It’s all about the numbers.

Gus Ariss drew my attention last week to a Tweet by Mark Clarke who had seen 37 Red Kites near Shipston and who wondered what was going on? I wondered too. The next day I was followed  on Twitter by Keith Jennings whose account had numerous references to a winter roost in north Gloucestershire. I had forgotten about winter roosts and the pieces now fell in to place. Had we an established winter roost in the south of the county? Or had the Gloucestershire roost recently moved north? Gus and I determined to take a look at the end of the week.

We met at Honington at midday. I periodically check that area, with Firecrest and Hawfinch in mind and having drawn a blank on my first post-invasion visit had finally found one of the latter on 11/01. Third time was lucky and I saw 14 on 23/01 when it became apparent they were feeding in Yews in the gardens which run along the western flank of the road to the church. The advantage to the number of birds present is that they are very active and vocal, presenting an excellent opportunity to commit the range of calls to memory and get used to seeing them at all sorts of ranges. That Friday afternoon we also discovered they were, along with c.60 Goldfinches, feeding in three incredibly tall London Plane trees at the churchyard boundary. Gus had quickly noticed the birds often flew west, in the direction of a strip of gallery woodland with an evergreen understorey full of Yew. We walked out of the village to check whether birds were commuting, Gus set up his scope and said quietly, ‘have a look in here’. A flock of Hawfinch were spread across the crowns of three Ash trees. Gus counted 19, I counted 20 and Gus resumed his place at the scope where he got a final count of 22, pretty good for Warwickshire, even this year.

Hawfinches, Honington. 

After a half-hour or so of trundling around in the general area for the kites we were driving along a narrow back-lane and discovered four siting in trees right next to the road.  There were ten in the immediate area and we knew we had found what we were looking for.

Red Kites at pre-roost gathering. 

Having checked that we were in a place consistent with the sightings (the Print brothers having seen a large flock too) we eventually began to see birds which had obviously come some distance, arriving at height on a purposeful track. the number we could see in the trees was not increasing though. Then I picked up two birds which overflew the area we were concentrating on and continued west. We followed them to a copse, Gus put his scope on the section of the wood the birds disappeared in to and found 11 birds in the canopy. We started our count with those and added every bird we saw fly in.

By dusk our tally was at exactly 60 when what Gus rather neatly describes as a ‘dread’ occurred. A crow flew in to the south side of the copse and a few kites moved, apparently in response. After a few minutes, what we took to be the entire roost got up and began milling around low over the tree tops. A precise count was impossible but we were fairly confident that 70-80 individuals were involved. This constitutes the highest tally for the West Midlands region, by a factor of 10 or more. It is, more significantly, a splendid afternoons birding, surrounded as you are by the glorious landscape of the Cotswolds.

Photo by Gus Ariss.

Gus and I have been wondering, why this particular copse? There are after all, woods everywhere in the Cotswolds. We completely forgot to ponder, why roost communally? The answer to the latter question may hint at the answer to the first. Red Kites are social raptors, there are few of them but their number also includes another group of scavengers, the vultures. It has been hypothesised that kites in a roost can see which individuals have fed well, as indicated by a bulging crop, allowing less fortunate birds to follow the corpulent ones back to the location of a carcass the next morning. This theory was not supported by radio tracking work in Spain however which did support another proposed explanation for winter roosts, that birds follow each other from them to forage together. The greater the number of birds searching, the greater the chance of success in finding food. Given the likelihood that a food source will provide amply for several birds or more there is no disadvantage to such cooperative behaviour. So perhaps the physical characteristics of the roost wood are not the key determining factor in its selection. Perhaps, that is simply the proximity of the wood to an expanse of optimal foraging ground.

Finally, in answer to speculation that this phenomenon may herald  a boom in the breeding population of Red Kites in Warwickshire, it appears probably not. The reason the species was reintroduced is that it has a really low dispersal rate naturally. I recently posted a photo of a first calendar-year bird taken nearby. What I didn’t know was that the first calendar year is about the only time a Red Kite wanders, after which it returns to the natal area to breed. Winter roosts are thus largely, though not exclusively, comprised of first calendar-year birds. Of the three in the photo included here, two belong to that age class. Keith Jennings has confirmed also that a significant number of birds from the Bourton roost appear to have gone.

I took this last photo at Long Compton some time ago, at a more amenable time of day.

 

Madagascar 2. The SW (Toliara and Nosy Ve).

