Month: August 2017

Floating pennywort

Floating pennywort is a highly invasive, non-native species that is choking up the river Cam once again. It doesn’t particularly need excess nitrates or heat to grow like this, just plenty of sunlight and relatively still waters.

In 2012, the Ely Standard reported how the Environment Agency had acquired a floating weed harvester and had pulled out four tonnes from Ely south to Bottisham Lock, Waterbeach. From my photo taken a few days ago, it looks like Hydrocotyle ranunculoides is causing problems on the river once again. The lock itself was choked up, but as you can see from the photo the weed is growing from both banks of the river. (This is downstream from the lock wear and not navigable anyway.

The trouble with this invasive American species of water weed is that it chokes up waterways and bodies of water depriving fish and invertebrates of oxygen, it blocks drainage and filtering systems and crowds out native water plants.

Fox on the run

Headed out before sunset today to see if we could spot the barn owl hunting again…no luck. Lots of linnets, wood pigeons, long-tailed tits and not much else. However, the sun had gone down and we were almost back to the main road when we spotted a (juvenile?) fox pouncing on insects in the recently mown hayfield adjacent to the road. It was almost dark, hence the noisy photos (really high ISO). The fox never seemed aware of our presence although we were no more than 100 metres away from it. There was no wind and we were partially shield by the broken hedgerow. Eventually, it ran to earth when it saw a tractor steaming up Rampton Road with lights whirring and beams on…

Departing are such sweet swallows

In some parts of the UK, the migrants have already departed, but there are plenty of swifts, house martins, sand martins, and barn swallows here in East Anglia, from the North Norfolk coast, to deepest Norfolk and west again to Cambridge (well those are the places I’ve seen them this week).

Back in early May, I photographed adult (barn) swallows (Hirundo rustica) getting it on at Bottisham Lock on the River Cam near Waterbeach (north of the city of Cambridge). The adults are still whirling around the skies and scooping up water and insects from the river. These two products of that springtime behaviour were anything but shy when I turned the camera on them.

On a sultry late August afternoon, they seemed to be relaxing, totally oblivious to the fact that in a few days time they will be flying some 300 kilometres a day south. They will cross the perilous Sahara Desert on an approximately 9500 km journey to their winter abode in South Africa. They’re less than four months old and it will take them a month or so to make that journey. And, early next March/April those that survive the journey and the South African summer will head north again to start the cycle once more.

Incidentally, it was not just before Christmas 1912 that we knew for certain that barn swallows seen in the English summer were migrating all the way to South Africa. A bird ringed in the summer by James Masefield in Staffordshire was identified in Natal on 23rd December that year.

Oh, and in case you missed it on Facebook back in May…here’s the earlier activity

Felt inspired by these gorgeous creatures to put together a sultry instrumental on a late summer’s day.

NWT Barton Broad

Heading home from a camping trip in North Norfolk, we had vague plans to visit an RSPB reserve in the area but sidled up to the second largest of the broads, Barton Broad in Barton Turf. The broad was apparently only accessible by boat until 2003 (when a boardwalk was piled and constructed to get you to a viewing platform) and is alleged to have been a splashing ground of local boy Horatio Nelson. It was acquired by Norfolk Wildlife Trust in 1945.

From the viewing platform in late August 2017, cormorants winging it on pontoons, lots of great crested grebes and a few gulls, roach with their red fins in the water, but more intriguing a couple of swallowtail caterpillars on the milk parsley readying themselves for pupation at the foot of the reeds where they will overwinter and emerge next Spring.

Also sighted a couple of reed warblers and various dragonflies, and an orange flower that seemed quite whitespread in the darkest recesses of the area surrounded by the Herons’ Carr Boardwalk, Facebook friends identified it as an invasive species, orange jewelweed (Impatiens capensis).

Earlier in the trip sandmartins and lots of cormorants on the North Norfolk coast, at least one meadow pipit with a mouthful of crickets and dragonflies and an exotic-looking sycamore moth caterpillar in the less exotic Mundesley car park, oh, and a somewhat exotic alpaca farm (all females, apparently).

You can check out various other arty farty fotos from our most recent trip to Norfolk on my Flickr page.

