Monday 20 April 2015

Green Hairstreaks & Holly Blue

Hemel (BMT): Just a few photos from today along the Bulbourne and at Roughdown Common

Lady's Smock or Cuckoo Flower (Cardamine pratensis), growing along the river,  Bulbourne Meadow & Harding's Moor

At Lower Roughdown, I was really pleased to find a couple of the rare Green Hairstreak (Callophrys rubi) butterflies. Purely by chance, I managed to photograph both of them. One had noticeable scuff marks across the underside of the right forewing.

Green Hairstreak (Callophrys rubi), specimen 1, Lower Roughdown



The second Green Hairstreak (Callophrys rubi), specimen 2 (scuff marks on right underwing), Lower Roughdown



Another lovely butterfly to see today was a female Holly Blue (Celastrina argiolus). I only saw one at Roughdown Common last year and, in 2013, only 2 were recorded on the butterfly survey. In the hours that I was on site today, it only settled once and briefly, so I had to be very quick to grab photographs!


There were at least 2 Willow Warblers, 4+ Chiffchaff & 3+ Blackcaps all singing close by. In the chalk bowel, there was a Willow Warbler and a Chiffchaff and both had very odd songs, as if trying to add a little of the other's song into their own. I didn't have the time to wait and record them, unfortunately - one for another day or someone else to investigate. There were a couple of Mistle Thrush pairs, one adult from each pair was busy collecting worms, presumably for young.

Sunday 19 April 2015

Nomansland Wood Warbler

Nomansland nr Wheathamsptead: I’m glad today’s Wood Warbler (Phylloscopus sibilatrix) sighting wasn’t the first time I’d seen or heard this species. It was a beauty but it was underwhelming in the “it stayed high up in the canopy, not singing, against a dazzling white, cloudy sky” kind of a way. But, the great thing about having experienced the species before is that you can superimpose previous joy and delight into the now. You can borrow from the past to enhance the present. And that’s what I did today. I remembered the first and only other time I’ve seen this species. It was in May 2012 at Frogmore Lakes in Hertfordshire, and it remains one of my top 10 birding moments, ever.

Wood Warbler, Frogmore Lakes, 27/05/2012. Throwing back his head in full song

Wood Warbler, Nomansland, 19/04/2015 (record shot)
It was a warm, sunny, blue-sky May day. Gathered under beech trees, bathed in dappled light, a group formed, completely captivated by a lemon-chested, white-bellied, singing male Wood Warbler. Although still back-lit and fast moving, he was lower in the trees than the bird at Nomansland. And, he was a singer. Boy, was he a singer...heart and soul and body. He was singing like his life depended on it and, in a way, I suppose it did. If you’ve never witnessed a Wood Warbler in full song, you’ve missed out. It is something to behold. He starts off slow and subdued, trills rolling out, and then the speed and volume increase until finally, head thrown back, the last notes are ballooned up into the canopy, far and wide, as his whole body shakes with the force of the crescendo. It is something incredibly pure, and wonderful to watch. I hope I get the opportunity again in the not too distant future and I’m very glad to have seen the shadow of it today.

Friday 17 April 2015

Distracted by a Shrew

Bovingdon Brickworks (BMT): I spent this morning at the Brickworks in pursuit of mining bees and Dotted Bee-flies (Bombylius discolor). I got slightly distracted by a freshly dead Common Shrew (Sorex araneus), lying on the path. There wasn't any sign of injury but, like the Common Toads from earlier in the month, the main defence mechanism of this little mammal is to secrete a foul tasting liquid from glands in the skin. Predators can quickly abandon them without tucking in.

Unless you have a license to trap and handle live mammals, it's rare you get to see these creatures up close. I wouldn't wish it dead but, since it was, I took the opportunity to check out and photograph its main features.

