Birds of Pambujan, Northern Samar, Philippines

Copyright © 2019 by author(s) and International Journal of Trend in Scientific Research and Development Journal. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0) (http://creativecommons.org/licenses/ by/4.0) ABSTRACT This assessment was specifically carried out to identify the avian species present in the study area, describe its distribution, determine its frequency, ascertain their conservation status, and enumerate the anthropogenic factors that influence their presence in the sampling sites.


INTRODUCTION
Birds evolved during the great reptilian radiation of the Mesozoic era, but they look very different from lizards because of their feathered bodies, the absence of teeth, and a four-chambered heart (Smallwood and Green, 1968).
Birds play very important roles in the environment, serving as dispersal agents, transporting a variety of things through the ecosystems. For example, birds help in plant dispersal, pollination, and even animals may be relocated. They are of great economic significance to human society, controlling insect pest populations, and providing protein-rich food for mankind (Blair, et al., 1957).
An analysis of habitat preferences of threatened birds in the Philippines indicate the overwhelming significance of forests for their conservation. Fifty nine of the 65 threatened species occur mainly in forest habitats, and native Philippine birds depend almost exclusively on the country's forests for their survival (Collar, 1999).
Another intensive inventory work conducted on Mt. Kitanglad in Bukidnon, also in Mindanao, reported 198 bird species, with about 172 of them likely to breed in the area. Three migratory species were detected on the island for the first time, and the massif holds populations of at least 17 of the 18 species narrowly endemic to Mindanao, as well as almost half the species endemic to the entire Philippine archipelago. Endemic species are concentrated at higher elevations, while migrants and widespread species are more frequent in lowlands (Peterson, et al., 2008). Mapalo (1990) has recorded 84 bird species, representing 32 families, inhabiting Mt. Hilong-Hilong, Agusan del Norte, and its vicinity, including one species declared by the IUCN as rare and threatened in the country.
In the province of Northern Samar, there is a dearth of literature and studies on avian species. The work of Quiles (2003) however, reported 28 species of birds found in Several studies have been reported that conversion of forested areas into agricultural lands was considered one of the major threats to bird species in various locations in the Philippines. Results reported by Pangcatan (2007) imply the need to conserve the avifauna of Lake Lanao (in Mindanao) and environs through habitat conservation. Sucaldito and Nuñeza (2008) also emphasized that changes in the structural and floristic composition brought about by forest degradation, logging, and hunting were seen as threats to avifaunal diversity in the country.
Generally, this research, done in 5 selected barangays of Pambujan, Northern Samar, aimed to document the avian fauna in different habitat types in the municipality, with a view of providing baseline information useful in the formulation of necessary management interventions in the protection and conservation of birds in the study area. Specifically, it intended to: 1) identify the avian species existing in the area; 2) determine its relative frequency; 3) describe its distribution in the area; 4) ascertain the conservation status of the birds identified; and, 5) enumerate anthropogenic activities affecting the existence of birds in the study area. The achievement of the study objectives was limited by the availability of equipment, particularly a camera equipped with telephoto lenses, and the ability of the researcher to spend longer observation hours for security reasons.

METHODOLOGY Locale of the Study
This study was conducted in Barangay Canjumadal, Barangay Don Pedro de la Cruz, Barangay Ginulgan, Barangay Senonogan, and Barangay Don Sixto Balanquit, Pambujan, Northern Samar, representing different habitat types.

Research Design and Sampling Technique
This study utilized the descriptive research design, with purposive sampling as the technique employed.

Data Gathering Procedure A. Observation of Avifauna
The researchers established a 1-km trail in each study area, visiting it twice a day (5:00 to 8:00 AM, and 3:00 to 6:00 PM), using a Sony 2,7-4,5/5,2-78 DSC-H50 Super Steady Shot to take photos of bird species in the study sites, noting the species and number of individuals found, for identification purposes. Data collection stopped after reaching the species Accumulation Asymptote.

B. Identification and Classification of Encountered Avian Species
Preliminary identification of the avian species was done by the researchers in their natural habitat. Final identification of the species was facilitated through photo documentation, appropriate books, and other available identification guides, particularly the book A Guide to the Birds of the Philippines by Kennedy, et al., (2000) and A Photographic Guide to the Birds of the Philippines by Fisher and Hicks (2000).

