Biology – Page 41 – David Bradley

Hobbies at RSPB Ouse Fen

The Eurasian Hobby is back over RSPB Ouse Fen (May 2019), one of 6 or 7 seen hunting on the wing. The bird’s scientific name is Falco subbuteo means “falcon below the buzzard”. But, yes, that’s where the name of the football game – Subbuteo – comes from, the inventor wanted to call it “Hobby”, but the company said that couldn’t be trademarked, so he went all cod Latin.

As you can probably tell, they fit into a sequence of falcons found in the British Isles, from largest to smallest: Peregrine > Hobby > Kestrel > Merlin. Hobbies mainly eat dragonflies on the wing and you can see them clipping off the wings and discarding everything but the insects’ bodies as the bird flies over you. I have also seen them take swifts out of the air on a couple of occasions, both midsummer above our garden with the hobby flying out of the sun towards the screaming, circling swifts high above.

Taking photos of birds on the wing is difficult at the best of times, but photographic quality is also compromised at this time of year by atmospheric disturbance (you cannot filter out the heat haze, unfortunately).

Heart & Dart, Agrotis exclamationis

Just added another new moth species to the mothematical list, the Heart & Dart (Agrotis exclamationis). Here’s a focus-stacked shot looking down on the moth so you can see its “darts” and its “hearts”.

Here’s a face-on closeup, also focus stacked using digiCamControl to capture a sequence of six photos at different focus positions, front to back, and then aligning and stacking together with CombineZP. The stacking has not worked brilliantly in this shot, the antennae have artefacts, but at least you can see this species’ distinctive black band visible only when looking at the front of the thorax head-on.

Apparently, the Heart & Dart is one of the most common of the so-called owlets, the Noctuid moths, common in Europe and widespread in the UK, attracted to light and its larvae (known as cutworms in this genus of moths). The larvae eat all sorts of garden and wild plants, turnip, potatoes, maize, spinach, strawberries, lettuce, beetroot, as well as oak leaves and brambles.

The moth’s common name is perhaps obvious, but so too, in some sense, is the scientific binomial: Agrotis from the Greek for farmer, exclamationis meaning an exclamation! A farmer’s exclamation. Not a species to be encouraged in one’s new #AllotmentLife.

Of course, some cultures get their own back on the plant-eating moths, by eating the moths themselves. The related Bogong moth (Agrotis infusa) is an icon of Australian wildlife due to its historical role as a food source for Aboriginal people of Southeastern Australia, Its gathering led to inter-tribal feasting. The moths are roasted to remove wings and scales and often made into moth meat paste, which apparently has a nice, nutty taste.

Light Emerald, Campaea margaritaria

Another one of those insects almost everyone else thinks of as grey or brown…just look at that pure greeeen.

Light Emerald (Campaea margaritaria). This is a geometer moth, which means its larvae “measure the earth”, they’re inchworms, in other words. Although I think it’s time they went metric AND they’re not worms…they’re larvae (moth caterpillars).

Although this moth is pretty much flat, I took three photos of it at different focus depths and then aligned and stacked them together (using digiCamControl and CombineZP, mentioned as my current free tools of choice for focus stacking some time ago on the blog.)

If you look closely you can see why moths and butterflies (essentially the same thing) are called Lepidoptera. (Lepis means scale, pteron means wing in ancient Greek, so – scaly wings)

Barred horsetail and more – Part 4 #PondLife

UPDATE: Part 4b Night of 6 MAY 2019, spotted what I think is the first inhabitant of the new pond, a surface-swimming beetle of some kind, perhaps a “diving beetle”.

Having redesigned, realised that the internal shelving of the pond isn’t quite what it should’ve been for the best views…

Anyway, a few plants are in now as is the weird double-handed milk jug we cadged off the blokes at the dump 20 years ago. Plants: barred horsetail, Equisetum japonicum. A tall marginal pond plant, with banded vertical stems. Hydrocotyle var. A pennywort oxygenator. Grows in the muddy margins and shallows of the pond. Scirpus cernuus, more colloquially known as bristle reed is in there too now as is Phragmites variegata, Norfolk reed.

Also in the shallows, an intriguing plant called Juncus effusus, the corkscrew rush. Iris pseudacorus, the yellow water iris, and Primula rosea.

That’s it for now. Full to capacity loaded with a few filtering and oxygenating plants. Needs some more landscaping although that patch at the back is going to be set aside as a micro-meadow, the repotted yucca will probably be relocated, although I’ve also taken 3-4 cuttings from the parent plant the main stem of which was dead.

Oh, we also need to deal with the gravel and mud from the hole…but there’s stuff to do on the allotment before then! None of this is really about aesthetics anyway it’s about creating a nano-ecosystem in our garden for insecta, amphibia, aves, and possibly some mammalia.

Photos of local birds for local people

I say local…most of them are anything but local having winged their way back to Old Blighty from their winter homes in Sub-Saharan Africa and elsewhere.

Common Whitethroat on Hawthorn along a Fenland drove

Our local bird world is awhirl right now, with lots of the summer migrants. Of course, the farmland residents, Meadow Pipits, Skylarks, Corn Buntings, Yellowhammers, are all very active too, and the countless Linnets and Goldfinches.

