Journal of Threatened
Taxa | www.threatenedtaxa.org | 26 September 2024 | 16(9): 25802–25815
ISSN 0974-7907
(Online) | ISSN 0974-7893 (Print)
https://doi.org/10.11609/jott.8999.16.9.25802-25815
#8999 | Received 28
February 2024 | Final received 19 June 2024 | Finally accepted 01 July 2024
Avifaunal diversity assessment
and conservation significance of Therthangal Bird Sanctuary, Ramanathapuram,
Tamil Nadu: insights about breeding waterbirds
H. Byju 1, H. Maitreyi
2, N. Raveendran 3 &
Reshmi Vijayan 4
1 Centre of Advanced Study in Marine
Biology, Annamalai University, Parangipettai, Tamil Nadu 608502, India.
2,3 Iragukal Amritha Nature Trust, 61,
Ramachandra Thadaga Street, Thirumangalam, Madurai, Tamil Nadu 625706, India.
4 Department of Zoology, BJM
Government College, Chavara, Kollam, Kerala 691583, India.
1 byjuhi@gmail.com (corresponding
author), 2 maithgd@gmail.com, 3 iantravee@gmail.com, 4
reshmidileeb@gmail.com
Editor: Taej Mundkur, Good Earth Environmental,
Arnhem, The Netherlands. Date of
publication: 26 September 2024 (online & print)
Citation: Byju, H., H. Maitreyi, N. Raveendran & Reshmi Vijayan (2024). Avifaunal
diversity assessment and conservation significance of Therthangal Bird
Sanctuary, Ramanathapuram, Tamil Nadu: insights about breeding waterbirds. Journal of Threatened Taxa 16(9):
25802–25815. https://doi.org/10.11609/jott.8999.16.9.25802-25815
Copyright: © Byju et al. 2024. Creative Commons Attribution 4.0 International License.
JoTT allows unrestricted use, reproduction, and distribution of this article in
any medium by providing adequate credit to the author(s) and the source of
publication.
Funding: Partially funded by The Integrated Development of Wildlife Habitats in
Wildlife Division, Ramanathapuram.
Competing interests: The authors declare no competing interests.
Author details: H. Byju works on the shorebirds and waterbirds in Gulf of
Mannar region for a decade and is in the biodiversity panel of five birds’
sanctuaries including two Ramsar sites and Gulf of Mannar Biosphere Reserve. H. Maitreyi is a research assistant working on seabirds in the region. N. Raveendran is a naturalist with a decade of experience in birds and awareness
education. Reshmi Vijayan is a
zoologist.
Author contributions: BH—conceptualization, design of work, writing and editing; MH—data
compilation, mapping, writing, and editing; RN—data compilation, writing;
RV—writing.
Acknowledgements: We sincerely thank the Gulf of Marine Biosphere
Trust for funding the project as well as providing us with logistical and staff
support during the work. We extend our gratitude to Mr. Bakan Jagdish Sudhakar,
I.F.S., for his valuable suggestions and co-operation in implementing the
Project. We also thank Melito Pinto in helping with the map and the APWs of TBS
in kindly following the instructions and overseeing the monitoring process
during each field visit.
Abstract: The study offers a comprehensive
avifaunal diversity assessment within the Therthanagal Bird Sanctuary (TBS) in
the Ramanathapuram district of Tamil Nadu, India, conducted from April 2021 to
March 2023, covering two breeding seasons. A total of 96 bird species from 18
orders and 44 families were recorded. The family representations by species
included: Ardeidae with 10 species, Accipitridae and Rallidae with six species
each, Anatidae with five species, Alcedinidae, Cuculidae, Columbidae,
Threskiornithidae and Cisticolidae with four species each. Four globally “Near
Threatened” species (IUCN Red List) were reported: Oriental Darter Anhinga
melanogaster, Black-headed Ibis Threskiornis melanocephalus, Asian
Woolly-necked Stork Ciconia episcopus, and Spot-billed Pelican Pelecanus
philippensis. The observed frequencies of species classes were: common
(n=58, 60%), uncommon (n=28, 29%), and rare (n=10, 10%). The majority of
species were residents (n=83, 86%), followed by winter visitors (n=12, 12%),
and a single passage migrant, (Rosy Starling Pastor roseus). Of
conservation significance was the finding that 23 of 40 waterbird species
recorded in the sanctuary were breeding on-site. Maximum numbers of birds and nests were
recorded in the second year, which was presumed to be due to improved rainfall
and water availability. The findings underscored the importance of the
sanctuary in providing bird habitat, and emphasised the need for its
conservation, particularly in safeguarding breeding waterbird habitat. This
study provided essential baseline data for any management plan that the forest
department may develop for the sanctuary.
Keywords: Breeding birds, conservation
policy, Gulf of Mannar Biosphere, heronry, land birds, bird migration, Near
Threatened, protected areas, waterbirds, wetlands.
INTRODUCTION
Wetlands in tropical and
sub-tropical Asia provide essential life support systems for many local
communities (Ranga 2006; Friend 2007), serving as centres of ecosystem
services, resources, and recreational values (Maltby & Acreman 2011). This
stresses the importance of wetland conservation (Sharma et al. 2019).
Worldwide, wetlands continue to be degraded (Zedler & Kercher 2005), with
the global area shrinking by 6% between 1993 and 2007 (Prigent et al. 2012) and
by 54–87% over the past three centuries (Davidson 2014). Degradation due to
human land use has raised serious concerns about many taxa dependent on
wetlands (Prigent et al. 2012), including waterbirds (Beyersbergen et al. 2004;
Bakker 2005).
Wetland ecosystems face significant pressures
stemming from extensive land alterations and infrastructure development (Pramod
et al. 2011). The intensification of agricultural and industrial activities
contribute to further stress (Bassi et al. 2014). These factors collectively
lead to a reduction in the extent of wetlands, consequently diminishing their
hydrological, economic, and ecological functions (Bassi et al. 2014). The link
between wetland degradation and loss of bird biodiversity is established in
earlier studies (Wang et al. 2021; IUCN 2023),
with losses being more pronounced than in terrestrial ecosystems
(Millennium Ecosystem Assessment 2005; Dudgeon et al. 2006;). Wetlands provide
essential breeding, feeding, and roosting grounds for numerous bird species.
Human activities that destroy or degrade these habitats (Brook & Aramde
2012) have a direct impact on the availability of suitable habitats for these
birds, leading to population declines (Rajpar & Zakaria 2010). It is
estimated that 55% of wetland bird species have declined worldwide, except for
some large herbivorous waterbirds, which are increasing (BirdLife International
2017; Pöysä et al. 2019). Birds serve as valuable indicators of the ecological
health of ecosystems (Peron et al. 2013), and play crucial functions as seed
dispersers and pollinators, highlighting their essential roles in maintaining
ecosystem balance (Bibi & Ali 2013).
