BIRD REPORT 13 – Glossing over any egrets

BIRD REPORT 13 – Glossing over any egrets

This post is an online version of my latest nature column, which I volunteered to write regularly for our bimonthly, printed village newsletter. the Xmas issue has an article about local starling murmurations, report 13 is for the next issue.

In the last Bird Report, I mentioned sightings around our local patch of some quite unusual birds, birds that are normally associated with sub-Saharan Africa, or at least the much warmer parts of Europe. There were two glossy ibis at RSPB Ouse Fen in November. Subsequently, there were sightings of more at RSPB Fen Drayton and close to Earith Sluice. It is likely there are about seven not too far from us.

I also mentioned Cattle Egrets in the last issue of which there were five or so on farmland on the edge of Fen Drayton and sometimes some seen in the nearby RSPB reserve roosting alongside the cormorants beneath skies filled with the shadowy forms of the starling murmurations. Now, many readers will know the little egret, the grey heron and perhaps the bittern, but the cattle egret is a less well-known member of the family.

3x Glossy Ibis at Earith Sluice

When I moved to Cambridge a little over thirty years ago, it seemed rare to spot a little egret, although grey herons definitely frequented the banks of The Cam not far from where I lived. Seeing a little egret on the Norfolk coast was an occasional treat, but now their numbers are up greatly, it seems. I’ve counted 30 or so at a time in fields at the edge of the Fen Drayton reserve. Also on the rise are great white egret numbers. They seemed to be a true rarity until very recently, now even the most novice birder will have “ticked” them several times on local reserves and I’ve seen them on several occasions feeding on the Cottenham Lode alongside grey heron and little egret. Those cattle egrets too, once a very rare sight, are seen more and more, with handfuls, trailing after any cattle they can find in our locale. On the Somerset Levels they are now reported in their hundreds.

bittern wmk 768px 1
Bittern

Climate change is no doubt playing a part in allowing these species to spread farther and farther north into the British Isles from their erstwhile homes in sub-Saharan Africa, to North Africa, The Mediterranean and beyond. The glossy ibis is found scattered around the warm regions of Europe, Asia, Africa, Australia, and the Caribbean, for instance, but birds that are breeding in southern Spain seem to opt to spend the winter in The British Isles over the last decade or so. But there seems to be another force driving these egrets and other wading birds. The non-native and very edible red swamp crayfish has in recent years thrived in the lakes of northern France, for instance.

Cattle Egret

I say edible, this delicacy known stateside as the Louisiana crawfish or crawdaddy, is a native to northern Mexico and the southern USA, but has been introduced to Asia and Europe and has established itself invasively in southern Europe and more recently spread to those French lakes. This has apparently given the birds that enjoy a few crawdad themselves a stronger foothold further north. It was perhaps inevitable that those species would find ways to extend their range and feed on the native aquatic species found in our coastal, brackish, and inland water, especially the species with a migratory tendency. If the red swamp crayfish gains a clawhold in those waters, it will be bad news for some of our native species, such as the European crayfish, but good news for the feathered fishers.

Great White Egret

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Spottin’em in Cottenham: Recent sightings

Some interesting recent activity in and around Cottenham. One cold and foggy November night, wigeon were reported flying over the High Street and a Sunday morning soon after saw a couple of Egyptian geese over Broad Lane, a first sighting for one reader of that non-indigenous, but widespread, bird in Cottenham.

There have been a couple of waders, green sandpipers, specifically, sighted along Long Drove, they’re not uncommon in the fens, but always nice to see. Also, at the time of writing, around 60 whooper swans were on farmland at the Twentypence Marina end of the Cottenham Lode where it drains into the River Great Ouse, sometimes known as the Old Bedford River.

Also, way off its normal patch, a dusky warbler has been seen in Aldreth at the part of the village known as The Boot. A white stork (possibly an escapee from a collection) has been seen in Somersham.

heron 2 e1507734037246
Grey Heron

 

Glossy Ibis in Cambridgeshire

I’ve mentioned local sightings of an ostensibly African/Mediterranean bird before, the Glossy Ibis, they have been spotted at various RSPB sites Ouse Fen, Fen Drayton, Ouse Washes, and elsewhere in the last month or so. I saw a couple of them at Ouse Fen not long after one was first sighted by the warden and others there. There is evidence of perhaps five or maybe seven locally. It is worth noting that over the last decade or so, some of these birds which have begun breeding in Southern Spain have opted to spend their winters in The British Isles.

