One for the Road

Motney, Apr '15

The Road Goose An old name in some parts, including Kent, for the Brent Goose.'Road' being the soft English version of the Scottish name, 'Rood Goose'.

My first spring back in Kent, 2013, saw a very cold May and I found myself surprised by the number of Dark-bellied Brent calls still to be heard around the Medway (and on into June). I'm sure I'd encountered them before in numbers, but they just hadn't registered. They were only Brent, after all.

Every spring since then, Brent have been present well into May, and every year other birders have been surprised to read my comments about them via, either my now-defunct Facebook account or on my Twitterfeed. So, last year I blogged a short photo-essay on them to help explain. This spring, I'm sorry to say, comes the verbose full blogpost. You have been warned. Hit that link for the short version if you like. Otherwise, enter freely and of your own free will.


Ancient Roads

Twinney, March '17

The old county avifaunas reveal Brent, like many wildfowl,only visited in very small numbers, unless the weather was extreme:

"...in an ordinary open winter, such as we now experience, a few of these birds are always to be found..."

"...in the year 1739-40, when these birds were so abundant on the continent... they were so plentiful on the coast of Kent that they were in so starving a condition as to suffer themselves to be knocked down with stones and sticks: and were carried in carts to the neighbouring towns, where a purchaser was allowed to pick and choose for sixpence apiece..."

"...in 1803 they were innumerable around Sandwich, and were so miserably poor and debilitated as not to be able to rise after alighting, and many were taken by hand..."

"...the Rainham creeks, says Prentis, are visited by small numbers in severe winters..."

A History of the Birds of Kent, Ticehurst, 1909

Road building in the 20th century

There is no real reason to think things changed in the decade after Ticehurst. Many birders do have an inkling of what happened in the 1930s, a collapse of the world population. Just how big numbers had been before the fall was down to speculation, but a correlation was seen between the decline and the world collapse of seagrass, a favoured foodplant. Today, most accept there was a bit more to it than just the seagrass, with evidence found later for other problems such as a long-running series of annual breeding failures. A perfect storm that saw the world population continued to slide for the next two decades, down to an estimated 15,000 in the mid-1950s.

Brent were removed from the UK Quarry list in 1954, and France banned hunting them in 1966. Denmark, a vital staging area, stopping shooting them in 1972.

Organised counts in Kent started in the 1960s. Brown and Grice quote five-year averages on the Medway for 1960/61- 64/65 as just 115, 1965/66- 69/70 little better at 205. But from the 70s onwards numbers improved and by the 1990s counts of over 4,000 were being made here. Recent WeBS surveys have been lower, but published records show the Medway still routinely holds nationally important numbers during winter:

For me, this was yet another species that showed a 1990s peak on the Medway, just as many other waders and wildfowl have done. My gut feel had been this was a reflection of an observer/effort bias from that time, and that numbers may well have gone under-recorded since then. This blogpost is about my findings during the spring months in the last five years.


By- Roads

Shoregate, Apr '15

First, a need to clarify the texts found in many summaries such as 'Birds in England' and 'The Migration Atlas'. They refer to numbers remaining in late spring 'on the North Kent marshes'. Not strictly true. The numbers are restricted to just one of the three estuaries making up the North Kent marshes, and that is the Medway. Brent numbers for both the south Thames (to the northwest) and the Swale (to the east) mirror the national tendency of a drop from February onward to virtually none by April and May.

There is a trend to 'lump' these estuaries together as one, based on theories of a large number of intra-seasonal exchanges of waders/wildfowl during a winter, but this really is one species which shows such a lumping to be a mistake.

The Swale mirrors the Essex marshes, where seagrass species still survive and provide good feeding for late autumn and the early part of the winter. Numbers then remain relatively stable as other food sources are available after that, but the birds do move off in February:

The Thames (here referring to Kent's southern Thames foreshore) does not really draw in the Brent in the late autumn/ early winter:

So, the pattern during the past 40 odd years has been clear- it is the Medway estuary that appeals to Brent during the early spring.

Monthly average mean totals 1971-2011

The only other sites in England where Brent hold on like this are along the north Norfolk coast, in particular, the Wash:

"...the majority of the flocks move off eastwards again in March, leaving smaller parties lingering in the north coast estuaries until May..."

"...a count of the Wash in May 1996 produced  a total of 7,220 birds still present..."

'The Birds of Norfolk', Taylor et al. 1999

The Stour in Suffolk and the Beaulieu in Hampshire are two other estuaries that have started to see a few hundred birds hang on during spring in recent years. But the Medway remains second only to north Norfolk.

The road to Siberia

"The birds start to leave in late February... gathering first on the Wash, and in recent years, on the North Kent marshes, where they remain until late spring..."