Wetlands play a crucial role in
supporting biodiversity, and in India, they have been instrumental in providing
a lifeline for various bird species. In India, wetlands encompass approximately
4.1 million hectares of land, excluding areas used for irrigated agriculture,
rivers, and streams. Among these, 1.5 million hectares are natural, while 2.6
million hectares are man-made. In recent years, there has been a growing
interest in promoting the sustainable utilization and adaptive management of
these ecosystems. However, challenges persist, including insufficient data and
disparities in management approaches applied to these ecologically significant
areas (Shan et al. 2021).
Colonial nesting waterbirds are
important indicators of changes in the environment (Roshnath & Sashikumar
2019), as they breed in limited locations (Kushlan et al. 2002). These birds
breed in single-species or mixed-species colonies, known as heronries, where
they maintain healthy ecosystems by providing nutrients (Green & Elmberg
2014). Numerous heronries have disappeared in the last century across India
(Subramanya 1996).
Studies on
avian distribution in the Ramanathapuram district and the Gulf of Mannar
Biosphere Reserve (GoM) in Tamil Nadu, India reported numerous additional
birding hotspots (Byju et al. 2023 a, b, c), including the discovery of rare
vagrant Light-Mantled Albatross Phoebetria palpebrata (Byju &
Raveendran 2022), and additional breeding records of the newly described taxon
Hanuman Plover Charadrius seebohmi (Byju et al. 2023 d). These findings
underscored the importance of continuous monitoring in GoM, an Important Bird
and Biodiversity Area (IBA) of the Central Asian Flyway (CAF).
This study on the avifaunal
distribution of the Therthangal Bird Sanctuary (TBS) in the Ramanathapuram
district was undertaken because the rainfed sanctuary faced problems of tree
wilting due to anthropogenic pressures like water removal from the tank for
agriculture and other related activities. An additional objective was to focus
on the conservation importance of breeding waterbirds, including colonial
nesters. This study aims to contribute to the management plan of the forest
department for the well-being and conservation of this wetland and its breeding
waterbird species.
METHODS
Study area
The Therthangal Bird Sanctuary
(9.4566 N, 78.7719 E) with an estimated area of 29.295 hectares in
Therthangal village (Image 1) was designated as a bird sanctuary in 2010 (Byju
& Raveendran, 2024).
The dominant vegetation in this
sanctuary is Babul trees, Acacia nilotica, which were planted by the
Tamil Nadu state forest department as part of the social forestry scheme which
started in 1960 (Wilson 1979). The sanctuary is mostly rainfed. It has, in
general, one to three metres deep tank embankments. Between the vegetation and
the embankments, there is a wide water-holding region (~30m). The area receives
an average rainfall of 503-–1000 mm annually. The lowest and the highest
temperature in Therthangal Bird Sanctuary ranges from 26-–36 0C. Agricultural lands surrounded the sanctuary
and marked the northern boundary (Images 2 & 3). The main habitat types
observed in the sanctuary are: 1. Open-water habitat (WL=Wetland), 2.
Agricultural land (AL), 3. Trees (Tr) like Babul, Mesquite Prosopis
juliflora, Palmyra Borassus flabellifer, and Tamarind Tamarindus
indica trees on the bund bordering the wetland, 4. Grassland (GL) on the
wetland area, and 5. Shrub habitat (OS=open scrub type). Three distinct
seasons were northern Winter (December–February), northern Summer (March–June)
and Monsoon (September–November).
Monitoring methods
This study was carried out
between April 2021 and March 2023. Field visits were conducted once every two
weeks to observe the status, breeding activity, number, and diversity of birds.
The field surveys were conducted in the morning (07.00–10.00 hrs) and the evening
(16.00 – 19.00 hrs), depending on the season when birds were most active. Data
were collected following direct count and block count methods (Bibby et al.
2000; Howes & Bakewell 1989). Waterbirds were counted at seven scanning
points separated by 100–200 meters (Image 1), depending on the landscape and
visibility of the birds. We stopped at each point for five minutes before the
actual count so that the birds could get acclimated to us. Observations
recorded while moving from one scanning point to another were entered as
incidental records. Birds were observed using Nikon binoculars (10x50) and
identified with the help of a field guide (Grimmett et al. 2011). This
communication follows the species nomenclature of Praveen & Jayapal (2023).
Species residential status was
determined as Resident (R), Passage Migrant (PM), or Winter Visitor (WV)
depending on the temporal patterns and duration of occurrence (Grimmett et al.
2011). Species were listed as per their
global Red List status (IUCN 2023). We
also documented any potential threats to the birds. The data collected in each
survey were later analysed for the relative abundance of families. Species were
classified based on observation frequencies as: Common (C) - frequently
observed in the study area (encountered on 6-8/10 visits); Uncommon (UC) -
spotted on 3-5/10 visits; Rare (R) - encountered on 1-2/10 visits) (Mackinnon
& Philips 1993). Relative diversity (RDi) was calculated with the following
formula (Koli 2014):
Number of species in a family
RDi = ––––––––––––––––––––––––––––– x
100
Total
number of species
We also documented the breeding
activities of waterbirds within the sanctuary. Active nests were identified by
fortnightly surveys and by monitoring the flights of adult birds commuting
between nests and foraging areas. We visited the sanctuary twice a month during
the breeding season to estimate the total number of nests, employing standard
techniques such as ground counts or using binoculars and spotting scopes for
nests, as the counts were less than 100 (Gibbs et al. 1988; Dodd & Murphy
1995). For sites with few nests or those that were completely
inaccessible, we utilized perimeter counts (Dodd & Murphy 1995) based on
visible nests and observed foraging flights from the colony edge, as other techniques
were impractical.
RESULTS AND DISCUSSION
Avian community structure
A total of 96 species,
representing 44 families across 18 orders, were documented in the study area; a
comprehensive checklist is provided (Table 1). Of the 96 species, waterbirds
were predominant with 40 species from 14 families (Figure 2). Notably, our
observations highlighted the prevalence of families such as Ardeidae (10
species), followed by Accipitridae and Rallidae (6 species each), Anatidae (5
species), and Alcedinidae, Cuculidae, Columbidae, Threskiornithidae, and
Cisticolidae (4 species each), representing the bird species of the region
(Figure 2 & 3). The most speciose order was Passeriformes comprising 18
families and 29 species. Relative Diversity (RDi) analysis (Table 2) indicated
that the most prevalent family in the Therthangal Bird Sanctuary was Ardeidae
with a relative diversity of 10% (n=10 species). This was followed by the
families Rallidae and Accipitridae with 6.2% (n=6 species each) and the
Anatidae family with 5.2% (n=5 species). The families Cuculidae, Columbidae,
Threskiornithidae, and Cisticolidae represented 4.1% (n=4 species each), while
the families Coraciidae, Ciconiidae, Corvidae, Muscicapidae, and
Phalacrocoracidae reported 3.1% (n=3 species each). The families that
represented 2.0% (n=2 species each) were Phasianidae, Meropidae, Scolopacidae,
Laniidae, Nectariniidae, and Motacillidae. The rest of the families had a
single species each.
