wgeoff

Transition Week - October to November. I had a visitor from England staying with me this week - Stuart Jack.

A Transition Week in time between October and November, and also a Transition Week in birds. Autumn is a season of two distinct birding halves, the first half to the middle of October for the early migrants, insectivores such as flycatchers and leaf warblers, and the second half from the beginning of November for the later frugivores such as thrushes and chats. In between, a short period with relatively less daily species, as can be seen from my Annual Expected Value Chart for 2012 to date



The white line shows my 'expected' number of non-resident species on any day, based on averages over the past six years. The red line shows what I have had in 2012.   
Two things to note
1. the dip in 'expected' value in late October (and also in mid-April)
2. this year, a below average spring and so far, a well above average autumn

Also a week of two halves, the first half wet and miserable, the second half sunny and dry. Miserable for the birds also, as these photos of an Amur Falcon and a male Chestnut Bunting taken on Tuesday show



Hawfinch!! - where did that come from. Not seen by me anyway, congratulations to the finder and commiserations to the Records Committee for another long and difficult decision. My bird of the week was a Golden-spectacled Warbler seen in Green Pigeon Lane on both Tuesday and Thursday, no photos and not quite identified to species but no wing bar, completed eye-ring and black crown stripes starting above the eye indicate Alstrom's again. Maybe the weekend punters will be luckier with the photos.

A new bird arriving on Thursday was a Pale-legged Leaf Warbler. I say that, but it could well have been a Sakhalin Leaf Warbler. My evidence on Po Toi is that there are two fairly distinct periods in both autumn and spring for this 'double' species.



In autumn, the first period is September and the second is from mid-October with a gap of two weeks between. I would like to believe these are splits of the two species, the first period Pale-legged and second period Sakhalin. This is only partially supported by data in Avifauna but it could be that at least 'most are' split like this.

This year, so many male Daurian Redstarts, in a proportion eight male to one female whereas in past years it has been three females to one male.



Any explanations?

Two Bramblings and at least 12 Siskins were there all week



Also new autumn species (for me) this week, Japanese Sparrowhawk, White's Thrush and Red-tailed Robin.

Finally, a surprise from the Ferry coming back - a flock of five Eurasian Teal which Brendan spotted, initially flying and then settling on the water, causing a panic as people scrambled for binoculars and cameras with the thought of rare seaducks whizzing through their brains before the real identity became evident



[ Last edited by wgeoff at 2/11/2012 17:20 ]

wgeoff

Hi Wilson

There are two factors at work here, genes and weather.

Genes cause the bird to migrate at particular dates mostly determined by length of daylight. In autumn, genes will instruct flying insect eating flycatchers to migrate earlier than seed eating buntings or fruit and ground insect eating thrushes. If flycatchers leave too late, they may die on migration due to lack of insects. If buntings are too early, the seeds may not yet have formed. The genes of each species have developed over a long period of time due to the principle of 'survival of the fittest' - those birds with the correct 'timing' genes are more likely to survive and pass their genes on to the next generation. It is genes which decide when they start, based upon length of daylight, not temperature.

Once they are on the move, weather can affect their day-to-day movements. Northerly winds tend to produce more migrants in the Hong Kong area because birds travelling in their natural direction from north-east China to south west China are diverted further south and are more likely to pass through coastal southern China. So weather can have short term effects.

The dip in species numbers in late October occurs in most years, and is due to flying insect eating species mostly passing through in September/early October, fruit and ground insect eating species arriving from the beginning of November with seed eaters such as buntings a little earlier. So the number of species is usually less in the second half of October although timings of individual birds are not absolutely precise and there are overlaps of late and early birds.

This year, we have had a particularly good season for the early migrants, for reasons which are not really known but may be due to a good breeding season. Whether this will continue for the later migrants, we don't yet know - it may not necessarily be the same.

In winter, once the birds are in their winter quarters, they may be forced to move further south during long periods of cold weather due to lack of food. But these movements, called cold weather movements, are not true migration.