Three have now taken to feeding on the southern end of the Ouse Washes.

Oh, and there’s a bird that’s usually found in Asia in our locale too, a Dusky Warbler, Phylloscopus fuscatus, seen for the first time in Cambridgeshire in December 2020 at “The Boot” in Aldreth. I took a detour on the way home from snapping the three Glossy Ibis  to see it, there were lots of twitchers, birders, and toggers around, but none had seen it at the time and I didn’t catch sight of it either…

The brand new moths of 2020

I have counted well over 300 species of moth in our garden this year(almost 9000 specimens), mostly at night, although there were one or two dayflyers (excluding butterflies, which are moths but are not usually listed as such). That is a small fraction of the total number of moth species listed in the British Isles which tallies at 2500 or thereabouts, 180,000 species of lepidoptera globally.

Of those 300 or so species about 30 were new to me having not ticked them in the garden before. Here’s a small selection starting with the rarest, the Clifden Nonpareil, a moth that was extinct in The British Isles by the middle of the twentieth century but is making a comeback.

Clifden Nonpareil
Clifden Nonpareil
Figure of Eighty
Figure of Eighty
Gypsy Moth
Gypsy Moth
Pine Hawk-moth
Pine Hawk-moth

 

Dark Crimson Underwing
Dark Crimson Underwing
The Lackey
The Lackey
Scarce Bordered Straw
Scarce Bordered Straw

The WormwoodThe Wormwood

The Knot Grass
The Knot Grass
Varied Coronet
Varied Coronet
Clouded Brindle
Clouded Brindle

Siberian White-fronted Geese

Migratory geese in huge numbers arrive on our coasts in the winter heading in from Greenland, Iceland, Scandinavia, and even Russia. Some of them end up further inland as did this small flock of White-fronted Geese, Anser albifrons (Russian sub-species), which I photographed on farmland adjacent to RSPB Ouse Fen in Cambridgeshire. Friend Steve Rutt, author of Wintering, tells me that there has been an influx of the Russian race of this species.

The bird is bigger than a mallard duck but smaller than a mute swan. The head of the adults has a large white patch. They also have bold black belly bars and orange legs. The Siberian sun-species, pictured here, has a pink bill whereas the bill is orange in the Greenland bird. We have something like 13000 of these geese that winter from Greenland in the British Isles, the Siberian race is less common.

I got a couple of snaps of the birds on the ground from several hundred metres away before the farmer’s cropsprayer spooked them and they took to the air and headed west towards the river that divides this reserve.

The RSPB warden who gave me the ID on the geese also said a Brent Goose had been seen on the reserve and a couple of Whooper Swans. He added that there are at least five Glossy Ibis in the area. Regular readers will know I saw a couple of those rare African visitors at Ouse Fen a couple of weeks ago. There are three on Swavesey Lake. See also Cattle Egret and Great White Egret for birds ostensibly of African origin that are increasinly common in The Fens.

Egrets, I’ve seen a few – Cattle Egret

Back in the early 1990s, Mrs Sciencebase and I visited Botswana and Zimbabwe. It was wonderful. The people, the landscapes, the wildlife. There were so many superb species around such as Golden Weaver Birds, Oxpeckers, Superb Starlings, various storks, ibis, vultures, Fish Eagles, Eagle Owl, and Little Egrets (probably Cattle Egrets too).

We were quite confused on our return on a visit to the North Norfolk coast (a place that would become a favourite haunt) that we saw a Little Egret there. Over the next three decades or so little egrets seem to have become increasingly common in East Anglia and although it’s still lovely to see them, they’re almost commonplace. Five years ago the same couldn’t be said of another type of egret. The Great White Egret, but that too is becoming more common. Similarly, Cattle Egret (Bubulcus ibis).

Is it simply an effect of climate change? These ostensibly African birds spreading their wings and thus their range and reaching farther north with each passing year? Well, climate change is definitely playing a role in species distribution when it comes to birds and many other forms of life. But, it’s more subtle than that. Deliberately or inadvertent introduction of the Red Swamp Crayfish (Procambarus clarkii) in freshwater lakes across Europe is providing egrets of all flavours as well as cormorants and other species with a ready, but unaccustomed food source and this is allowing them to expand their numbers and their range. (Barbaresi and Gherardi 2000, Rodríguez et al. 2005)

The presence of the introduced North American crayfish, often known as the freshwater lobster, in the lakes of Northern France now means those egrets that were so rare this far north have but a short hop across the channel and upwards into East Anglia where they will find food and a foothold in small numbers.