Within the sanctuary, the avian
community was categorised based on the observed frequency, revealing that 58
species (60%) were Common (C); 28 species (29%) were Uncommon (UC), and the
remaining ten (10%) were rare (R). Regarding residency status, the majority of
species within TBS were Resident (R), accounting for 83 species (86%), while 12
species (13%) were Winter Visitors (WV) and the remaining one was a Passage
Migrant (PM) Rosy Starling Pastor roseus. Common residents included the
Peafowl Pavo cristatus, Indian Robin Copsychus fulicatus, Asian
Koel Eudynamys scolopaceus and White-throated Kingfisher Halcyon smyrnensis. Our study documented seven diurnal and
nocturnal raptors, including the Black-winged Kite Elanus caeruleus,
Western Marsh Harrier Circus aeruginosus, Booted Eagle Hieraaetus
pennatus, Shikra Accipiter badius, Oriental Honey Buzzard Pernis
ptilorhynchus, Brahminy Kite Haliastur indus and Spotted
Owlet Athene brama.
The distribution of waterbird
species across families is graphically represented in Figure 1. Numerous
wetland factors influenced waterbird abundance and diversity, including wetland
area, water depth and quality, trophic level structure, and the availability of
suitable roosting and breeding sites for birds (Wiens 1989; Mukherjee et al.
2002; Ma et al. 2010). Notably, migratory duck species such as Garganey Spatula
querquedula and Northern Shoveler Spatula clypeata along with
shorebirds like the Wood Sandpiper Tringa glareola and Common Sandpiper Actitis
hypoleucos were recorded. The presence of these migratory bird species in
reasonable numbers during both the migratory seasons of the study highlighted
the importance of sanctuary in providing critical wintering grounds during
their migration (see Figure 2 & 3).
During the observation period, the sanctuary
recorded five major waterbird species:
Asian Openbill Anastomus oscitans (n 1324), Spot-billed Pelican Pelecanus
philippensis (n 785), Glossy Ibis Plegadis falcinellus (n 411),
Black-headed Ibis Threskiornis melanocephalus (n 289) and Painted Stork Mycteria
leucocephala (n 226). Additionally, the five major land bird species
recorded included the passage migrant Rosy Starling (n 2200), Barn Swallow
Hirundo rustica (n 200), Rose-ringed Parakeet Psittacula krameri (n
170), Baya Weaver Ploceus philippinus (n 120) and Common Myna Acridotheres
tristis (n 82). TBS also supported four Near-Threatened waterbirds –
Black-headed Ibis, Asian Woolly-necked Stork Ciconia eniscopus,
Oriental Darter Anhinga melanogaster, and Spot-billed Pelican -
highlighting the sanctuary’s critical role in conserving near-threatened
species.
The habitat changes observed in
the study area support different groups of waterbirds and terrestrial birds,
each with distinct habitat preferences for activities like foraging, nesting,
and roosting (Hattori & Mae 2001). Waterbirds,
in particular, utilised various habitat changes in the region for different
activities throughout the year (Kularatne et al. 2021). As many of the trees
began to wilt and decay, the stronger trees were preferred by colonial nesters
during the second breeding season.
Breeding waterbird population and
diversity
Of the 40 species of waterbirds
recorded, 23 were observed breeding in the sanctuary (Table 3). This heronry had partially submerged trees
within the waterbody as the preferred habitat for nesting birds. The
Spot-billed Pelicans and Painted Storks occupied the Acacia nilotica
trees (Images 3 & 4). The predominant nesters were Asian Openbills closely followed by Spot-billed Pelicans. The
maximum number of nests and birds were recorded in year 2. It could be inferred
that an increase in rainfall in the second year compared to the previous year
may have enabled the increase in nesting attempts (Frank et al. 2021). Oriental
Darters, Eurasian Spoonbills, and Asian Openbills nested in the medium-sized
trees like Prosopis juliflora, Black-headed Ibises nested in the canopy,
and Cormorants, Egrets, and Pond Herons occupied the lower strata of the
habitat of the trees. Most of the nesting materials were collected from the
nearby agricultural fields.
Conservation status of avian fauna
Understanding the importance of a
site requires an examination of its significance in relation to its species
richness (Bruford 2002). The TBS supports four ‘Near Threatened’ species, such
as the Black-headed Ibis, Oriental Darter, Asian
Woolly-necked Stork, and Spot-bellied Pelican (IUCN 2023); the remaining
92 are ‘Least Concern’ (LC) species (Table 1). Previously, no proper scientific
studies had been conducted in this sanctuary, and 96 species, including 40
waterbirds, were recorded during the present study. The number of breeding
waterbirds supported in the sanctuary is dependent on various factors mentioned
earlier. This data provides fundamental information for future studies aimed at
shaping management plans to enhance wetland conservation, supporting both
resident and migratory bird populations.
Potential management issues
Wetlands account for 24% of
invasive species globally (Zedler & Kercher, 2004; Kaushik & Gupta
2014), including invasive trees like Prosopis, which support breeding
birds. The invasive Prosopis were being removed to prevent water loss,
destruction of habitat and hindrance to native trees without a proper plan for
their replacement which impacted birds like Asian Openbill and cormorants as they
currently prefer to nest in these trees. The native Acacia nilotica was
the main species on which the birds roosted in the sanctuary. Recently, some
trees wilted and died due to changes in monsoon patterns. The removal of Prosopis coupled with
drought driven wilting of Acacia trees reduced the number of potential
nesting sites for the birds and also resulting in the abandonment of
nests by waterbirds, affecting their nesting behaviour (Roshnath & Sinu
2017). Therefore, it is very important that the new trees planted are native
and have greater adaptability to survive drought as well as excess water, to
support the breeding population of waterbirds.
The two-year nesting observations highlighted the difference in nesting
preferences (Table 3) and the impact of irregular monsoons (Jabaraj & Gopi
2020) due to climate change affecting the habitats of waterbirds (Wormworth
& Mallon 2006). Ipomea carnea was another invasive species that
rapidly replaced the native vegetation at the site, with the potential to
affect ground-nesting birds. Hence, we suggest long-term monitoring of nesting
locations and breeding seasons (Urfi 2011; Pavon-Jordan et al. 2020).
During the study, we observed a
few minor threats that affected the sanctuary.
One such threat was the grazing of cattle during the drought seasons,
which led to the destruction of trees. Cattle, in search of food, climbed the
trees and ate the bark due to the scarcity of leaves, causing the trees to
slowly die. Additionally, the adjacent agricultural lands were sprayed with
pesticides during cultivation. The impact of these chemicals on breeding birds
needs to be ascertained for future studies. Furthermore, the local caste
dynamics played a significant role among villagers surrounding the sanctuary. Conflict arose over water usage rights and
the lack of clear boundary markings between the sanctuary and the villagers’
lands, leading to disputes with the forest department. Consequently, the officials and staff needed
to be proactive to prevent any acts of retaliation against the birds and trees
by the aggrieved parties.