Common Shrew (Sorex araneus). Body = 70mm long (against my little finger), tail = 35mm (0.5 x length of body)

Pointed nose, small eyes and ears

Alternative view of the long, pointed nose & tiny eyes

Red-tipped teeth

Back feet (from above)

Back feet (from below)

Back foot (from the side)

Front feet
5 Facts About Common Shrews (Sorex araneus)
  1. They rarely live beyond 12 months
  2. They feed on insects but also eat earthworms and small slugs and snails
  3. They don't hibernate but during the winter they actually shrink to make survival easier
  4. Their main predators are Tawny Owls, Barn Owls and larger mammals
  5. During breeding, if the nest is disturbed or the mother wants to train the young, they form a "caravan". Each shrew grasps the base of the tail (or rump) of the one in front of it, forming a caravan of little shrews all running along behind the mother!
The Mammal Society have a great leaflet on Common Shrews HERE, if you'd like to know more.

As for the mining bees, there was plenty of activity but I'll need to sort out IDs etc before posting. No sign yet of the Common Whitethroats but a Willow Warbler was singing.

Thursday 16 April 2015

Serenaded by a Wheatear


Last Spring, I had a severe Meniere's flare up (degenerative inner ear condition) and was essentially confined to home or to within a 5 mile radius of home….for 3 months. I missed Spring migration! It's not surprising then that this year's sights and sounds are especially fresh and exhilarating. Every Wheatear is a bonus! And, when 23+ were reported on Ivinghoe Beacon on Wednesday, it seemed silly not to go and take a look. I didn't bother counting them. I just enjoyed them. I sat on the hillside, in the sunshine, and watched these pretty little travellers flitting and calling and even singing.

I'd never heard a Wheatear sing before. I'd heard the tongue-clicking "chack", which these guys also did but, in flight, and especially from a prominent perch on the hillside, one male in particular was singing.

The best, similar recording I can find on Xeno Canto is this one:


What made my day, though, was, as I sat in the warmth, that male (photographed above, in the messiest setting possible!), stood tall on his mound of earth, just a few metres from me, and sang his subsong. Quietly but determinedly as if he was unable to hold it in any longer. As he sang, he looked left and right and backwards and forwards, projecting the quiet, sure sound all around him. Having never seen or heard it before, it was pretty special.

A similar subsong recording from Xeno Canto


You can never see too many Wheatears!

Tuesday 14 April 2015

Firecrests


Wendover Woods: This morning, just beyond The Hale avenue, this little Firecrest (Regulus ignicapillus) briefly came down from the tree tops and into the sun. S/he was there but a split second. I fired off a burst of shots and the moment was gone. Magical.

I dread to think how many hours I’ve spent standing under trees in Wendover Woods, listening to the ringing of Firecrests, waiting for them to pop out or to come a little lower. Photographing them requires the patience of a saint or an endless reserve of energy, neither of which I have, and today’s one shot is definitely my best in the 4 years I’ve been trying.

I spent about an hour quietly and carefully listening to the woodland today. The trees really were alive with Firecrests. I saw at least 6 different birds and heard more. They aren’t easy though and every Spring I have to reacquaint myself with their song before heading to Wendover.

Sunday 12 April 2015

The Birds & The Bees

At this time of year especially, you'd be forgiven for wondering what a title like that might allude to! Nothing explicit here, I promise, just a brief mention of a few pretty birds around Tring reservoirs last week, and then a switch to the dark and divisive world of mining bees. These tough little loners aren’t afraid to dive into combat, writhing around in the dirt, bodies discarded left, right and centre. It’s worse than a "Die Hard" feature! But, more on that to come...

First up, a pair of Mandarins on Wilstone reservoir on Friday, on choppy waters.



A pair of Garganey were also around and I spotted my first Common Tern & first House Martin of the year - a single bird of each flying amongst the Black-headed Gulls over the barley bales.

But, it was earlier in the week, along the footpath of the NW shoreline of Tringford reservoir, that there had been this mass emergence and frantic, aggressive mating event of mining bees, worthy of an 18 Certificate. I’ve not been able to narrow down the ID from the broad classification of an Andrena species. With at least 60 to choose from in the UK, it's not straightforward, although there are a handful of likely candidates. (Note: see update at end of post, on 13/4/2015 - species very probably Yellow-legged Mining Bee (Andrena flavipes)).