'Birds in England', Brown and Grice, 2005

This simplistic map of Dark-bellied Brent Goose passage is based on 'Birds of the Western Palearctic' with timings from 'the Migration Atlas'. Adults (yellow), in general, stage in the Waddenzee off Denmark, then move to the White Sea. Their final jump is then into the eastern Palearctic to breed, with nests and eggs building in number only from around mid-June. Their journey is long, the weather window for breeding is open only for a few weeks, so it makes sense to break the journey down and stop short to wait for the weather to break. As soon as the breeding season is finished, the end of August, the main outbound migration gets underway again, essentially using the same route.

At the start of spring youngsters (green) will be disowned by their parents from February onwards as migratory urges kick in. Brent do not breed in their first summer so, although some will return to nearer the colonies, some will stop short just above the White Sea. A useful strategy seen in many slower maturing species.

Could it be that these late staging Geese on the Medway have a higher percentage of young non-breeding birds among them? The alternative would be a good percentage of adult breeders hang on among the spring birds and then make either a much longer staging flight in May, or pause for only a short while at one of the sites. That possible if milder winters are leaving them in better condition for such changes. Questions, questions.

Ageing Brent Geese at this time of year, at a distance, is really quite a job. Without boring people, you are looking for retained juvenile coverts in the wing. You can do first summer birds, and even some second summer, but never with certainty for a fair proportion of any flock. I've been trying. Armed with 'scope and working through the closer birds at places such as Bloors, or simply looking for behavioural clues (obvious 'pairs'), the Medway in April seems to give off a feel of a slightly higher number of young when compared to mid-winter flocks most years. Nowhere near a significant observation though, but an interesting idle thought getting me through these cold April days this year.


Road traffic surveys

A distant gathering at the tip of Stoke Ooze, May '15 

Could such a change in the adult/young ratio indicate some of the 'Medway winterers' being replaced by non-breeders birds from further south? Doubtful. There's no evidence of overland migration, unlike in the autumn when flocks head south/south-west from the Medway. There's no obvious westerly passage along north Kent coast, either (but then the passage would be considerably smaller, of course). Perhaps disowned youngsters could be arriving from Essex? I rarely record flights of Brent into the Medway, but then I'm not at the estuary mouth every day.

My original plan in '13 was to count the estuary waders (and wildfowl) throughout the winter through to the end of March in 10 day periods rather than just monthly. April and May were set at 15 day periods (I wanted a bit of a rest). For Brent, there is no straight line decrease as winter ends, the totals wobble. I'm no statistician, so can't say if significant levels, but this could be a hint of a Medway hub. Some Medway birds could be taking off on their long inter-continental journey while at the same time they were being replaced by more local birds planning on taking a later flight.

All highly fanciful thinking. and I'm no scientist. The main point is, as with so many species, there is still a lot to learn.

One example, there really aren't that many Brent ringed in the UK. Ringing and Migration v31 p2 dropped through the letterbox recently. In 2015 just eight Brent were ringed in the whole of the UK, bringing the grand total up to just 1,164 with 92 recoveries to date. Colour-ringing elsewhere in the UK is starting to provide more data. Perhaps here one day?


The local Road network

During the first half of April this year Brent numbers have been spread throughout the estuary, from Folly Point to Cockleshell beach, some eleven kilometres apart as the Brent flies. The google earth map shows the main favoured areas. Their usual pattern. Not many groups are close to shore for any length of time, other than at freshwater inlets such as Bloors wharf.  The shoreline birds at Cockleshell beach on Grain seem to be an exception, they often commute to and from Deadman's island. But the vast majority of the Brent enjoy the relative peace mid-estuary, scattered around the relatively undisturbed islands.

All this makes getting any realistic count problematic. Hard enough with a group of birders co-ordinating efforts, pretty mad for someone operating alone. There really is nowhere from which to count both halves of the estuary at the same time; a series of mad dashes from west to east are needed to prove the birds quite lazy and staying to their discreet groups on certain parts of the estuary (yes, I am that strange birdwatcher who stands on the bench at the tip of Horrid Hill to get any height advantage he can.) Thankfully the eastern basin, Oakham to Cockleshell, can be scanned in one go from high ground, such as at Tiptree Hill. I still have yet to see another birder there, perhaps because the birds are now distant specks. Not many birders enjoy something akin to Napoleon watching battlefield troop movements(!) Of course, the counts are relative, some will undoubtedly be missed, especially among those up on the saltings. By putting up with such challenges, it is possible to show there are more than a thousand birds present this April (keeping the estuary at a nationally important level and continuing in line with counts the past few springs).


Road fuel

Frog farm, Mar '17

The special geography of the Medway clearly offers safe refuge. What about food?

Brent are vegetarian. Many texts highlight their reliance on seagrass, in particular eelgrass (why they love Foulness in Essex in the autumn).

There's not enough eelgrass to get by on. As winter sets in Brent make a second movement (why those large Essex flocks move, some into Kent) and will next take a great deal of green algae where available, chiefly sea lettuces.

Still not enough. From the 1970s onwards improved grasslands have played a much more important role in Brent diet, particularly crops; autumn-grown cereals (wheat and barley), and sometimes oil-seed rape.