Corn Bunting among the rape on a Cambridgeshire farm

Cuckoo and Turtle Dove have been heard near our home, Swallows and Housemartins abound, Common Whitethroats and Lesser Whitethroats are along and around the local lodes and droves and there are Reed Warblers among our reedbeds.

Sporadic Swifts have been sighted around the wider area and not too far from our patch a migrant Montagu’s Harrier has been on the wing.

If one Swallow does not a summer make, then what about two…or more?

Montagu’s Harrier Circus pygargus

Rather pleasantly surprised to have seen a male Montagu’s Harrier, Circus pygargus recently on a day away from my desk. The bird’s altitude and the atmospheric conditions (heat haze) precluded clearer photos. It circled above me, climbing as it did so.

This is a +ID, confirmed by 2-3 other birders on Facebook from the snaps.

According to the RSPB website: The Monty isÂ an extremely rare breeding bird in the British Isles. It is a Schedule 1 listed species and each pair has to be specially protected because its survival is precarious. A summer visitor (wintering in Africa), it seems that whereas like other Harriers, such as the Marsh Harrier it would favour marshes, over arable farmland is a more likely place to see them.

Cetti’s Warbler Calling at Wicken

The “song” of the Cetti’s Warbler (Cettia cetti) is anything but a warble, but what’s a warbler anyway? It’s a shockingly loud call for such a tiny bird; listen here. Been hearing a lot of them around RSPB Ouse Fen over the last few weeks and caught sight of a few. Also heard at least one or two during a walk around NT Wicken Fen on 26th April 2019, then heading back to the car via one of the hides thought we’d have a quick look to see if we could see the Reed Warblers (we could hear their raucous, but less tuneful calls from the reeds)…a Cetti’s called out and darted into the corner of the pond and scuttled around among the reeds search out titbits from the water.

After a couple of minutes, it grappled its way up a reed from water level, called again, and then darted out of sight. I fired off a couple of reels of film (actually 60 shots on a digital camera) in an attempt to get one of this furtive fellow feeding. The contact sheet did not look promising…

A closer inspection, cropping into the area where the warbler was, turned up a few almost shots…see above and below

My old cock linnet

Many readers will perhaps have heard the music hall song “My Old Man (Said Follow the Van)” by Fred W. Leigh and Charles Collins and made popular just after The Great War by singer Marie Lloyd (who never actually recorded it). The song contains the lyric:

I walked behind wiv me old cock linnet.

Cock linnet perched on a lichen-covered hawthorn branch showing the blush of his breast

The “cock linnet” mentioned is the male of the passerine bird species Linaria cannabina (previously known as Carduelis cannabina until DNA analysis separated it from the genus that carries the likes of the Goldfinch, Carduelis carduelis). Captive songbirds were a favourite of all classes for centuries and certainly at the time of the writing of this song may well have been a favoured pet of a Cockney housewife.

The male of the species takes on a rather suggestive blush to its breast when in its mating plumage at the height of spring. The allusion to the male member being rather obvious and commented upon in several sources including the excellent “The Red Canary: The Story of the First Genetically Engineered Animal” by Tim Birkhead:

Moth of the Month – Maiden’s Blush

The Maiden’s Blush moth, Cyclophora punctaria, Spring form is not as well marked as the Summer form where the blush is more obvious, but you can still see it here.

This species is a geometer moth, which means its larvae (caterpillars) move in such a manner that they seem to measure the earth, they’re known as inchworms in the USA and elsewhere. Specifically, this member of the Geometridae is a member of the sub-family Sterrhinae, which includes the “Least Carpet” and several “Wave” moths as well as the “Blood-veins”. The species was first described by Carl Linnaeus in 1758 in the 10th edition of Systema Naturae.

According to the UK Moths site, the species occurs in oak woodland, its larvae feeding on that tree. It is fairly common in the south of England, but scarcer up north and into Scotland. As with several other moths in the genus Cyclophora, in Western Europe it flies in the spring/early summer (May to June) and then has a second brood in August. The adults of the second brood are markedly smaller than the spring specimens.

This specimen of Maiden’s Blush flew to 40W actinic light trap overnight 24/25 April 2019. Along with a host of other moths: Brimstone, Muslin, Garden Carpet, Early Grey, Spectacle, Nutmeg, Powdered Quaker (another new for me pictured below), Shuttle-shaped Dart (6 of them).

You will not that I have called this post “Moth of the month”, don’t worry there will be more moths than once a month…

Spring Moths

I’m slowly seeing new moths to my actinic light trap as the spring surges forward, a new one or two each day now. But, one of the stalwarts of the British mothing world posts to the major Facebook mothing group how he had almost 300 different moths to his trap, with 50+ species new for the year. I’m not sure I could cope and certainly wouldn’t be able to identify from memory all of the ones he cited.

My “haul” from last night was a lot more modest but interesting nevertheless…and manageable:

Shuttle-shaped Dart (7)
Male Muslin moths (3)
Double-striped Pug (2)
Brimstone
Hebrew Character
Common Plume
Waved Umber
The Mullein
Pebble Prominent
Nutmeg
Spectacle

Recent moths new to my “list” for the year, so I’d never seen before.