TOPIC 7 Birds of Wetlands Friday, 9 November 2007 : 08.30 12.00 - PowerPoint PPT Presentation

Spoon-billed Sandpiper Eurynorhynchus pygmaeus Status: endangered, declining World population: > 1000 individuals Winter visitor in small numbers to tidal flats, salt-pans in S and SE Asia. Largest concentrations on passage around the Yellow Sea (single counts of 100-180 birds) Declined by 60-80% in two decades

A variety of human uses continues alongside use of the area by waterfowl

Mudflat “reclamation” Yellow Sea- Korea & China Spoon-billed Sandpiper •Used by ca. 2,000,000-3,000,000 –perhaps 50% of the migratory shorebirds per year world populatiom) •36 shorebird sp. in internationally important concentrations •tidal flats ca. 20,000 km 2 - 40% already reclaimed •Plans in hand to reclaim a further 43 % Great Knot Calidris tenuirostris 300,000- 400,000 – 90% of the world population

One reclamation alone at Saemangeum, Korea is in the process of destroying 400 km 2 of coastal; flats

Large areas of shoreline are:- Industrialization Urban sprawl Pollution little remaining space for shorebirds Mudflat reclamation the next step?

Shorebirds •511 discrete populations worldwide •96 (19%) declining •72 stable •32 increasing •304 (59%)– no information

Conservation issues Wetlands are probably the least well conserved habitat of all tropical habitats -human use for x 000s of years •hunting/fishing •agriculture •transport & communications •Other?

Wildfowl: including ducks, Anatidae : Mobile and adaptable Key requirements: undisturbed water bodies on which to roost feeding areas (usually croplands such as rice paddy)

Lesser Adjutant Giant Ibis Sarus Crane Unmodified floodplain – open forest and small ponds / waterholes – once supported a megafauna of large birds and mammals. Now largely cleared and replaced by rice-paddies

Almost entirely lost! Kulen Promthep Wildlife sanctuary one of the last extensive areas supporting an intact lowlandfauna

The lowland bird megafauna Giant Ibis White-shouldered Ibis Most of these species are Sarus Crane endangered/critically endangered in SE Asia Woolly-necked Stork Black-necked Stork Lesser Adjutant Greater Adjutant Bengal Florican All species associated with grasslands/ponds /open forests of little- disturbed lowland floodplains

Some larger waterbirds: vulnerable or near- threatened- may be increasing again Painted Stork Spot-billed Pelican Why? Oriental Darter

Species that are threatened/near-threatened but which may be again increasing Better protection at breeding Painted Stork colonies in Cambodia Spot-billed Pelican Can use artificial wetland habitats, e.g., Oriental Darter fish-ponds, irrigated areas Fish-eating- benefit from increased aquaculture In some cases numbers may be augmented by released captives

Paddies: traditional paddies – one crop per year, long fallow period and low pesticide input. Still support a rich array of birds

Agricultural intensification Two or three crops of irrigated high-yield rice: use of herbicides, pesticides and rodenticides Area of irrigated rice increased from < 1600 km 2 in 1974 to 6400 km 2 by 1996 (Source: Molle et al ., 2001) •Habitat mosaic- always some wet areas May benefit some waterbirds such as egrets and Asian Openbill Anastomus oscitans •Loss of the fallow period •loss in overall biodiversity driven by reduction in populations of insects and weeds

Changes in abundance of farmland birds around the Lower Central Plain 120 100 Shrikes 80 schach 60 cristatus 40 20 0 Insectivorous species have 4 5 6 7 8 9 0 1 2 2 3 3 4 4 5 6 7 8 9 0 1 1 2 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 9 9 9 0 0 0 0 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 shown a marked decline 600 500 Egrets 400 Egretta 300 Bubulcus 200 100 Egret numbers have remained 0 more or less stable 4 5 6 7 8 9 0 1 1 2 2 3 3 4 4 5 6 7 8 9 0 1 1 2 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 9 9 9 9 0 0 0 0 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2

Cascade of extinctions/effects 1) Ibises, White-winged Duck, Sarus Crane; mammal megafauna Cause: low-intensity use, hunting, etc . 2) Storks, Adjutants, Pelicans Cause: large-scale habitat conversion 3) Collapse of insectivorous bird community Cause: adoption of high-yield rice cultivation, irrigation, pesticides, etc.

Rivers present special problems •Linear habitats •Resources shared by many users ( e.g ., Mekong River, 6 countries) •Used for transport and communications •fisheries, irrigation, etc . and very heavily impacted Peoples’ Republic of China is currently engaged in blasting rapids and dredging sandbanks to allow the passage of large boats (500 tonnes) along the Mekong between S. China, N. Thailand and Laos. This will destroy habitat for sand-bar nesting birds such as River Tern Sterna aurantia and Great Thick-knee Esacus recurvirostris (above).

