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Emu - Austral Ornithology
ISSN: 0158-4197 (Print) 1448-5540 (Online) Journal homepage: http://www.tandfonline.com/loi/temu20
Roosting patterns of the Edible-Nest Swiftlet
(Aerodramus fuciphagus) of the Andaman Islands:
effects of lunar phase and breeding chronology
Akshaya Mohan Mane & Shirish S. Manchi
To cite this article: Akshaya Mohan Mane & Shirish S. Manchi (2017): Roosting patterns of the
Edible-Nest Swiftlet (Aerodramus fuciphagus) of the Andaman Islands: effects of lunar phase and
breeding chronology, Emu - Austral Ornithology
To link to this article: http://dx.doi.org/10.1080/01584197.2017.1336065
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Roosting patterns of the Edible-Nest Swiftlet (Aerodramus fuciphagus) of the
Andaman Islands: effects of lunar phase and breeding chronology
Akshaya Mohan Mane
a,b
and Shirish S. Manchi
a
a
Division of Conservation Ecology, Sálim Ali Centre for Ornithology and Natural History, Coimbatore, Tamil Nadu, India;
b
Department of
Zoology, Bharathiyar University, Coimbatore, Tamil Nadu, India
ABSTRACT
Environmental conditions and biological rhythms can affect the behavioural routines of animals.
However, the effect of lunar phase on individual roosting behaviour remains uninvestigated in most
species. Here, we monitored the effect of lunar phase, sunset time, temperature, humidity and the
breeding chronology on the roosting patterns of the Edible-Nest Swiftlet (Aerodramus fuciphagus)of
the Andaman Islands, across breeding stages. Counts revealed that more than 98% of the population
returned to the roosting caves during peak roosting hours, i.e. 1700–2000h. The proportion of birds
roosting in caves was highest during the ‘new moon’phase and when birds were at the nest-building
and fledging stage of their breeding cycle. We confirmed that the variation in the roosting behaviour
of the Edible-Nest Swiftlet is linked both to the stages in the breeding cycle and to the lunar phase.
We hypothesise that the cause for the lunarphilic roosting pattern is an anti-predator strategy.
Feeding habits and food requirements during different breeding stages are presumed to influence
the roosting pattern of the species. An improved understanding of the association of the behaviour,
physiology and the environmental conditions which influence these traits can only help us improve
conservation outcomes for this economically important species.
ARTICLE HISTORY
Received 15 July 2016
Accepted 21 May 2017
KEYWORDS
Roosting; behavioural
ecology; environment;
habitat; movement
Introduction
Both abiotic and biotic factors affect the roosting and
foraging habits of animals (Anthony et al.1981;Bakken
and Lee 1992;KlompandFurness1992; Rahman et al.
2004;Langet al.2006;Cozziet al.2012; Lillywhite and
Brischoux 2012). Of several abiotic factors, the effect of
moonlight is known to alter animal behaviour, often
driven by predator activity (Trillmich and Mohren
1981; Gursky 2003;Langet al.2006). Animals that are
active under moonlight are known as lunarphilic animals
(Brigham and Barclay 1992;Gursky2003;Ramenofsky
et al.2008), whereas lunarphobic animals restrict their
activity under moonlight (Morrison 1978;Usmanet al.
1980; Trillmich and Mohren 1981; Nelson 1989;Börk
2006;Langet al.2006).
Many studies (Nelson 1989; Mougeoto and
Bretagnolle 2000; Powell et al.2008) focus on changes
in foraging and predator–prey interactions of different
taxa in moonlit or dark nights. For instance, Common
Poorwills (Phalaenoptilus nuttallii) in southern Arizona
are comparatively more vocal andforage less during a full
moon than a new moon (Woods and Brigham 2008).
Studies on Freckled Nightjars (Caprimulgus tristigma)
in South Africa have demonstrated more intense foraging
activity on moonlit nights and their heterothermic nature
during dark nights (Smit et al.2011). At the same time,
studies of colonial seabirds have shown a decrease in food
delivery and feeding frequency to chicks on full moon
nights, in order to reduce predation risk (Klomp and
Furness 1992; Bourgeoisa et al.2007; Riou and Hamer
2008). All the studies mentioned are related to nocturnal
birds, since we failed to find literature concerning the
diurnal foraging bird.
