Birds of
Sabaragamuwa University campus, Buttala, Sri Lanka
Thilina Dilan Surasinghe 1& Chamitha De Alwis 2
1Teaching Assistant in Biological
Sciences, Graduate Student in Wildlife and Fisheries Biology, Department of
Forestry and Natural Resources, 261, Lehotsky Hall, Clemson University,
Clemson, SC 29634-0317, USA
2Department of Natural Resources,
Sabaragamuwa University of Sri Lanka, Buttala, Sri Lanka
Email: 1 tsurasi@clemson.edu
Date of publication (online): 26 May
2010
Date of publication (print): 26 May
2010
ISSN 0974-7907 (online) | 0974-7893
(print)
Editor:Rajah Jayapal
Manuscript details:
Ms # o2113
Received 28 December 2008
Final revised received 12 March 2010
Finally accepted 09 April 2010
Citation:Surasinghe, T.D. & C. De Alwis (2010). Birds of Sabaragamuwa University
campus, Buttala, Sri Lanka. Journal
of Threatened Taxa 2(5): 876-888.
Copyright: ©
Thilina Dilan Surasinghe & Chamitha De Alwis 2010. Creative Commons
Attribution 3.0 Unported License. JoTT allows unrestricted use of this article
in any medium for non-profit purposes, reproduction and distribution by
providing adequate credit to the authors and the source of publication.
Author Details: Thilina Dilan Surasinghe has conducted a
significant number of research on biodiversity of Sri Lanka and published
several peer-reviewed scientific articles in numerous journals. He has served
as an junior faculty in several Sri Lankan public universities. Currently, he
is reading a PhD, majoring Wildlife Biology. His dissertation work is on
diversity and distribution of stream salamanders in the montane temperate
areas.
Chamitha De Alwisis well experienced and has good knowledge about biodiversity of Sri Lanka. He
has worked in multiple research projects on ecological and conservation related
research in Sri Lanka.
Author
Contribution: TDS
contributed in formulating the idea of the research, writing and structuring
the paper, planning the field procedures, analyzing and presenting the data,
literature review on the topic. CDA contributed in conducting and
coordinating field research, formulating and executing the field procedure.
Acknowledgements: We
would like to express our gratitude to the undergraduate students of the Sabaragamuwa
University Campus for providing their support during the fieldwork and Ms.
Enoka Kudavidanage for her valuable insights during this research.
Abstract: We
conducted a bird survey in the Sabaragamuwa University premises in southeastern
Sri Lanka between 2001 and 2004. We recorded 145 bird species, representing 17 orders and 51 families
from the campus. The birdlife
included Red-faced Malkoha, a globally Vulnerable species and four Near
Threatened taxa. The university
premises suffer from severe habitat alteration largely owing to fire,
filling-up of aquatic habitats, resource over-extraction, improper waste
management, invasion by exotic species and livestock grazing. Several conservation measures, including
habitat management strategies such as restoration of riparian vegetation, and
wetlands, increasing plant diversity in home gardens and prevention of
secondary successions in grasslands are recommended to protect the campus
environment and to conserve its avifaunal diversity.
Keywords:Birds, conservation, habitat management, Sabaragamuwa University, Sri Lanka
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INTRODUCTION
The
Indian Ocean island of Sri Lanka (65610km2) is rich in avifaunal
diversity. Over 471 species of
birds representing 20 orders and 76 families have been recorded in Sri Lanka,
(Kotagama et al. 2006). These include 225 breeding residents, 128 winter visitors,
four summer visitors, 106 vagrants, and two passage migrants (Rasmussen &
Anderton 2005). Of them, 33 are endemic to the island (Kotagama et al.
2006). Owing to this high
diversity and endemism, Sri Lanka has been recognized as a country with “Important
Bird Areas”, a “key Asian region for threatened birds” and an “Endemic Bird
Area” (Kaluthota & Kotagama 2005). Therefore, it is imperative to document distribution, habitat
association, threats and conservation measures on avifauna.
