Sunday, 22 December 2019

January 2020 - Thrushes, Re-wilding


We saw a couple of thrushes on the field at the back recently.  They were quite a distance away so it was difficult to see what sort of thrushes they were even with binoculars.  There are four possibilities for thrush-like birds in this country – song thrush, mistle thrush, redwing and fieldfare.  (The thrush family – Turdidae - is a large family that includes robins, redstarts, wheatears and our more familiar blackbird.)  The redwing and fieldfare are more numerous in the winter as they are joined by immigrants from Scandinavia, but these are distinctive birds – the fieldfare is well marked and has a grey back, and the redwing has a distinctive eye stripe.  The thrushes on the field were not so distinctive which meant they were either mistle thrushes or song thrushes.  The mistle thrush has slightly bolder speckles on its breast and a more upright stance.  I could see both of those characteristics so I guessed at mistle thrush.  This was confirmed when they flew off and I saw a flash of white under their wings.  The four thrushes each have a patch under the wing near the shoulder – which could be called an armpit if there no ornithologists about – that is diagnostic.   The fieldfare and mistle thrush both have a white patch, the song thrush has a buff-coloured patch and the redwing is aptly named.
Song Thrush

Fieldfare  (This one found in its summer residence - Sweden)


Wildlife can be difficult to see as it is, quite rightly, wary of humans.  I saw a book recently that addresses that problem.  It is by Simon Barnes and is called Rewild Yourself.  The theme of the book is things you can do in your garden to attract wildlife.  Rewilding is becoming a popular concept if not a popular way of managing land.  The idea is that larger mammals or predators are introduced to an area which then changes the ecology and allows nature to recover from human intervention.  It is a ‘stepping back’ from nature and is the polar opposite to conservation which seeks to preserve what may already be a degraded habitat.  The Knepp estate in West Sussex and Yellowstone Park in the USA are famous examples of rewilding.  Yellowstone has been hugely successful.  Wolves were reintroduced and the water quality improved!  How so?  Basically, the wolves killed the deer that were overgrazing riverside habitat which meant that the deer couldn’t graze where they could be easy targets.  This allowed trees and bushes to grow, which in turn attracted beavers that built dams which slowed the rivers and allowed fish to thrive and a balance was restored that improved the water quality.  It has had other benefits as well.  Trees and bushes have stabilized the riverbanks and reduced soil erosion, and remarkably, pronghorn deer that were becoming rare are now thriving as there is more grazing available due to the reduction in red deer numbers. (Red deer are called elk in the USA by the way.)  The trees and bushes meant more insects, more birds, and more small mammals and more birds of prey.  This process whereby the introduction of a species at the top of the food chain has a dramatic effect on many other species is called a trophic cascade.
The Knepp estate in West Sussex has had similar success.  No top predators there but free roaming cattle, pigs, deer and ponies have created a mosaic of different habitats that have resulted in thriving populations of purple emperor butterflies, turtle doves and nightingales in little more than a decade.  It’s on our list for a visit in the near future.  Meanwhile we’ll just have to carry on working on our own small patch where just allowing the grass to grow allows a lot more species to get a foothold.  I guess wolves and bears aren’t an option here?

Sadly, I find that I don't have any good pictures of mistle thrush or redwing.  Something I hope  to remedy in the near future.

December 2019 - Moths


We’ve had a couple of moths in the garden recently.  Actually, we have probably had hundreds, we just haven’t seen most of them.  The two that I’m talking about weren’t attracted by the moth trap, which we haven’t actually used recently, but were discovered in full daylight.   The first was a moth found early in the morning apparently lifeless, balanced on the door mirror of the car.  A gentle prod made it slide off the mirror, but some instinct made it put out a leg and cling to a tiny ledge at the base of the mirror.  Thus suspended it was easy to lift from the mirror and once on the warmth of the hand it spread the rest of its legs with just the sort of grumpy shrug you may expect from disturbing a teenager before midday.  Once photographed it was transferred to a more natural and secure location to continue its sleep.  The moth in question was a ‘Merveille du Jour’ which even with my limited French vocabulary I could translate as ‘Wonder of the Day’.It is a very pretty and bright green moth that helps give the lie to the idea that most moths are dull because they only fly at night.  The Merveille du Jour does fly at night especially in September and October and we have seen several in the moth trap.  This makes me wonder then, why is the moth so called when there are plenty of moths that do fly during the day with nothing in their name to suggest a daytime habit?

Merveille du Jour - Dichonia aprilina
The second moth that we saw does have a daytime habit and is marveled at by many when it is seen – the humming-bird hawkmoth.  Both moths were seen in the first week of November – the humming-bird hawk-moth on one of the rare sunny days.  It flew up onto the wall of the house in full sunshine and basked there for an hour or more.  When the heat from the sun faded it flew onto the last few flowers of the verbena for a quick snack before flying off.  Humming-bird hawkmoths have been hibernating and breeding in the south-west of the country for a number of years now and we found one a couple of years ago hibernating in our carport which suggests that their breeding range is spreading northwards and eastwards.  The behaviour of this most recent one suggests that it may be doing the same.  The one essential component for breeding is the food plant of the caterpillars which is lady’s or heath bedstraw which we don’t yet have in the garden.
Hummingbird Hawkmoth on Blackcurrant Sage

The adult moths with their long proboscis feed only on nectar and they favour plants that have a deep nectary such as lavender, verbena, and in our garden at least, blackcurrant sage (Salvia microphylla var. microphylla) that has a long flowering period and plenty of nectar.  I found an interesting article recently about humming-bird hawk-moths dying in Bulgaria.  They were feeding on an introduced plant (from America) called white evening-primrose.  This is also known as pink ladies, or pink evening-primrose – Oenothera speciosa.  Apparently glandular hairs inside the nectar tube corresponded with grooves in the proboscis in such a way that the insect is not able to withdraw its tongue.  The insect then exhausts itself trying to escape and eventually dies.  So if you are thinking of planting any white evening-primroses, then please don’t – insects are having a hard enough time as it is.  (I have just discovered that blackcurrant sage is also an import from Central and South America.  Luckily, the moth has no trouble taking nectar from it.)
We are on holiday in the Canary Islands at the moment getting used to a different set of wildlife.  There are plenty of familiar species though – the crow family is well represented with choughs and ravens and we have seen a lot of painted lady butterflies – they really do get everywhere.
The Hummingbird Hawkmoth at rest could easily be overlooked