But still not enough. Brent will take Glassworts and 'wild' grasses including salt grasses, fescues and cordgrasses. Arrow-grass and sea aster are also taken. These higher salt-marsh plants will have been first taken alongside the algae, and exhausted quickly but, come the start of spring and fresh regrowth, the Brent are back for seconds.

So, where a good enough mix of food types is available, good numbers of Brent can remain all winter and on into spring.

Eelgrass deserves a special mention at this point. Here in Kent it went extinct in the mid-1930s. A close relative, Narrow-leaved Eelgrass, hung on and is still found at the eastern end of the Swale and on the south Thames around the mouth of the Yantlet but within the Medway, Narrow-leaved Eelgrass was only recorded for the latest Kent Flora atlas from around the mouth of Otterham creek. Now the author of the atlas admits it being 'probably under-recorded through difficulty of access', which was down to his insistence on not relying on the reports of others and having to see every less common specimen at each site for himself during his many years of exhaustive fieldwork.

Here I admit I struggle to recall ever knowingly seeing eelgrass. It favours mudflats close to the low-water mark, or grows, floating, below the low-water mark in estuary channels, somewhere pretty much impossible to get to view from the shore here. The author also failed to find any examples of a third species, Dwarf Eelgrass, on the Medway, even though it is found in similar areas to Narrow-leaved on both the Thames and the Swale. So, what is the true picture for eelgrass species on the Medway? Watching the Brent in the autumn, many seem to be feeding on algae. Bearing in mind this single-minded approach to recording for the flora atlas, there is certainly room for someone to check matters out. If anyone knows, I'd love to hear. (And, yes, eelgrass is on my bucket list.)

Along the southern shore suitable grassland is available at Ham Green, Barksore, and on large areas of Chetney. This is in the main is 'permanent' standing grass. Over on the north shore, cereals can be important; the fewer such crops sown on the south-facing slopes of Hoo, the fewer the Brent in the western basin during a winter.

So, the spring. If Brent were relying on eelgrass regrowth in April and May, surely birds would also be on the Thames and Swale? There are saltings on both these other estuaries, but mostly are on the shoreline meaning, perhaps, too much disturbance? Algal regrowth is often greater, earlier, in the relatively sheltered Medway, so might well play some part in the choice. Crops and grass appear to be rarely touched in spring.

In all probability both good food supplies and safe feeding areas are needed. The volume of saltings edge available among the islands, away from disturbance, must be a win bonus.

The feeding routine is essentially diurnal, and tidal. This lends itself to the island complex. At this time of the year, many of the birds will be hidden up in the saltings over high tide then some, not all, will work a short distance over adjacent flats to continue feeding as the tide drops.

Again, this creates problems for obtaining highest counts when checking a creek or bay. Often only the Brent nearest the edges of the islands can be seen easily and often out of decent binocular range. Because only some Brent some follow the tide out, often easy to think the 100 Brent in open view on the mud, to loaf/feed on algae, are the whole group, whereas a strain of the eyes along the island edge will often double that number as the birds loafing/feeding among the salt marsh plants give themselves away.


A pothole in the Road

Bartlett Creek, May '15

"Any Brent you see in the late spring and summer have been shot, and can't migrate."

A much-chanted mantra over the years here. Believed it for decades myself, heard it again a couple of times this past winter. Since coming to understand the complexities of Brent migration a little better, I have looked for summering Brent carrying any obvious injury. Early summer sees the small numbers remaining keeping together, often flying together for short distances. The problem comes when numbers drop further and lone birds starts routinely strolling between their low- and high-tide areas. I have yet to see a shot bird. It really is time for birders to reconsider over-summering birds as perhaps not being walking wounded, but more likely lazy birds with very weak migratory urges.


Anti-Road protestors

Motney, May '15

In April and May more users are venturing out onto the estuary. Most boat owners cause little concern, but smaller craft are known to make landing on various of the islands. Brent can be pushed out of the western basin, especially over weekends, by personal watercraft such as jetskis and hovercraft.

Human encroachment on the shoreline saltings can keep birds off of feeding areas and cause damage to the salt marsh foodplants themselves, an example being the widening paths out onto one reserve on the southern shore. Vegetation disappears, the mud becomes soft and the walkers move to the side; wide paths grow through the sea-purslane and glassworts.

Bait diggers working nature reserve saltings, Mar '17

The biggest problem for the geese in the eastern basin this spring would appear to be seaplane activity, as the birds cannot tolerate the low banking turns over them when on the saltings and islands- with both of the authorised landing strips being placed adjacent to the island complex, such disturbance is routine.

Brent landing at Twinney after flighting from Ham, May '17-
the seaplane completing maneuvers in the distance over Ham Ooze

Thankfully flights have been few so far this spring, but will become more frequent as the weather improves during May. Other species are affected as well; the over-summering Curlew have already been pushed from Greenborough this spring and are proving difficult to relocate.