Extensive
studies on ecology and distribution of birds of Sri Lanka have so far been
conducted in and around protected areas in the wet and dry zones of Sri
Lanka. Studies on avifauna of the
intermediate bioclimatic zone and landscapes outside protected areas are very
scarce. Several such sites outside
protected areas yet remain undocumented leading to gaps in knowledge of
distribution of the island’s avifauna. Further, the role of human-altered landscapes in conservation of birds
has been greatly neglected. In the
face of rapid economic development and increasing human population, the extent
of conservation lands is gradually reducing. It is essential to study the suitability of semi-natural
landscapes such as human settlements in rural areas for the long-term survival
of native biodiversity (Hietala-Koivu et al. 2004).
With
this rationale, we surveyed the premises of the Sabaragamuwa University of Sri
Lanka in Buttala to study diversity and habitat associations of birds. We also studied threats on birds and
then recommended conservation and management actions that would enhance the
avifaunal diversity of the site, while continuing with innocuous human
activities and habitation.
Study site
The
study site is situated in a rural village of the southeastern Sri Lanka, (6046’28.32”N-81015’28.58”E
and 6046’3.54”N-31015’35.65”E). Our study area was originally a homestead, comprising home
gardens, private lands and a teak plantation (De Alwis & Surasinghe
2006). In 1988, the site was the
focus of a government sponsored rural area development scheme that altered the
original condition of the area due to heavy anthropogenic disturbance. In the year 1993, the Sabaragamuwa
University of Sri Lanka established the Faculty of Applied Sciences in this
land area, with significant changes in the land-use and land-cover structure
after the rural development program. Since then, the vegetated area of the university premises did not
receive any major spatially-extensive disturbances. However, local disturbances continue to prevail in different
frequencies and different intensities (De Alwis & Surasinghe 2006). Currently, the university premises
consist of rocky grasslands, dry-mixed semi-evergreen forests, scrublands,
residential areas, home gardens and wetlands. These wetlands include lotic habitats such as perennial
streams and seasonal creeks and lentic habitats such as seasonal pools and
semi-permanent man-made ponds (Image 1) (De Alwis et al. 2006). The university premises are 125 acres
in area. Thirty percent of the premises are covered scrublands, with 40% of the
area covered by residential areas and home gardens. Both rocky grasslands and dry-mixed semi-evergreen forests
occupy a similar area of extent accounting for 30% of the whole area. The
overall region comprises forest fragments, grasslands, scrublands, riverine
forests and marshlands, each habitat vary in size. Further, there are large
extents of home gardens and agricultural lands cultivated with annual crops
such as vegetables and tobacco in this region.
In
terms of geo-climatic regionalization, the site falls under the lowland
(elevation less than 300m in average) dry intermediate zone of the island. The
annual precipitation ranges between 900-1500mm and the annual average
temperature is approximately 270C (Survey Department 1988). Floristically, the university premises
fall within the tropical moist semi-evergreen forests and savannah forests
(Aston & Gunetilleke 1987a, 1987b). Although, the terrain of the entire region can be considered as
undulating, the university premises are relatively flat. The study area, topographically and
ecologically is a habitat island which lies in close proximity to two
relatively large hilly forest fragments; “Andampahura” forest and
“Rahathangala” forest. The
university premises are separated from the two fragments mentioned above by the
Colombo – Potuvil highway (Image 2) (Survey Department 1987). Following are some of the flowering
plants recorded in this region: Melia
dubia, Mangifera
zeylanica, Pometia eximia, Artocarpus nobilis, Filicium decipiens, Turpinia malabarica, Rejoua
dichotoma, Anamirta cocculus, Artabotrys uncinatus, Paramignya monophylla,
Anodendron manubriatum, Entada spp., Pothos scandens Micromelum ceylanicum, Goniothalamus spp., Dracaena thwaitesii, Ophiorrhiza
mungos.
METHODOLOGY
The
bird survey in the university premises was done for four years from 2001 to
2004. The survey techniques used
included visual encounter surveys, line transects, spot counts and mist net
trapping covering all the habitat types within the study site, as outlined
above. The survey was done during
various time periods of the day using binoculars, monocular telescopes and
direct observations. In order to consider both diurnal and nocturnal species,
the survey was conducted in three sessions: 0600-1200 hr, 1600-1900 hr and
2100-2300 hr. Surveying in three
different time frames of the day adequately sample the realized temporal niche
of the birds in the university premises. The avifaunal species richness of six distinct habitat types
(grasslands, open grounds, dry-mixed semi-evergreen forests, scrub forests,
residential areas and home gardens, limnotic habitats) within the university
premises is recorded. For the purpose
of identification of birds, popular field guilds like Harrison (1999) and
Kotagama & Wijesinghe (1998) were used. During the bird surveys, human activities that potentially
pose threats to the bird populations were also noted.