Migrants and the problem of longitude

How do migratory birds like the Eurasian Reed Warbler (Acrocephalus scirpaceus) know which way to go when heading south for the winter? Indeed, how do they find their way back from sub-Saharan Africa in spring to breed among the reeds in the wetlands of Europe and Asia?

The answer may lie with magnetic lines and how they change depending on where on the globe you are.

“It seems that…the Reed Warbler (pictured above) may have a geographic map or memory that enables it to identify its longitudinal position on the globe, only by detecting the magnetic north pole and its variance from true north,” to quote one expert in the article. The birds can detect magnetic declination in other words.


It’s worth noting that another warbler, the Blackcap (Sylvia atricapilla, immediately above) is usually a summer visitor to the British Isles, but some Eastern European and German specimens in migrating south-west to Iberia and south to Africa for the winter have ended up heading west and overwintering in the UK in recent years. They seem to favour our garden feeders over warmth. We had a male Blackcap overwinter with us 2016/2017 and a male and a female during 2017/2018 winter.

Chasing Wild Geese

Scopelessly in love with birds

I’ve always had a soft spot for our feathered friends. After all, they’re the great British wildlife that seems the most abundant and most accessible. There are more birds and more bird species than there are large wild mammals and domesticated animals put together, by a long way. If you start counting the latter: fox, badger, hare, rabbit, stoat, weasel, bank vole, red deer, roe deer, fallow deer, muntjac, cow, sheep, goat, dog, cat etc you quickly come to a halt.

But, start listing the birds and the list goes on and on from Barn Owl and Barn Swallow to Pied Flycatcher and Pied Wagtail, Firecrest to Goldcrest, Crested Tit to Great-crested Grebe. And, don’t forget all those warblers: Barred, Bonelli’s, Cetti’s, Dartford, Fan-tailed, Garden, Grasshopper, Great Reed, Icterine, Marsh, Melodious, Moustached, Reed, Sardinian, Savi’s, Sedge, Subalpine, Western Bonelli’s, Willow, and Wood.

I never took birdwatching too seriously. I was certainly never a twitcher chasing around hill and vale, coast and cove. I was happy to see a new bird, but never jotted down details, never ticked it off in a book.

Superzoom

That changed when superzoom lenses got cheaper. I had a few snaps of birds taken with a small zoom lens, but the purchase of an affordable 150-600mm lens brought the whole world closer. Especially useful for photographing the moon, the ISS or comets in the night skies. Of course, the lens might otherwise be redundant during daylight if it wasn’t for the birds. Birds, I assume have absolutely no concept of just how close you can be through such a lens without really disturbing them.

 

Twitching or birding?

And so, my latent twitching/birding inclinations began to grow early in 2017. I had a lucky first day with the new lens: flighty blue tits in the garden and a sharp-eyed heron after our neighbours’ goldfish in the pond. Lucky for those pesky piscines, our neighbour had protected them from such aquatic hunters with strong wire mesh. I got a nice close of the frustrated bird up from an upstairs window before he lumbered into the air to find breakfast elsewhere. My first lunchtime dog walk in the winter sun, led me to a majestic Kingfisher perched on the reeds. I’d spotted her once or twice before on walks without a camera. This time, she posed for a moment while I got her close-up all electric blue and saturated orange.

I started to blog about the birds and to build an online gallery. Trips to local nature reserves and country houses added more to the list as did trips to the coast. Before long, I had more than 100 different species: Red Kites, Marsh Harriers, Hobbies, Blackcaps, Great Spotted Woodpeckers, Green Woodpeckers, House Martins, House Sparrows, Tree Sparrows, Dunnocks, Gannets, Kittiwakes, Puffins, Razorbills, Bullfinch, Greenfinch, Chaffinch, and so many more.

Who’s counting?

Birders will tell you that identifying your first 100 is just the start, it gets serious and harder when you are targeting 250. So, here’s a selection of the first few birds you might see should you take up the sport and science of observing birds. Your mileage may vary, you might see a marsh harrier before you spot a Hen Harrier, and Ringed Plovers may come your way before Golden Plovers. You may also try to count Lapwings, Peewits, and Green Plovers as different species, but they are one and the same.

In less enlightened times people preferred to shoot birds with a gun and steal their eggs. But, with a camera, you get to hunt and shoot the same bird again and again. I hope this short guide gives you some clues as to what you might look out for and where you might look in figuratively bagging your first 100 birds.