Edible-Nest Swiftlets of the genus Aerodramus are
exceptional among birds which frequently occupy caves
as colonial roosting and breeding sites (Lim and
Cranbrook 2002). In flight in darkness, within the roost-
ing cave or outside, all swiftlets of genus Aerodramus and
one species of Collocalia utter audible frequency sounds
(from 1.5 kHz to 10 kHz), described as ‘echo clicks’
(Medway 1967; Griffin and Suthers 1970; Medway and
Pye 1977;Priceet al.2004; Thomassen 2005). As the
echolocation ability of the Edible-Nest Swiftlet is not as
developed as that of bats (Chiroptera), Edible-Nest
Swiftlets apparently echolocate only for navigation in
the darkness (Medway 1967;Langham1980;Collins
CONTACT Shirish S. Manchi ediblenest@gmail.com
Supplemental data for this article can be accessed here.
EMU - AUSTRAL ORNITHOLOGY, 2017
https://doi.org/10.1080/01584197.2017.1336065
© 2017 BirdLife Australia
and Murphy 1994), within or outside their roosting caves
(Medway 1967;WaughandHails1983; Chantler 2000;
Manchi and Sankaran 2010). However, their roosting
behaviour isthought to vary in relation to breeding stages
(Nguyen et al.2002;Manchi2009).
The economic importance of Edible-Nest Swiftlet
nests for human nest consumption has resulted in
the detailed investigation of the breeding biology and
habitat use among members of the group in different
places within their distribution (Medway 1962a,
1962b;Nguyen1992; Lim and Cranbrook 2002;
Manchi and Sankaran 2010; Manchi and Mane
2012). Moonlight controls the plasma melatonin
levels (Tarlow et al.2003) and also affects sexual
signalling and territorial displays (York et al.2014)
in some birds. Overall, these studies have highlighted
the effects of moonlight on the physiology and activ-
ity pattern of birds. This is the first document sub-
sequent to the natural history observations by
Medway (1962b) on the temporal roosting patterns
of the Edible-Nest Swiftlet (Aerodramus fuciphagus)
in its wild population in caves in Sarawak. The pre-
sent study documents the temporal roosting pattern
of Edible-Nest Swiftlets (Aerodramus fuciphagus
inexpectatus) (Birdlife International 2014)inrelation
to lunar phases and with stages in the breeding cycle.
Material and methods
The Edible-Nest Swiftlet of the Andaman and Nicobar
Islands (hereinafter A&N Is) is the nominate subspecies
of the Grey-rumped Swiftlet (Aerodramus inexpectatus). It
is the westernmost representative of the species, which is
distributed eastwards in the Oriental region through the
coasts and islands of Myanmar, Thailand, Vietnam,
Malaysia to Kalimantan, Indonesia (Nguyen 1992;
Nguyen et al.2002; Cranbrook et al.2013). Observations
by Lim and Cranbrook (2002) have shown that related
species of Aerodramus swiftlets are monogamous and
have strong nest site fidelity.
Study area
We studied the Edible-Nest Swiftlets occupying (120
known) caves in a complex of more than 175 limestone
caves spread within 0.77 km
2
(12°07′N, 92°47′E) on
Baratang Island of the A&N Is in the Bay of Bengal,
India (Manchi and Mane 2012). The area is formally
protected as Baratang Reserve Forest, which contains
virgin evergreen, mixed-evergreen and mangrove forests
(Manchi and Mane 2012).
Data collection and analyses
The narrow openings of most of the caves and the
relatively small size of the swiftlet populations within
them made population estimates easily achievable. We
estimated numbers using the audible rattling echo
clicks and visual sightings of the movements of the
Edible-Nest Swiftlet at the cave openings. Birds enter-
ing into and exiting from the cave were counted
visually during light hours. We made 24 h counts at
the entrances of six accessible caves during the breeding
season from January to May 2013. We collected data for
over 1169 h, covering 32 full moon nights (when >98%
of the moon’s disc is illuminated) and 49 new moon
nights (the moon’s disc is <3% illuminated when it
crosses the local meridian). Observations were divided
into 10-min slots. We followed Indian Standard Time
(IST) for data collection and interpretation. To avoid
any potential bias linked to rain and cloudy weather, we
collected data only during clear weather conditions. We
estimated the breeding populations using the nest count
method (Sankaran 2001; Manchi and Sankaran 2014).