RESULTS AND ANALYSIS
During
the survey, a total of 145 bird species including 15 Sri Lankan endemics were
recorded in the study period, representing 17 orders and 51 families. This would make up nearly 31% of the
Sri Lanka’s total avifaunal diversity. Among them, 15 species were winter
visitors and 122 were breeding residents.
Our
results showed that the residential areas including home gardens harboured the
highest number of species representing 68% of the all the species recorded in
the survey (Fig. 1). Although the
limnotic habitats had the lowest species richness accounting only for 12% of
the total avifaunal diversity of the study area, most species recorded in
limnotic habitats were restricted to such aquatic habitats. The details of habitat occupancy are
shown in the Table 1. Further
analysis on habitat association revealed that 32 species of birds (forming 22%)
were habitat specialists as they were recorded from only one habitat type. For instance, White-necked Stork,
Common Sandpiper, Stork-billed Kingfisher and Small Kingfisher were restricted
to limnotic habitats. Similarly,
Sri Lankan Lorikeet, Blossom-headed Parakeet, Layard’s Parakeet were only
recorded from the home gardens. The Racket-tailed Drongo, Black-capped Bulbul,
White-rumped Sharma and Layard’s Flycatcher were limited to the dry-mixed
semi-evergreen forests. The Indian
Pipit was only observed in open grounds. Blyth’s Reed Warbler and Great Reed Warbler were some of the species
that were seemingly confined to grasslands. Interestingly, the number of birds that occupied all five
habitat types in the campus premises was significantly low (5 species). On the contrary, the number of bird
species that occupied only one type of habitat was significantly high (32
species). Thirty percent of the
species recorded in this study associated two habitat types within the campus
premises.
DISCUSSION
The
diversity of birds (Table 1) and their distribution with respect to available
habitat types show the importance of the university premises as an ideal bird
habitat, within the intermediate zone of Sri Lanka. Five birds recorded in this study are listed in the Global
Red Data Book (IUCN 2009). Among
them, one species (Red-faced Malkoha) is Vulnerable and four are Near
Threatened (Spot-billed Pelican, Malabar Pied Hornbill, White Ibis, and Painted
Stork). Besides, 12 species are
considered nationally threatened according to the 2007 List of Threatened Fauna
and Flora of Sri Lanka (IUCNSL & Ministry of Environment and Natural
Resources 2008). The high
preference of birds to this site can be attributed to many factors:
1.
The university premises consist of a mosaic of habitats. Grasslands, open grounds, dry-mixed
semi-evergreen forests, scrub forests, home gardens and limonitic habitats are
the major habitats. Riparian
vegetation, road verges and small Teak estates are minor habitats. Habitat heterogeneity favors habitat
specialists (through niche partitioning) and birds with broad niches. The
mosaic nature yields multiple habitat edges enriched with many microhabitat
features suitable for different species (Cramer & Willig 2005).
2.
The university premises are significantly high in resource availability for the
birds. For instance, several
species of nectarine and fruit-bearing plant species are grown within the study
site, especially in the home gardens. Further, multiple habitats provide ample niches and microhabitat
conditions for invertebrates. Hence, the university premises provide ample food for different feeding
guilds of birds.
3.
The study site connects the adjacent forested hills; “Andampahura” and
“Rahathangala” by functioning as a corridor facilitating the movement of
birds. Besides, it is a habitat
island that facilitates colonization of species from adjacent forests.
In
this study, we noted that home gardens had the highest avifaunal diversity
followed by scrub forests. However, Shahabuddin & Kumar (2006) found that
bird diversity was significantly low in disturbed habitats. This discrepancy can be explained with
the intermediate disturbance hypothesis which states that species diversity is
highest when disturbances are moderate in intensity and frequency (Connell
1978).
Threats and conservation measures
Despite
being human-inhabited, the university premises are relatively safe from threats
that endanger avifauna devoid of hunting and timber extraction pressures. We
noted significant extents of habitat destruction and modification. Villagers of Buttala set fire to
grasslands annually in the dry season for cattle ranching that rapidly spread
to the grasslands in the campus. Uncontrolled pyrrhic events are disastrous for birds (Freckleton 2004).