It is perhaps only a matter of time before the red swamp crayfish becomes widespread in the freshwater lakes of The British Isles too and those egret numbers will rise still further.

We saw five Cattle Egrets in Fen Drayton this morning, feeding in between the hooves of a herd of cattle. Last winter we saw a flock of some 60 or so Little Egrets in the reserve that abuts the village and I have seen half a dozen Great White Egrets there (alongside lots of Little Egrets and lots of Grey Herons).

It’s possibly the same phenomenon leading to more frequent sightings of Glossy Ibis in East Anglia lately too.

Local birds for local people

Sunday morning was bright, cold, a few streaky clouds in the sky, but sun shining through. We were not quite up with the lark, but we got booted up and headed out for a brisk walk at one of our local patches where we often see Kingfishers and various other bird species. River Great Ouse running through farmland and along the bank top of one of the lodes that drain the fens, once around a fishing pond. Was expecting to see maybe a dozen bird species, but we counted all of these and maybe a couple more for which we didn’t get a positive identification, little brown jobs (LBJs), in other words.

Blackbird
Blackheaded Gull
Blue Tit
Bullfinch
Buzzard
Chaffinch
Collared Dove
Coot
Cormorant
Dunnock
Fieldfare
Goldfinch
Great Spotted Woodpecker
Great Tit
Grey Heron
Grey Wagtail
Kestrel
Kingfisher
Linnet
Little Grebe
Mallard
Mute Swan
Pied Wagtail
Redwing
Reed Bunting
Robin
Rook
Song Thrush
Whooper Swan
Wood Pigeon
Wren

2020-11-23 UPDATE: Today’s outing was to the village of Fen Drayton to see the five Cattle Egrets that have settled there temporarily. We saw those birds and quite a few more besides, venturing only a little way into the RSPB bird reserve that is adjacent to the village. Today’s list:

Cattle Egret, Blackbird, Blackheaded Gull, Blue Tit, Chaffinch, Collared Dove, Coot Cormorant, Dunnock, Gadwall, Goldfinch Green Woodpecker, Kestrel, Mallard, Mute Swan, Pied Wagtail, Pochard, Red Kite, Redwing, Robin, Rook, Tufted Duck, Wigeon, Wood Pigeon

Local starling murmurations

Back in September, the number of starlings on farmland around the village seemed to build. It seemed early for the European winter influx, maybe it was just wishful thinking. I was hoping for large numbers that would begin to murmurate over the Broad Lane balancing pond before diving into their nocturnal roost in the reed bed there. (This particular video of mine was from November 2018)

Other concerns took over my thought processes, as they are, in October and early November, and I’d all but forgotten about the starlings by the time the local birders started pinging me about rising numbers 30 to 20 minutes before sunset over the pond. When I finally got the opportunity to check out the swooping and swirling of these maestros of social distancing, the murmurations were occurring most evenings and the numbers, I and birding friend Neil (watching at two-metres distance) estimated there were about 6000 there. Quite an amazing sight and the whooshing as they soar close overhead before diving into the reeds is astonishing. The next evening, the numbers had grown, perhaps to around 7000.

That was the peak for Cottenham’s murmuration. Over subsequent nights and having shared video on social media and mentioned to a few friends, the numbers began to decline as the number of observers rose. At the human peak, I think there were about 20 people, adults and children and a few pet dogs, waiting patiently for Dave’s Spectacular. It hadn’t happened in Cottenham again as far as I know. Another friend, Liz, reported that their daughter suggested 12 starlings wasn’t quite what you’d expect from Sir David…

Meanwhile, the Cottenham birder list alerted me to a large number at RSPB Fen Drayton, some 7000 birds were murmurating there over Elney Lake. It could easily be the same flock that apparently had departed Cottenham. There was also a peregrine falcon there hunting through the flock. Indeed, murmurating is flocking behaviour to reduce the risk to the individual bird being predated by such raptors ahead of bedding down for the night. I got a little distant video footage of those birds.