We also recorded environmental temperature, humidity
and sunset time on each observation day. Following
Manchi (2009), breeding chronology/seasonality data
were collected from the accessible nests in 10 different
caves (six caves selected for roost counts along with
four other caves). Though the Edible-Nest Swiftlet
breeds between December and August in Baratang,
our observations were restricted to the period January
to May, as the data gathering was hampered by nest
harvesting after the first brood. Our team visited a
sample of selected nests each day to assess the breeding
stage. We numbered all the selected caves and nests for
their individual identification. Along with nest identity
number, we also noted the number of eggs and chicks
in the nest for each date. We followed 148 nests over
140 days (20 720 observations of nests during different
breeding stages). As observed in the earlier studies
(Medway 1962b), while there might be traffic in and
out during the day, most birds returned to the caves to
roost between 1700 and 2000h (Figure 1). We recog-
nised this period as Peak Roosting Hours (PRH) and
used this for analyses.
Statistical approach
For analysing time-series of count data collected from
various caves, we used generalised linear models
(GLM) with a Poisson error distribution and log link
function (Gregory and Strien 2010) to test the effects of
environmental and biological factors on the birds’arri-
val patterns at the roost sites. Since the data collected
2A. M. MANE AND S. S. MANCHI
were from various caves with different population sizes,
we counted the total number of birds roosting inside
the caves from a 24 h count and calculated the percen-
tage of birds entering at each hour. The proportion of
birds coming to roost or leaving a roost every hour was
calculated using the formula (100 × t)/T(where tis the
number of birds coming to roost or leaving a roost in a
particular hour and Tis the maximum number of birds
estimated roosting in a particular cave). We then com-
pared the proportion of birds entering during PRH
with the explanatory variables (i.e. the effect of lunar
illumination, breeding stages, time of sunset, environ-
mental temperature and humidity) (Table 1: online
supplementary material). We used the best-fit model
(Burnham and Anderson 2002; Mazerolle 2006)to
evaluate the impact of environmental and biological
factors on the roosting behaviour of the Edible-Nest
Swiftlet. In order to rank the models, the Akaike infor-
mation criterion (AIC
c
) corrected for small sample
sizes, ΔAIC
c
(the difference in AIC
c
between each
candidate model and the model with the lowest AIC
c
value) and Akaike weights (w
i
) were used (Burnham
and Anderson 2002). We started with a global model,
using all variables and selected those models with
ΔAIC
c
below 4.00. By comparing the support for each
model, we excluded those with little support (ΔAIC
c
>
4.00). We then conducted model averaging by selecting
Figure 1. Mean percentage bird activity at the openings of different roosting and breeding caves at Baratang, Andaman Islands,
India. A53, B27, B30, B45, B59 and C12 are the identification codes assigned for different caves. Positive values represent the
percentage of birds entering the caves and negative values represent the percentage of birds leaving the caves. For the box-plots,
boxes indicate interquartile ranges and the line inside the box shows the median. Limits of the whiskers represent minimum and
maximum values of the data.
Table 1. Selection table for fits of the 15 competing general-
ised linear models
Models KAIC
c
ΔAIC
c
w
i
Cum. w
i
LL
MP*BS 7 568.35 0.00 0.73 0.73 −276.41
MP*BS+SST 8 570.45 2.10 0.26 0.99 −276.22
BS*MP+SST*Hum*Temp 14 577.18 8.83 0.01 1.00 −271.41
MP+BS+SST+Temp
+Hum
8 618.79 50.44 0.00 1.00 −300.40
MP+BS+SST+Temp 7 631.37 63.01 0.00 1.00 −307.92
MP+BS*SST 7 635.97 67.62 0.00 1.00 −310.22
MP+BS 5 637.90 69.55 0.00 1.00 −313.55
MP+BS+SST 6 639.85 71.50 0.00 1.00 −313.36
BS*SST 6 672.36 104.01 0.00 1.00 −329.61
BS 4 674.67 106.32 0.00 1.00 −333.07
BS+SST 5 676.92 108.57 0.00 1.00 −333.06
MP+BS*SST 2 684.63 116.28 0.00 1.00 −340.24
SST+Temp+Hum 4 703.37 135.02 0.00 1.00 −347.42
SST 2 729.28 160.93 0.00 1.00 −362.56
Birds ~1 1 750.55 182.19 0.00 1.00 −374.25
MP = lunar/moon phase, BS = breeding stage, SST = first bird arrival with
respect to sunset time, Temp = temperature, Hum = humidity. K=number
of parameters, AIC
c
= Akaike information criterion, ΔAIC
c
= delta information
criterion. Model probabilities: Akaike weights (w
i
), cumulative weight (Cum.
w
i
) and the log-likelihood (LL) for different models fitted to count observa-
tions (N= 81) of the Edible-Nest Swiftletfrom caves at Baratang Islands, A&N
Is, from January to May 2013. The largest w
i
is shown in bold.
