lunes, 12 de febrero de 2024

Endemic birds thriving in Otago

From previous visits to Aotearoa New Zealand, I was expecting endemic land birds to be few and far between, with introduced British and Australian species dominating the landscape. So it was a pleasant surprise to find the tables turned in favour of the natives in the Otago Lakes District. The first bird I encountered on venturing outside was a Tui, perched at the top of a conifer. Then on entering a patch of manuka/kanuka scrub, an unfamiliar bird popped up. It proved to be a South Island Tomtit, actually one of the Australasian robins belonging to the genus petroica. The orange chest markings indicated a male, springing into action to investigate or challenge the intruder.
After sitting down to investigate some bird calls emanating from the scrub, I was soon surrounded by curious passerines investigating the intrusion into their territory. First to arrive were South Island Fantails, displaying at point-blank range by fanning their tails. They were soon joined by a chattering group of Pipipi or Brown Creeper, a relative of the endemic Whitehead and Yellowhead which inhabits scrub across the South Island. Also in the scrub were a Grey Gerygone, the most widespread of the endemic land birds, and a Silvereye, a species of whiteye from Australia. A Swamp Harrier, the commonest raptor in New Zealand, was hunting over the pine forest.
The resilience of the native passerines owes much to the use of trapping to control introduced predators such as stoats and rats. This is a step towards the goal of making the islands predator-free by 2050.

Publicado el lunes, 12 de febrero de 2024 a las 11:58 PM por stephenmatthews stephenmatthews | 8 observaciones | 0 comentarios | Deja un comentario

sábado, 13 de enero de 2024

An uncommon gull at San Tin

Large flocks of Black-headed Gulls winter in Deep Bay and forage around the fishponds of San Tin, occasionally accompanied by other gulls. In January 2024 they have been joined by an immature Common Gull, which in Hong Kong is enough of a rarity to attract a crowd of birdwatchers and photographers. The main subspecies breeding in northeast Asia, known as the Kamchatka Gull, is rather larger that the European Common Gull. A single Whiskered Tern, the only tern species to be seen locally in winter, was over the fishponds, along with a Pied Kingfisher. Also present were wintering ducks including Pintail, Shoveler and Garganey, Common Snipe, and Green, Wood and Common Sandpipers.
The winter of 2023-24 may be the last at San Tin as we (and the wintering birds) know it: a substantial chunk of the wetland area is to be the site of a San Tin Technopole, part of the Northern Metropolis development. Substantial loss of habitat and disturbance due to construction are to be expected, though a wetland park is included in the proposal. The gulls, at least, should be sufficiently adaptable to continue using the site.

Publicado el sábado, 13 de enero de 2024 a las 11:16 AM por stephenmatthews stephenmatthews | 8 observaciones | 0 comentarios | Deja un comentario

jueves, 04 de enero de 2024

The curious tailorbirds

Tailorbirds are named for their nests which are built inside a cradle 'stitched' together from large leaves. Hong Kong has two "tailorbirds", though phylogenetic research reveals that they are not closely related.
The Common Tailorbird is a resident species, common in urban as well as country parks. It will often "scold" intruders with its insistent call.  
Our other tailorbird is the Mountain Tailorbird, a winter visitor and one of several forest species which have recolonized Hong Kong as the forest cover has increased and matured. According to Birds of the World, it favours "bushy thickets, bamboos and hanging tangles within broadleaf evergreen forest, especially along watercourses." This is exactly where it can be found wintering along streams on the campus of the Chinese University campus, as well as at Lung Fu Shan. As its name suggests, it prefers mountain habitats, although these sites are only 100-200 meters above sea level.
As my "record shots" attest, this is quite a secretive species, typically located by its distinctive piercing whistle or chattering call. However, both tailorbirds are curious creatures which will often approach an observer, offering a brief opportunity for a photo. After satisfying their curiosity they will disappear into the forest or return to their foraging.

Publicado el jueves, 04 de enero de 2024 a las 09:40 AM por stephenmatthews stephenmatthews | 2 observaciones | 0 comentarios | Deja un comentario

sábado, 16 de septiembre de 2023

Return of the 'Swintail' snipe

Following record September rainfall in Hong Kong, sports fields have been flooded, forming ideal habitat for passing snipe, and just at the right time of year too: groups of snipe pass through on migration in April and September, having been observed at Kowloontsai Park on April 24, 2020, September 6, 2020, and from (at least) September 8 to 10, 2023. On these occasions there were respectively 2, 4 and 6 birds present. Since snipe are known for their 'site fidelity', revisiting the same spots each year, it seems likely that the same family group is involved.
Now for the difficult part: which species of snipe are these? Local expert John Allcock has identified them as either Pin-tailed or Swinhoe's Snipe, both of which have shorter bills and subtly different markings than Common Snipe. But these two species are so similar that separating them requires either sound recordings or photos showing a spread tail in exquisite detail, failing which, they are known as 'Swintail' snipe. Since photos from Kowloontsai to date do not suffice to distinguish the two species, the puzzle looks set to remain for another year.

