squirrels, Jays bury lots of acorn seeds as a larder to come back to in cooler months, and like squirrels, they sometimes forget where they put them. They fly with them, secure in their beak for some distance, until they find a spot where they want to store them, and dig a hole with their beak and push the acorn in. It seems a shame that they can then forget where they are, and their larder can also be raided by clever corvids and squirrels watching their efforts. But being forgotten is a positive for the acorn, as it can grow into a new tree. The posh name for seed dispersal by animals is zoochory - which would be a great Scrabble word too!
The botanical name of Quercus Robur means sturdy, and the dense, durable timber of oak, together with its lovely colour, made it widely used for construction over many centuries. Laws were passed in Elizabethan times to protect the oak, as too many trees had been felled for house and ship building, and there was a subsequent, extensive planting of new oaks in royal forests; many of which still survive and can be enjoyed today.
Oak has dense timber because it grows so slowly, therefore it is used mainly for furniture rather than in the paper industry. Standard oaks will live easily up to 300 or 400 years, and can reach 140 feet tall, but the much shorter, ancient pollard or coppiced oaks can be up to 1000 years old, and are mostly found in medieval parkland.
If you ever get the chance to visit Wistmans Wood on Dartmoor, do go, or look up some images of it if you can. I used an image of these woods in the October Nature Notes. It looks rather scrubby from a distance, with some oaks clinging to a valley by the West Dart river, and has no signposts to help you find it. But once inside, you are transported to a totally unique and amazing place. The oaks are all ancient, many over 1000 years old, contorted and barely 15 feet tall, because they were all coppiced; and now lie neglected amidst huge granite boulders, all covered in masses of moss, lichen and ferns.
The unique ecosystem of these woods has evolved untouched for so long because the boulders protect them from grazing sheep and deer, and the very difficult, lumpy ground and short trunks means they are of no use to destructive logging, and defeat most walkers.
Hurrah for some truly neglected wild places I say. Long may that wood be left alone, but enjoy some local woods nearby if you can.
Click here for a downloadable pdf version of Pendunculate Oak Trees
Garrulus Glandarius from the Latin for ‘noisy acorn eater’
A medium sized member of the corvid family of birds, all of whom are incredibly intelligent, the jay is the brightest coloured of them all. It is about the same size as a pigeon, 13 inches long, and with a wingspan of 22 inches. But it remains elusive, even with its striking plumage and harsh, loud alarm call.
This is because they are woodland birds, favouring oak woods as well as living in coniferous, mixed forests, so are less likely to be seen in gardens or parkland. This is changing due to the loss of their traditional habitats, so they are adapting to living closer to us in more urban environments, which are called ‘analogue habitats’ and include our gardens and parks. You’ll be very lucky if they come to your garden, but you will need to have mature trees for them to visit.
Widespread, the jay we see is one of more than 30 species, all with colourful distinct plumage. Both sexes are very similar, with the lovely blue flash on the outer wing feathers. This glorious patch of colour led to it being heavily persecuted and shot in Victorian times, as the blue feathers were used to decorate hats and other desired accessories. Thankfully, this vile practice has mostly ceased, and their numbers are now stable.
Rarely straying very far beyond their birthplace, each autumn our resident UK population is swollen by jays moving west from Europe, when food is scarce. Sometimes we have huge numbers joining us, which is called an irruption, due to extreme continental weather.
Autumn is the time for stocking our larders, and unusually for birds, jays are well known for hoarding nuts. They are especially fond of acorns and beech nuts, and when they have eaten their fill, they carry the nuts in their beaks to a favoured spot and either bury it, cover it with leaf litter, or jam them into crevices in tree bark. A single jay has been known to hide as many as 5,000 acorns in one season, which is an impressive pantry! Although they have excellent memories, not all the acorns are re-found, so jays are also fantastic at helping new oak saplings establish, away from the parent tree.
Jay also eat insects, invertebrates, berries, fruits and also small mammals and eggs and chicks of small birds. Their omnivorous diet and ability to adapt to changing habitats helps them to survive better than many other birds. They have an average lifespan of 4 years, although one ringed jay survived for over 16 years.
They are predated by gamekeepers, tawny owls, sparrowhawks, peregrines and goshawks, and will work together, ‘mobbing’ roosting owls in the daytime. Another fascinating behaviour that jays exhibit is ‘anting’. This is when the jay seeks out an ant nest, then picks up ants in its beak and rubs them all over their wings, or simply lets the ants crawl over it. Feeling threatened, the ants release formic acid, which kills any parasites, bacterial and fungal infections that the jay may have. This may also be a way for the jay to ensure the ant has released its formic acid before eating it, so it tastes more palatable.
Corvids are some of my most favourite birds, all highly intelligent - tool users, able to plan ahead, often very sociable and collaborative in how they live - and the jay is the most gorgeously coloured and easily recognisable of this clever family of birds.
Click here for a downloadable pdf version of The Eurasian Jay
© Jan Flamank 1st November 2020. All rights reserved. Images used in the document have been sourced free for use in this social, educational, non-commercial setting