Immaculate Plumage

They may be commonplace but you have to admit that black-headed gulls look pretty slick when they're decked out in full-breeding plumage. Mind you, when they open their beaks and let loose a volley of abuse at a near neighbour, the cacophony can make you wince... 

Spring Beauty

This unusual plant is spring beauty Claytonia perfoliata, which has flowers that appear in the centre of a leaf that surrounds the stem - what botanists call a perfoliate leaf. Some honeysuckle species have perfoliate leaves and so does the delightful native yellow wort Blackstonia perfoliata ............ but spring beauty is an exotic introduction, hailing from North America, all the way from Alaska down to Mexico.

With such a broad geographical range it's perhaps not surprising that it has escaped from British gardens and settled into the countryside, establishing itself in areas of disturbed sandy soil. We found a lot of it in bloom along the landward edge of Holkham NNR last week - an alien species that doesn't seem to present any kind of threat to our native flora, merely adding a little unconventional botanical interest to the countryside. 

Something Lurking in the Undergrowth

We thought at first that this was a large dog, lurking in the undergrowth at Holkham NNR in Norfolk, until be realised that we were looking at a muntjac. They are so small that they can easily conceal themselves in a patch of brambles.

These miniature deer, first introduced at Woburn from China in 1901, have spread rapidly throughout much of England over the last three decades and are now well established as far north as Yorkshire, with small populations in Scotland. They can have a devastating effect on the ground flora of woodlands, grazing the flower buds of bluebells, orchids and most other woodland wild flowers, including rarities like the oxlip. There's an interesting article on the ecological effect of the deer population explosion of native and introduced deer in the April 2010 issue of the excellent British Wildlife magazine.

Holkham NNR

We spent a couple of days last week exploring Holkham National Nature Reserve, just east of Wells-next-the-Sea on the Norfolk coast. It has a wonderful variety of habitats, including sand dunes and salt marsh....

- conifer woodland behind the dunes .....

... and then deciduous scrub ............

which is excellent bird and butterfly habitat, where on this trip we saw ....

... comma butterflies ....

.. long-tailed tits...

.... wild cherry that was a magnet for bumblebees ....

.... and a lot of silver birches loaded with catkins.

It was still a bit early for most wild flowers but on the dunes we found the ....

... miniscule early forget-me-not, 1cm. tall with flowers  that were only about 1mm. in diameter and .....

... stork'sbill - you can find fine pictures of these last two wild flowers at Rob's excellent Wight Rambles blog

There were a couple of other rather more unusual species that we saw while we were there, but I'll save those for subsequent posts. An excellent reserve to visit, at any time of year ... we'll be going back in the summer

Vegetarian Ladybirds

Ladybirds have a fine reputattion as greenfly-slayers, but what do they feed on in spring, before the aphid population explosion gets underway and animal food is hard to come by? This one - and scores like it - was feeding on the nectar of Alexanders Smyrnium olasatrum flowers. This is one of the commonest flowering plants along some parts of the Norfolk coast at this time of year, and must be a very welcome food resource for the large numbers of ladybirds that have recently emerged from hibernation.

Meanwhile, for those ladybirds for whom there was no conveniently blooming Alexanders, the pollen from silver birch catkins seemed to be an acceptable substitute. The dangly yellow catkins are male, the upright green catkins are female, and after pollination (which will be courtesy of the wind rather than the ladybirds) the female catkins will become spikes of tiny winged seeds that are favourite food for siskins and redpolls in winter.

Call That a Warble?

There we were, sitting under a hedge in the afternoon sun on the Norfolk coast, listening to the dulcet tones of willow warblers and the like, when out of the bushes came a rasping sound that I can only like to a piece of machinery in the seconds prior to seizing up. It took a long time to locate the culprit, but it eventually revealed itself......

.......... and I think ( with a bit of help from Keith) that it's a  whitethroat ........

.... but then, if I was a bird with a voice like that I'd want to stay hidden too.

I feel on more secure ground with this one - a raucous jay that took exception to our presence in Holkham NNR (of which more later)

Silent Flight

Just returned from a few days birdwatching on the Norfolk coast at Wells-next-the-Sea, where one of the highlights was the barn owls. We spotted this wary individual along the Peddlar's Way coastal path...

.... and watched it hunting low over the edge of the saltmarsh with that floating, ethereal silent flight, coming ever-closer until...

...it spotted us. We thought that might be the last we'd see of it..

... as it banked away, revealing....

... this classic flat-faced profile...

... but then it spotted a movement in the grass, stalled....

.... hovered for a few seconds...

... and then dropped onto something small and furry in the grass....

... and then it was away, off towards...

... the church tower in Wells, where I guess it's a reasonable bet that it might be nesting.

300 Million year-old Survivors

These are the fertile shoots of great horsetail Equisetum telmateia, photographed along the Long Walk at Howick on the Northumberland coast last weekend. Each one of those small polygon-shaped objects in the cone-shaped head releases hundreds of spores. You can see some micrographs of spores from a similar field horsetail here. Horsetails are the last living descendants of a group of plants that flourished back in the steamy Carboniferous swamps, 300 million years ago, when the coal measures were laid down. Carboniferous horsetails, classified in the genus Calamites, were essential similar to their living descendants but much larger, some reaching 10 metres in height. As soon as the fertile shoots of great horsetail have shed their spores they wither away, but by then the green vegetative shoots of this year's plants will have begun to elongate and will eventually form dense one metre-tall thickets of stems - minute compared with their extinct ancestors, but still impressive.

Genes on the Run

There were some fabulous patches of primroses in flower along the Northumbrian coast near Howick last weekend and amongst them were a few plants like the one below, with pink petals.