EMU –AUSTRAL ORNITHOLOGY 3
best-fit models. All models were implemented using
the package AICcmodavg (2.0–4) for Model Selection
and Multimodel Inference Based on (Q)AIC(c) and
Model Averaging (Mazerolle 2006).
The PRH were further classified into three time classes
(Table 1: online supplementary material). We used these
time classes to understand the temporal variation, if any, in
the roosting pattern across the days of observation.
ANOVA was used to determine the temporal variation in
roosting behaviour. Tukey’s honest significance test was
performed to check the pair-wise difference of time classes
holding roosting population (Zar 2008). Further, we tested
thesignificanceoftheinfluenceoflunarphaseonthetime
and proportion of roosting birds by performing the
Wilcoxon signed rank test, with continuity correction.
We analysed 43 observations using the Kruskal–Wallis
test with continuity correlation to examine the variations
in Edible-Nest Swiftlets’roosting behaviour after sunset
with breeding stage. We classified the breeding stages fol-
lowing Manchi’s(2009)method(Table 2:onlinesupple-
mentary material). We used the Kruskal–Wallis rank sum
test on 81 observations (28 observations during nest build-
ing, 25 during incubation, 24 during nestling and 4 during
fledging) to examine the variation in the proportion of
birds roosting in PRH during different breeding stages.
We used the statistical programming language R 3.2.3
with R-Studio as an interface (R-Studio Team 2015)for
data analyses.
Results
The roosting patterns of the Edible-Nest Swiftlet
Most of the Edible-Nest Swiftlet populations
(mean = 77.48 ± 18.67% SD) left the roost sites between
0400 and 0700h in the morning. In the evening, more than
98%oftheEdible-NestSwiftletpopulationsreturnedto
their roost sites within PRH (Figure 1). The first bird
returned to the roost site at 1719 ± 0.01 h SD, and the
lastbirdat1929±0.03hSD,excluding22birds(1.5%of
the total birds observed entering) in 14 counts which
returned after PRH up to 2350h. The numbers of birds
returning during three time classes of PRH varied signifi-
cantly (F=86.05,df=2,P= 0.000). Time class 1700–1800h
had the highest proportion (mean = 48.06 ± 19.40% SD) of
birds returned followed by time class 1800–1900h
(mean = 44.06 ± 17.32% SD) and time class 1900–2000h
(mean = 07.30 ± 09.82% SD). The variation between
classes 1700–1800h and 1800–1900h was not significant,
indicating that the PRH are essentially from 1700 to 1900h.
Modelling responses to biological and
environmental factors
The best-fit models depicted that the timing of the
return to roost by these Edible-Nest Swiftlets was influ-
enced by several variables (Table 1). The moon phase
and breeding stage were estimated to be the most
significant predictors in the first best-fit model
(Figure 2). Further, the second best-fit model with the
lowest AIC
c
also included the sunset time as one of the
significant variables, affecting the roosting decisions of
the individuals (Table 1). According to the models,
temperature and humidity do not affect the timing of
roosting behaviour of the Edible-Nest Swiftlet.
Effect of lunar phase
The new moon phase was the factor with the highest
coefficient (0.665) in the average model fits (Table 2).
This supports the conclusion that fewer birds returned
to roost during PRH on full moon nights than new moon
nights (Z = 10.063, n=81,P< 0.0001). Furthermore, the
first bird returned earlier to roost during new moon
nights (mean = 1720 ± 0.01 h SD) compared to full
moon nights (mean = 1717 ± 0.01 h SD), (Z = −7.851,
P< 0.0001). The last bird returned to roost significantly
later during a full moon night (mean = 1935 ± 0.04 h SD)
(Z = −7.428, P< 0.0001) than on a new moon night
(mean = 1925 ± 0.03 h SD), after excluding the single
event of six late arriving birds at 2350h on the same full
moon night. Moreover, there was a significant difference
(W=127.5,P< 0.02) in the proportion of birds returning
during PRH to roost on new moon nights
(mean = 87.91 ± 12.14% SD) compared to full moon
nights (mean = 70.10 ± 17.14% SD).