Road Planning Departments

Rainham Creek, May '16

The estuary is protected, but is a multi-purpose site with few actual 'reserves'. In respect of looking after the Brent, rather than bang on about the 'usual suspects' birders know about such as the EU Birds Directive, SSSI, MPA, Ramsar, etc., this time I'll big up some responsibilities listed as objectives under AEWA (The African-Eurasian Migratory Waterbird Agreement, an international treaty overseen by the United Nations Environment Programme). Yes, thankfully, political bodies and organisations do try to uphold such things. Brent are just one of the 254 species dependent on wetlands covered by the agreement, requiring action such as;-

- Population monitoring-  here in the UK mainly via data collected through WeBS.
- Minimum disturbance- potentially damaging activities having to be controlled within disturbance-free refuge zones.
- Reduction of conflicts with agriculture- a suite of policies/schemes available to landowners.

This time I'll also big up an umbrella group interested in considering such matters for here- MSEP is the Medway Swale Estuary Partnership, looking to co-ordinate and promote sustainable management and use of these two estuaries through bringing together the likes of councils, conservation bodies, wildfowlers, boating associations, fishermen, port authorities...

Getting the balance of interests right is never going to be easy, and I wish them luck in such things as keeping the Medway 'roadworthy'.

Twinney, May '16

Ebenezer and Florinda

Some readers might have spotted from the embedded twitterfeed on this blog that I rather like taking photographs of old boats on the Medway. There is a good reason, one which I explained a couple of years back on my (now defunct) Facebook page- so, apologies if you read parts of this story back then- bear with me, I have changed the punchline.

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A century ago my Grandfather, Harry, would have been out on the Medway most days trawling the very creeks and channels I now sit and watch most days.

I remember him, but only just- he died when I was about seven or eight. My late mum Kath had been named after two of the bawley boats he'd sailed on, the Kathleen and the Florinda. (She was the youngest of seven children, I rather think they'd run out of names by that point.)

I posted all of this on Facebook a couple of years ago because I had finally tracked down a second-hand book featuring both Harry and the Florinda. Also really pleased to discover (because of a sketch in another book by same author) that Grandad actually appears on the cover of the book.

Different times, I certainly don't think there's any need nowadays for his specialist skill as described in the book:

I do like to think he'd have had a good knowledge of the birds, and might have treated them a little better. Medway fishermen certainly noted the birds- they called the period of slack spring tides from mid-April onwards the 'bird tides', the short window of opportunity when the saltings stayed dry long enough for nesting. The last high spring tide of late winter has gone this year and we are well and truly into the bird tides again. The nesters have got until late July to get away with it. I'd want to ask him about the wildfowl- were the geese and duck really so scarce as the old texts make out? Did my family have a treat of gulls' eggs? Did he notice visible migration downstream, were there really big clouds of small birds back then?

A real shame Masher and I never got to talk on such things. But I do like to wonder what he'd have to say on estuary birds back then, when I'm out and lost in my own thoughts on the seawall now.

-------

So, mum was, for better or worse, named after not one, but two, boats. Makes the modern trend of naming your kids after entire football teams, Australian soap stars or districts of New York seem not quite so bad.

Having made the decision not to have kids myself, I have sometimes mused what names I might have saddled imaginary offspring with. Could I have ever gone for something 'exotic'? Well, thanks to a chat with a local wildfowler the other week, yes I most certainly could, because I have the perfect choices (cheers Clive!).

A daughter would have to be Florinda. Links to the river, links to mum.

A son? The poor lad would have to be Ebenezer. No doubt about it. Charles Dickens loved the marshes around here, I love Dickens. One of his earliest works, hardly mentioned nowadays, was 'The Mudfog Papers', based on and around my home town of Chatham and the marshes.

I'd have changed my surname by deed poll to Mudfog to complete the ensemble.

Ebenezer and Florinda Mudfog-

 Eb and Flo.

A north-west Kent passage- White Wagtails and the land of Ice

After the broadbrush strokes of the last post on spring passerine migration, a post looking at just one species, the White Wagtail.

Already setting up a game there, in that short opening sentence. What is a White Wagtail? Some birders will be on auto pilot for the continental version, not 'our' subspecies that we call the Pied Wagtail. But they are the same species, and that is the 'correct name' for the majority of the range.

Similarly, when a birder reads the code 'alba wagtail' on another birder's blog then they might have one of two ways of interpreting that, The species is Motacilla alba. So, interpret that- a bird, perhaps a flyover, they cannot readily assign to race, or a bird the observer can confidently assign as M.a.alba. Often it is left to the reader to apply their own interpretation.

Recently played a game in a facebook group. A Wagtail pic there was called as White, then said to be Pied, based on the flanks. I was prompted to comment (after some more brief definite replies) on attributing a particular bird to subspecies and at the same time I deliberately avoided saying whether I felt the bird in question was M.a.yarrellii (Pied) or M.a.a. (White). For the poor souls who suffered that, I'm sorry, I'll be doing that again here- but I promise there are elements I didn't include before, bear with me. And for those who want to see the pic to judge it and say deffo one or other, no link- not really the point of this post.