Publicado el sábado, 16 de septiembre de 2023 a las 11:36 AM por stephenmatthews stephenmatthews | 1 observación | 0 comentarios | Deja un comentario

domingo, 16 de julio de 2023

In Aoteroa: half a native avifauna

Aotearoa ("Land of the long white cloud") is the traditional Maori name for the North Island of what is now Aotearoa New Zealand. For the naturalist, it is a fascinating but frustrating place. Like Hawaii, it is fascinating because the isolation of the islands has given rise to a wealth of endemic species; and frustrating because so many of these are reduced to a marginal existence. Also like Hawaii, Aotearoa has gone through two waves of extinction: one following Polynesian settlement of the islands, and another following European colonization. The extinctions brought about by these two waves amount to around half the native land birds, from the flightless moas and the eagles which preyed upon them to the iconic huia and piopio. The gaps have been filled by introduced species. Especially bizarre is the suite of British birds, half a world away from home -- Eurasian Starling and Blackbird, Song Thrush, Chaffinch, Goldfinch and Yellowhammer -- juxtaposed with Australian species like Eastern Rosella, Common Myna and Australian Magpie.
Of the surviving endemic species, a few are widely distributed around the main islands. These include the Grey Gerygone, New Zealand Fantail, Tui, New Zealand Scaup and Red-breasted (New Zealand) Dotterel. The New Zealand Pigeon and Bellbird have a patchy distribution on the mainland. The remaining endemic land birds have been extirpated from most of the mainland, surviving only in sanctuaries -- offshore islands like Tiritiri Matangi, or enclosed areas of the mainland from which predatory mammals have been eradicated, like Shakespear Regional Park. In creating these sanctuaries Aotearoa has acted more swiftly and decisively than Hawaii. The sanctuaries have proved so successful that surplus birds can be translocated to new sanctuaries. The success has prompted a bold "moonshot" project: to eradicate predators from the whole of the country by 2050. Local efforts towards this goal are already bearing fruit, with native birdsong returning to more and more areas of the country.
Aotearoa has another claim to ornithological fame -- as the seabird capital of the world. Thousands of shearwaters congregate in the fish-rich waters of the Hauraki Gulf north of Auckland, and can be viewed from ferries or from the shore, including Auckland's North Shore and the Whangaparaoa peninsula. Although few breeding colonies of shearwaters and petrels remain on the main North and South islands, offshore island colonies have benefited from eradication of rats and other predators.

Publicado el domingo, 16 de julio de 2023 a las 02:35 AM por stephenmatthews stephenmatthews | 28 observaciones | 0 comentarios | Deja un comentario

miércoles, 07 de junio de 2023

The Pheasant-tailed Jacana

With their long feet and toes, Jacanas are built to walk on floating vegetation and have quite specific habitat requirements, ideally ponds with water lilies or similar plants on which to walk. Formerly there were many such ponds in the New Territories and Pheasant-tailed Jacanas (水雉 'water pheasant', Hydrophasianus chirurgus) bred around Mai Po until the 1970s. Since then, Jacanas have occurred mostly on passage, typically stopping over in wetlands such as Mai Po and Long Valley in May.
In order to tempt the birds back to breed, an ideal Jacana habitat has been created at the Lok Ma Chau wetlands. Visible from the Lok Ma Chau MTR platform, the lily pond is part of a mitigation project to compensate for the loss of wetland to make room for the new rail connection. But the habitat is small, and the Jacanas first have to find it. This year a bird has instead taken up residence in the unlikely setting of the Cyberport on Hong Kong Island, which has an artificial lake at its centre. The two levels of the lake are separated by a concrete structure, effectively forming a catwalk on which the Jacana has been strutting, to the delight of the assembled photographers.
Let us hope the Jacanas eventually return to breed in more suitable habitat. Like Greater Painted-snipes, female Pheasant-tailed Jacanas are polyandrous, keeping a harem of males to whom they delegate the childcare.

Publicado el miércoles, 07 de junio de 2023 a las 10:57 AM por stephenmatthews stephenmatthews | 2 observaciones | 0 comentarios | Deja un comentario

martes, 16 de mayo de 2023

Rewilding reaches Kai Tak

Following the successful revitalization of the Jordan Valley Channel, Hong Kong's Drainage Services Department has undertaken another 'green river' project at the Kai Tak River, formerly known as the Kai Tak Nullah (drainage channel). The river still flows though a concrete channel but rocks have been added to create elements of a natural river. While increasing the drainage capacity of the channel, vegetation has been planted along the banks. To date, the most extensive revitalization has affected the 'midstream' section of the river between Tai Shing Street and Prince Edward Road East.
As in the case of the Jordan Valley Channel, ecological effects are already visible. Butterflies and birds forage in the foliage. Numerous Black-crowned Night Herons and a few egrets use the riverbanks, while a recent observation seems to show a migrating Malayan Night Heron on one of the newly reinstated rocks. This would explain why I seemed to hear a Malayan Night Heron calling at night in Kowloon City last May.
Most encouraging of all is the presence of several species of fish, including snakehead and mullet, attesting to the water quality. To those old enough to remember the 'notorious' Kai Tak Nullah, this a remarkable transformation.

