42
CHAPTER- III
Materials and Methods
Study area
The area selected for the present study of white breasted
water hen, Amaurornis phoenicurus phoenicurus was the wetland
habitats in Mannar village in Alappuzha District, Kerala state, India.
It is a low land area at the bank of the river Pampa and lies between
9 01’ N latitude and 76 03’ E. longitude.
Household ponds, temple ponds, swamps, small stretches of
paddy fields and natural canals connecting water bodies were the
major wet lands in the study area. Wild vegetation and sacred groves
associated with these wet lands provided good habitat for white
breasted water hen. Screw pine ( Pandanus odoratissimus), Ochlandra
scriptoria and Bamboo (Bambusa bambos) were abundantly present
near the banks of water bodies. Coconut trees ( Cocos nucifera ),
Arecanut trees ( Areca catechu), mango trees ( Mangifera indica )
cashew trees ( Anacardium occidentale ), Thespesia populnea,
Ailanthus malabaricus, and jack fruit tree (Artocarpus heterophyllus)
BROOD NESTS OF WHITE BREASTED WATER HEN
On Pandanus
In a swamp
PLATE - 17 PLATE - 1
×
MAP OF THE STUDY AREA
43
were the common garden trees. Banana plants and vegetables were
cultivated in the garden lands of the study area. Paddy fields were
almost uncultivated.
The study site had a total area of 1.545 sq. km. divided into
three sectors, viz., sector - I. Kuttamperoor – Kurattikkattu – (South)
sector-II. Kuttamperoor– Kurattikkattu – (North), sector-III.
Thrikkorati Temple – Kottakal kadavu comprising a total of 24
habitats; 7 in sector I, 8 in sector II and 9 in sector III. (plate -1)
Selection of the three sectors in the study area was based on the
prevailing varied ecological conditions.
1. Kuttamperoor – Kuratikkattu ( south) sector
This sector extended from Kuttamperoor bridge to
Kurattikkattu lying south to the Chengannur - Mannar road covering
an area of 0.528 sq. km. with 7 habitats.
2. Kuttamperoor – Kuratikkattu ( north) sector
This sector also extended from Kuttamperoor bridge to
Kurattikkattu lying north to the Chengannur - Mannar road covering
an area of 0.508 sq. km. with 8 habitats.
3. Thrikkorati temple – Kottakkal kadavu sector
This sector extended from the east of Thrikkorati temple to
Kottackalkadavu covering an area of 0.509 sq. km. with 9 habitats.
HABITATS OF KUTTAMPEROOR KURATTIKATTU
SOUTH SECTOR (SECTOR 1)
PLATE - 2
HABITATS OF KUTTAMPEROOR KURATTIKATTU
NORTH SECTOR (SECTOR 2)
PLATE - 3
44
Methodology
General habits and roosting behaviour, population, food and
feeding behaviour and breeding and breeding behaviour were studied
during the period 2002 to 2005.
A Carls- Zeiss binoculars of the power 8 x 30 was used for all
field the observations.
General habits and roosting behaviour
Study of the general habits and roosting behaviour was car-
ried out in three pond habitats in the sector II. Gullion, (1952b
&1953b) and Krantz & Gauthreaux, Jr. (1975) were followed for this
study. For these studies weekly observations both in the morning
and in the evening were carried out from the month of January to
December in 2002. Adult birds were closely followed during morn-
ing and evening hours in the study area. The practice was to reach
the roost site early in the morning before the bird had moved out of
the roost it had settled the previous night. In the evening the roost
was located by the following the birds till they stopped for the last
time.
Awakening time ( time of the first sign of activity of the bird
in the morning), roost exit time ( time at which the bird flew out of
the roost ) and first feeding time ( time at which the bird began to
feed for the first time in the morning after flying out of the roost)
were noted in the morning.
Similarly in the evening, last feeding time ( time at which
the bird stopped foraging for the day ), roosting time ( time at
HABITATS OF KUTTAMPEROOR KURATTIKATTU
SOUTH SECTOR (SECTOR 1)
PLATE - 2
HABITATS OF KUTTAMPEROOR KURATTIKATTU
NORTH SECTOR (SECTOR 2)
PLATE - 3
45
which the bird entered the roost ), sleeping time ( time when the
activities such as moving and calling stopped ) were noted. The
common plants used for roosting and the height at which they roost
were also noted.
Vocalisations, displays and maintenance activities of the bird
were also studied.