I wanted to put over the idea separation is not as simple as many of the guidebooks make out, even in spring. For those going 'pish and tosh' right now, have a look at this excellent article from Dutch Birding- some of the simplest diagnostic features we use are not as clear cut as we hope- 'kodak grey scales' used in it to show the back colouration does overlap, and illustrations of dark washes on flanks with percentage scores to race- what we go around saying is 100% diagnostic, may only work in 80% of the birds.

Having muddied the water with that, I went further with another link to an article where a series of photographs of M.a.a. rumps taken in Belgium in spring were also nowhere near as clear as the guide books make out.

Identity shouldn't really be nailed with just one character, it needs a suite. And even then, it should only lead to a conservative call of 'showing the characteristics of' because there is a clinality between the races. Yet we often never pause to think about that. Heck, even a coasting yarrellii might not be the British race- these darker birds are also found breeding on the near continent and some nest up in Norway.

Of course, 'showing the characteristics of...' is a phrase we don't like to use in our everyday 'it is' or 'it isn't' dialogues. But we've all had the birder in the hide pronouncing 100% certainty on one feature, some might even have had certainty claimed from features not usually listed (I've known some who nail M.a.a. on flight call alone).

The other question I avoided throughout the debate was this- if the characteristics are a tad muddier than we like to believe, and some identify birds with certainty on briefer views than others, what is the true status of White Wagtail here in the south-east? And the other Kent chestnut- have all the Whites we see have really been overshoots over from the near continent?

Like some keyboard superhero I found myself muttering 'Robin, Alfred, to the Bat-library!'


The avifaunas

Sussex (James) "...birds showing the characteristics of the nominate continental race M.a.alba are recorded locally and have bred. Most records... are of 1-3 birds at coastal localities in spring..." Goes on to mention a couple of noteworthy falls (up to eight) and then documents a 'pure' pair breeding in the Cuckmere valley, and some mixed pairings. The update from Thomas starts 'Few Pied or White Wagtail are noted on passage...'
(Oh James, you may have been updated and replaced by Thomas, but this is why I love you still, you go with 'showing the characteristics'.)

Wood (Essex) mentions some mixed pairings. Mentions (as others also do) a lack of autumn records down to problems with in the field identification with juveniles and that females of both races can be difficult to distinguish from each other (not even risking going there in this post!) The Essex spring peaks were mid-April, with individuals reported from end February to 'right throughout summer' And numbers had increased in recent decades thanks to increased observer coverage.

Taylor et al state that Norfolk spring peaks are in April, with movement between mid-March and mid-May but that numbers were generally small, involving 'single figure counts at coastal sites' First breeding of a pure pair of M.a.a. was in 1997.

Suffolk (Piotrowski) goes for a status of 'common'- 'often occurring during the second week of April with Yellow Wagtails'. Earliest arrivals from 21st February. Numerically, common is then refined as 'around 50-100 occur in good passage years'.

Not exactly a consensus then. The lesson? The status we hold in our heads might well just be a cognitive bias. Individuals we've nailed may well not be as definitive as our subconscious would lead us to think. And we could have a lot more fun with these birds if we just bore that in mind.

Many authors go on about the nominate continental race, which makes us southern softies always think of birds overshooting the channel. Most birders north of the Watford Gap realise this isn't always the case, but us down here..?


G'wan, for a laugh, let's call some 'islandica' for a minute

Yup, here among Kent birders the immediate thought seems to often be that any coastal M.a.a. has drifted over from the near continent. Could be, but most probably not. What? We tend to overlook the fact that the large population in Iceland, and the smaller numbers from Greenland, are highly migratory. They are the ones that move through our islands on a definite, purposeful migration.

Go to the BTO's birdfacts webpage for Pied Wagtail and click on the two links for maps of ringing recoveries and from 'Time to Fly' (an excellent read by Kent's own Jim Flegg). Kent birders should then never again think immediately a White Wagtail is suffering continental drift. Stumble on a small flock, you'll now be able to imagine them as long-distance refuelers, all doing the Icelandic wing clap before taking off northwards again. Joking aside, this could well be why some coastal sites, with suitable feeding habitat, sometimes have flocks of tens and twenties. Or why Dungeness Bird Observatory records many fewer whites than the Bird Reserve a little way inland. These birds might well be tired long-distance migrants putting down in suitable habitat preparing for that next leap home.

North Kent could well have a put down incentive for Icey Whites. As a mainly diurnal migrant they can see a chunk of the greater Thames and decide to coast west then north, perhaps drop in to feed?

Of course, observer bias sneaks in to the official public records, often these sites have the same observers listed against such reports each Spring. The main point is all other Kent birders should never feel reporting their M.a.a. sighting is not really necessary in this day and age. We are fooling ourselves if we think we know what's going on, or if we think we know how many birds pass through Kent.

Yes, there have been records of 'pure' M.a.a. pairs breeding in recent years that are more likely of near continental ancestry. But is a spring bird be more likely to be a longer-distance passage migrant?

The more we find out, the more there is to know.

