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Location:
Manila Bay
(starting from Navotas, National Capital Region up to Baluarte,
Obando, Bulacan province only)
Date: January 25, 2004 (Sunday)
Time: start (7am) - 2/8 cloud cover,
end (3pm) - 4/8 cloud cover
Kitty Arce, Nilo Arribas Jr., Mads Bajarias, Lala Española,
Lu-Ann Fuentes, Jon Villasper
First,
big thanks to Kitty for arranging the boat trip without which
the trip would not have been possible.
The part of Manila Bay stretching from the Navotas wharf in
the National Capital Region upwards to Obando, in Bulacan
province is characterized by shallow intertidal mudflats and
occasional sandbars.
Patches of mangrove swamp survive, but most have been converted
to various aquaculture schemes particularly
fish and shrimp ponds in the Baluarte, Obando area.
Since
it was lowtide, the water was extremely shallow for our boat
to come close to shore. We had to disembark from the boat
and stand in about 2 feet of water and set up the scope with
the mud sucking at our feet making movement difficult.
Needless to say, this was a novel way to watch shorebirds:
This was the first time I've ever watched birds while I was
in the water and the birds generally were on the dry side.
I think the others also shared this somewhat peculiar predicament.

According to Mallari etal. in "Key Conservation Sites
in the Philippines", "Large numbers of migratory
shorebirds use the intertidal mudflats, fishponds and salt
pans...in winter and during the migration season. [Manila
Bay] has consistently registered the highest numbers of waterbirds
at any site in the Philippines during the Asian Wetland
Counts in 1990-1994. There have been records of several
threatened waterbirds there, but it is unclear whether this
area is of significance for the conservation of any of these
species."
Two rare species mentioned in the book are Black-faced Spoonbill,
of which there is said to be 2 possible records in the early
20th century, from near Manila and at Baluarte, Obando, Bulacan
province; and Nordmann's Greenshank,
which has been recorded at Obando, Bulacan province in 1927.
Prior to the trip, Arne had emailed Kitty detailed descriptions
of the specific sites where he had encountered large concentrations
of shorebirds, along with photos of Nordmann's greenshanks
to aid us in identification, if we come
across any.
Although we weren't lucky enough to spot either of the 2 rare
species, we were able to see individuals of the
vulnerable Chinese egrets in the company of Little
egrets and Great egrets. This group of egrets were feeding
in the shallow waters in the coast of Obando. We viewed the
birds through the scope for about 20 minutes at a distance
of 200 meters.

Admittedly, we had difficulty in getting field ID of Chinese
egret in their non-breeding plumage, due to their
similarity to Intermediate egret and the white phase
of the Eastern Reef egret.
Try as we might, even with the Club's Bushnell scope turned
to full power, we could not determine the orbital skin of
the birds.
However,
below are the three aspects which we considered in identifying
the birds as Chinese egrets:
1) The extent of black on the upper mandible. The birds which
we suspected to be Chinese egrets had just a smidgen of black
on the top part of their upper mandibles, and the lower mandible
is all-yellow. Looking at the plates in Kennedy etal, Intermediate
egret has more black on the upper mandible and on the tip
of both mandibles.
2) Foraging behavior. The birds were more animated than the
Little egrets. They flapped their wings, and generally moved
about in the shallow water more than the Little and Great
egrets.
3) Greenish leg color. This is very apparent even from afar.
Arne and the census takers had ticked off 17 Chinese
egrets the previous week, if this is the same spot
then most likely it is the same group.
By the way, I looked through the book, "Threatened Birds
of the Philippines" by Collar etal. (Bookmark 2000) and
found that there were no reports of Chinese egrets in Obando,
Bulacan. The closest areas with records were Puerto Rivas
in Bataan, Parañaque, and in Matabungkay, Batangas.
The reports from those places were in the 80s and 90s. Aside
from the egrets, we saw about a thousand terns while scanning
the horizon from the Navotas wharf. This guesstimate is the
result of estimating the number of individuals that fit in
the scope's field of vision, and then counting the number
of shifts made to move the field of vision from one end of
the horizon to the other.
Another
great concentration of terns were seen in a large dried pond
behind the white chapel in Baluarte.
Another
species seen in great numbers is the Common greenshank, which
numbered hundreds.
Dozens of Black-headed gulls were also seen both in flight
and "sitting" on the water like ducks.
BIRD
LIST:
1. Grey heron [Ardea cinerea] - 1. Standing motionless.
2. Great egret [Egretta alba] - 7. Standing on shore with
Little egrets and suspected Chinese egrets.
3. Chinese egret [Egretta eulophotes] - 6
4. Little egret [Egretta garzetta] - 50+.
5. Little heron [Butorides striatus] - 4. Standing motionless
in dried pond.
6. Black-crowned night-heron [Nycticorax nycticorax]. 2
7. Cinnamon bittern [Ixobrychus cinnamomeus] - 1. In flight
8. Plover species [Charadrius sp.] - 500+. on shore, sand
bars and dried ponds.
9. Asian golden-plover [Pluvialis fulva] - 6. Feeding on pebbly
mud next to a rivulet.
10. Common redshank [Tringa totanus] - 50+
11. Common greenshank [Tringa nebularia] - 200+.
In tight flocks both on shore and in sand bars within dried
ponds.
12. Stint species [Calidris sp.] - 5.
13. Black-headed gull [Larus ridibundus] - 30+.
14. Tern species [Chlidonia sp.] - 2,000+
15. Common kingfisher [Alcedo atthis] - 1.
16. White-collared kingfisher [Halcyon chloris] - 2. |