Also to be seen at Fen Drayton, four cattle egrets, birds that until recently were rarely seen in the British Isles, but whose numbers like those of the Little Egret and Great White Egret, ostensibly “foreign” birds have been growing over the last couple of decades. Climate change may well be playing a part in how such species are extending their range.

The story doesn’t end there. We visited RSPB Ouse Fen (Reedbed Trail side, accesses from the car park at the Over edge) one morning in mid-November. The RSPB warden – Hannah Bernie – was still there with her team hacking back reeds with a view to increasing plant, and thence animal, diversity on the reserve. She told us that they had spotted another rare visitor, a glossy ibis. The bird had been spotted at Fen Drayton a couple of nights before, but had flown, and this was presumably the same bed making Ouse Fen its temporary home. One birder I spoke to on the day I saw the GI told me he’d seen five or six on the reserve during the last decade or so.

The warden also mentioned in passing that they had a large starling murmuration of about 10000 birds. I felt obliged to return that evening to witness the spectacle. That night I would estimate that there were at least twice as many birds as there had been at Cottenham’s peak, so perhaps 14000.

Of course, such numbers are minuscule compared to other murmurations such as the knot (a wader, or shorebird) that one sees at this time of year, hopping the tide at RSPB Snettisham in North Norfolk. We saw 68000 of those birds there in September and the numbers had doubled by late October. And those numbers are dwarfed by the multi-million strong murmurations one might see in the original sub-Saharan homes of some of those “foreign” birds I mentioned. Where vast, entrancing murmurations swoop and swirl above the cattle egrets pecking at the feet of herds of majestic wildebeest. Still, we must enjoy the nature to which we have relatively easy access, especially in times of covid.

Sir David Attenbradley

Please send unusual bird and nature sightings to [email protected]

Glossy Ibis – Plegadis falcinellus

UPDATE: As of 2020-12-08 there have been sightings of about seven Glossy Ibis around the area at RSPB Fen Drayton, Ouse Fen, Ouse Washes, at Earith Sluice, and elsewhere. This is almost an irruption!

You don’t expect to turn up at a Cambridgeshire wildlife reserve to be told by the warden (Hannah Bernie) that there’s an African bird species hanging around. But, in early November, that’s what we heard at RSPB Ouse Fen. Actually, I’d heard that this species was at RSPB Fen Drayton, but I’m not a real twitcher so hadn’t gone out of my way to see it there. We were actually there on a fairly calm day to see if we could sight the Bearded Reedlings.

Bearded Reedling
Bearded Reedling

Warden Hannah told us there was a Glossy Ibis, Plegadis falcinellus, present and it had been seen but it was lurking behind the reeds at the time. She also mentioned a 10000-starling murmuration the night before. I visited the same sight later that day and reckon there are 14000 starlings murmurating there.

Anyway, back to the GI, we didn’t see it and we only heard Beardies. So I headed back again today, I usually visit once a week. Parked up and within 200m of the car, there it was, on the edge of the reeds. Apparently, a birder had predicted one might turn up, the RSPB having cleared a lot of old reeds from these former gravel pits. I got a few record shots, nothing clear nor sharp.

Fellow walker – name of Richard – with a birding ‘scope, stopped 2-3 metres away from me as I was snapping the bird on my return pass. He mentioned that they are not as rare as one might imagine in the British Isles these days. He said he’d seen them five or six times over a decade of visiting this reserve. Given that other African birds – Little, Great White, and Cattle Egret are also rising in numbers here we mused on how even the most casual birders are no longer as impressed as they once were at the sight of such species. Indeed, the presence of a Whinchat or a Pied Flycatcher might be more exciting than any Egret or even the GI, amazingly.

Climate change will definitely be driving the northwards flights of these birds which originate in sub-Saharan Africa but are spreading their range. But, Richard also mentioned that the accidental introduction of Red Swamp Crayfish (Procambarus clarkii) to lakes in northern France had provided a lot of food for such species and they are thus much further north partly because of that. It is only a matter of time, perhaps, before that invasive crustacean finds a niche in the former gravel pits of East Anglia and we begin to see even greater numbers of these African birds settling in this part of the world.

First time I saw a wild Glossy Ibis was in Botswana in the early 1990s, if memory serves. Most recent sighting was on the edge of a former gravel pit in a windswept patch of South Cambridgeshire.