In spite of coming across a good 200+ busy bees all zooming about the sandy pathway together, these guys live solitary lives. Females can and will share entrance holes to nest burrows but that's as sociable as they get. The female digs her own chamber underground and, after mating (if she survives!), she’ll deposit each egg in a sealed cell with pollen and nectar.

Entrance hole (approx 7mm diameter) and a bee using an alternative route!

The bees were approx 12mm long. There were subtle but distinct differences between the sexes. The males (I presume) were a little more slender and lacked the dense, rich orange scopal hairs on the hind legs.

Male on top of female
Female (left) & Male (right): note the female's rich, darker orange scopal hairs on hind legs

I took some video footage with my macro lens (my first attempt - bigger depth of field needed next time). The opening scene appears fairly innocuous: bees buzzing around the path where there were 100s of tiny entrance holes to chambers underground, often just 5cm apart. Getting a little closer to the action, I filmed one hole and it revealed a number of males going in and then backing out, presumably looking for a female. However, getting intimate, the behaviour I most wanted to capture was the aggressive, mass mating attempts (I assume, although, the violence and mortality rate looked decidedly counterproductive!). Females were mobbed by numerous males, all seemingly trying to mate with her. Bee bodies were strewn along the path, listless or lifeless, both male and female causalities. In fact, I managed to photograph a male apparently feeding on or killing another bee with his tongue (see, I told you it was worse than "Die Hard"!). I can't quite discern whether it's another male or the female he is attacking (there are 3 bees involved)?! Either way, the female ended up dead/dying.

A male with his proboscis (tongue) in another bee's thorax!
Dead/dying female

Back to the video footage. As you watch the ball of bees rolling around on the ground, picking up dirt and horse hairs, it’s possible to spot the single female in amongst them. She has the rich, darker orange scopal hairs on the hind legs. I slowed down a sequence of footage which shows her seemingly trying to escape the clutches of the males, only to be pulled back into the ball (I removed the audio as it was mostly road noise).


I would love to know what species of mining bee this is and to get a better idea of what on earth was going on in this gladiatorial mating frenzy. Comments/mails welcome.

A little shy - A preening Greylag Goose by Marsworth reservoir last week

Update 13/4/2015: I've been following a mining bee sighting on ISPOT which looked identical to the bees at Tringford. The identification given there is for a Yellow-legged Mining Bee (Andrena flavipes). After doing a little research, I'm satisfied this is probably the correct ID for these bees. There's a nice fact sheet on them HERE. "The males look different to the females. They are slimmer, covered in sparser hair and lack the dense brush of orange-yellow hairs on the hind leg" & their length ranges from 10-13cm. Both these facts, as well as appearance, fit exactly with my observations. They are common in southern England, will collect pollen from a wide range of plants and flowers, flying from March to May and again from June to early August.

Friday 10 April 2015

The Embrace of Common Toads

Hemel (BMT): I spent Monday morning with a crowd of frisky Toads. That’s not a euphemism for the sort of people I hang out with, I do mean the amphibians, warts and all. Bank Holiday Monday dawned bright and still. However, I wasn’t going to be fooled and frozen and had put on woolly jumper, hat and gloves. Needless to say, with temperatures reaching above 13 deg C, all 3 were eventually discarded. The warmth of Spring has finally arrived. Thank goodness.

Sunday evening I’d learned that Common Frogs (Rana temporaria) and Common Toads (Bufo bufo) had spawned on Trust land (many thanks to the keen observer). I don’t remember ever having seen Toad strings so their presence was too interesting a sight to resist. In fact, not only were there Toad strings, there were Toads and they were still locked in the mating embrace, amplexus, and spawning.