SW Madagascar is arid and we began our exploration of it’s xerophytic habitats in the near-impenetrable Euphorbia scrub on the limestone plateau of La Table, in the Toliara region. A visit here is now mandatory on any Madagascan birding itinerary as it one of the few sites known for Red-shouldered Vanga, a species described as recently as 1997 though it was first collected in 1948. We arrived, having waited for the heat to abate a little, in the late afternoon and had a a bit of a job finding the most notable avian resident of the area. The scrub is too high to see over for the majority of time spent walking the tracks through it and the critical thing is to hear a bird singing or calling then zero in on it. It took us a while to hear one and some time to walk in through the spiky bush to a point where we could see it. Even then it was not sitting still to be admired, but there were a pair present and we all eventually had great views. The birds remained low down though and I failed to get an unobscured photo.

Red-shouldered Vanga, La Table. 

Other notable birds seen in the area included Verreaux’s Coua, Madagascar Lark, Madagascar Cisticola, Subdesert Brush Warbler and just as we left, good views of our first Madagascar Buttonquail which crossed the road in front of us quite rapidly but remained visible for a while as they made their way in to the brush.

Madagascar Lark, La Table. 

Early next morning we set off for the harbour to take a boat to the island of Nosy Ve. Few birds were encountered on the crossing, save for some Lesser-crested Terns, but once we got close enough to the islands Grey Plover, Bar-tailed Godwit, Whimbrel and Sanderling could be seen wandering the beaches. Unfortunately there were no Crab Plover present. The other main attraction on Nosy Ve is the presence of a large colony of Red-tailed Tropicbird and we spent a pleasant hour ashore with them before it was time to move on.

Red-tailed Tropicbird, Nosy Ve. 

Our return boat journey was punctuated by a stop at a beach front resort near the village of Anakoa to see Littoral Rock Thrush, which is endemic to the coastal SW and was quickly located without leaving the resort grounds.

Littoral Rock Thrush. 

Back at the harbour we were bundled on to small carts for the second time that morning and hauled across the mud by pitifully skinny Zebu cattle, I would far rather have walked.

Park Life 2018

I posted a blog last February titled Park Life as it concerned a pair of Whooper Swans that had appeared on Abbey Pool in Kenilworth and a Juv. Iceland Gull which had taken up residence on Swanhurst Pool in the Birmingham suburb of Moselely, both of which are located in parks. I took close up photos of the heads each Whooper Swan (as did Gus Ariss and John Judge) hoping that the Wildfowl and Wetlands Trust (WWT) ran a database, like that they have created for Bewick’s Swan, which would allow us to identify the individual birds and learn something of their movements. My on-line research indicated that such a database was not held for Whooper’s.

History has repeated itself to a remarkable degree. The Iceland Gull has returned to Swanhurst Park, along with a large gull also present there last winter and which caused considerable controversy regarding it’s identity. This gull was the subject of another blog which I recently reproduced as the debate ignited all over again.  A Whooper Swan was found by Chris Matthews on Abbey Pool four days ago and I immediately wondered if 1. it was one of last years birds returning? And 2. whether we could answer question 1 by obtaining photos and comparing the bill patterns? Gus Ariss visited Kenilworth on 01/01, obtained the necessary photos and contacted Julia Newth at WWT Slimbridge. It seemed to us both that the bird currently present could confidently be identified as one of last years visitors and Julia confirmed that, though the individual differences in bill patterns of Whooper Swans are more subtle than those of Bewick’s they can none-the-less be used and this was indeed a returning bird. Gus has prepared a comparative plate utilising photos I took last year and his own taken yesterday.

Images A and B are of the returning bird and image C is the other individual present in 2017. The circled area indicates an obvious individual marking. One difference that is apparent is in the amount of black immediately in front of the end point of the white feathering at the base of the bill. It seems likely this is due to relative regrowth following moult, the Handbook of Birds of the Western Palearctic (BWP) gives body moult as completed in December and the 2018 photo was taken a month earlier than that obtained in 2017.

Another thing I speculated about in last year’s blog was the origin of the Kenilworth swans, given their confiding nature. It occurred to me that this could easily be explained by the fact that large numbers of wild Whoopers are now fed at WWT reserves around the country, though I didn’t discuss the hypothesis. I did however refer to an observation made by John Oates that the species would take food on lakes in the Icelandic capital of Reykjavik. Julia confirmed both of these facts may explain the Kenilworth birds readiness to come to food and that in her opinion the birds were indeed wild. She also confirmed that increasing numbers of Whooper Swans now occur at Slimbridge. This accords with experience in Warwickshire where Bewick’s Swan has become increasingly rare, as the number wintering in the UK (and Slimbridge) has decreased but Whooper Swan occurs more regularly than it used to.

