Here are Jan Flamank's Nature Notes for October 2020. Click on each photo to see a larger photo in a new page. For downloadable pdf versions of each topic see the links below.
The Goldcrest is our smallest native bird, found mainly in coniferous woodland and often heard more than seen, as it is only up to 3.5 inches long and weighs less than a quarter of an ounce, or 5-7 g. It is always on the move in the dense foliage, well camouflaged as it flickers round the branches, hovering and picking insects and spiders from the tree. They can also hang upside down when searching for food beneath leaves, and have very sharp, thin beaks that act like tweezers. Usually well hidden in conifers, they sometimes visit the ground to peck seeds and insects from snow covered surfaces.
Well named, it has a bright yellow or orange crown on the top of its head, bordered in black, and this bright crown is raised into a small crest when alarmed. They have a high pitched song and alarm call.
What amazes me for such a tiny bird, is that in our autumn, our resident population can increase fivefold by large numbers of Goldcrests migrating across the North Sea to spend winter here. They fly here from the Baltic, Finland and even Russia, covering over 600 miles in one week.
They are effective breeding birds, with 2 broods a year of up to 20 nestlings in one season. They have also benefitted from widespread conifer plantations across the UK, with the fast growing trees used in lumber and paper production. Both parents make the small spherical nest, with 3 layers for insulation, made with cobwebs, lichen, moss and lined with feathers and hair. It is so small and well concealed in the dense foliage, it is rarely predated.
They feed all day in autumn, building up energy for the cooler nights, huddling together in thick cover to keep warm. I would love to see that! I have seen Goldcrests in conifer woodland, but it was mostly an impression of fluttering movements as they restlessly foraged for insects.
The Firecrest is another tiny bird, closely related to the Goldcrest, similarly secretive, but they do sometimes interbreed. Firecrests are less numerous here, but are found mainly in the South East. They migrate from central Europe, but prefer more open mixed woodland, and may also inhabit gardens with exotic conifers. When they feed together with Goldcrests they tend to feed lower down in the trees than the Goldcrest, so leaving space for each other to hopefully find enough food. Sensible and kind, this is a lovely lesson for us all from these very small birds.
We tend to think of hail as winter phenomenon, as it is ice, but in fact we always have hailstorms in the warmer summer months, so why is this?
It is all because the big convective clouds reach their highest elevation in summer, when the surface is strongly heated by the sun, and also when they have the most moisture in them, so evaporation is at a high rate too. Both of these occur in the summer months. The higher the clouds go, away from the warm surface of the earth, the colder they become.
Cumulonimbus clouds, which produce hail, are convective clouds, formed by warmer, summer air pulling away from the surface of the earth, contrasting with the relatively much cooler air above the cloud. The clouds form and transport heat up into the atmosphere by the process of convection, and the strong updraughts of ascending air, and downdraughts, enable hail to form inside the cloud.
These clouds contain large water droplets and hail forms within the cloud from tiny ice crystals called graupel. The hailstones become bigger inside the cloud, due to the accumulation of supercooled water droplets as they are borne upwards on rapidly rising air. The hailstones have to build up sufficient layers of ice to be heavy enough to fall out of the cloud onto earth. They do this by moving up and down in the cloud on the water- rich updraught, adding icy layers to themselves. It is possible to count the ice layers in a large hailstone and have an idea of how many times it moved up and down in the cloud.
So, the next time we have a summer hailstorm, think of the tiny ice crystals becoming larger as they move up and down in the cloud, encountering very cold water droplets and making extra layers of ice, prior to making headlines in the local news. It is a summer weather event to marvel at - buy try to avoid being out in it, as they can hurt if they land on your head!
This is our most tiny shrew, widespread throughout the UK and surprisingly resilient given its minute size. It is only 2.5 inches long, but its long hairy tail of 1.5 inches adds to the overall length.
As such a small warm bloodied mammal, it has a proportionately larger surface area than bigger mammals and so loses body heat quickly. Many mammals grow longer fur to combat the cold, but this tactic would hinder the movement of such a small creature, so after the moult in autumn, its fur stays at about 3mm long all over. We don’t know why it happens or how it is controlled, but the autumn moult starts on the rump, working up towards the long nose, but the spring moult does the reverse, starting at the nose then working towards the rump. Wild indeed.