Ecology of Population
Population studies of white breasted hen was carried out in
the in the whole study area during the period 2002 to 2005. A
regular monthly count of adults, chicks and juveniles was conducted
from January 2002 to December 2005 in the three sectors, (i)
Kuttamperoor – Kurattikkattu – (South) sector, (ii) Kuttanperoor –
Kurattikkattu – (North) sector, (iii) Thrikkuratti Temple - Kottackal
Kadavu Sector. Observations were carried out in the morning on a
suitable day in the first week of every month. Simple total count
method was followed for the observation (Verner, 1985; Manual &
Carey, 1991). A count consisted of recording all the birds seen or
heard for 5 minutes at a time. Counting of same birds more than
once was avoided. All adults, chicks and juveniles were enumerated
separately. Loud and frequent vocalizations during the breeding
period was very much helpful in locating birds day after the
observation.
Food and feeding behaviour
Food and feeding behaviour of white breasted water hen were
studied from April 2003 to March 2004 in four habitats in sector III
of the study area.
Of the four habitats two were large ponds fully covered by
Salvinia and the other two were swamps. A mixed vegetation of
46
grass and herbs were present both on the floating plants and in the
margins of the water bodies. Three substrata, (i) Grass sward in the
wet lands and garden lands (ii) Exposed mud floor and (iii ) Shallow
water were recognized in the study area where the white breasted
water hen continuously fed. (plate 8 & 9)
For measuring the frequency of activities and feeding intensity,
the birds were observed from temporary hides for three days every
month from April 2003 to March 2004. Observations covered two
hours after sunrise and two hours before sunset. Most of the birds
were observed within 50 m of the hide while some were less than 30
m distant. The standard work of Fordham (1978 ) was followed for
this study .
Feeding and associated activities
Activities of white breasted water hen associated with its
foraging behaviour were : (a) Feeding (b) Look at ground (c) Look
about (d) Bodily care (e) Agonistic (f) Courtship (g) Alarm and ( h)
‘Other’.
Components included in these activities were the following.
(a) Feeding : Peck at food while standing or walking
(b) Look at ground : Look at ground with head and neck turned
downwards while walking, sitting or standing which invariably
preceded feeding.
(c) Look about : Look around while walking, sitting or standing
(d) Bodily care : Preening, scratching, stretching and bathing
(e) Agonistic : Fight, challenge and mutual retreat
(f) Courtship : Meet and pass, courtship chase, bow and nibble
HABITATS OF THRIKKORATTI TEMPLE -
KOTTACKALKADAVU SECTOR (SECTOR 3)
PLATE - 4
WHITE BREASTED WATER HEN -
CHICKS, JUVENILES & ADULTS
CHICK (10 days old)
JUVENILE
(2 months old)
ADULT
PLATE - 5
47
(g) Alarm : Sudden and sharp stopping of activity resulting from
the perception of an imminent danger.
(h) Other activities : Fly, sit, swim and drink
Activity for each bird was catergorised at 5 minute intervals .
The frequency of each activity was scored by hour, period of day and
month. This indicated the proportion of time spent on any particular
activity. The probability of scoring an activity depended upon the
amount of time the bird spent on it before switching over to another.
The 5 minute interval was taken based on the assumption that it did
not parallel any natural periodicity of behaviour. Therefore the
summed frequencies of activities were equivalent to the proportion
of time spent on each activity by an average bird.
The rate of food collection was monitored by counting the
number of pecks at the substrate made in 30 seconds as measured
by an automatic timer. This interval was chosen because pilot
observations suggested that white breasted water hen did not feed
consistently for as long as one minute. Only uninterrupted 30 seconds
intervals were used for the analysis. The pecking movements in which
the beak did not contact the plants or substrate were not counted as
pecks. Since swallowing was found to be too difficult to record
accurately, the measurement of pecking rate could have included
some unsuccessful pecks. The pecking counts were ignored if the
bird was disturbed or changed activity during the 30 seconds. The
pecking of each feeding bird was recorded only once during a five
minute period. Counts of pecks per 30 seconds interval were started
only when a bird had taken some pecks and was therefore confirmed
to be in the feeding activity. Counts were ignored if the bird was
disturbed or changed the activity during the 30 seconds.
An index of overall feeding intensity was prepared by combining
48
pecking rates and frequency of feeding. Assumptions implicit in the
index were that the frequency of feeding was equivalent to the time
spent on that activity by an ‘average‘ bird and that rates of pecking
were representative of the specific one hour period in which it
occurred. The amount of time spent on feeding was obtained by
expressing the proportional occurrence of feeding in terms of 30
second interval.
Food
Food of white breasted water hen was determined by analyzing
the data procured from field observation ( Clarke et al., 1986 ),
stomach contents, droppings and regurgitation samples
(Mathew,1980). Four dead specimens ( two adults and two chicks )
obtained during the study were dissected for the gut content analysis.
