NATURE NOTES - Written by Dr Martyn Stenning
Nature Notes September 2021
There is a bird, fairly common in Britain, namely, about 80,000 pairs, that anyone living near or in a town or in the countryside, can see easily, and frequently, during the months of May, June and July, but is impossibly rare during the remaining months. This bird weighs from 31 – 56 grams, has a wingspan of 42-48 cm and is dark brown to black or slate grey for the most part with a small light patch beneath its beak.
This bird almost exclusively eats insects, but will also take spiders that are ballooning on gossamer webs. All this while flying continuously.
This bird remains on the wing all its life for about 10 months of the year even roosting on the wing at altitudes between 1000 and 2000 metres, gliding and sleeping on and off until dawn. This bird can also mate and drink water on the wing. The only time this bird lands is to make a nest in a building, tree hole (such as an old woodpecker hole) or in a nest-box, or on a craggy cliff-face. This bird is most fond of church buildings.
Both males and females share nest duties and often preen each other (allopreening) while at the nest. Their clutch of eggs can be from 1-4 but are usually 2 or 3. The eggs are long, elliptical smooth and white, but not glossy. Incubation takes from 19 to 27 days. This is so variable, because, in the nest, the young of this bird can endure short periods of hibernation in and out of the egg and their little bodies become dormant. This is when the adults find it hard to find food during cold spells of inclement weather often flying far and wide to feed, abandoning their nestlings for days at a time. The nestlings are in the nest from 37–56 or sometimes more days during which the parents feed, clean and warm them.
When they are ready to fly, the fledglings leave the nest at about 08:00 h when their parents are absent, and they find their own food from that day on for the rest of their lives of up to 20 or more years during which they fly the same distance as if going to the moon and back up to 7 times. By the beginning of August, most of these birds have left Britain and flown to Zaire, Tanzania, Zimbabwe and Mozambique. This bird, known for its screaming, very fast flying flocks, is the Common Swift (Apus apus).
Dr Martyn Stenning
Nature Notes August 2021
Prof. Brian Cox concluded one of his recent documentaries about the cosmos by saying that “we are here because we have to be”. I have just been watching the wildlife in our garden, and there are fledgling jackdaws calling to each other and their parents, collared doves trying to defend their nest from a magpie, a grey squirrel eating an unripe apple in our fruit tree and a Planet Earth-coloured blue tit taking sunflower hearts from a bird feeder. This is in a background of tall birch trees, an herby lawn allowed to grow with clover and birds-foot-trefoil and a pond full of metamorphosing tadpoles/frogs. All there because they have to be!
I try not to make value judgements about the organisms in the garden, simply because they have to, or should, be there. However, it may be that we humans have to sometimes attempt to correct mistakes of the past by ‘gardening for wildlife’, which does sometimes mean making value judgements, i.e., weeding, especially in favour of those animals and plants that have been rendered rare by some of our human predecessors.
Every plant and animal species has a history, jackdaws are a type of crow and all crows originated in Australia before radiating naturally around the globe due to their ability to fly. Grey squirrels originated in North America but were introduced by humans to Britain in 1876. They have decimated Britain’s native red squirrels, but are still innocent animals with entertaining behaviour. If we get too judgemental about an organism, we could end up persecuting them all unfairly for some reason or another. After all, we are part of nature as well. However, the natural world needs management because we humans have a responsibility of stewardship due to our disproportionate numbers and impact upon it. As Sir David Attenborough has said “We have overrun the planet”. Do we have a moral duty to carefully share this blue, yellow, green, white and black Earth with all other forms of life that should be where we find it?
When I was a teenager, I discovered a lovely piece of prose called ‘The Desiderata’ (Things Desired) written by Max Ehrmann (1920) who pre-empted Prof. Cox’s words as it includes: …”whether or not it is clear to you, no doubt the universe is unfolding as it should ”.
Dr Martyn Stenning