Blasting of rapids and dam construction on the Mekong River

Coastal areas Conventionally, most emphasis placed on mangroves BUT very few waterbirds are limited to this habitat Key habitats for shorebirds: -intertidal mudflats offshore - extensive zone of low intensity prawn ponds/salt pans onshore

Planting mangroves on mudflats alters the habitat: -prevents access for feeding by shorebirds - Impact on mudflat benthos not fully understood. ca. 130 km 2 of mangroves planted on intertidal areas in 18 Thai provinces during the last 6 years

Climate change Global temperatures have increased c. 0.6 C in last 100 years Particularly threatening for high arctic nesting waterbirds Breeding areas - more fires Thawing of permafrost causing drying out of tundra wetlands Wintering areas Rising sea-levels Inundation of mudflats Reclamation- construction of sea barriers

Disappearing duck! •Formerly 100+ at several sites in Thailand (largest count 596) •No more than 10 have been seen anywhere in recent years Baer’s Pochard Aythya baeri •Yangtse Valley >500,000 waterbirds counted 2005 - only 8 Baer’s Pochards

East Asian Australasian flyway •Human pressure greater than in any other •80% of all wetlands are classified as threatened •Very high percentage of the world’s threatened waterbirds •( e.g . holds 58% of all the world’s threatened species of shorebirds) Many of the most immediate threats come from governments • Korea and China “reclaiming” mudflats of the Yellow Sea • Thailand at least 7 out of 10 Ramsar sites are threatened by government schemes Government support for monitoring Integrate findings in better land-use planning

Asia Pacific Migratory Waterbird Strategy adopted at the Ramsar Convention in 1996. Action plans for Anatidae, Cranes, Shorebirds developed • Key elements include: – Information exchange – Training – Education and awareness – Migratory bird research – Development of site networks • East Asian-Australasian Shorebird site network : 31 sites in nine countries

Techniques

How to estimate numbers of waterbirds? Wetland habitats are discontinuous direct counts appropriate, especially when birds are concentrated •At roosts •breeding colonies •feeding areas Transects across feeding areas yield information on habitat use Coordinated counts by teams of observers in larger wetlands

Black-faced Spoonbill Platalea minor 2005 Census 1,475 birds

Sometimes estimates may be wrong by even an order of magnitude Oriental Pratincole Glareola maldivarum Wetlands International (2003) estimate was 75,000 BUT 2.88 million were counted in NW Australia in February 2004 (Sitters et al ., 2004)

Turnover -complicates assessment of the numbers of birds using a site “Rule of thumb” for migratory shorebirds, estimated migratory population at a site is roughly 4 x the maximum count

Usage (bird-days): average of a series of counts x time interval (days) may provide a more meaningful estimate of total usage than just numbers

Different populations or subspecies may use different wintering sites/staging areas How do we identify them? Red Knot Calidris canutus

Capture and marking Mist-nets erected for catching waterbirds

Methods of marking Ringing or banding: used for over 100 years Numbered metal band applied to the leg of a bird

Recoveries of ringed birds build up a picture of origins and destinations. Ruddy Turnstones wintering in UK come from two discrete breeding areas, from Greenland and Scandinavia

Colour-marking methods Enables place of origin of marked individuals to be identified non-intrusively. One colour combination per flyway site Ringed in S. Australia A leg-flagged Curlew Sandpiper Resighted Inner Gulf of Thailand, April 2005 7062 km, with a bearing of 316 degrees, from the marking location

Leg-flagging >250,000 shorebirds ringed in Australia 126,000 leg-flagged (since 1990 ) •534 recoveries •3903 sightings

LEG FLAG CODES FEBRUARY 2007 RUSSIA CHINA Pale Blue Pale Blue Pale Green Yellow Yellow Green White Black White nothing nothing Black White Orange Black White Wrangel Isl. NChukotka S Chukotka Kamchatka Sakhalin N Yellow Sea Chongming Dao Chongming Dao Taiwan Hong Kong Korea Blue Blue Blue Blue (angled) Blue White White White Blue nothing White White (angled) Orange Blue Yellow Orange Hokkaido C Japan S Japan L. Komuke Shunkunitai Obitsu Yatsu Tidal Flats Kyushu SINGAPORE PHILIPPINES THAILAND INDONESIA AUSTRALIA Green Black Black Black Yellow Yellow Green Orange White Blue Green Orange Orange nothing nothing Green Singapore N Philippines Inner Gulf Java SW WA NWA QLD NSW AUSTRALIA NEW ZEALAND USA Orange Orange Orange Orange Orange White White Yellow band nothing Blue Yellow Blue Yellow nothing Green Green flag Victoria Tasmania SA Tasmania SA North Island South Island Alaska

Radio-telemetry Often used to study movements of e.g territorial birds that only move short distances Advantage: transmitters are small and light-weight (down to 0.4 g) Disadvantages: - can only be used where the bird can be tracked at short range. – of limited use for highly migratory species

Radio telemetry- may be used for species that do not disperse long distances e.g, tracking feral /released Painted Storks

Satellite telemetry Advantage: •Can follow birds for long (globe-spanning) distances Disadvantage: •very expensive •Transmitters are rather large (4-15 g) and can only be fitted to larger birds

Satellite tracking of Lesser Whitefronted Goose Anser

Satellite-tracking of the Black-faced Spoonbill Platalea minor

Counting methods Direct counts or direct estimates Make life easy for yourself! Use a tally counter for large numbers Block off in groups of ten, or twenty, or fifty, depending on the size of the flock (After Howes and Bakewell, 1989)

How many birds? This flock contains 9 blocks of an estimated 50 birds per block = 450 birds. Actual flock size = 491 birds After Howes and Bakewell (1989) With practice, counts will usually be accurate within 10%

n= 21 HOW MANY? HOW MANY? � �