[ Last edited by wgeoff at 2/11/2012 19:07 ]

wgeoff

A good week this week with lots of species (and photos) although nothing very unusual.

Raptors represented by two Amur Falcons, a Japanese Sparrowhawk, a Crested Goshawk (a regular November arrival, possibly to over-winter) and a Kestrel on the South Peninsular. Here an Amur Falcon (looking into the sun, so outline only) and Japanese Sparrowhawk



Wintering chats and thrushes are now coming back, right on schedule. Red-tailed Robin and Red-flanked Bluetail joining the Siberian Rubythroat and Daurian Redstart already present for two weeks, similarly Japanese, Eyebrowed and Grey-backed Thrush joining the noisy and showy Blackbirds

  

I mentioned the numbers of male Daurian Redstarts last week. This week, the females joined, doubling the numbers and easily exceeding past records for the species



What will happen now? Can the area sustain so many or will some have to move on?

Warblers well-represented. Asiab Stub-tail and Mountain Tailorbird now back in numbers, also a few Japanese and Russet Bush Warblers, an unexpected Black-browed Reed Warbler nowhere near any reeds, Arctic, Greenish and Pale-legged Leaf Warblers as well as the common Yellow-browed.



This has been a good year for Raddes Warblers and I had two on Wednesday with very different under-body plumage. One the standard buff with brighter undertail, one quite yellow with streaking.



But yellow and streaked does not mean Yellow-streaked, I've made that mistake before, the huge bill on the second bird here means it's still a Raddes

Flycatchers not well represented, just two Asia Brown and this one Mugimaki on Wednesday



On to buntings and finches. Still many Chestnut Buntings but always difficult to photograph, with Black-faced and the first Tristram's. Also one Brambling and a pair of Siskins, maybe the Siskins are new arrivals but the Brambling is an old friend



Finally, someone photographed a juvenile male Plumbeous Redstart on Tuesday (facebook). A great bird for Po Toi, second record, unfortunately I didn't see it.

[ Last edited by wgeoff at 9/11/2012 08:18 ]

wgeoff

The first photo is Japanese Yellow Bunting. This is the fourth year of autumn records in Hong Kong since the first in 2007.
The warbler is a Golden-spectacled Warbler, probably Bianchi's Warbler.
The other id's are correct and also good records.

Thanks for posting the photos.

[ Last edited by wgeoff at 12/11/2012 14:22 ]

wgeoff

Another week with high species counts which has characterised this autumn. But it didn't last all week.

Light north-east winds and clearish skies on Wednesday night were an invitation for birds to start their next migration leg. Birds are not stupid, at least the survivors aren't, so they took the call. Whether they can predict future weather is still uncertain but I believe they can sense changes in air pressure as well as understanding the current weather. Anyway, the smart ones took the opportunity. On Wednesday evening I started seeing Blackbirds flying off over the harbour as I was having dinner. Later in the dark I could hear Japanese Thrush doing the same.

By Thursday morning it was clear that many birds had left. From a high count of 44 species on Wednesday, I was down to only 27 on Thursday. Numbers of Blackbirds, Japanese Thrush and Dusky Warblers fell significantly, Blackbirds from 21 on Wednesday to 6 on Thursday, Japanese Thrush from 14 to 6 and Dusky Warblers from 15 to 4. Some didn't change at all - Daurian Redstart still in record numbers (23) on Thursday, also Asian Stub-tail (5). But mostly bad news for the Thursday day-trippers.

Best birds of the week, a Chestnut-eared Bunting, only the second Po Toi record, and a very late Japanese Paradise Flycatcher, both on Wednesday

  

Oriental Turtle Doves are now at peak numbers, a few Chestnut Bulbuls have arrived possibly indicating another winter influx. This species only appears in occasional winters, 2006-7, 2009-10 and 2010-11 to date so these are the first for nearly two years. Wintering Chinese Bulbuls and Japanese White-eyes are now also at peak numbers and although I don't keep counts of them, I'm sure Crested Mynas also increase numbers at this time.