Records along the south Medway? Nowhere near as many birds showing the characteristics of M.a.a. turn up as seen at either, say, the Hoo Peninsula or Reculver, both closer to that Greater Thames coasting flightpath. Here? Not an obvious flightline. Any passing over would need a reason to land and much of the better feeding habitat here is private. Even so, footpaths around places such as Chetney never turn up many. Any bird seen showing characteristics of M.a.a. will always get an underlining in my notebook. I hadn't had one this spring up to a week ago when I started drafting this; at the time of posting, finally on a score of 'one'. Must look harder. For them, and at them.


Bibliography

James, P (ed.) The birds of Sussex 1996 Sussex Ornithological Society (Over Wallop)
Pennyworth, A. A catalogue of the Wayne Manor library vol. XXVI 2000 (Gotham City)
Piotrowski, S. The birds of Suffolk 2003 Helm (London)
Taylor, M. The Birds of Norfolk 1999 Pica Press (Robertsbirdge)
Thomas, A. (ed) The Birds of Sussex 2014 BTO Printer Trento (Trento)
Wood, S. The Birds of Essex 2007 Helm (London)

The Bee Ness Monster

Well, 'Birds of the Western Palearctic' states Egyptian Geese can nest sixty metres up a cliff face and they often defend an 'open water' breeding territory of about a hectare, but I really wasn't expecting what I watched the other week.

'Scoping the main channel some two and a half kilometres out I noticed two Avocets trying to make their way upriver but being continually buzzed by an Egyptian Goose. On first sighting I almost called it as some sort of "Arthritic Skua", seeing how it mirrored their piratical movements. Some of the best acrobatics I'd seen in a while. Once happy the Avocets were on their way, he returned to part of the broken head of Bee Ness Jetty, where he performed a triumph ceremony (head up, wings out and flapping) to his partner.

That teeny tiny pale blip to the right of the old 'crane' is one of the pair- honest guv'nor(!)

That teeny tiny red circle at the top end of the red line marks the site, honest guv'nor.

The BTO Birdfacts page has an interesting quote- the failure of the Egyptians to spread outside of East Anglia was probably due to (i) their nesting in the winter months (so productivity in chilly ol' Blighty is often low) and (ii) the lack of recent introductions (it is not a quarry species, so game shoots have no incentive to release).

Actually,a tad off the mark on two counts- (i) the spread is happening, albeit painfully slowly. Better weather in March may be helping. And (ii) it can be a 'quarry species' of sorts, thanks to the general licence. Listed on there (with a dozen more species) as a pest species, these invaders can either be shot or have their nests/eggs destroyed. It adds you can then eat them yourself should you want to, but you can't sell on for human consumption.

Thankfully this pair really shouldn't have been bothered by anyone way out there on that rusting, rotten framework.

The tide was low in the photograph. The structure looks big, but looks can be a tad deceiving- what appears as a crane at a distance is a raised jib, once used for unloading oil. The most you see of the jetty out of the water is roughly about twelve, thirteen metres high. If they had built a nest on the structure, any young would have to jump eventually; looks hairy, but they could halve the drop by about six metres if they timed it on the full so, perhaps not that bad a choice of site. Certainly over the past few week it looks as if things have moved on. The male has been back a couple of times, his partner has not been seen and the gulls have reclaimed the jetty. The aliens may well have landed already, over on the north shore saltings.

Elsewhere on the south side, a second pair has been a bit more conservative in their choice of nest site (a tree back on terra firma) and the one often mooched around nearby, on a pond where the owner has set up a feeding station for the local Greylags and Canadas (piles of rotting fruit from the orchards).

This pair were not being bothered under the general licence either, as quite a few of the locals seem to find them endearingly exotic (for now). Chatted with one local shooter this week, who was aghast to hear these Geese were on the alien watch list. He also knew where the tree nest was, and of an additional unpaired male locally.

So why is it on the general list?
- could it prove a threat to crops? Doubtful.
- will it crossbreed with our native species? Well it has done with Mallard.
- could it out-compete locals? Well, being fresh-water loving they shouldn't really compete with Shelduck out on the estuary. Even if they do nest smack in the middle.

The more we learn, the more there is to find out. So I'll be watching out for resightings of the Bee Ness Monster next year.

Another Egyptian.
From the free-flyers just inland of the estuary, at Gore Farm.

The search for the north-west Kent passage

Just how good is the Medway for spring passage? Interesting question, but judging by the perennial debate in some of the forums the question the county readership would probably want looked at first is- 'why is it that spring passage in Kent never seems as good as elsewhere?'

Last year blogged a rough outline, this time I'll just take on a few of the passerines. The African-Palearctic nocturnal migrants to be precise.

The first thing a birder has to understand is just how different their autumn and spring migration behaviour is, because our views of how spring should be are heavily influenced by the spectacle of autumn passage.

The first autumn

A typical nocturnal passage migrant passerine arrives in the world with inherited (endogenous) programming. It does not have all the information needed, and still has to learn quickly. Only about one in three will survive to return the following spring. (These odds are, in fact, better than for most sedentary species- one of the reasons why so many species choose to migrate.)