CONCLUSIONS
Therthangal Bird Sanctuary serves
as a suitable habitat for a wide variety of bird species, both resident and
migratory. This is a testament to the ecological richness and conservation
value of the sanctuary. Conservation strategies for these ecological indicator
species (Ogden et al. 2014) necessitates a comprehensive approach that
addresses threats to wetland habitats and waterbird populations, as they have
high site fidelity. Conserving a wetland like the TBS and its associated
waterbird populations requires a collaborative effort involving diverse
stakeholders to ensure sustained management interventions, education, and
advocacy programmes. The local villagers
are dependent on the water for household activities, agriculture, and grazing
their cattle during drought periods. Conservation efforts should focus on
habitat preservation, restoration, and sustainable management to ensure the
long-term survival of these species. Habitat destruction, pollution, and
anthropogenic activities in the surrounding areas pose serious challenges.
Conservation strategies must address these threats to safeguard the sanctuary
and its avifauna.
Table 1.
Checklist of avifauna recorded from Therthangal Bird Sanctuary, Tamil Nadu.
|
Scientific name |
Common name |
Migratory status |
IUCN Red List status |
Frequency of observation |
Habitat type |
|
Order: Galliformes |
|
||||
|
Family: Phasianidae |
|||||
|
Pavo cristatus |
Indian Peafowl |
R |
LC |
C |
AL/OS |
|
Francolinus pondicerianus |
Grey Francolin |
R |
LC |
C |
GL/OS |
|
Order: Anseriformes |
|
||||
|
Family: Anatidae |
|||||
|
Sarkidiornis melanotos |
Comb Duck |
R |
LC |
C |
WL |
|
Anas poecilorhyncha |
Indian Spot-billed Duck |
R |
LC |
C |
WL |
|
Spatula querquedula |
Garganey |
WV |
LC |
UC |
WL |
|
Spatula clypeata |
Northern Shoveler |
WV |
LC |
R |
WL |
|
Dendrocygna javanica |
Lesser Whistling-Duck |
R |
LC |
UC |
WL |
|
Order: Podicipediformes |
|
||||
|
Family: Podicipedidae |
|||||
|
Tachybaptus ruficollis |
Little Grebe |
R |
LC |
C |
WL |
|
Order: Piciformes |
|
||||
|
Family: Picidae |
|||||
|
Dinopium benghalense |
Black-rumped Flameback |
R |
LC |
C |
Tr |
|
Family: Megalaimidae |
|
||||
|
Psilopogon haemacephalus |
Coppersmith Barbet |
R |
LC |
UC |
Tr |
|
Order: Bucerotiformes |
|
||||
|
Family: Upupidae |
|||||
|
Upupa epops |
Common Hoopoe |
R |
LC |
UC |
AL/GL |
|
Order: Coraciiformes |
|
||||
|
Family: Coraciidae |
|||||
|
Coracias benghalensis |
Indian Roller |
R |
LC |
C |
OS/AL |
|
Halcyon smyrnensis |
White-throated Kingfisher |
R |
LC |
C |
WL |
|
Alcedo atthis |
Common Kingfisher |
R |
LC |
C |
WL |
|
Family: Meropidae |
|
||||
|
Merops orientalis |
Green Bee-eater |
R |
LC |
C |
OS/AL |
|
Merops philippinus |
Blue-tailed Bee- eater |
WV |
LC |
C |
OS/AL |
|
Order: Cuculiformes |
|
||||
|
Family: Cuculidae |
|||||
|
Centropus sinensis |
Greater Coucal |
R |
LC |
C |
OS |
|
Eudynamys scolopaceus |
Asian Koel |
R |
LC |
C |
OS |
|
Clamator jacobinus |
Pied Cuckoo |
R |
LC |
UC |
OS |
|
Hierrococcyx varius |
Common Hawk Cuckoo |
R |
LC |
UC |
OS |
|
Order: Psittaciformes |
|
||||
|
Family: Psittacidae |
|||||
|
Psittacula krameri |
Rose-ringed Parakeet |
R |
LC |
C |
Tr |
|
Order: Strigiformes |
|
||||
|
Family: Strigidae |
|||||
|
Athene brama |
Spotted Owlet |
R |
LC |
UC |
OS/AL/Tr |
|
Order: Columbiformes |
|
||||
|
Family: Columbidae |
|||||
|
Columba livia |
Rock Pigeon |
R |
LC |
C |
AL/OS/GL |
|
Streptopelia decaocto |
Eurasian Collared-Dove |
R |
LC |
C |
AL/OS/GL |
|
Spilopelia senegalensis |
Laughing Dove |
R |
LC |
C |
AL/OS/GL |
|
Spilopelia chinensis |
Spotted Dove |
R |
LC |
C |
AL/OS/GL |
|
Order: Apodiformes |
|
||||
|
Family: Apodidae |
|||||
|
Cypsiurus balasiensis |
Asian Palm- swift |
R |
LC |
C |
Tr |
|
Order: Gruiformes |
|
||||
|
Family: Rallidae |
|||||
|
Gallinula chloropus |
Common Moorhen |
R |
LC |
UC |
WL |
|
Porphyrio porphyrio |
Grey-headed Swamphen |
R |
LC |
UC |
WL |
|
Amaurornis phoenicurus |
White-breasted Waterhen |
R |
LC |
C |
WL |
|
Fulica atra |
Eurasian Coot |
R |
LC |
C |
WL |
|
Zapornia pusilla |
Baillon’s Crake |
WV |
LC |
R |
WL |
|
Gallicrex cinerea |
Watercock |
R |
LC |
R |
WL |
|
Order: Charadriiformes |
|
||||
|
Family: Scolopacidae |
|||||
|
Tringa glareola |
Wood Sandpiper |
WV |
LC |
UC |
WL |
|
Actitis hypoleucos |
Common Sandpiper |
WV |
LC |
UC |
WL |
|
Family: Jacanidae |
|
||||
|
Hydrophasianus chirurgus |
Pheasant-tailed Jacana |
R |
LC |
UC |
WL |
|
Family: Charadriidae |
|
||||
|
Vanellus indicus |
Red-wattled Lapwing |
R |
LC |
C |
WL |
|
Family: Recurvirostridae |
|
||||
|
Himantopus himantopus |
Black-winged Stilt |
R |
LC |
C |
WL |
|
Family: Laridae |
|
||||
|
Chlidonias hybrida |
Whiskered Tern |
WV |
LC |
R |
WL |
|
Order: Accipitriformes |
|
||||
|