It is often said there is no such thing as a free lunch. It appears that for wild birds there sometimes is and it’s value is apparent from the the fact that they commit locations where it has previously been available to memory.

I have yet to return to Swanhurst Park but plan to do so and expand this blog, or create another follow up, soon.

Madagascar 1. Tsitongambarika (realm of the Red Owl).

I spent two months in Madagascar in 1999 as part of a team attempting to assess the effect of proximity to human habitation on the population densities of various diurnal lemur species in Sector 4 of the Zahamena National Park, which lies in the rainforest belt running along the eastern side of the country. Our survey site was at mid-altitude and though we were there in the austral winter and had no sound recording equipment we saw a good number of birds. Indeed when we compared our sightings to the list for the area, compiled from survey data collected by Frank Hawkins, we had succeeded in finding most of the birds we could have hoped to. I have wanted to return ever since and finally made it this November courtesy of a trip organised by Zack Weber and advertised on Bird Forum (whereby Adam Hudson and Steve Greenfield had joined). Ground arrangements and guiding were handled by Madagascar Tour Guide and the trip cost around 3000 Euros for what became a fairly extended itinerary.

Our very first birding excursion involved a 4.5 hour hike in to the edge of the Tsitongambarika Forest, the most significant tract of rainforest in the south-east. Our principal reason for this trek, which is seldom made by visiting birders, was the presence in the forest of Madagascar Red Owl. This species is a peculiar one. It went unrecorded between 1934 and 1973 and has generally only been seen by visiting birders who are taken to day roosts located during radio-tracking work undertaken by the Peregrine Fund in the NW of the country. It is classified as Vulnerable with a population estimated at around 10 000 in a range of some 52 200 km². I always thought of it as a rainforest bird and it has historically been regarded as  such, occurring in undisturbed growth between 800-1300 m. It does however have some facility to utilise degraded habitats and was recently discovered in dry forest in the far north. There was little light left by the time we had set up camp on day one and though we heard the Red Owl on our first attempt along the trails that night the first good bird seen was a Madagascar Scops Owl which came in right above the tents.

Tsitongambarika campsite.

The highly recommended Tsitongambarika Restaurant. 

Next morning we began birding in a clearing above the campsite from which, over the next two days, we ran up a list of vangas that included Tylas, Pollens, La Fresnaye’s, Red-tailed, Chabert’s, Hook-billed and the super attractive Nuthatch and Madagascar Blue. Other species recorded here included Madagascar Green Sunbird, Madagascar Cuckoo-shrike, Stripe-throated Jerry and Nelicourvi Weaver. Red-tailed Newtonia was calling but we couldn’t locate the bird so we dropped down to a fairly open area of forest close to camp. I took the view that having climbed all the way up the hill we wanted to make sure we saw those species we couldn’t encounter elsewhere and after some dedicated effort and a bit of trawling we eventually got good views of this species, which Zack subsequently saw pass right by his tent. There followed a long walk which yielded very little save for our first Long-billed Tetraka. After lunch I had just collapsed in my tent when I heard a magical name being spoken, Scaly Ground-roller. I headed in to the forest with my shoelaces flapping, desperately fighting the urge to simply run towards the source of the sound as fast as possible, for fear I may scare the bird off. I need not have worried for it was on territory and in no hurry in the mid-day heat and I cursed myself for not having brought my camera as the bird hopped up on to a log a short distance away. I went back with the camera later but the light had gone and it was Zack who secured the best results.

Scaly Ground-roller. Photo by Zack Weber. 

Scaly Ground-roller. 

The highlight of an afternoon walk was a Short-legged Ground-roller, the one species that we saw regularly in Zahamena but one I was more than pleased to see again after all those years.

Short-legged Ground-roller. Photo by Steve Greenfield. 