The weak juvenile feathers are enough to get it out the nest, and for the next few weeks, abandoned by parents, the youngster will search the local area, getting to know the good areas. This might be a few kilometres, it might be the whole of Kent, but soon a post-juvenile moult kicks in to replace the poor body feathers and, at the same time, the internal programming calls for an increased feeding regime, a laying down of fat and a building of flight muscles. By the time the post-juvenile moult ends, the bird has an overriding urge to travel. It has learnt the fixed position of the pole star, and the direction of night sky revolution. These factors will be what gets a bird back roughly to the natal area in the spring when those weeks spent wandering will give a youngster a choice of suitable sites to aim for.

Back at the start of the autumn, the first nocturnal flights during the completion of the post-juvenile moult are short; they take off not long after sunset, but land within a few hours. The jumps get longer slowly until the main thrust over north Africa, then slow again, finally terminated by the internal clock- the journey to their furthest point south can actually take three to five months.

The first spring

The young bird is now much better prepared for the journey. It has perfected reading the star-map, and polished up on polarisation of ultra-violet light and using a magnetic compass. Some scientists now theorise nocturnal calls are not for co-ordinating with others but more of a type of echo-location to find leading-lines; all these skills are now finely tuned.

It had suffered wind, rain and fog, andnow  has better coping mechanisms for such adverse weather, often putting down earlier rather than trying to push on through bad conditions.

Yet many species will again be relying on their internal pre-programming to take a slightly different route back ('loop migration').  Some take a large detour, with others it can be slight. It explains why 'our' UK breeders tend to come in to the west of the country in the spring- better for dealing with drift from prevalent winds, avoiding being blown out over the North Sea. After all, it knows roughly where the pre-chosen target area is, relative to any position- it can home in. The route home for many northerly breeding UK migrants is from the south-west up via the Midlands, no need to bother with Kent.

There is a correlation between arrival and temperature. The ten degree isotherm is often seen as a rough average mean- get the temperatures up at this level and the movement is on. Of course, this isotherm had arrived first in the UK in the south-west for millenia, slightly later in the south-east. The returners are aiming for the south-west for a reason. Why places like Portland start getting numbers before us.

The return journey only takes about a third of the time of the outbound journey, with migratory jumps adapted in length more for good weather than for the physical rigours of the journey - unlike in the autumn, they do not slow as they near their destinations and the longest jumps can even be those that get them home, their internal urges only beginning to switch off, somewhat abruptly, when they near their target point.

This explains why we do not have many passerine species from the near continent trying to breed in Kent. Those breeding in northern France and the Low countries are switching off when they get close to the Channel and really won't have an urge to cross the water. Birds breeding higher up in northern Europe can get drifted over the Channel, but even when they do, they want to keep moving.

Any birds coming in over Kent have a better control on fat reserves and will be able to choose to fly further inland for the optimal habitats rather than just flop down on the coast.

The second autumn

Birds know the good staging areas from the first outbound trip around the loop, and are less likely to get caught up in falls. They have often just had a full moult after completing breeding, so have an extremely strong set of flight feathers to carry them south- no wonder so few adults get caught up in autumn falls; they leave early and they leave fast. Why the vast majority of autumn migrants we see are youngsters.

The second spring

As with the second autumn, the return half of the loop migration is now known, having been completed once, and the bird has a good knowledge of the route to their breeding site- older birds are less likely to go off course, especially as they will also have a working plan for good refueling spots. Really no reason to drop into Kent in good weather, unless they breed here.

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Kent birders and rose-coloured binoculars

So, the bad news for Kent birders is just because there are a lot of migrants piling into the south-west, and some have already reached spots further north in the UK, we really shouldn't be expecting similar numbers of birds here.

Fog or rain over the south coast of Kent won't produce a big fall; quite a few of the birds will have known to put down before piling into the rough stuff, either over mainland Europe or, if over water, simply turning around mid-flight; reverse migration adjustments are common in spring. The best chance of any half-decent fall is if the hurdle starts right on the coast itself.

Coming in over the coast in good weather, a spring migrant will have the chance to keep flying on until it reaches preferred habitat- why waste time at Dungeness?

Spring. The season that consistently under-delivers for Kent birders. Expectation over reality. I could go on for other types of migrants, but far too much to cover this year.

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South Medway movements

The ideal, absolute ideal for nocturnal passerines is wet weather, or fog, starting over the Hoo peninsula northwards. A barrier.  If that arrives just before dawn, birds can stop short along the south Medway. On such a forecast get out for dawn, and pray the rain arrives (it often doesn't; north-west Kent is one of the driest areas in the UK). Search the marshes, hard, and you might find a few nocturnal migrants have dropped in. Only a few, because numbers trying to pass overhead will have been low.

Check during the first couple of hours after dawn for any travelers looking for the more suitable feeding areas; the eastern half of the south Medway is much more productive than the more urban west.