A Brown Shrike appears to be settling in for the winter around the ferry pier area and a White's Thrush around the Upper School. Two Lanceolated Warblers were seen during the week, one on Tuesday just hopping around a path keeping a few photographers very happy (not me, I didn't see it) and one I nearly trod on next to the sister's cafe. This has been a good autumn for sightings of Lanceolated. Pallas's Leaf Warbler is now back and there was still a Pale-legged Leaf Warbler on Wednesday. Flycatchers in quite short supply now, the Japanese Paradise above, a good count of three Red-throated on Tuesday and a single Mugimaki on Thursday. Bunting numbers are now well down on October but some rare species are possible in November, unfortunately I didn't see any of the specials from last weekend.

Here some photos of various species, I was particularly pleased to find a co-operative Mountain Tailorbird, they're normally impossible to photograph



Another weather change coming, maybe will bring some new species next week

[ Last edited by wgeoff at 16/11/2012 06:53 ]

wgeoff

Another week with high species counts and a large influx of thrushes on Tuesday night, mostly Pale Thrush but with some Eyebrowed and Brown-headed Thrush also.

On Thursday there were at least three different Brown-headed Thrushes, a new HK high count I believe. Herman has already posted a good photo of one from Tuesday (under Pale Thrush). Here are a mixture of rather poorer photos of Brown-headed, Eyebrowed, Japanese and Pale Thrushes



Also good species in the week, a Japanese Sparrowhawk, a Japanese Quail which I disturbed from the helipad very late on Tuesday evening, a migrant White-breasted Waterhen freshly arrived also on Tuesday, a Hoopoe seen briefly near the sister's cafe on Tuesday, my first of the year, a Red-rumped Swallow, rare on Po Toi, a very late migrant Grey Wagtail which appeared in poor condition on Tuesday but had recovered by Thursday, an influx of Red-flanked Bluetail including a very fine but elusive adult male near the restaurant on Thursday which Aquagras followed for 30 minutes without getting a single photograph, at least five different Japanese Bush Warblers and similar numbers of newly arrived Brownish-flanked Bush Warblers, yet another Raddes Warbler, this one on the South Peninsular, a brief sighting of a spectacled warbler around the sister's cafe on Wednesday, almost certainly Bianchi's and possibly the bird seen there ten days before, a Red-breasted Flycatcher which arrived one day after Brendan's at Mount Davis (but unfortunately a first-year bird), and finally a very noisy Common Rosefinch which flew around repeating a 'choowhee' call before leaving altogether.

Here photos of the Raddes Warbler, Red-breasted Flycatcher and an unusually co-operative male Siberian Rubythroat which chose to sit on a rock for ten minutes!



As I have mentioned to several people, this is my last autumn to stay on Po Toi after seven years regular weekly trips. I will probably do two more weeks this year and then finish. Age is catching up and I'm finding it increasingly difficult to summon the energy needed to keep going. So I will be looking for a new patch and a new challenge starting from autumn next year - Mount Davis is looking very good. At the moment I still intend to do another spring on Po Toi next year, basically because I love watching the seabirds. But that will be my last Po Toi.

[ Last edited by wgeoff at 23/11/2012 09:51 ]

wgeoff

Thanks for all these comments.

Just to clarify, I do intend to go back to Po Toi for one more spring, from March to May 2013, mostly to go seabird watching.

I made this statement about finishing at Po Toi very early for two reasons. Firstly, to convince my wife that I really meant it this time (there have been several previous false alarms). Secondly to give anyone who wants to take over time to prepare.
So if anyone wants to do it, please contact me and we can discuss options.

wgeoff

Tuesday is a day that few of those lucky enough to be there, and crazy enough to brave the cold and rain, will ever forget.

Six photographers and four regular birders were on the ferry that morning. The photographers were targeting the Vivid Niltava and Hill Blue Flycatcher. The birders were just hoping to see anything while keeping as dry and warm as possible. As the ferry arrived, we split up as usual, me heading for my house to drop off food and clothing, the photographers heading for the sisters’ café and the birdwatchers going their own way. Fortunately, the rain held off for most of the next three hours.

