Thursday, February 27, 2014

Bluethroats before breakfast

An hour in the Mae Sot Rice Fields this morning produced three Bluethroats, a Wryneck and male and female Pied Harriers as the highlights.


At one point I fund myself peering into a field and finding Bluethroat, Wryneck and two Siberian Stonechats on view simultaneously (good practice for next autumn's trip to Fair Isle!). Other common species seen this morning included a Shikra, Pied Bushchat, at least four Brown Shrikes, several Zitting Cisticolas and Paddyfield Pipit, whilst a Siberian Rubythroat called from deep cover.

Siberian Stonechat
One of many Scaly-breasted Manakins seen feeding on rice

Wednesday, February 26, 2014

Burma Border Breakfast Birding

A short visit to Mae Sot Rice Fields this morning produced the same Black-winged Kite as last night, several moulting Dusky Warblers, at least three Thick-billed Warblers, two Brown Shrikes, three Siberian Stonechat, five Pied Bushchats, two Richard's Pipits and a skulking Siberian Rubythoat that was heard but not seen.

Sibe Stonechat

 This Horsfield's Bush Lark sat up for a while and sang - a couple of pointers to the ID (when compared to Indochinese Bush Lark) are the more discreet streaking on the sides of the neck, and the white outer tail feathers.

Horsfield's Bush Lark

Tuesday, February 25, 2014

Working on the Thai-Myanmar border

I'm in Mae Sot for a few days this week, so spent an hour after work checking out my "local patch" here, behind the airport.

2CY Black-winged Kite

Highlights included this Black-winged Kite, which from the neatly white-tipped greater coverts I assume is a 2CY bird (?), and a less co-operative male Pied HarrierPied Bush Chats were much in evidence, with several males holding territory, whilst there were also a couple of Siberian Stonechats and a Zitting Cisticola active just before dusk.  I also heard  Siberian Rubythroat calling off in the distance, but it was too far away to warrant seeking out.

Monday, February 17, 2014

Pond Herons

The current discussion on Pond Heron identification in the UK, triggered by the discovery of this bird, and this post on Birding Frontiers suggesting that Indian and Chinese Pond Herons may be separable in non-breeding plumage caught my attention.

Chinese PH is an abundant winter visitor to Thailand, whilst Javan PH is resident in some parts of the country, including Bangkok. When I first moved to Thailand I momentarily took an interest in the Pond Herons (because I wanted to tick both species!) but I had to wait until I saw birds coming into breeding plumage before I could convince myself; the received wisdom is that Javan and Chinese PH cannot be separated in non-breeding plumage, and the same message seems to go for Indian Pond Heron too. Indian PH is rare or very scarce in Thailand, but is reported more often these days (there is even a claim of breeding) perhaps due to greater awareness, but Javan also seems to be expanding its range, possibly as a result of larger areas of land under irrigation (Phil Round pers comm.).

This means that I've kept an interest in looking at Pond Herons in late winter/spring in the hope of finding an Indian PH on my patch, and indeed I found a crispy adult in April 2011. Then last July I found an "odd" Pond Heron which was suggested to me might be a hybrid Javan x Indian!

The whole issue about the the Pond Herons being unidentifiable to species in non-br plumage has always left me thinking "somebody is eventually going to figure these things out, it just needs some (perhaps a lot!) of effort" -  the Birding Frontiers blog post made me think that Martin Garner and Ian Lewington might be on to something. Clearly Pond Herons present some interesting questions in terms of ID and range expansion.

Here are the main protagonists in breeding plumage, which is acquired by the pre-breeding moult of the body feathers and inner secondaries (del Hoyo et. al, 1992):

Chinese PH, 7th March 2009, Bangkok

Javan PH of the subspecies continentalis, 13th April 2011, Bangkok

Indian PH, 22nd April 2012, Bangkok (attaining maroon mantle)

putative hybrid (Javan x Indian?) Pond Heron, Bangkok, 2nd July 2013

The possibility of the bird above being a hybrid was based upon it appearing to have a head and neck colour closer to Indian PH, but the mantle and back being entirely dark grey (closer to Javan PH).

With regard to birds in transition from non-breeding to breeding plumage, Martin Garner in one of his BirdingFrontiers posts put out a request for photos of Pond Herons in February, so I was only too happy to contribute some images taken last week, and some text on my interpretation of each bird.  The post can be seen here, and I have adpated the text below.

Bird 1: a fairly classic non-breeding Pond Heron spp, for which conventional thinking is that it cannot be done to species.  This bird appears to have clean wing coverts, so I'm guessing it is an adult.