Much of the time, the pairs remained under water but it was still possible to see the string of double-stranded eggs emerging from the rear of the female (the string can also be triple-stranded, whilst single-stranded egg strings would indicate the far more rare Natterjack Toad (Epidalea calamita)). The male on her back releases sperm cells to fertilise the eggs as they are laid.





The whole process was extremely slow. I spent over 2.5 hours watching them and 1 pair produced perhaps 30cm of eggs. The female steered proceedings, at one point climbing up, through, onto and over vegetation and slowly, slowly going back into the water, her trail of spawn behind her. Somehow, she manages to manoeuvre herself and the male, so as to tie the spawn to vegetation. Very clever indeed.





Toad strings can contain between 400-5000 eggs and be between 3 and 4.5 metres long. One of the Toad pairs on site had opted to spawn where there wasn’t any vegetation to attach the strings to. As a consequence, the pair were hidden and wriggling inside a large ball of eggs approx 20cm in diameter. I’m not sure how long that will last before perhaps a Fox gobbles it up.

Speaking of predators, I did wonder if maybe one of the female Toads had survived an attack of some sort. She had a very badly damaged right back foot. Unlike Common Frogs, Common Toads posses a fairly potent defence mechanism. When under threat, they secrete a foul tasting toxin, bufagin, from glands in the skin. Unfortunately, this doesn’t seem to dissuade species like Grey Herons, Mink, Rats and Hedgehogs from guzzling them.

The female's badly damaged right back foot

The male's right back foot for comparison

Making their way over the reeds

Common Toads are nocturnal, solitary creatures, coming together only for the short breeding period, following hibernation. Adults return annually to the same breeding ground. And, research suggests that those adults will also have been spawned at that site and their spawn too will return there to breed. Their diet consists mainly of invertebrates caught with their sticky tongue using a “sit and wait” or “whilst I’m passing” strategy. Basically, they are opportunistic feeders, responding to movement.

Until this week, I knew next to nothing about Common Toads and it was interesting to discover that they are 1 of only 6 (or 7, depending on your view on re-introductions) native UK amphibians. It’s a small and select group made up of 1 or probably 2 species of Frog; 2 species of Toad and 3 species of Newt:

NewtsToadsFrogs
Great Crested Newt (Triturus cristatus)Common Toad (Bufo bufo)Common Frog (Rana temporaria)
Smooth Newt (Lissotriton vulgaris)Natterjack Toad (Epidalea calamita)*Pool Frog (Pelophylax lessonae) 
Palmate Newt (Lissotriton helveticus)

* Evidence suggests that there was/is a native species of British Pool Frog, which was re-introduced within the last decade, into East Anglia. There are, of course, a few non-native amphibian species around too but I won’t list those here.

So, within the first week of April, we’ve had both Common Frogs and Common Toads spawning. Having watched 4 pairs all still releasing and fertilising eggs, it should be possible to follow their progress quite accurately. Tadpoles should hatch within about 10-14 days from laying. It’ll take a further 8-12 weeks for the toadlets to fully develop, leaving the water en mass. And, it’ll be 4 years before these youngsters reach sexual maturity, ready to return here to spawn themselves. The cycle of life continues.

Monday 6 April 2015

Scarce & Secretive: GARGANEY!

Stills taken from video footage, showing male and female Garganey at Long Crendon

Long Crendon: The RSPB describe the ever-so-attractive little dabbling Garganey duck as “scarce and very secretive”….Shhh.... I say those rich, chocolatey tones with vanilla accents make me think of Viennetta ice-cream or Tiramisu. No? Just me then. Ok, anyway, the species is strictly migratory, spending the harsh winter months far, far, far away in southern Africa, India and Australasia. But, now is the time of their return to UK breeding territory in central and southern England. Just 14-93 pairs will breed here, according to the RSPB. By my reckoning that makes this Easter’s sighting of 3 males and 1 female, at Long Crendon, west of Aylesbury, pretty special.