We noted drastic declines of grassland birds since the fires destroyed nests,
eggs and hatchlings. Besides, gardeners regularly mow taller grasses using
machinery which destroy the nests of many ground and undershrub nesters such as
prinias, quails, munias, weavers and babblers. Mowing reduces the thickness of
the grassland vegetation and makes birds and their eggs vulnerable for
predation, especially by domestic cats. Although lumbering is not practiced much, felling trees for timber,
construction and firewood in forest areas deter forest-specialists and allow
opportunistic predators and invasive species to invade forested areas
(Rosenberg 1990; Buckley et al. 2007). Seasonal and perennial pools of the site, which were used by
waterfowl, were land-filled. Domestic animals such as cats were noted to
extensively predate on birds (adults, eggs and young) such as yellow-wattled
lapwing, black robins, babblers and doves. Our frequent observations on litters size of 8-10 across
years indicate increasing abundance of domestic cats. The ship rat (Rattus
rattus) is rapidly colonizing this site. They predate on birds, compete with
granivore birds (Yom-Tov et al. 1999) and serve as vectors for diseases (Couraet al. 2002).
With
respect to the threats observed, we suggested several conservation measures.
Setting fires on grasslands should be prohibited through legislation by the
local government. Grasslands
should be mowed less frequently. Complete mowing should be discouraged. However, the establishment of
dichotomous forest species within grasslands and scrublands should be prevented
to stem secondary successions. This requires intensive monitoring and eradication of seedlings of
ecological “invaders”. Old-grown
woody tress in the grasslands may facilitate the colonization of more woody
species by shading seedlings from intense solar heating. Therefore, it is important to trim the
canopy of old-grown trees in the grasslands (Fischer et al. 2005).
In
order to attract more core-forest avifauna such as pheasants, partridges,
pigeons, doves, true owls and largely-arboreal birds, it is imperative that
extraction of timber and firewood is minimized in the forested habitats
(Wohlgemuth et al. 2002). Nevertheless,
actively managing the abundance of dominant woody species and allowing other
subordinate native forest species to establish will enhance the habitat
heterogeneity of the forest habitats (Ricklefs 1977).
Land-fillingof limnotic habitats and other wetlands should be stopped. We suggest that the longevity of these
habitats be ensured by preventing sedimentation through maintenance of riparian
vegetation. We advise that ship
rats be eradicated from the campus with non-fatal traps where non-targeted
captives can be released back unharmed (Atkinson 1977). Monitoring and subsequent eradication
of invasive plants is essential since human activities make the site vulnerable
for invasion.
Apart
from threat mitigation, we recommend several management strategies that would
enhance the existing avifaunal diversity. Maintaining snags in home gardens and forest habitats will recruit more
arboreal, cavity nesting birds such as parrots, owls, kingfishers, barbets and
woodpeckers. Protection of
wetlands from land-filling and draining will improve the on-site reproduction
success of waterfowls Dickson et al. 1983). Floral diversity of home grades should be enriched via
introduction of native nectarine species and fruit-bearing plants. Garden
wastes should not be burnt but be disposed sanitarily, encouraging colonization
of invertebrate prey. We proposed that application of synthetic pesticides in
campus premises be minimized and alternatives be sought. Building up small cascades or ponds to
replenish water and thermoregulation will effectively attract birds (Solecki
& Rosenzweig 2004).
Further
studies should be targeted on ecology, especially reproductive biology,
population dynamics and health of birds of the university premises. For efficient management and conservation
of avifauna, a comprehensive knowledge on the ecology and the life histories of
the birds are required. With such
information, the habitats of the university premises can be managed much more
appropriately to enhance the resource availability and habitat suitability for
different species of birds which in turn will improve the long-term viability
of a rich assemblage of avifauna in the university premises.
REFERENCES
Aston,
P.S. & C.V.S. Gunathilleke (1987a). New light
on the plant geography of Ceylon I. Historical plant geography. Journal of Biologeography14:249-285.
Aston,
P.S. & C.V.S. Gunathilleke (1987b). New light
on the plant geography of Ceylon II. The ecological biogeography. Journal of Biologeography14:295-327.