Publicado el martes, 16 de mayo de 2023 a las 12:11 PM por stephenmatthews stephenmatthews | 8 observaciones | 0 comentarios | Deja un comentario

lunes, 15 de mayo de 2023

A chorus of cuckoos

Spring in Hong Kong is announced by a veritable cacophony of cuckoos. First, as early as late February, come the resident Asian Koels (噪鹃, "noisy cuckoos") and hooting Greater Coucals (褐翅鴉鵑) whose songs inspire their onomatopoeic names. In April the Plaintive Cuckoos (八聲杜鵑) join in with their falling, accelerating 8-syllable song. By early May, the Large Hawk-Cuckoos (鷹鵑) with their feverishly repeated 3-syllable song are heard throughout our woodlands but rarely seen except at Mai Po, where they are joined by the Indian Cuckoos (四聲杜鵑) with their 4-syllable song, sometimes transcribed as 'one more bottle'. Adding to the cuckoo chorus are other birds which mimic their songs, notably the Oriental Magpie-Robin which does a passable imitation of the Plaintive Cuckoo.
A surprise in recent weeks has been the addition of two 'Common' or Eurasian Cuckoos, perching and occasionally singing around the police post at Mai Po. They appear to be a male and a female, presumably a pair on northbound passage, with the female showing a rufous throat. In much of Europe, the two-syllable song of these birds marks the arrival of spring and gives rise to the onomatopoeic name "cuckoo". It makes its way into Beethoven's 'Pastoral' Symphony and even inspired a piece of its own, Delius's 'On hearing the first Cuckoo in Spring'. Curiously, late in the breeding season the song shifts from a falling major 3rd to a falling major 6th, giving rise to the rhyme "The Cuckoo comes in April, sings his song in May, changes his tune in the month of June" and to further musical possibilities. In his 1st Symphony Mahler even transforms the interval into a 4th, taking a certain poetic license in order to echo the primeval falling 4th of his opening bars.

Publicado el lunes, 15 de mayo de 2023 a las 01:44 PM por stephenmatthews stephenmatthews | 1 observación | 0 comentarios | Deja un comentario

sábado, 22 de abril de 2023

Spring migration at San Tin

San Tin is a maze of fishponds, rather like an anarchic version of the nearby Mai Po Nature Reserve. In spring the ponds attract marsh terns, and today a flock of Whiskered Terns was busy fishing.
The fish farmers have apparently been persuaded to leave at least one pond half-drained of water to serve as a feeding site for passing shorebirds. In particular all four species of stint pass through in spring. Today saw a flock of Red-necked Stints, the most numerous of these species on the East Asian-Australasian Flyway; a few Long-toed Stints, which indeed have unusually long toes when one gets close enough to see them; and one or two Little Stints. The diminutive stints do not form a genus of their own, and one of their larger relatives, the Sharp-tailed Sandpiper, is extremely similar in plumage to the Long-toed Stint. A reliable way to distinguish the two is to compare the size to "control" birds such as the resident Wood Sandpipers, which are about the size of the Sharp-tailed and much larger than the Long-toed Stint. As for the Little and Red-necked Stints, they can be difficult to distinguish unless the latter is in red-necked breeding plumage. By catching the two side by side one can spot subtle differences such as the longer legs (black in both species) and longer, more finely pointed bill of the Little Stint.
Other passage migrants present recently have included Curlew Sandpipers, Pacific Golden and Kentish Plovers, Oriental Pratincoles and Eastern Yellow Wagtails.

Publicado el sábado, 22 de abril de 2023 a las 11:38 AM por stephenmatthews stephenmatthews | 12 observaciones | 3 comentarios | Deja un comentario

viernes, 07 de abril de 2023

Spring passage at Po Toi

The island of Po Toi, readily accessible by ferry from Hong Kong Island, is a favoured spot for observing birds on migration.
Since much of the island is bare or has low scrub cover, the trees surrounding the village and along the creek behind it are the main 'hotspots' offering shelter for migrants. A variety of buntings pass through, which today included Black-faced, Little and Yellow-browed Buntings, mostly foraging in the tree litter on the north side of the creek. The trees beside the creek harboured a flock of Ashy Minivets, while a Pacific Swift was feeding with Barn Swallows near the harbour.
By mid morning, raptors can often be seen soaring on the thermals. Today these included two Grey-faced Buzzards on northbound migration and a Crested Serpent Eagle. Soaring with them was an immature Lesser Frigatebird, a scarce spring and summer visitor which typically pursues terns to rob them of their fish.
The ferry ride between Aberdeen or Stanley and Po Toi offers a chance to view occasional seabirds. For most of the year there are few birds on this stretch of sea, but resident White-bellied Sea Eagles can sometimes be encountered perched or in flight. In spring and autumn, Red-necked Phalaropes are often present on the water.
Another attraction of Po Toi is that several butterfly species which are scarce on the mainland are common here. The Green Flash and Yellow Orange Tip were examples today.

Publicado el viernes, 07 de abril de 2023 a las 11:46 AM por stephenmatthews stephenmatthews | 9 observaciones | 0 comentarios | Deja un comentario