Category: Biology

Having bumped into friends while owl spotting in the fens, we pointed out a male Little Owl on a woodpile at Priory Farm near Burwell. After our friends had moved on, however, Mrs Sciencebase spotted a second owl (a female). The female is in the darker photo, on the higher perch (a bigger bird than the male as is usual with owls and raptors).

We didn’t see any Short-eared Owls on NT Burwell Fen nor Tubney Fen today, unfortunately, although one or two have been seen this winter there hunting in the early afternoon as opposed to the more likely hour or two before sunset.

There are it seems half a dozen Shorties hunting at Great Fen in Huntingdonshire. Interestingly, there are theories about the lack of Shorties when that happens. One suggests that the birds only head south from Scandinavia if the lemming populations up there are low. However, the half a dozen in Huntingdonshire suggests that more likely is that the presence of the Konik ponies on Burwell Fen over the summer has left the scrub grazed too heavily giving the owls no choice but to find an area with longer scrub in which to roost. Add to that the lack of hunting Kestrels there recently which suggests that the vole population has pulled back its breeding to reduce predation this summer, something that prey species are known to do as it then temporarily reduces breeding success of the predators giving the prey species a better chance in the next season. This seems to happen on a three-year cycle.

We headed back to NT Wicken Fen visitor centre having been tipped off to a sunset roost of Hen Harriers (a couple of proper birders confirmed that some of the harriers we were watching were three male Hen Harriers quite a significant time before sunset, there were also several Marsh Harriers, and a couple of Barn Owls hunting over the reeds.

UPDATE: Thursday, 7th Jan 2020, on a walk, we inadvertently flushed a Short-eared Owl from its scrubby roost in the nature reserve behind a research park north of Cambridge. It flew into an adjacent field to watch us for a few minutes before taking flight.

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.

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.

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.

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.

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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.

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…

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.

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

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]

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.

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.