Bird 1

Bird 2: A few small patches of maroon appearing on the neck indicate that this is a Chinese Pond Heron

Bird 2

Bird 3: A few small patches of maroon (note the one behind/below the eye) indicates that this is a Chinese Pond Heron

Bird 3

Bird 3

Bird 4: This bird shows no indication of breeding plumage (well, perhaps the whitish feather shafts on the bird's back?). It was feeding in the same area as Bird 3, at the same time, and the photos were taken from the same place, just a few seconds apart.  When comparing this image with Bird 3 (shot 2) I am particularly struck by the difference in ground colour (bird 4 being much paler).  Is this within the range of variation of a single species?  It looks like an adult from the clean white wing coverts.

Bird 4

Bird 5: another fairly classic non-breeding plumaged Pond Heron spp. - dirty wing coverts suggest it is a 2nd CY

Bird 5

Bird 5

Bird 6: a Chinese Pond Heron, the most advanced I saw yesterday in terms of its transition to breeding plumage

Bird 6

Bird 6

Bird 6

Bird 7: an adult bird based on the clear white wing coverts, and definitely not Chinese, given the pale yellowish-buff colours that are appearing on the neck.  It could be Indian PH (a rarity in Thailand), but the default species would be Javan PH.  At this stage I think it is too early to be certain.  Javan seems to be quite variable in the intensity of the neck colour, or perhaps it gets darker as the breeding season progresses?  I note that the ground colour of this bird is very similar to Bird 4, which makes me think that bird 4 is the same species (ie probably Javan).

Bird 7

Bird 7

Bird 8: an apparent 2nd CY bird (dirty coverts).  No indication of breeding plumage that I can see.

Bird 8

Bird 8

There are still several unknowns that I'm trying to figure out.  These include:
  • What is the significance of  "dirty" lesser coverts? Wells (1999) suggests that these are an indicator of 1CY/2CY birds.
  • There is significant variation in leg colour  in the images that I have included above - most peculiar is the colour of the legs (which are pink) on the putative hybrid, whereas nearly all the other Pond Herons (Indian/Chinese/Javan) in images on Oriential Bird Images, and in my pictures have yellow legs, though interestingly a couple of photos on OBI from Thailand show breeding plumaged Javan Pond Herons with pink legs (see here and here).  Leg colour seems to change in both Chinese PH and Javan PH during courtship (del Hoyo et. al, 1992; Round, 2008).  What might the significance of this be?
  • Are there any differences in Pond Heron non-breeding plumages in autumn/early winter that will allow specific identification?  This is the million dollar question! I'll be honest and say that in autumn I have always ignored Pond Herons in favour of hunting down interesting warblers and flycatchers on my patch, though counts of 50-100 Pond Herons on days in October have indicated to me that there is a significant passage (presumably of migrating Chinese PHs, rather than "sedentary" Javans, but perhaps there are some Indian PHs in there too?).

Monday, February 10, 2014

8th February

A couple of hours in Suan Rotfai  on Saturday morning where quite productive, with the Northern Boobook still present, a female type Siberian Rubythroat offering exceptional views, a Peregrine stooping across the north end of the park, and a single Black-naped Monarch.

Northern Boobook

The most confusing bird was a singing Cinereous Tit - where the hell did that come from?  A bird of mountain forests in Thailand, with all populations being sedentary. The suspicion must be that it is an escapee from the Chatuchak weekend market, but what is the possibility of it being a genuine vagrant from one of the more northerly populations during cold weather?

Other notable species seen included two Thick-billed Warblers and a White-rumped Sharma.

Siberian Rubythroat

Yellow Bittern

Tuesday, February 4, 2014

Collared Pratincole in Thailand?

A pratincole spp. showing a white-trailing edge to the wing, and other features supportive of Collared Pratincole was seen at Wat Komnaran (nr Laem Pak Bia) by visiting birders on 22nd January.  It has apparently been seen again this morning...

A broad white-trailing edge to the wing is considered by Driessens & Svensson (2005) to be a clinching feature of Collared Pratincole, so this bird sounds very interesting.  Apparently there is a small population of Collared Prats that breeds in Pakistan and winters in western India where they may come into contact with Oriental Pratincoles (all other Collareds winter in Africa).  There is apparently a record of a vagrant Collared from Sri Lanka and also from the Chagos Islands (500 mile south of the Maldives), so a bird appearing in Thailand is not beyond the realms of possibility.

Monday, February 3, 2014

Thailand on fire (in a good way!)

There have been some very interesting bird records in various parts of Thailand in recent weeks that remind local birders to expect the unexpected, to keep an open mind and to look very hard at everything.

The latest gem is a Jouanin's Petrel seen off Leam Pak Bia yesterday, which follows hot on the heels of Thailand's first identified Bay-backed Shrike that has been present at Laem Pak Bia (and overlooked for a month!) until Peter Ericcson saw it and queried the ID last week. Subsequent trawling of photos shows at least one previous record of the latter species from Bang Poo in 2009.  

Add to this the drake Baer's Pochard and a pair of Long-tailed Ducks (Thailand's second record) at Chiang Saen, plus a Greater Adjutant (which would be the first in Thailand for several years) reported near Khao Sam Roy Yot NP and you have a pretty amazing set of records.