Family: Accipitridae |
|||||
|
Circus aeruginosus |
Western Marsh Harrier |
WV |
LC |
R |
OS/GL |
|
Elanus caeruleus |
Black-winged Kite |
R |
LC |
C |
AL/OS |
|
Hieraaetus pennatus |
Booted Eagle |
WV |
LC |
R |
OS/Tr |
|
Accipiter badius |
Shikra |
R |
LC |
UC |
AL/GL/Tr/OS |
|
Pernis ptilorhynchus |
Oriental Honey Buzzard |
R |
LC |
R |
Tr |
|
Haliastur indus |
Brahminy Kite |
R |
LC |
C |
WL/GL |
|
Order: Suliformes |
|
||||
|
Family: Anhingidae |
|||||
|
Anhinga melanogaster |
Oriental Darter |
R |
NT |
UC |
WL |
|
Family: Phalacrocoracidae |
|
||||
|
Microcarbo niger |
Little Cormorant |
R |
LC |
C |
WL |
|
Phalacrocorax carbo |
Great Cormorant |
R |
LC |
UC |
WL |
|
Phalacrocorax fuscicollis |
Indian Cormorant |
R |
LC |
C |
WL |
|
Order: Pelicaniformes |
|
||||
|
Family: Ardeidae |
|||||
|
Ixobrychus sinensis |
Yellow Bittern |
R |
LC |
UC |
WL |
|
Ardea cinerea |
Grey Heron |
R |
LC |
UC |
WL |
|
Ardea purpurea |
Purple Heron |
R |
LC |
UC |
WL |
|
Egretta garzetta |
Little Egret |
R |
LC |
C |
WL |
|
Bubulcus ibis |
Cattle Egret |
R |
LC |
C |
WL |
|
Ardea alba |
Great Egret |
R |
LC |
C |
WL |
|
Ardea intermedia |
Intermediate Egret |
R |
LC |
C |
WL |
|
Ardeola grayii |
Indian Pond Heron |
R |
LC |
C |
WL |
|
Nycticorax nycticorax |
Black-crowned Night Heron |
R |
LC |
C |
WL |
|
Butorides striata |
Striated Heron |
R |
LC |
UC |
WL |
|
Family: Threskiornithidae |
|
||||
|
Threskiornis melanocephalus |
Black-headed Ibis |
R |
NT |
C |
WL |
|
Plegadis falcinellus |
Glossy Ibis |
R |
LC |
C |
WL |
|
Pseudibis papillosa |
Red-naped Ibis |
R |
LC |
C |
WL |
|
Platalea leucorodia |
Eurasian Spoonbill |
R |
LC |
C |
WL |
|
Family: Pelecanidae |
|
||||
|
Pelecanus philippensis |
Spot-billed Pelican |
R |
NT |
C |
WL |
|
Order: Ciconiiformes |
|
||||
|
Family: Ciconiidae |
|||||
|
Anastomus oscitans |
Asian Openbill |
R |
LC |
C |
WL |
|
Mycteria leucocephala |
Painted Stork |
R |
LC |
C |
WL |
|
Ciconia episcopus |
Asian Woolly-necked Stork |
R |
NT |
R |
WL |
|
Order: Passeriformes |
|
||||
|
Family: Artamidae |
|
||||
|
Artamus fuscus |
Ashy Woodswallow |
R |
LC |
C |
OS/AL |
|
Family: Laniidae |
|
||||
|
Lanius schach |
Long-tailed Shrike |
R |
LC |
R |
OS |
|
Lanius cristatus |
Brown Shrike |
WV |
LC |
UC |
OS |
|
Family: Dicruridae |
|
||||
|
Dicrurus macrocercus |
Black Drongo |
R |
LC |
C |
GL/AL/OS |
|
Family: Corvidae |
|
||||
|
Dendrocitta vagabunda |
Rufous Treepie |
R |
LC |
UC |
OS |
|
Corvus macrorhynchos |
Indian Jungle Crow |
R |
LC |
C |
OS/GL/WL |
|
Corvus splendens |
House Crow |
R |
LC |
C |
AL/OS/WL/GL |
|
Family: Sturnidae |
|
||||
|
Acridotheres tristis |
Common Myna |
R |
LC |
C |
AL/OS/GL |
|
Pastor roseus |
Rosy Starling |
PM |
LC |
UC |
AL/OS/GL |
|
Family: Hirundinidae |
|
||||
|
Hirundo rustica |
Barn Swallow |
WV |
LC |
UC |
AL/WL |
|
Family: Pycnonotidae |
|
||||
|
Pycnonotus cafer |
Red-vented Bulbul |
R |
LC |
C |
OS/AL/GL |
|
Family: Timaliidae |
|
||||
|
Turdoides affinis |
Yellow-billed Babbler |
R |
LC |
C |
OS/AL |
|
Family: Cisticolidae |
|
||||
|
Prinia socialis |
Ashy Prinia |
R |
LC |
C |
AL/OS/GL |
|
Prinia inornata |
Plain Prinia |
R |
LC |
C |
AL/OS/GL |
|
Orthotomus sutorius |
Common Tailorbird |
R |
LC |
C |
AL/OS/GL |
|
Cisticola juncidis |
Zitting Cisticola |
R |
LC |
UC |
AL/OS/GL |
|
Family: Acrocephalidae |
|
||||
|
Acrocephalus dumetorum |
Blyth’s Reed Warbler |
WV |
LC |
R |
OS |
|
Family: Alaudidae |
|
||||
|
Galerida cristata |
Jerdon’s Bushlark |
R |
LC |
UC |
AL/OS/GL |
|
Family: Muscicapidae |
|
||||
|
Saxicola caprata |
Pied Bushchat |
R |
LC |
C |
OS |
|
Copsychus fulicatus |
Indian Robin |
R |
LC |
C |
AL/OS |
|
Copsychus saularis |
Oriental Magpie Robin |
R |
LC |
C |
AL/OS |
|
Family: Nectariniidae |
|
||||
|
Cinnyris asiaticus |
Purple-rumped Sunbird |
R |
LC |
C |
OS/GL |
|
Cinnyris asiaticus |
Purple Sunbird |
R |
LC |
C |
OS/GL |
|
Family: Ploceidae |
|
||||
|
Ploceus philippinus |
Baya Weaver |
R |
LC |
UC |
OS |
|
Family: Estrildidae |
|
||||
|
Euodice malabarica |
Indian Silverbill |
R |
LC |
UC |
AL/GL/OS |
|
Family: Dicaeidae |
|
||||
|
Dicaeum concolor |
Pale-billed Flowerpecker |
R |
LC |
C |
OS |
|
Family: Passeridae |
|
||||
|
Passer domesticus |
House Sparrow |
R |
LC |
C |
AL/GL |
|
Family: Motacillidae |
|
||||
|
Motacilla maderaspatensis |
White-browed Wagtail |
R |
LC |
C |
WL |
|
Anthus rufulus |
Paddy-field Pipit |
R |
LC |
UC |
GL/AL |
Migratory status: R—Resident |
WV—Winter visitor | PM—Passage migrant | IUCN Status: CR—Critically Endangered
| EN—Endangered | LC—Least Concern | NT—Near Threatened | VU—Vulnerable | WPA
Frequency of observation: R—Rare | C—Common | UC—Uncommon | Habitat type:
WL—Wetland | GL—Grass land | OS—Open scrub | AL—Agricultural land | Tr—Trees on
the bund adjoining the wetland and agricultural lands.