There are plenty of birds to watch…about ten thousand species worldwide at the last count. So crack out the binoculars and your walking boots or just watch from your garden and maybe tick them off in your head after you confirm the species in the books. It’s not a wild goose chase, honest.

I keep a constantly updated gallery of bird photos on my Imaging Storm site, along with a “tick list”.

Flying visit to RSPB Snettisham

…always escaping to the coast when we can, headed up the A10 (not quite as the crow flies, as we were in a car), took almost as long to get around King’s Lynn north to Snettisham as it had from here to King’s Lynn. Not to worry, we made it by midday. We’d missed the high tide turning, although I could’ve sworn the site’s website said that was just close to 11:20 am not the 10 am that it seems to have been, so the water was way out and the mudflats exposed. Not a huge variety of birds nor large numbers on the day, but we got there at the wrong time of day and at the wrong part of the tide. There were vast flocks of black-tailed godwits and knot on the horizon. A few oystercatchers, ringed plover, turnstones, and sandpipers.

Finally got a snap of a curlew, in fact, there was an adult and a juvenile feeding on the mud.

Overhead lots of common tern heading out to see and back again to feed their chicks on the islands in the lagoons behind the flood bank and out of sight of the mudflats. Several grey wagtails and pied (white) wagtails around, and a few linnets, and the inevitable LBJs. Plenty of lapwings, cormorants, and greylag geese on the lagoons. Don’t think we spotted any of the pink-footed geese for which Snettisham is renowned at certain times of year with their spectacular flocking activities as the tide rises.

Mrs Sciencebase spotted a tern bearing a silvery fish in its beak and it was quite close so got a half decent shot of that bird and some of the adults fed chicks on a more distant island. Here are a few of the very active common terns (Sterna hirundo), known to some people as sea swallows. And having watched so many birds feasting on seafood, we headed to the local fryer and had cod and chips for a very late lunch…

What is fipronil and why is it in our eggs?

Fipronil – broad-spectrum insecticide, one of a group of compounds known as phenylpyrazoles. Andy Brunning over on Compound Interest cracks open the story…

To quote Compound Interest:

It appears that Fipronil was mixed in with a red mite treatment, Dega-16, in order to enhance its effectiveness. Red mites are common pests on  poultry farms. Fipronil is not authorised to be used around or on food-producing animals. How the Dega-16 product became contaminated is unclear and a criminal investigation is underway.

He adds that:

The amounts present in the contaminated eggs are much lower, and at these levels it is unlikely to be a risk to public health.

More to the point:

Affected products have already been withdrawn from sale

The hemp-eating linen weaver – Linaria cannabina

Don’t often see avian couples together…or more to the point, I don’t often catch them “on film” together. Here are Mr and Mrs Linnet (Linaria cannabina) at their residence in Rampton Pocket Park a few miles north of Cambridge. The bird’s English name comes from the species’ fondness for flax seed from which we make linen, the second part of its scientific name from its liking for hemp seed (Cannabis sativa). The bird is found across Europe into western and central Siberia and is non-breeding in north Africa and southwest Asia.

As you can hopefully see from my not particularly sharp photo the species is sexually dimorphic (the male and female are different): the male in summer has a red breast, grey nape, and red head-patch, while the females and juveniles lack the red colouring and have white underparts, with a buff-speckled breast.

Originally, the linnet was placed in the genus Carduelis, putting it squarely in with a finch grouping within the Fringillidae. Indeed, the linnet rather resembles the chaffinch and its high-pitched call (not always a “linnet-linnet-linnet”) resembles the jangling coins sound of the goldfinch. However, DNA evidence suggests that the linnet is not of the same genetics as the Carduelis finches and that it is on its own branch of the taxonomic tree of life. Hence, it is now in its own genus, Linaria, meaning linen weaver from the Latin.

There are several sub-species of Linaria cannabina in different parts of the world:

L. c. autochthona – Scotland
L. c. bella – Middle East to Mongolia and northwestern China
L. c. mediterranea – Iberian Peninsula, Italy, Greece, northwest Africa and Mediterranean islands
L. c. guentheri – Madeira
L. c. meadewaldoi – western Canary Islands (El Hierro and Gran Canaria)
L. c. harterti – eastern Canary Islands (Alegranza, Lanzarote and Fuerteventura)