A simple identification
guide for birds
|
Sighting of INDIAN POND-HERON (Ardeola
grayii) in Penang
I have been
monitoring the rice fields in the Penaga area, on the mainland part of Penang State, since
January 1999 for almost every day. This is around the area where I work which is
almost at the border to southern-western Kedah.
In mid January 1999, large
numbers of birds of the family Ardeidae were seen over the area in the mornings and
evenings but were not present in such large numbers as in October/November 1998 and even
in previous years. Most likely this was used as a staging point for the 1999
spring migration. My estimate of Chinese Pond Heron (Ardeola bacchus) that
roost in this area is over 1000, which is 1% of the world population. There are also
Javan Pond Heron (Ardeola speciosa), may be about 10 to 15 and a few hundred
Great Egret (Casmerodius albus), Little Egret (Egretta garzetta), Cattle
Egret (Bubulcus ibis) and a small number of Intermediate Egret (Mesopoyx
intermedia). I have not identified any Chinese Egret so far in this
area.
The first Indian Pond Heron (Ardeola
grayii) was sighted on 12 April 1999. Probably this is the first reported
sighting of this species in Peninsular Malaysia but there is a 1994 sighting report for
Singapore whose status was undetermined.
At 0738 hours,12/04/1999, Penaga
District, Seberang Perai, one bird in the rice fields. There were Chinese, bacchus
and Javan, speciosa in the same rice plot and adjacent plots for comparison, the grayii
had reddish-brown (maroon) back and complete white crest plums. The central
part of the back was fairly dark but not of the same colour of bacchus and speciosa.
The breast and neck was grayish white with a tinge of golden-yellow and slightly
darker crown. The lower breast was much darker. The bird was
observed for about 3 minutes at a distance of about 100 feet using 8 X 30 field
glasses. Longer observation was not possible as the more and more farmers
started working the fields, all the birds took off and headed up north towards the Kedah
rice belt. Just as the bird spread its wings, as it was taking off the maroon
back was unmistakable. The area was checked every day but the species was not
sighted, not unusual considering the Seberang Perai rice fields stretches into the Kedah
rice bowl.
At 0745 hours, 17/04/1999,
Penaga, Seberang Perai, 1 bird sighted and another individual very likely of the same
species was sighted. At 0720 hours on 18/04/199 at the same location, 1 grayii
was sighted, 3 other birders (James Ooi, Hoe Eng Seng and Tai Keat Eam) also observed it.
The species was not sighted again
until on 27/04/1999 at Kampong Tok Otek/Permatang Tok Labu, Seberang Perai, at
0743. 1 bird observed at a distance of about 50 feet in newly ploughed rice
field, this site is about 3 to 4 kilometres from the original observed area.
Surprisingly a grayii was present in the same rice plot at 1802 hours that very
day but was at the extreme end of the rice plot. Whether it was the same
individual observed that morning is anybody's guess.
At 0820, 04/05/1999, 2 birds in
full breeding plumage in freshly ploughed but not flattened rice fields behind Pulau
Mertajam village. The maroon back of the birds and white crest plums were very
clear in the morning light. The central part of the back was slightly more
dark maroon (this can be subjective depending on the lighting conditions and the distance
from which the bird is observed).
On 06/05/1999, 4 birds were in
the same fields. On 10/05/1999, only 1 bird was sighted and the ploughed plot
had been flattened. This individual was at the edge of a flattened plot
adjacent to a ploughed but unflattened plot. There were a few Ardeola
bacchus in full and intermediate breeding plumages in the same plot (still not
flattened yet). On 12/05/1999, same location, 3 grayii were in an
unflattened plot. There was also 1 Ardeola speciosa in breeding
plumage in the area. For some reason the grayii were more often than
not in ploughed plots that have not been flattened yet. This probably could be
associated with greater abundance of food source in unflattened plots.
I have sighted 4 individual Ardeola
grayii in this district but I feel there could be more as the rice fields are very
extensive and I was only able to check the fields near my office.
On a spotting scope, the dark
central part is darker maroon then the rest of the back but not all the birds observed had
a darker central back. All the grayii sighted had slightly darker
lower breast then the rest of the breast. Javan Pond in intermediate plumage
phase have a much darker and broader lower breast area and gives the impression that the
bird is wearing a beard. All the grayii had complete white crest
plums but speciosa (Javan) have yellow tinged crest plums but one must be careful
as some of the speciosa although in full breeding plumage had almost whitish
crest plums except for yellow tinge towards the base of the crest and from a distance will
appear white if careful attention is not paid.
Reported by Kanda Kumar
|