Table 2.
Relative diversity (RDi) of various avifaunal families at Therthangal Bird
Sanctuary.
|
Family |
Number of species observed |
Relative diversity (%) |
|
Phasianidae |
2 |
2.08 |
|
Anatidae |
5 |
5.20 |
|
Podicipedidae |
1 |
1.04 |
|
Picidae |
1 |
1.04 |
|
Megalaimidae |
1 |
1.04 |
|
Upupidae |
1 |
1.04 |
|
Coraciidae |
3 |
3.12 |
|
Meropidae |
2 |
2.08 |
|
Cuculidae |
4 |
4.16 |
|
Psittacidae |
1 |
1.04 |
|
Strigidae |
1 |
1.04 |
|
Columbidae |
4 |
4.16 |
|
Apodidae |
1 |
1.04 |
|
Rallidae |
6 |
6.25 |
|
Scolopacidae |
2 |
2.08 |
|
Jacanidae |
1 |
1.04 |
|
Charadriidae |
1 |
1.04 |
|
Recurvirostridae |
1 |
1.04 |
|
Laridae |
1 |
1.04 |
|
Accipitridae |
6 |
6.25 |
|
Anhingidae |
1 |
1.04 |
|
Phalacrocoracidae |
3 |
3.12 |
|
Ardeidae |
10 |
10.4 |
|
Threskiornithidae |
4 |
4.16 |
|
Pelecanidae |
1 |
1.04 |
|
Ciconiidae |
3 |
3.12 |
|
Artamidae |
1 |
1.04 |
|
Laniidae |
2 |
2.08 |
|
Dicruridae |
1 |
1.04 |
|
Corvidae |
3 |
3.12 |
|
Sturnidae |
2 |
2.08 |
|
Hirundinidae |
1 |
1.04 |
|
Pycnonotidae |
1 |
1.04 |
|
Timaliidae |
1 |
1.04 |
|
Cisticolidae |
4 |
4.16 |
|
Acrocephalidae |
1 |
1.04 |
|
Alaudidae |
1 |
1.04 |
|
Muscicapidae |
3 |
3.12 |
|
Nectariniidae |
2 |
2.08 |
|
Ploceidae |
1 |
1.04 |
|
Estrildidae |
1 |
1.04 |
|
Dicaeidae |
1 |
1.04 |
|
Passeridae |
1 |
1.04 |
|
Motacillidae |
2 |
2.08 |
Table 3.
Breeding waterbirds of Therthangal Bird Sanctuary.
|
Common name |
Scientific name |
Maximum nest count during the
study |
Maximum bird count during the
study |
||
|
|
|
Year 1 |
Year 2 |
Year 1 |
Year 2 |
|
Spot-billed Pelican |
Pelecanus philippensis |
54 |
182 |
335 |
785 |
|
Little Cormorant |
Microcarbo niger |
10 |
65 |
106 |
264 |
|
Indian Cormorant |
Phalacrocorax fuscicollis |
15 |
45 |
62 |
155 |
|
Oriental Darter |
Anhinga melanogaster |
9 |
30 |
40 |
90 |
|
Great Egret |
Ardea alba |
5 |
8 |
15 |
32 |
|
Intermediate Egret |
Ardea intermedia |
4 |
11 |
13 |
42 |
|
Little Egret |
Egretta garzetta |
3 |
8 |
20 |
63 |
|
Cattle Egret |
Bubulcus ibis |
6 |
18 |
50 |
126 |
|
Grey Heron |
Ardea cinerea |
5 |
15 |
18 |
40 |
|
Purple Heron |
Ardea purpurea |
2 |
5 |
9 |
15 |
|
Indian Pond Heron |
Ardeola grayii |
2 |
11 |
45 |
45 |
|
Black-crowned Night Heron |
Nycticorax nycticorax |
13 |
41 |
50 |
124 |
|
Painted Stork |
Mycteria leucocephala |
18 |
61 |
92 |
226 |
|
Red-naped Ibis |
Pseudibis papillosa |
2 |
2 |
5 |
8 |
|
Asian Openbill Stork |
Anastomus oscitans |
80 |
264 |
556 |
1324 |
|
Glossy Ibis |
Plegadis falcinellus |
4 |
12 |
167 |
411 |
|
Black-headed Ibis |
Threskiornis melanocephalus |
22 |
72 |
117 |
289 |
|
Eurasian Spoonbill |
Platalea leucorodia |
6 |
12 |
20 |
42 |
|
Spot-billed Duck |
Anas poecilorhyncha |
1 |
4 |
9 |
23 |
|
Comb Duck |
Sarkidiornis sylvicola |
1 |
2 |
8 |
20 |
|
Black-winged Stilt |
Himantopus himantopus |
2 |
4 |
20 |
46 |
|
Red wattled Lapwing |
Vanellus indicus |
1 |
2 |
16 |
42 |
|
Lesser Whistling Duck |
Dendrocygna javanica |
1 |
1 |
18 |
38 |
For figures & images - -
click here for full PDF
References
Bakker, K.K.
(2005). South Dakota
all bird conservation plan. In: Wildlife Division Report 2005–09.
Pierre, SD: South Dakota Department of Game, Fish and Parks, 151 pp.
Bassi, N., M.D.
Kumar, A. Sharma & P. Pardha-Saradhi (2014). Status of wetlands in India: a
review of extent, ecosystem benefits, threats and management strategies. Journal
of Hydrology: Regional Studies 2: 1–19. https://doi.org/10.1016/j.ejrh.2014.07.001
Beyersbergen,
G.W., N.D. Niemuth & M.R. Norton (2004). Northern Prairie and Parkland
waterbird conservation plan. Prairie Pothole Joint Venture, Carol Lively,
Coordinator. United States Fish and Wildlife Service, Denver, Colorado, 186
pp.
Bibby, C.J.,
N.D. Burgess, D.A. Hill & S.H. Mustoe (2000). Bird Census Techniques.
Academic Press, London, 302 pp.
Bibi, F. &
Z. Ali (2013). Measurement of
diversity indices of avian communities at Taunsa Barrage Wildlife Sanctuary,
Pakistan. Journal of Animal and Plant Sciences 23: 469–474.
