Research
Barn Owls
BARN OWL RESEARCH
Being one of the most utilized biological controls, barn owls are often a topic of interest in rodent pest management. Concurrently, most of our barn owl researches currently focus on barn owls and their role as biological control. This also includes the vital step of introducing and/or translocating barn owls to a new habitat and further studies on biology of barn owls following translocations. Below are our research topics concerning barn owls, along with brief details on ongoing and completed research studies.
Urbanization of Barn Owl
Recognizing the value of barn owls as expert rodent hunters, this project intends to utilize barn owls as potential biological agent to control rat population in urban and sub-urban areas. Since 2014, barn owls introduction programs were initiated in Subang Jaya and Minden Campus, Universiti Sains Malaysia (USM) as a biological agent for controlling rat populations. The establishment of barn owl in the urban garden areas of the USM campus and in Subang Jaya would enrich the biodiversity in the areas and more importantly control the rat population within the campus. Additionally, the study includes observations of barn owls to better understand their biology.
Introduction of Barn Owls, Tyto javanica javanica, in Pulau Rawa, Johor, Malaysia for Biological Control of Rats
Initiated in 2016, the main objective of this research was to introduce barn owls to a new area to control the local rat population and to further study the effectiveness of barn owls as a biological control. As the study site is a small island with minimal human activity, it is easier to study the impact of barn owls on rodent populations and other native fauna compared to larger scale studies.
The objectives of this research are:
- To introduce and establish Southeast Asian barn owls, Tyto alba javanica, on the tropical island of Rawa Island, Johor, Malaysia,
- To estimate the rat population on Rawa Island to study the impact of barn owl introduction, and
- To monitor the local bird and bat population on Rawa Island to evaluate the impact of non-target interactions of introduced barn owls.
Completed at the end of 2017, the research concluded with results indicating that introduced and established barn owls managed to maintain an already lowered rat population. The study also concluded that the best background of owls to introduce and establish in an area with minimal human presence and activity are hand-raised owls. Barn owl introductions on Pulau Rawa also had no significant impact on the island bird and bat populations.
Barn Owl Translocation to FELDA Sahabat, Lahad Datu, Sabah
The natural presence of the barn owl, Tyto javanica has not been recorded in Sabah or Sarawak, nor has it ever been recorded on the whole island of Borneo (Taylor, 1994). Prior to this project, two barn owl translocation programmes from Peninsular Malaysia to Sabah and Sarawak have been carried out.
This project initiated in 2013 by Felda Global Ventures (FGV) involved the translocation of barn owls from Peninsular Malaysia to oil palm plantations in Lahad Datu, Sabah. A successful breeding population has been established following the most recent barn owl releases in 2015. The early effectiveness of the natural propagation of barn owls for rat control was also assessed.
Studies on the assessment of the success of the translocation and introduction of the barn owl in Sabah are still ongoing.
Barn Owl and Parasites
This study began in 2018 and revolves around ecto- and endo-parasites of both wild and captive barn owls. Wild barn owls are sampled from two rice fields around Penang Island while captive barn owls are sampled from those housed in the USM aviary. The objectives of this research are:
- To study the diversity of parasites in barn owls,
- To compare the prevalence of parasites between wild and captive barn owls,
- To investigate any correlation between parasites abundance and barn owl health.
Ectoparasites will be sampled by direct examination on feathers of barn owls while endoparasites will be obtained from fecal samples. The microbiome from the fecal samples will also be analysed for metagenomic studies.
Sexing of Southeast Asian Barn Owls, Tyto alba javanica, using Morphological and Molecular Methods
Juvenile barn owls are impossible to sex using morphological traits and sexing of adult barn owls using morphological traits alone is difficult due to ambiguous differences. In order to determine the most accurate morphological traits for sexing adult Southeast Asian barn owls, Tyto javanica javanica, we compared sexing using morphological traits with sex determined through a molecular sexing methods. We used six morphological traits to sex the owls; the shape and colour of the facial disc, the colour of the throat area, the tail plumage, the colour of their tarsus, the back plumage, and the frequency of spotting on the chest and underside of wings. Molecular sexing was carried out using DNA extracted from blood and feathers.
Our results comparing sex identified using morphological traits and molecular sexing showed that morphological traits were only about 70 % accurate to sex barn owls, with most owls identified morphologically as females proving to be males through molecular sexing. Our results also showed that the best morphological trait for sexing barn owls is the frequency of spotting on their chest and underparts, as well as their throat colour. Additionally, we found that blood was a better and more reliable source of DNA than feathers.
Population Ecology of Southeast Asian Barn Owls (Tyto javanica javanica) in one Native and one Introduced Population in Malaysia
Following the successful establishment of a barn owl population was by C.M. Rizuan in FELDA Sahabat 06, Lahad Datu, Sabah, this study is being conducted to determine population characteristics of the native population (population where individuals were selected and chosen for the translocation program) in Jengka, Pahang, Peninsular Malaysia, and the translocated and introduced population in Lahad Datu, Sabah, Borneo Malaysia, in order to determine the medium-term success of this introduction.
The population characteristics investigated in this study to assess success of the release program will be breeding, recruitment, survival and mortality, as well as diet of the owls. As the small number of translocated individuals and same-sibling parents of the captive-bred owls are indicators for a strong possibility of reduced genetic variation among the current population of barn owls in Sahabat, genetic variation of both populations will also be analysed. This study will also attempt to study threats to barn owl populations, by investigating pesticide residue among barn owls and also by assessing the knowledge, awareness and perception of the local community and native tribespeople towards barn owls.
Reference:
*Taylor, I (1994). Barn Owls; Predator-Prey Relationship and Conservation. Cambridge: Cambridge University Press. pp. 304.