The birds were first spotted on the 4th and I didn’t hold out much hope that they’d still be there on Easter Day. By 14:15 on Sunday, I couldn’t resist any longer. I jumped in the car and thought I’d give it a go. I was fully prepared to arrive to an empty pond or, if I was lucky, a pair of Mallards.

As I parked up, the skies darkened and started to spit rain at me. Pah! It was going to take more than that, especially when I discovered that the fantastic little birds were still there. The rain eventually cleared away although the thick, dark clouds weren’t quite so forgiving. I watched the energetic ducks paddling fast, twisting this way and that, picking off insects that had landed on the surface of the water and occasionally even displaying. They would produce strange crackles, clicks and whistles. The males would create this quick display motion where they’d put their heads behind their wing and fan it out, whilst still paddling forward. It was over in a flash. There was also a lot of head waggling, neck stretching and shaking of tail feathers. All in all, a sight to brighten any dull Spring day.

I took some video footage although light levels, rain and distance were against me. It’s not great but it’s a record of this “scarce and very secretive” (shh..) migrant.


At 15:30, the stillness was shattered by the crack of gun fire just 100 metres from the pond. “Shhh...” wasn’t going to cut it. The steely Mallards didn’t flinch but the rather more sensitive Garganey, accustomed to the quiet marshes of Norfolk and Suffolk, were up and out of there. They flew as if to return to the water only to be scared off by further shots. That was it. They flew east, likely along the river, and I lost them.

Hoping that the birds might yet decide to come back, I stayed in the area. South of the pond there were numerous Red Kites, circling high and in flocks. I counted at least 19 and, with them, 5+ Common Buzzards. By 15:50 the Garganey hadn’t come back, the shooting party was still going strong and I called it a day. Those were the best views I’ve had of Garganey and were well worth the drive, the rain and the gun fire.

Thursday 2 April 2015

A Stonechat Calls & A Greenshank Hops

Pitstone Hill & College Lake: It’s got to be at least 2 weeks since I posted any ropey video footage. You’re in for a real treat this Easter with not just one, not even two but three gloriously average (some might even say poor) short film clips. At least the sun was shining and the rippling images induced by strong gusts of wind weren’t too frequent.

First up is the pair of Stonechats (Saxicola rubicola) on Pitstone Hill. I half expected them to have gone by today so it was a lovely surprise to find them still fluttering and calling. The first film is a montage of clips featuring both birds and, in particular, the male and a few of his calls. The second film (which is also included in the first) is a very short clip of just the male perched and calling, producing his stones-being-bashed-together noise. The sound quality leaves a lot to be desired but is hopefully good enough.



Next up, I’ve saved the best (oh, ok, I mean worst) till last. Leave them wanting more (and better?!)! Having watched a flock of about 15 brilliant Yellowhammers fly up from the crop field and land in a tree, I bumped into Lee. We exchanged bird news and he let me know there was a Greenshank (Tringa nebularia) over at College Lake.

Comfortably settled in at the Octagon hide, I found what I thought was the Greenshank. I’d expected it to be moving and feeding and thus easy to spot, and had stupidly left the scope behind. Anyway, I whiled away a very pleasant hour with a family who was also there enjoying the birds. Between us we decided the wader next to the “dead male Shoveler” (which turned out not to be dead) was indeed the Greenshank. It spent most of its time roosting but did occasionally rouse itself to preen and hop about on one leg. In fact, I never saw its second leg in the whole hour I was there. If ever it wanted to move, it hopped. And, at one stage, it even seemed to be making a half hearted attempt at feeding on one leg, hopping in the water and simultaneously scanning the shallows for food. At approx 65 metres distance the footage is pretty awful but I think you can just about tell it's a Greenshank. I’ve removed the audio because it was principally bird-hide-banter about Coots killing each other (aka mating), male Shovelers rising from the dead (mmm... a bird-themed Easter message perhaps!?!) and the mouth-watering prospect of homemade hot cross buns. That reminds me, I must get to M&S for my annual indulgence of toffee fudge & belgian chocolate hot cross buns. Golly, I hope they still sell them!


Happy Easter!