BirdLife
International (2017). Waterbirds are showing widespread declines, particularly in Asia.
http://datazone.birdlife.org/sowb/casestudy/waterbirds–are–showing–widespread–declines–particularly–in–asia.
Accessed on 09 February 2024.
Brook, H.D.L.
& F. Aramde (2012). Aspect of climate change and its associated impacts on wetland ecosystem
functions. Journal of American Science 8(10): 112–160.
Bruford, M.W.
(2002).
Biodiversity–Evolution. Species, Genes, pp 1-19. In: Norris, Ken, and Pain,
Deborah J. eds. Conserving Bird Biodiversity: General Principle and their
Application, Conservation Biology, Cambridge University Press 7: 1–19.
Byju, H. &
N. Raveendran (2022). First Asian record of Light–mantled Albatross Phoebetria palpebrata
(Foster, 1785) from Rameswaram Island, Tamil Nadu, India. Journal of
Threatened Taxa 14(7): 21473–21475. https://doi.org/10.11609/jot.7992.14.7.21473–21475
Byju, H., N.
Raveendran & S. Ravichandran (2023a). Distribution of avifauna on
twenty–one islands of the Gulf of Mannar Biosphere Reserve, India. Journal
of Threatened Taxa 15(2): 22574–22585. https://doi.org/10.11609/jott.8112.15.2.22574–22585
Byju, H., N.
Raveendran, S. Ravichandran & R. Kishore (2023b). An annotated checklist of the
avifauna of Karangadu mangrove forest, Ramanathapuram, Tamil Nadu, with notes
on the site’s importance for waterbird conservation. Journal of Threatened
Taxa 15(3): 22813–22822. https://doi.org/10.11609/jott.8356.15.3.22813–22822
Byju, H., N.
Raveendran, S. Ravichandran & R. Kishore (2023c). Importance of conserving a critical
wintering ground for shorebirds in the Valinokkam Lagoon—a first study of the
avifaunal distribution of the southeastern coast of India. Journal of
Threatened Taxa 15(8): 23696–23709. https://doi.org/10.11609/jott.8494.15.8.23696–23709
Byju, H., N.
Raveendran, S. Ravichandran & R. Kishore (2023d). Additional breeding records of
Hanuman Plover Charadrius seebohmi E. Hartert & A.C. Jackson, 1915
(Aves: Charadriiformes: Charadriidae) from southeastern coast of India. Journal
of Threatened Taxa 15(4): 23114–23118. https://doi.org/10.11609/jott.8317.15.4.23114–23118
Byju, H. &
N. Raveendran (2024). Report of study on bird migratory pattern with respect to change in
habitation for water birds and land birds in Therthangal bird Sanctuary of
Wildlife Division, Ramanathapuram. Iragukal Amritha Nature Trust, Madhurai,
Tamil Nadu, 28 pp.
Dudgeon, D.,
A.H. Arthington, M.O. Gessner, Z.I. Kawabata, D.J. Knowler, C. Lévêque, R.J.
Naiman, A.–H. Prieur–Richard, D. Soto, M.L.J. Stiassny & C.A. Sullivan
(2006). Freshwater
biodiversity: importance, threats, status and conservation challenges. Biological
Reviews 81: 163. https://doi.org/10.1017/S1464793105006950
Davidson, N.C.
(2014). How much
wetland has the world lost? Long–term and recent trends in global wetland area.
Marine and Freshwater Research 65: 934–941.
Dodd, M.G. &
T.M. Murphy (1995). Accuracy and
precision of techniques for counting Great Blue Heron nests. Journal of
Wildlife Management 59(4): 667–673.
Finlayson, M.,
R.D. Cruz, N. Davidson, J. Alder, S. Cork, R.S. Groot, C.
de; Lévêque, G.R. Milton, G. Peterson, D. Pritchard,
B.D. Ratner, W.V. Reid, C. Revenga, M. Rivera, F. Schutyser,
M. Siebentritt, M. Stuip, R. Tharme, S. Butchard,
E. Dieme-Amting, H. Gitay, S. Raaymakers & D. Taylor (2005). Ecosystems and human well–being:
wetlands and water synthesis. A report of the Millennium Ecosystem Assessment. World Resources
Institute, Washington, DC. Island Press, 69 pp
Frank, S.J.D.,
G.V. Gopi, B. Pandav (2021). Heronry distribution and site preference dynamics of tree-nesting colonial
waterbirds in Tamil Nadu. PeerJ 9: e12256. https://doi.org/10.7717/peerj.12256
Friend, R.
(2007). Securing
sustainable livelihoods through wise use of wetland resources: reflections on
the experience of the Mekong Wetlands biodiversity conservation and sustainable
use programme, (MWBP). Vientianne, Lao PDR: Mekong Wetlands Biodiversity
Conservation and Sustainable Use Programme, 52 pp.
Gibbs, J.P., S.
Woodward, M.L. Hunter & A.E. Hutchinson (1988). Comparison of techniques for
censusing Great Blue Heron nests. Journal of Field Ornithology 59:
130–134.
Green, A.J.
& J. Elmberg (2014). Ecosystem services provided by waterbirds. Biological Reviews
89(1): 105–122. https://doi.org/10.1111/brv.12045
Grimmett, R., C.
Inskipp, T. Inskipp & R. Allen (2011). Birds of the Indian Subcontinent.
Christopher Helm, London, 480 pp.
Hattori, A.
& S. Mae (2001). Habitat use and diversity of waterbirds in a coastal lagoon around Lake
Biwa, Japan. Ecological Research 16: 543–553.
Howes, J.G.
& D. Bakewell (1989). Shorebird studies manual. Asian Wetland Bureau, Publication No 55,
Kula Lumpur, 362 pp.
IUCN (2023). The IUCN Red List of Threatened
species. Version 2020–1. Accessed on 7 September 2023. https://www.iucnredlist.org.
Jabaraj, D.F.S.
& G.V. Gopi (2020). At the behest of rainfall: a case of heronry formation failure in Tamil
Nadu. Bird-o-Soar #43. In: Zoo’s Print 35(3): 21–24.
Kaushik, T.K.
& R.C. Gupta (2014). Deteriorating rural ponds: a threat to overseas migratory wetland birds in
Kurukshetra suburbs, Haryana, India. Journal of Applied Natural Science
6(2): 570–577.
Koli, V. (2014). Diversity and status of avifauna in
Todgarh-Raoli Wildlife Sanctuary, Rajasthan, India. Journal of Asia-Pacific
Biodiversity 7(4): 401–407.
Kularatne,
R.K.A., J.M. Harris, P. Vinobaba, S. Thanusanth, S. Kishoran & C.E.
Kankanamge (2021). Use of habitats
by aquatic and terrestrial avifauna in tropical coastal lagoons. Regional
Studies in Marine Science 47: 101926. https://doi.org/10.1016/j.rsma.2021.101926
Kushlan, J.A,
M.J. Steinkamp, K.C. Parsons, J. Capp, M.A. Cruz, M. Coulter, I. Davidson, L.