C. Determination of the Effect of Anthropogenic
Activities on Avian Species in the Study Area Data and information on anthropogenic activities in the study area was gathered through a researcher-made interview guide, with 10 respondents in each study site, whose response for each question was noted and interpreted.

D. Site Selection
The diversity of bird species was monitored through establishing a permanent monitoring plot in each type of ecosystem. The selection of study sites considered diverse ecological needs and diverse behavioral patterns of bird species. It covers a wide range of elevation of land and an adaptable habitat of rice fields, riverbank, coastal areas, and forest areas.

RESULTS AND DISCUSSION
Presented in Table 1 are the twenty-seven (27) species of birds identified in five sampling areas of the study site, and they belong to 17 families. Each of these families is represented by at least one identified specimen.
These findings do not necessarily mean that avifauna in the study sites are rare or extinct. Rather, because of their high mobility, and sometimes dense vegetation, especially in the forested areas, the presence of a specimen may have escaped the researchers' notice. Thus, the number of representative samples of the diverse bird fauna in the locality may have been limited to only these families and representative species.

Species Frequency and Relative Frequency
The avian species varied in their frequencies and relative frequencies.
In Barangay Ginulgan (rice field area), 14 species were present. The Eurasian Tree Sparrow, Intermediate Egret, White breasted wood Swallow, Chestnut Munia, and Pacific Swallow had the highest frequency of 1.0 and a relative frequency of 12.19 %. The least frequent were the Black kite, Pacific Golden Plover, Lesser Sand Plover, and Whimbrel, which had a frequency value of 0.2, with a relative frequency of 2.44%, indicating it had the least number of individuals observed in the study area.
In Barangay Canjumadal (riverbank area), 13 species were present. The White-throated Kingfisher, and Collared kingfisher had the highest frequency of 0.8 and a relative frequency of 11.76%. The least frequent were the Little Egret and Whimbrel with a frequency of 0.2 and a relative frequency of 2.94%.
In the coastal area (Barangay Camparanga), 8 avian species were present. The Common Sandpiper, Pacific Swallow, Gullbilled Tern, Grey-tailed Tattler, Pacific Golden Plover, Lesser Sand Plover, and Whimbrel had the highest frequency of 1.0 and a relative frequency of 13.16%. The least frequent was the Little Egret, with a frequency of 0.6 and a relative frequency of 7.89%. In

Species Distribution of Avian Species
Birds inhabit different habitats to survive. Majority of the bird species inhabit the forest areas, with a significant number of species inhabiting the rice fields and the riverbank areas, while the least number of species were found in the coastal area. Of the 27 species identified, 17 species were present in the forests, fourteen (14) were found in the rice field, thirteen (13) species were found the in riverbank, while eight (8) species were found in the coastal habitat.
Seven of the identified avian species were present exclusively in the forest habitats. Lonchura malacca was found only in the rice fields, while Gelochelion nilotica was present only in the coastal habitat. Egretta intermedia was observed in the rice fields and riverbanks.
Five species were found both in the rice field and forest habitats, another five species were found both in the riverbank and forest habitats, while 7 species were present in the rice field, riverbank, and coastal habitats. Table 3 presents the distribution of the 27 avian species identified among the five habitat types in the study area. 1 = Ricefield (Barangay Ginulgan) 2 = Riverbank (Barangay Canjumadal) 3 = Coastal Area (Barangay Camparanga) 4 = Forest (Barangays Senonogan and Don Sixto Balanquit

Conservation Status
The conservation status of a group of organisms, for instance, a species, indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors must be taken to account when assessing conservation status. It is not simply the number of individuals remaining, but the overall increase or decrease in the population over time, breeding success rates, and known threats. All the avian species found in the study area were under the category of "Least Concern" and are still far from extinction, except for the Philippine dwarf Kingfisher, which was categorized as "Vulnerable" (IUCN Red List, 2017).
Of the avian species identified, twelve (12) species were residents, while ten (10) were migrants, with five (5) species endemic to the Philippines.