Being so small has some advantages, and the pygmy shrew can hide effectively in a wide range of habitats, including fissures in rocky outcrops, but prefers long grass and shrubby vegetation in woodland where they can also easily feast on their prey. They mainly eat spiders, beetles, woodlice and snails and feed almost constantly, as they have to consume 25% more than their own weight every day, just to keep alive. That is a huge amount of tucker!
Luckily, it has a very efficient digestive system, and excellent hearing that picks up the minute sounds of moving invertebrates. Their wonderfully long nose is covered with hairs that detect movements of prey in the undergrowth. Once they pounce on a spider or woodlice they bite it with teeth that are red at the tip, due to iron oxide in their enamel. Juicy snails also provide water for them. Pygmy shrews have a very high metabolic rate, with a heart rate of 250 beats per minute, and a breathing rate of 200 breaths a minute and live a short, fast life of only up to a year in the wild, with many dying within 4 months of birth.
Solitary creatures apart from mating, they usually have 2 litters of 4 to 7 young, born mainly April to September. They grow rapidly on the rich milk of their mother, increasing their size 10 fold in just 2 weeks. They are independent at about 3 weeks old, and then leave the nest to establish their own territory. Wet and cold weather is the biggest cause of mortality, as they impede the shrew’s ability to keep warm and find enough food.
We are unlikely to see live pygmy shrews, who are themselves a tasty snack for owls, but the next time you walk near woodland or long grass, imagine them rushing about, foraging and feasting on small invertebrates, resting only in very short naps of a few minutes in their hidden undergrowth homes. And the proud possessors of red tipped teeth.....
Most of us are much more aware now of the unavoidable fact that humans are by far the most destructive species on this planet. Thankfully, we are also more aware of what we can do to change our behaviours, rebalance our relationship with the natural world and repair some of the damage we have done.
An important concern with regard to increasing global warming is the vital issue of carbon capture and the role of trees. As with all these complex environmental challenges, our responses need to be equally multifaceted and thought through to ensure long term benefits. We can do this.
High quality research is ongoing in the UK and beyond, and the Woodland Trust and Wildlife Trusts are doing fantastic work on our responses, along with many environmentalists, Defra and other organisations. This all helps, a lot.
We know that trees are excellent at capturing and storing carbon, but which are the best and how can we intelligently plan ahead to reduce climate change and restore some of the vast losses of natural habitats for wildlife? It is not enough to just pledge to plant vast numbers of trees in the UK. We need to know what to plant, where to plant and to avoid the mistakes we made with huge conifer plantations. We must also stop stripping the soil of all its nutrients with chemicals and overgrazing. As I have said before, many times, if we have poor soil, we cannot have healthy plants and without plants, we will ultimately, have nothing....
So, a huge challenge faces us, but we have reflection, intelligence (with notable well known exceptions!) and environmental sciences to help us plan well and make a real, positive difference. Phew.
Here are some useful facts about carbon capture from the Woodland Trust:
Broadleaf trees are better at storing carbon than conifers, with beech trees in the top 5 for locking up destructive CO 2. This is due to their high timber density. Fast growing conifers are good for easy financial gain, but not for long term sustainability, eco -diversity and reducing climate change. Soils store a huge 72% of the total carbon capture for a wood, with tree trunks, limbs and leaves locking up 17%, tree roots 6% and deadwood 5%.UK woodland captures 20million tonnes of CO 2 annually, and we can improve on this by planting trees most effectively across our small island.
We may not all have the resources or space to contribute to mass tree planting, but we are all aware of the small, incrementally useful things we can do to help now:
If you have a garden, or community space, plant a new tree if you can. Autumn is the best time to do this, when the earth is still warm and the trees have time to establish before new growth in the springtime. Think small and native, and make a square planting hole as the roots establish more firmly than in a round one. Ensure it is well watered in the first few years of growth.
All the usual daily eco-helpers of reduce, reuse, recycle to avoid waste.
Don’t fly! Leave that to our perfectly adapted feathered friends, but do put out some sustaining seeds and water for them throughout the cooler months.
Enjoy the glorious colours of autumn as our broadleaf trees lose their leaves and prepare for a period of dormancy over winter.
If you get the chance, read The Hidden Life of Trees by Peter Wohlleben, an inspiring book for the longer evenings.
© Jan Flamank October 1st 2020. All rights reserved. Images used in the documents have been sourced free for use in this social, educational, non-commercial setting.