Atkinson,
I.A.E. (1978). Evidence for effects of rodents on the
vertebrate wildlife of New Zealand islands, pp.7-30. In: Dingwall, P.R., I.A.E.
Atkinson & C. Hay (eds.). The Ecology and Control of Rodents in New Zealand
Nature Reserves, Department of Lands and Survey Information Series No 4,
Wellington, New Zealand.
Connell,
J.H. (1978). Diversity in tropical rain forests and
coral reefs. Science199:1302–1310.
Coura
J.R., A.C.V. Junqueira, O. Fernandes, S.A.S. Valente, & M.A. Miles (2002).emerging Chagas disease in Amazonian Brazil. Trends in Parasitology 18:171-176.
Cramer, M.J. & M.R. Willig (2005). Habitat heterogeneity, species diversity and null
models. Oikos108:209-218.
De
Alwis, C. & T.D. Surasinghe (2006).Diversity of butterflies in the premises of Sabaragamuwa University, Buttala,
Sri Lanka. International Forestry & Environment Symposium 2006, Annual
Symposium Proceedings of the Department of Forestry and Environmental Science,
University of Sri Jayewardenepura, Sri Lanka.
De
Alwis, C., T.D. Surasinghe & E. Kudavidanage (2006).Diversity of birds in the premises of Sabaragamuwa University, Butthala, Sri
Lanka. International Symposium on Issues and Challenges of the 21st Century,
Sabaragamuwa University of Sri Lanka, Belihuloya.
Dickson,
J., G.R.N. Conner & J.H. Williamson (1983).Snag retention increases bird use of a clear-cut. Journal of Wildlife Management 47: 799-804.
Fischer,
R.A., C. Eberly & D. Keough (2005). Supporting
Habitat Management for Bird Conservation Planning on Fort Belvoir, Virginia. USDA Forest Service General Technical
Report 191:1178-1183.
Hietala-Koivu,
R., T. Järvenpää & J. Helenius (2004). Value of semi-natural areas as biodiversity indicators in agricultural
landscapes. Agricultural Ecosystems & Environment 101: 9-19.
IUCN
(2009). IUCN Red List of Threatened
Species. Version 2009.1. <www.iucnredlist.org>. Downloaded on 24 July
2009.
Kaluthota,
C.D. & S.W. Kotagama (2008). Historical
changes in number of Endemic birds in Sri Lanka from 1852 to 2006.Annual Forestry and Environment Symposium, University of Sri Jayewardenepura,
Sri Lanka.
Kotagama,
S.W., R.I. De Silva, A.S. Wijayasinha & V Abeygunawardena (2006).Avifaunal list of Sri Lanka, pp. 164-203. In: Bambaradeniya, C.N.B (eds.). Fauna of Sri Lanka: Status of
Taxonomy, Research and Conservation. The World Conservation
Union, Colombo, Sri Lanka, 308pp.
Ricklefs,
R.E. (1977). Environmental heterogeneity and
plant species diversity: A hypothesis. The American Naturalist 111: 376-381
Shahabuddin,
G. & R. Kumar (2006). Influence of anthropogenic disturbance
on bird communities in a tropical dry forest: role of vegetation structure. Animal Conservation9: 404–413
Solecki,
W.D. & C. Rosenzweig (2004). Biodiversity, Biosphere Reserves, and
the Big Apple: A Study of the New York Metropolitan Region. Annals of the New York Academy of Sciences1023:105–124.
Survey
Department (1987). Sri Lanka 1:50,000 Topographic Quadrangle Maps. 1:50,000.Survey Department, Colombo, Sri Lanka.
Survey
Department. (1988). National Atlas
of Sri Lanka. Survey Department, Colombo, Sri Lanka.
Temple,
S.A. (1977). The concept of managing endangered
birds. pp3-8. In: Temple, S.A. (ed.). Endangered Birds: Management Techniques for Persevering
Threatened Species. University of Wisconsin Press, Wisconsin,
USA.
Wohlgemuth, T., M. Bürgi, C. Scheidegger
& M. Schütz (2002). Dominance
reduction of species through disturbance: a proposed management principle for
central Europe forests. Forest
Ecology and Management 166: 1-15.
Yom-Tov,
Y., S. Yom-Tov & H. Moller (1999). Competition, coexistence, and adaptation
amongst rodent invaders to Pacific and New Zealand islands. Journal of Biogeography26: 947-958.