Dickson, N. Edelson, R. Elliot & R.M. Erwin (2002). Waterbird conservation for the
Americas: the North American waterbird conservation plan, Version 1. U.S. Fish
and Wildlife Service, Washington, DC, 78 pp.
Ma, Z., Y. Cai,
B. Li & J. Chen (2010). Managing wetland habitats for waterbirds: an international perspective. Wetlands
30(1): 15–27. https://doi.org/10.1007/s13157-009-0001-6
Maltby, E. &
M.C. Acreman (2011). Ecosystem services of wetlands: pathfinder for a new paradigm. Hydrological
Sciences Journal 56(8): 1341–1359.
MacKinnon, J.
& K. Philips (1993). A Field Guide to Birds of Sumatra, Java and Bali. Oxford University
Press, 512 pp.
McMohan, B.J.,
G. Purvis & J. Whelan (2008). The influence of habitat heterogeneity on bird diversity
in Irish farmland. Biology and Environment: Proceedings of the Royal Irish
Academy 108 B(1): 1–8. http://www.jstor.org/stable/20694841
Mukherjee, A.,
C.K. Borad & B.M. Parasharya (2002). A study of the ecological
requirements of waterfowl at man–made reservoirs in Kheda District, Gujarat,
India, with a view towards conservation, management, and planning. Zoos’
Print Journal 17(5): 775–785. http://doi.org/10.11609/JoTT.ZPJ.17.5.775–85
Ogden, J.C.,
J.D. Baldwin, O. L. Bass, J.A. Browder, M.I. Cook, P.C. Frederick & J.J.
Lorenz (2014). Waterbirds as
indicators of ecosystem health in the coastal marine habitats of southern
Florida: 1. selection and justification for a suite of indicator species. Ecological
Indicators 44(3): 148–163. https://doi.org/10.1016/j.ecolind.2014.03.007
Pavon-Jordan,
D., W. Abdou, H. Azafzaf, M. Balaž, T. Bino, J. J. Borg, L. Božič, S. H.
Butchart, P. Clausen, L. Sniauksta &
M. Dakki (2020). Positive impacts of important bird and
biodiversity areas on wintering waterbirds under changing temperatures throughout
Europe and North Africa. Biological Conservation 246: 108549. https://doi.org/10.1016/j.biocon.2020.108549
Péron, G., Y.
Ferrand, G. Leray & O. Gimenez (2013). Waterbird demography as indicator
of wetland health: the French–wintering common snipe population. Biological
Conservation 164: 123–128.
Pöysä, H., S.
Holopainen, J. Elmberg, G. Gunnarsson, P. Nummi & K. Sjöberg (2019). Changes in species richness and
composition of boreal waterbird communities: a comparison between two time
periods 25 years apart. Scientific Reports 9(1): 1725. https://doi.org/10.1038/s41598-018-38167-1
Pramod, A., V.
Kumara & R. Gowda (2011). A Study on physicochemical characteristics of water in Wetlands of hebbe
range in Bhadra Wildlife Sanctuary, Mid-Western ghat Region, India. Journal
of Experimental Sciences 2: 9–15.
Praveen, J.
& R. Jayapal (2023). Taxonomic updates to the checklists of birds of India and the South Asian
region. Indian BIRDS 18(5): 131–134.
Prigent, C., F.
Papa, F. Aires, C. Jimenez, W. Rossow & E. Matthews. (2012). Changes in land surface water
dynamics since the 1990s and relation to population pressure. Geophysical
Research Letters 39(8): https://doi.org/10.1029/2012GL051276
Rajpar, M.N.
& M. Zakaria (2010). Indah Wetland Reserve, Selangor Peninsular Malaysia. Journal of
Biological Sciences 10(7): 658–666.
Ranga, M.R.
(2006). Transformation
of coastal wetland agriculture and livelihoods in Kerala, India. Master’s
Thesis. University of Manitoba, Winnipeg, 169 pp.
Roshnath, R.
& C. Sashikumar (2019). Conservation challenges of the heronries in Kerala. Journal of the
Bombay Natural History Society 116: 63–67.
Roshnath, R.
& P.A. Sinu (2017). Nesting tree characteristics of heronry birds of urban ecosystems in
peninsular India: implications for habitat management. Current Zoology
63(6): 599–605. https://doi.org/10.1093/cz/zox006
Salimi, S.,
A.A.A.N. Suhad, Almuktar & M. Scholz (2021). Impact of climate change on wetland
ecosystems: A critical review of experimental wetlands, Journal of
Environmental Management 286: 112160. https://doi.org/10.1016/j.jenvman.2021.112160
Shan, V., S.K.
Singh & A.K. Haritash (2021). Present Status, Conservation, and Management of Wetlands
in India. 235–256, In. Al Khaddar, R., Kaushika, N.D., Singh, S., Tomar, R.K.
(eds) Advances in Energy and Environment. Lecture Notes in Civil
Engineering, vol 142. Springer, Singapore, 235–256 pp. https://doi.org/10.1007/978-981-33-6695-4_22
Sharma, R., B.
Rimal, H. Baral, U. Nehren, K. Paudyal, S. Sharma, S. Rijal, S. Ranpal, R.P.
Acharya, A.A. Amer & P. Kandel (2019). Impact of land cover change on
ecosystem services in a tropical forested landscape. Resources
8(1): 18.
Subramanya, S.
(1996). Distribution,
status and conservation of Indian heronries. Journal of Bombay Natural
History Society 93: 459–480.
Urfi, A. (2011). Climate change and its impacts on
Indian birds: monsoon phenology and monitoring heronry birds. Current
Science 101(9): 1140–1142.
Wiens, J.A.
(1989). The Ecology of
Bird Communities. Cambridge
University Press, Cambridge, 539 pp.
Wilson, J.
(1979). Social forestry
in Tamil Nadu. Indian Forester 105: 700–706
Wormworth, J.
& K. Mallon (2006). Bird Species and Climate Change. The Global Status Report. A
synthesis of current scientific understanding of anthropogenic climate change
impacts on global bird species now, and projected future effects. Climate
Risk Pty Limited (Australia), 75 pp.
Wang, X., X. Li,
X. Ren, M.V. Jackson, R.A. Fuller, D.S. Melville,
T. Amano & Z. Ma (2021). Effects of anthropogenic landscapes on
population maintenance of waterbirds. Conservation Biology 36(2): 1–8. https://doi.org/10.1111/cobi.13808
Zedler, J.B.
& S. Kercher (2004). Causes and consequences of invasive plants in wetlands: opportunities,
opportunists, and outcomes. Critical Review of Plant Science 23: 431–452
Zedler, J.B. & S. Kercher (2005). Wetland resources: status, trends,
ecosystem services, and restorability. Annual Review of Environmental
Resources 30: 39–74.