The gut contents were dried on the blotting papers for 15 to 20
minutes and plant matter and animal matter were sorted out. Plant
matter was preserved dry and animal matter was preserved in 70%
alcohol for further identification.
Samples for the analysis from the foraging area of white
breasted water hen were collected from the grass sward, mud and
water. Sweeping method using an insect net was employed for
collection from the grass sward. 180 sweep samples, 140 mud
samples and 112 water samples were taken.
Breeding and breeding behaviour
Breeding and breeding behaviour of white breasted water hen
were studied in all habitats in the study area during the period 2002-
2005 . Keen attempt was made to locate all nests in the study area
during the breeding season, April to October. Ten to fifteen hours
were spent per week searching for nests. Many of the nesting sites
were located by hearing loud and noisy calls( Andrews, 1973) and
49
some were located by tracing the activities of the breeding pair. A
few nests were located while being built by watching the birds carrying
the nesting materials. As far as possible nests were visited daily
noting the progress in nest building, egg laying and incubation.
Distribution of nests and their height of location on plants were also
noted.
The nest building activities and rhythms of incubation were
studied by continuous observation on selected nests. Total number
of initiated and completed nests, initiated and completed clutches,
eggs laid and hatched and chicks fledged were noted. Hatching
success was calculated by taking the % hatching of eggs from the
total eggs laid (Rizi et al., 1999) where as % of fledging from the total
eggs laid was taken as the breeding success (Vijayan, 1978). Nest
desertion and predation of eggs and chicks were also noted The
detailed structure of the nests were studied from the deserted ones.
Eggs were measured with Vernier calipers and weighed with a two
pan field balance true to 100 mg. Incubation period was calculated
as the time elapsed between the laying of the last egg and completion
of hatching process in a clutch. Walk in traps ( Andrews, 1973)
were used to capture the adults, juveniles and chicks from the study
area.
Statistical analysis
The data collected on the variations in the population of white
breasted water hen in the different study sectors was subjected to
General linear model (GLM ) – univariate analysis for ANOVA, Duncan
test and multiple regression analysis using SPSS Version -11.0. The
Pearson correlations between the different roosting, feeding and
breeding activities were also derived .
50
References
Andrews,D.A., 1973. Habitat utilization by zora, Virginia rails
and king rails near the south western lake Erie Colorado.
Wilson Bull., 92: 96-102.
Clark,R.G.,Greenwood,H,Sugden,1986. Influence of grain
characteristics on optimal diet of field-feeding mallards. Anas
platyrhynchos. J. Appl Ecol., 23:763–771.
Fordham, R.A., 1978. Differential intensity of Moorhen
(Gallinula chloropus) feeding at dawn and dusk in spring. New
Zealand Journal of Ecology 1:109-117 © New Zealand Ecological
Society.
Gullion, G.W., 1952b. The displays and calls of the American
Coot. Wilson Bull., 64: 83-97.
Gullion, G.W., 1953b. Territorial behavior of the American
Coot. Condor, 55: 169-186.
Krantz, P.E. and S.A. Gauthreaux,. Jr., 1975. Solar radiation,
light intensity and roosting behaviour in birds. The Wilson
Bulletin . 87 (1): 120-126
Manual, A D. &. A. B. Carey, 1991. Methods for measuring
population of small forest birds. Pp. 9-11. Gen.Tech. Rep. PNW-
GTR278 Porland. USDA. Forest Service. Pacific North west
Research station, Portland Oregon.
Mathew, D. N., Narendran, T. C. and Zacharias, V. J., 1980.
A comparative account of the food habits of some species of
birds affecting agriculture. J. Bombay Nat. Hist. Soc. (Suppl.)
75: 1178 -1197.
51
Pettingill, O. S., Jr., 1985. Ornithology in Laboratory and Field,
5th Edition. Academic Press,San Diego, California.
Rizi. H; Slim Benyacoub, Yassine Chabi & Jerzy Banbura,
1999. Nesting and Reproductive characteristics of Coots,
Fulica Atra Breeding on two lakes in Algeria Ardeola, 46(2):
179-186.
Verner, J., 1985 . Assessment of counting techniques. Current
Ornithology ( ed. Johnston, R.F) Plenum Press, 2: 247- 302.
Vijayan, V.S., 1978. Breeding biology of Bulbuls Pycnonotus
cafer and p. luteoleus with special reference to their ecological
isolation J. Bombay Nat. Hist. Soc., 75 : 1090-1115.