Noc Mig Redux

Months ago, at the beginning of lockdown 1.0 I think I mentioned nocmigging. It’s the nocturnal audio recording and analysis of overnight sounds that might include the calls of migrant birds flying overhead. In April, I set up a microphone and recording software and poked it out of my office window and left it running overnight. In the morning I checked to see what had recorded and sadly it seemed at the time that the software had failed and all I had was the first 20 minutes from when I set things running.

NocMig recording in Audacity Spectrogram view showing the rise of the dawn chorus, 2020-04-07

I had tried a few more times and had managed to record the dawn chorus once or twice, but I didn’t think I had captured a long period of nocturnal noises until I was scanning my hard drive with the aim of deleting unwanted large files to clear some space. I found a 6h45m 4.5 gigabyte audio file. Exciting stuff.

So, now processing with Audacity in spectrogram view with the aim of feeding the output into the nocmig software. Here’s how to configure audacity for a nocmig recording.

Turns out there’s very little to hear other than occasional motorbikes and cars, at least until the first Blackbird of the dawn chorus, followed by Robins, Dunnocks, Wrens, and Wood Pigeons. Nothing was apparent and high-pitched in the spectrogram during the preceding hours. And, an audio scan didn’t even give me muntjac, foxes, nor even cats in the night, possibly one very distant dog barking. It was all very quiet, sadly. Still, there’s always next year.

Catocala Underwings

UPDATE: Greece, June 2024 – Added Catocala nymphaea to my list of photographed Erebid “underwings”.

Catocala nymphaea moth with its orange and black marked hindwings

UPDATE: New Forest, 25 Aug 2022 – I finally trapped the Light Crimson Underwing (Catocala promissa) at our holiday house in North Poulner, Hampshire, which completes the British set for me, I believe. There’s a short video clip of the LCUW on the Sciencebase Instagram, with Going to the Chapel as the background music for good reason.* In the summer of 2023, Adrian Matthews caught an LCUW in Chesterton, a first for Cambs.

Light Crimson Underwing, Catocala promissa
Light Crimson Underwing, Catocala promissa

The Catocala moths are a group of relatively large moths in the family Erebidae. They are often known as “underwing moths” because of the intriguing colours and patterns of their hindwings, which are usually hidden from view under the forewings while the moths are at rest and only revealed either in flight or when the insect is startled.

Clifden Nonpareil
Clifden Nonpareil, Catocala fraxini, the Blue Underwing

Not to be confused with dozens of others species in the Noctuidae that have the word underwing as part of their common name (e.g. Yellow Underwing, Straw Underwing, etc) and Geometridae (Orange Underwing).

Clifden Nonpareil, Catocala fraxini, the Blue Underwing
Clifden Nonpareil, Catocala fraxini, the Blue Underwing

These large Catocala underwings are not common in The British Isles and where they are known are often localised to particular niches. In my time mothing since late July 2018, I have trapped, photographed and released three of the group: Red Underwing, Dark Crimson Underwing, and the (once extinct here) Clifden Nonpareil (the Blue Underwing). Actually, I had the Red in the garden in 2019 and then saw it a few days later on a camping trip to the eastern coast of Norfolk.

Red Underwing, Catocala nupta
Red Underwing, Catocala nupta

I am yet to see the Oak Yellow Underwing, the Rosy Underwing, the Minsmere Red Underwing, or the French Red Underwing. There are 30 Catocala species in Europe and 250 globally.

Red Underwing, Catocala nupta
Red Underwing, Catocala nupta, wings hidden
Dark Crimson Underwing, Catocala sponsa
Dark Crimson Underwing, Catocala sponsa
Dark Crimson Underwing, Catocala sponsa
Dark Crimson Underwing, Catocala sponsa, camouflaged on mottled bark

*Interesting to note that they all have scientific names alluding to nuptials and wedding nights. The naturalists who named them, whimsically imagining that the brightly coloured hindwings were like a bride’s brightly coloured bloomers! So we have C. sponsa, C. nuptia, and C. promissa. The Clifden Nonpareil is the exception, its scientific name, C. fraxini, alluding to the ash tree, wholly inappropriately as its food plant is the aspen.

More moths, birds, and other nature shots via the Sciencebase Instagram, please join me there.