By that evening Zack had become ill but Steve, Adam and I made the second trek for the Red Owl. Steve and I had stopped for a break not far from where we heard the bird the previous evening and Steve decided he would not continue as a long-standing knee injury was causing him some trouble. I went on and soon became aware that something was happening ahead of me. What was happening was that an owl had swooped right over Adam’s head in the dark. We settled down, turned off all our torches and urged the guide to use playback sparingly. It is both ethical and effective to use playback economically and best with night birds to wait until you think the bird has come in before commencing the search by torch. The bird called back then went quiet, Adam waited, turned on the torch and rapidly located the bird perched on the other side of a slightly open area adjacent to the trail. A radio tagged bird on a day roost would afford better views but I was delirious to have seen one at all, especially after all the effort it took. I will hold my hands up here in that I thought it was a hopeless task. The guides however, reckon they can find the owl regularly.

Returning to camp we discovered Zack was seriously ill but after long discussion it was decided that with just 5 hours or so till daybreak the porters would not attempt to carry him out in the dark. Heroically he walked out the following morning, a task which damn near finished me!  He did not even miss out that badly bird-wise as he was booked on to an extension for the Red Owl and the Serpent Eagle. Blue Couas around the campsite and a Red-fronted Coua on the walk down were the stand-out birds of the final morning.

The forest is marvelous, surveys there have recorded most of the country’s rainforest birds and the presence of the Red Owl and Red-tailed Newtonia are testament to the quality of the habitat. Numerous discoveries have been made among the plants and herptiles occurring in the area and may yet be made among it’s birds as the higher elevations remain unsurveyed. Until recently the forest had no conservation designation but an application has been put forward to accord it Protected Area status. It cannot be granted too soon, there has been total clearance of the lower slopes on the walk up and we witnessed selective logging going on inside the forest throughout our 2.5 day visit. We were told that timber was being taken for house building but that seems unlikely given the amount of felling activity occurring. An explosion of illegal logging, fuelled by demand for Rosewood from China took place in Madagascar following the 2009 coup and we were also told that the problem is far from over.

Red-tailed Newtonia habitat in Tsitongambarika Forest, close to our campsite.

A forested ridge at Tsitongambarika, of the type utilised by Madagascar Red Owl. 

Pristine lower slopes, Tsitongambarika Forest.

Cleared lower slopes, Tsitongambarika Forest.

The Green-winged Teal x Eurasian Teal hybrid at Draycote Water.

I arrived to do the Draycote Water roost this afternoon and stopped off briefly at the overflow as the precious few gulls already in had collected off there. They were mostly head on but before I moved round to the inlet I had a quick look through the ducks between the overflow and Rainbow Corner. I soon noticed a drake Common Teal with a vertical white stripe running down the breast side. I called up John Judge, who was already at Draycote and resumed looking at the bird. There was a pale line running along the lower scapulars but it appeared grey.

Green-winged Teal x Eurasian Teal hybrid, Draycote Water.

Once John had arrived we moved closer to the bird and discovered that the line along the lower scapulars appeared grey because the upper scapulars were overlaying it to some extent and it’s appearance altered with posture, clearly white when exposed.

Green-winged Teal x Eurasian Teal hybrid, Draycote Water.

This, combined with the weakness of the white line along the breast sides was a serious cause for concern so John put up a Tweet asking for opinions as to whether the bird was a hybrid. A little while later we looked up some images of hybrids which pretty much settled it when we received a message from Bob Hazell who also thought it a hybrid and a reply to the Tweet from Andy Mackay who confirmed that a pure Green-winged Teal should not show any white in the lower scapulars. In addition John had noticed that the yellow border to the green face patch was rather broad along its upper edge, consistent with Eurasian Teal.

Green-winged Teal x Eurasian Teal hybrid. Photo by Theo de Clermont.

The British Ornithological Union (BOU) will adopt the taxonomic treatment currently followed by the International Ornithological Congress (IOC) as of midnight tonight. The IOC treat Eurasian and Green-winged Teal as a subspecies group (under the common name Common Teal), that is a unit comprising subspecies which are currently lumped but for which there is significant evidence that species specific treatment may be merited.

The 2nd W  Iceland Gull was in the roost for it’s second night. This is the third Iceland Gull of the early winter period, following a Juv. on 28/12 and an Ad. on 16/12. The first Glaucous Gull of the winter was a Juv. 08/12 on which had spent the day at Shawell and was thought to be the bird that had been roosting at Chasewater (to which it I believe it returned the next day). The only other was an Ad. which remains the only white-winger this winter to arrive early, on the afternoon of 23/12.

Ad. Glaucous Gull, Draycote Water. 

Two Hawfinches, one paler than the other and with less black around the bill base but no obvious pale secondary panel, are still using the car park and birds have also been recorded flying over Rainbow Corner in the evenings.

Hawfinch, Draycote Water.