There are a couple of better periods for the higher volume of movers- we tend to fixate on earliest arrival dates, but if you check the dates for multiple/highest counts for several nocturnal passerines is around the middle of the second half of April, then followed about a week to a fortnight or so later by a second pulse (the females and first summers generally arrive after the adult males). These peaks may be slightly hidden by not-so-local breeders but, as already explained, there shouldn't really aren't going to be that many stopping off. Grit your teeth and hope for that 'patch gold'.

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That's a very rough outline for these long-distance nocturnal passerines. Sorry to have had such a downer on prospects for this, and, sadly, every subsequent spring. Only going to get worse. Read the blogs for some sites in the south-west and they too are beginning to bemoan the lack of passage even though they are in a much busier part of the country). Common species won't be any more common, and rares will be, well, rare.

Is all this 'missing out' really such a bad thing? Not if you just go out birding with really low expectations because you'll find you come back happier much more often, trust me.

Growing pains

Just days after my note on Oystercatcher roosts, and the final paragraphs mentioning the rebuilt cairn out on the RSPB reserve at Motney Hill, it seems that tresspassers are continuing to add to the pile, now visible at a distance easily from the likes of Bloors and Horrid Hill.

From land I visit (with permission) out on Motney, the 'path' over the reserve saltings has become more apparent of late (the middle distance rich green to very left in picture)- on this particular morning a digger had used it to access Rainham creek beyond. In the latest Google Earth imagery the path can be made out as a pale line skirting the southern edge of the saltings.

Today I was told by a local that the cairn has been rebuilt as a marker for illicit landings. Bit of a tall tale? Probably. But if that cairn continues to grow in size, it will just as surely grow in attraction for the off-piste general public.

One to watch.

Singles nights

The texts will tell you first summer non-breeding Grey Herons will attend their heronry, staying mainly to the edges, being tolerated (just) by the adults there, with only a small handful breeding (most first attempt breed at the age of two).

Some locals fail to read these texts and go awol each spring.

From about the time the adult birds start displaying, right up until the eggs are hatched, a small roost comes into operation in Berengrave LNR. Small indeed, only getting up to around double figures, but regular, happening each year since I started counting the Magpie roost there in 2013.

One or two might already be in position an hour before sunset, with the last join in nigh-blackness. I say the last, Herons are famous for arriving at roost at all sorts of time of day and night, depending on their feeding preferences (some crepuscular feeders, a few, nocturnal).

During the 90  minutes or so I'll spend there, squabbling always happens. Birds might join in aerial chases for ten, fifteen minutes over the old flooded chalkpit, but eventually they all settle down together, high up in the trees along the water's edge. This favoured area is extremely close to the main path, but they have learned to ignore the few dogwalkers that pass by, heads down.

If I mention the Grey Herons, birders go '...didn't know they nested there, how many pairs?'. And then have trouble computing the answer 'none'. Such roosts are simply not on the radar of many birders.

'Club Loser' will be closed down by the end of the month. Perhaps this roost behaviour, at its start, is similar to something seen in many other colonial species- recognisably immature birds aren't really wanted in the heart of a colony. Perhaps at its end, those adult breeders who drove them off are way too busy providing food for their young to waste time bossing the immatures about. No need to play 'who's the daddy?' now the eggs have hatched.

The old text of 'Birds of the Western Palearctic' hints at limited information on nocturnal roosting but goes on to say that youngsters roost close to the colony throughout the year. The main local colony here is, of course, Northward Hill, the UK's largest. As the Crow flies, some six miles away. The crow's route suits the Herons perfectly throughout most of the year. The estuary is only really beginning to close at Pinup Reach, but has the western island complex scattered around it, and many non-waterbirds choose to cross in this area rather than over more open waters. Of course, the yellow line on the map below is only representative, birds in transit being more widespread than shown, but you get the idea.

The two spurs marked show routes less often used to join that flyway. Interestingly, used more times for 'returning' towards Hoo and Northward Hill than leaving. To me, that implies the birds may well be spreading east during the course of a day, away from the concrete of the Medway Towns, checking a series of feeding areas as they go, before returning direct. Studies have shown adults not only know the better spots, they also know the best times to be there. Youngsters might spend a big part of their hunting time staking out one good spot, not yet appreciating the subtle skills of the seasoned angler. Which might be another appeal for Berengrave- as well escape from all that harassment, somewhere a lot closer to what remains of the southside marshes off to the east.

It also knocks holes in the 'migrating Herons' cognitive bias I suffer when lines of mainly young birds cross Pinup on an early autumn morning.
"Hey, you at the back, you all migrating?"
"Nah, just hungry, that one in front found something yesterday, just following him."

All highly fanciful thinking of course, from my mantra of 'not all movement is migration'. But dreaming about Herons helps pass the time counting the Magpie roost right now. Those numbers are in freefall with their own nesting underway. Couples are coming in together though, feeling safer at the old communal roost than risking a night in a still egg-less nest. But of course there's quite a few single Magpies turning up. Quite a few. 'Club Loser' is open to all, 365 nights a year.