Plants like this are almost certainly the product of crosses between our native primroses and exotic cultivated species ..... perhaps between plants growing in the gardens at Howick Hall and their wild cousins on the grassy bank just above the strand line at Howick Haven, cross pollinated by a bee. Some people get very steamed-up about potential threats to our wild flora posed by occasional crosses with GM crops (not that we grow any of these in Britain yet) but there's no doubt that some cultivated, exotic plant species in gardens have been exchanging genes with some of  closely-related native wild flowers for a long time. The garden polyanthus is the product of hybridisation between primroses, cowslips and an unknown continental Primula species that contributed blue and red pigments to the mix, and when polyanthus is grown in the proximity of primroses and cowslips it exchanges genes with them. Exotic columbine (Aquilegia) species have a propensity to hybridise with our native wild columbines - now rare - so any Aquilegia vulgaris growing within bee-flight distance of a garden with cultivated Aquilegia species is potentially at risk of 'contamination'. Does it matter? I think not. I've been admiring the primroses between Cullernose point and Howick for thirty years now and there are no more pink-flowered primroses there now than when I first walked that path. They just add to the interest of this glorious coastal footpath.

Very Hungry Caterpillars

These two caterpillars crossed our path on Saturday when we were walking along the Northumberland coastal path from Craster to Howick. I'm pretty sure the 'woolly bear' above is a garden tiger moth larva and if so that's good news, because it's a species that has been declining during the long run of mild, wet winters over the last decade or so. I seem to remember reading that it's likely to be an early victim of climate change...

I'm not so sure about this one but I'm thinking it might be a drinker moth larva.....mainly because Abbey Meadows has something very similar on his blog. Can anyone out there help me out with this one?

Assuming I'm correct in my identification, both species overwinter as larvae and resume feeding in Spring, so right now they must be pretty hungry....

Insect Fuelling Station

Butterbur is in full flower all along the banks of the river Wear, where its creeping rhizomes thrive in silty soil left by winter floods. They're often buried to a considerable depth by silt after floods but the starch food reserves in the rhizomes provide the energy needed for early growth before the flowers and leaves force their way up into the light, in much the same way that colt'sfoot's rhizome food reserves allow it to tolerate burial. Butterbur is a plant that seems to be sensitive to winter climate because after very mild winters - of the kind we experienced for a decade before the most recent - it will often begin to produce leaves at the same time as flowers, but after severe winters, like the last, it reverts to its normal behaviour and delays producing any leaves until flowering is well underway. When they finally expand the leaves are spectacularly large, but before that happens the flowers are an excellent food source for insects in spring....

.... when bees visit for pollen and nectar....

.... and the nectar is an irresistible lure of newly-emerged peacock butterflies.

Butterbur exists as separate male and female plants, with their creeping rhizomes forming very large clonal, single gender patches. In some parts of England only male clones are present but here in the North East we have both sexes. The plants at the top of this post are males but the females (immediately above) are easy to spot because once they've been pollinated their stems elongate very rapidly and within a week or two they begin to produce large numbers of tiny plumed seeds. They do seem to expand their leaves more readily than the males, presumably because of the need to supply sugars to the developing seeds once the bees and butterflies have done their work.

Is Sallow Britain's only Native Bird-Pollinated Plant?

It’s been a slow spring in North East England and there still aren’t many flowers around, so the blooming of sallow catkins must provide a real lifeline for newly emerged pollen-eating insects like this hoverfly. Sallow – aka goat willow, aka pussy willow – is unusual in that it exists as separate male and female trees and pollen must be transferred between the two - which may be some distance apart - for seeds to be produced. Catkins of both sexes produce nectar, which is what attracts butterfly and bee pollinators, but it’s mainly pollen that most hoverflies are looking for; visiting and cross-pollinating female trees isn’t high on their agenda.

But blue tits are attracted by the nectar too and they visit trees of both sexes. Quentin Kay at Swansea University first noted this, back in 1985 (you can read his original research paper in Bird Study here) and it may be that goat willow is our only native bird-pollinated plant. Bird pollination is common in the tropics and sub-tropics, where hummingbirds have become nectar specialists, but it’s rare in cooler climates.

For more posts on tree ID click here

A Trawling Caddis fly, a Hot Climb and a Railway Revival

This is Philopotamus montanus, aka the dark-spotted sedge, a caddis fly that we found on this morning's walk along Shittlehope burn, that flows down from the moorland above Stanhope in Weardale to the river Wear in the valley bottom. Most caddis fly larva live in a tube that they construct from plant material or grit, but this beautiful little caddis has an even more remarkable life cycle. The larva spends its formative years below waterfalls, where it spins a silken net that resembles a trawl net, attached to a rock with the mouth facing upstream, filtering out food particles that the current delivers.

The adult, more or a flutterer than an accomplished flier, is beautifully camouflaged against the dead leaves that still persist along the edge of the burn at this time of year.

And here's the dark-spotted sedge's preferred habitat, one of the many small waterfalls that punctuate Shittlehope burn's route to the river. The burn has carved out a steep-sided gorge whose banks are currently dominated by wild garlic, but other elements of the flora here include primroses, violets and globe flower - although it's a few years now since I've seen the latter here; it's much less often seen in Weardale than it is in Teesdale, the next dale south from here.

This is the middle section of the burn, before it cascades downhill. By the time we reached here we were pretty breathless - I'd forgotten what it was like to be too hot when out walking and today's soaring temperatures had us labouring a little as we headed uphill, but it was worth it because we reached the high pastures just in time to see...

... the 10.45am from Wolsingham chuffing into Stanhope station.

After a bit of a financial struggle the Weardale Railway is running regular steam-hauled services at weekends and the sight and sound of a steam train puffing up the dale marks the welcome return of a branch of the rural rail network that many believed had vanished for ever...