Effect of sunset time
Although some Edible-Nest Swiftlets returned to their
roosting caves before sunset, most (mean = 92.68 ± 9.03%
SD) of the individuals returned to their roosting caves only
after sunset (Z = 2.160, P< 0.05). However, the variation in
sunset timing did not significantly affect the proportion of
birds arriving for roosting within PRH (χ
2
= 4.876, df = 3,
Table 2. Model-averaged parameter estimates from best-fit
models from Table 1
Birds encountered Estimate SE Adjusted SE zvalue Pr(>|z|)
(Intercept) −0.750 0.053 0.054 13.903 <2e-16*
NM 0.665 0.065 0.066 10.011 <2e-16*
Incb 0.450 0.068 0.069 06.519 <2e-16*
Nest 0.617 0.073 0.074 08.373 <2e-16*
NM:Incb −0.719 0.088 0.090 08.030 <2e-16*
NM:Nest −0.565 0.086 0.087 06.471 <2e-16*
* Significance P< 0.001.
NM = new moon, Incb = incubation, Nest = nest building, SE = standard
error.
4A. M. MANE AND S. S. MANCHI
P= 0.181) or the timing of the first bird arriving to roost
(χ
2
= 4.645, df = 3, P= 0.2). Nevertheless, the frequency of
the first bird returning before sunset was higher (64.03%)
than after sunset (35.07%). Among the breeding stages, the
proportion of birds returning after sunset differed signifi-
cantly (χ
2
= 8.742, df = 3, P< 0.05): a higher proportion of
birds returning after sunset during the stage of nest build-
ing and fledging (94.43 ± 07.03% SD, n=22and
92.58 ± 10.47% SD, n= 2, respectively), as compared
with incubation (mean = 85.94 ± 05.87% SD, n=8)and
nestling stages (mean = 88.72 ± 12.54% SD, n=11).
Effect of breeding stage
The next most important variable entered into the model
was breeding stage (Table 1). The species had a mean nest-
building period of 61.10 ± 10.96 days SD (n=207),incu-
bation period of 22.73 ± 2.19 days SD (n=245),anda
nestling period of 36.31 ± 4.15 days SD (n=85)followed
by fledging of chicks. Among the breeding stages, the
proportion of birds returned within PRH differed signifi-
cantly (χ
2
= 9.162, df = 3, P< 0.05). A higher proportion of
birds returned within PRH during nest-building and fled-
ging stages (94.06 ± 07.05% SD, n= 28 and 95.80 ± 07.91%
SD, n= 4, respectively), as compared with the incubation
(mean = 71.13 ± 12.55% SD, n= 25) and nestling stages
(mean = 71.07 ± 24.77% SD, n= 24). Further, we found a
significant variation in the time of the first arrival among
different breeding stages (χ
2
= 15.276, df = 3, P< 0.005). In
addition, the first bird arrived significantly later during the
nest-building stage (nest building = 1724 ± 0.01 h SD;
incubation = 1714 ± 0.00 h SD; nestling = 1718 ± 0.01 h
SD; fledging = 1715 ± 0.00 h SD). The significant average
coefficient for interaction between new moon phase and
incubation stage (−0.719) and new moon phase and nest-
building stage (−0.565) showed that the effect of lunar
phase on the roosting behaviour of the swiftlets is signifi-
cantly influenced by the breeding stage.
Discussion
As with other bird species, the Edible-Nest Swiftlet
demonstrates a rhythmic roosting pattern. The return
to roost commenced before sunset on most occasions
but, unlike most avian species, the ability to navigate in
the dark by echolocation enables Edible-Nest Swiftlets
to return to their roosting/breeding sites after sunset.
Unlike most diurnal foraging birds, including many
non-echolocating swifts and swiftlets, more than
92.68 ± 9.03% SD individuals of the Edible-Nest
Swiftlet returned to their roosting caves after sunset.
However, besides the capability of echolocation,
Medway (1962a,1962b) and Harrisson (1976) have
recorded that Black-Nest Swiftlets (Aerodramus max-
imus) and Mossy-Nest Swiftlets (Aerodramus salanga-
nus) forage by night in bright moonlight. Also,
Tarburton (1987) observed the White-rumped Swiftlet
(Aerodramus spodiopygius) returning comparatively
later to its roost sites on bright moonlit nights.
During new moon nights, most of the Edible-Nest
Swiftlets at Baratang returned to their roost sites imme-
diately after sunset. On full moon nights, some pre-
sumably foraged far from the breeding site after sunset
and returned later to the roost (Manchi and Sankaran
Figure 2. Mean percentage of birds returning to roosting and breeding caves between Peak Roosting Hours (1700–2000h) on new
moon night, incubation time and nest-building time at Baratang, Andaman Islands, India. Boxes indicate interquartile ranges and
the line inside the box shows the median. Limits of the whiskers represent minimum and maximum values of the data.