As I slowly made my way back towards the ferry pier, it was obvious that a good fall of thrushes had occurred. There were thrushes flying over or in trees, Japanese, Grey-backed, Eyebrowed and Pale Thrush fairly easy to find with at least one Brown-headed and many noisy Blackbirds. In fact, birds were to be seen everywhere so it was 1.15pm before I climbed the steps to the sisters’ café. At the top, I could see the assembled group of photographers, including Aquagras (Daniel Yau) and Paul Kam.

They were all wildly excited at having had spectacular close views of the Vivid Niltava. After making suitable ahh and ooh noises at their photos, I finally asked whether they had seen anything else. Daniel replied – ‘well, we had this greenish-looking pigeon when we first arrived’. Emerald Dove I thought, good record, so I asked to see any photos. After a long wait stumbling through hundreds of Vivid Niltavas, he eventually found one of the ‘greenish-looking’ pigeon – a perfect photo of a real Green Pigeon! OMG! Definitely a first record for Po Toi, probably a fourth or fifth record for Hong Kong.

After looking at this and a few others, on the small screen, I assumed it was a White-bellied Green Pigeon. Apparently it was first found in the tree beside the football field. This is the first real tree for any migrant arriving at the South Peninsular making its way towards the main Po Toi area and I have often found newly arrived migrants sitting there having a rest before moving on. Later it had flown off towards the central area.

By this time it was only 20 minutes to the ferry departure so we made our way down the concrete steps. By luck, everyone from the ferry was assembled together. As we reached the bottom of the steps, Paul said – ‘it’s there – in the tree’. Rather stupidly, I said - ‘what is?’. ‘The Green Pigeon, you idiot’ should have been the answer but he more politely missed off the last two words. And it was, sitting hunched up in the bare tree at the bottom of the steps.

We all managed good views and a dozen or so photos before it took off and flew across to the trees just below the school and it was time for the others to run for the ferry, and for the rain to start again and not stop for the next 24 hours. My own photos are very poor, for some crazy reason I had decided to experiment with an old lens which really wasn’t working.
Fortunately the professionals are not so stupid and here are three which Paul has kindly loaned me and allowed me to reproduce here





As we can now all see, the long undertail coverts and underbelly pattern show the bird is, in fact, a Whistling Green Pigeon, as suggested by Koel Ko. Moreover, the large size of the bird and the narrowness of the white markings on the undertail coverts show this is the Ryukyu Islands subspecies, given as a separate species Ryukyu Green Pigeon in Birds of East Asia. It appears from the researches of various individuals into Taiwan birding websites as here

http://nc.kl.edu.tw/bbs/showthread.php?t=47215

that this species has turned up at Chigu, Tainan and Matsu just off the coast of Fujian within the last week, according to EXIF data on the photos. So it seems that the Po Toi bird is a genuine wild bird. I have often seen racing pigeons from Taiwan on Po Toi (they all have Taiwan rings) so it’s not an impossible journey.

It really doesn’t matter that it rained for most of the rest of the week, or even that most of the birds left on Tuesday night (obviously the cold and rain was too much for them also). We had seen the big one. Po Toi has this fantastic ability to attract the big ones – species that are unlikely to ever occur again in Hong Kong. This year so far, the Brown-backed Needletail and the Varied Tit come in that category for me (incidentally, the arrival of this pigeon on Po Toi has convinced me that the Varied Tit was a genuine wild bird).
Let’s hope the Whistling Green Pigeon has copied the behaviour of its earlier counterpart, the Orange-breasted Green Pigeon, and is hiding somewhere on Po Toi in a fruiting tree, only to re-appear at monthly intervals for the lucky ones.  

All I can say is, thanks to AFCD, HKBWS and other environmental groups plus all those individuals for their support in keeping the developers off Po Toi. If they had allowed it to happen, the site where most of these birds have been seen would now be a construction site with tens of workers and heavy equipment. Let’s remember that and fight to keep Po Toi unspoilt for ever.

[ Last edited by wgeoff at 30/11/2012 08:54 ]