EMU –AUSTRAL ORNITHOLOGY 5
2010). Also, further, detailed understanding of the
foraging range and habits of this swiftlet, perhaps
through satellite tracking studies, will help explain the
delayed individuals at roost sites.
Similar to the observations of Manchi (2009)from
Chalis-ek, in the Andaman Islands, breeding chronology
affected the roosting pattern of the Edible-Nest Swiftlet
at Baratang. The food/energy requirements in different
breeding stages (Manchi 2009)mayinfluencethe
changes in the roosting patterns. The percentage of
birds roosting within PRH during incubation and nest-
building periods is significantly higher than nestling and
fledging periods. The Edible-Nest Swiftlet of the
Andaman Islands constructs its nest only during nights,
while roosting (Manchi 2009). The nest construction
period was extended (61.10 ± 10.96 days SD) in the
study area, during which individuals returned early
(after dusk) for longer roosting bouts. The birds were
also seen leaving the roost site before dawn, for foraging,
perhaps to accomplish the relatively high protein/energy
requirement during the nest-building season to produce
enough saliva in the seasonally enlarged salivary glands
(Lim and Cranbrook 2002). Like other swiftlet species
and the subspecies of Grey-rumped Swiftlet, one parent
is obliged to be at the nest during the incubation period
(Medway 1962b;LimandCranbrook2002;Nguyen
et al.2002; Manchi 2009). However, both parents endea-
vour to forage to the maximum just before roosting, and
try to return to attend the nest and eggs as quickly as
possible, whereas during the nestling and fledgling per-
iod, throughout the day, parents make multiple visits to
the nests and chicks for feeding the chicks (Manchi
2009). This also allows them to forage longer before
roosting, resulting in a comparatively smaller proportion
of birds returning to roost within the PRH. As Manchi
(2009) has described, fluctuations in the number of birds
roosting in caves during the fledging period may be
related to food availability (Manchi and Sankaran 2014).
Similarly, with the effect of lunar phase, the roosting
pattern of the Edible-Nest Swiftlet of the Andaman
Islands changes significantly during its breeding season.
When arriving at and leaving the roost, lunarphilic
Edible-Nest Swiftlets must have adapted their anti-pre-
dator (Tarburton 2009), foraging or successful breeding
strategies. At Baratang Island, owls are more active dur-
ing dawn and dusk (Mane and Manchi 2013). The arrival
of most individuals within the PRH, during darkness on
new moon nights, fits well with the hypothesis that it is
the result of the anti-predatory strategy. Also, the late
return for roosting on full moon nights compared to
new moon nights allows us to consider the Edible-Nest
Swiftlet as lunarphilic to some extent, if not completely.
The present study demonstrates that different bio-
logical and environmental factors do affect the beha-
viour of the Edible-Nest Swiftlet in the Andaman
Islands and highlights the need to conserve this fasci-
nating species, which is globally declining in the wild.
Acknowledgements
We sincerely thank all the Edible-Nest Swiftlet protectors
(Rajender, Nuel, Sukra, Thomas, Ashisan, Dilbar, Birsa,
Fabianus,Vinod,Paval,Martin,Sumit,Rakesh,Baijuand
Ranjan) at Baratang for their dedicated involvement, participa-
tion in the conservation of the Edible-Nest Swiftlet and assisting
inthefield.WeacknowledgetheMinistryofEnvironment,
Forests and Climate Change, Government of India for the finan-
cialsupporttoimplementtheprojectwork.Wegratefully
acknowledge the Department of Environment and Forests,
Andaman and Nicobar Islands for their long-term collaboration
towards executing the Edible-Nest Swiftlet research and conser-
vation programme in the area. We thank Prof. Dr K. Thiyagesan
(Ret.), AVC Collage, Mayiladuthurai for his statistical inputs. We
sincerely thank Dr Chris Bowden from the RSPB, Dr R. P. Singh
from the SACON and the Earl of Cranbrook, pioneer of swiftlet
research from Saxmundham, England for providing valuable
comments and suggestions on the draft of the manuscript. Our
sincere thanks to the reviewers, Editor Kate Buchanan, and the
concerned Associate Editor of EMU –Austral Ornithology,
whose inputs and queries resulted in significant improvement
of the manuscript. We also thank all those who were involved
directly and indirectly in the documented work.
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