Sustaining the birds and animals of PNR October 11, 2015, Sunday Cecilia Sman, firstname.lastname@example.org
Hornbills feeding on the fruits at the nature reserve. — Photos contributed by Cecilia Sman, Professor Alex, Ishak Chin and Musa Musbah
Some of the fruits and seeds favoured by birds.
MIRI: The newly established Piasau Nature Reserve (PNR) famous for its hornbills is an ideal research centre and conservation area for its multiple bird species.
Studies conducted in 2013 by the Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak (Unimas) have recorded 45 species of carnivores, omnivores and frugivores (fruit eaters) in the nature reserve.
Prof Dr Andrew Alek Tuen, a Research Fellow at the institute unveiled PNR’s secrets of supporting its diverse community of birds in a working paper at the National Hornbill Conference held here from Aug 11 to 13.
The paper titled ‘Potential Role of Fruit Trees in Sustaining Frugivorous Bird Population in Piasau Nature Reserve, Miri’ was jointly compiled with two other Research Fellows, namely Gabriel Tonga Noweg and Pang Sing Tyan. Sarawak Shell Bhd, Piasau Camp residents including staff of Sarawak Forestry Cooperation (SFC).
The paper was among the 25 papers presented at the inaugural conference attended by 73 foreign and local delegates working on hornbills.
Dr Alek also co-chaired the conference with SFC deputy general manager (protected areas and biodiversity conservation) Oswald Braken Tisen.
The ‘residents’ of PNR
Spanning 88.5 hectares, PNR has 17 fauna species protected under the Wildlife Protection Ordinance, 45 bird species, three mammal species, five amphibian species, 12 reptile species, 10 butterfly species and 107 plant species.
To date, 20 individual hornbills have been recorded and the males named Jimmy, Anthony, Han, Ibrahim, Munyung, Robert, Kareem, Sam, Abong, Moses, Ah Kaw and Musa. The female hornbills are Faridah, Cathy, Alice, Julia, Ah Moi, Rosita, Juliet and Cecilia.
The role of fruit trees
According to Dr Alek, the mature forest and its fruits trees are among the major factors that support PNR’s diverse community of birds and other animals.
The birds disperse seeds from trees, thereby improving survival rates of seeds and seedlings by reducing competition and predation (Howe and Smallwood 1982) while omnivores consume both animals and plants, therefore also playing a role in seed dispersal.
“65 per cent of the birds such as green pigeons, Asian glossy starlings and yellow-vented bulbuls eat fruits and seeds,” Dr Alek said.
A yellow-vented bulbul sits in its nest.
The nutritive values of fruit trees
According to Dr Alek, all potential fruit plants at the nature reserve were recorded and the samples were brought back to Unimas for nutritional analysis.
The samples were taken from 31 tree species, 16 species of shrubs and bushes, nine species of palms, 11 species of ferns and fern allies, 12 species of climbers and creepers and 22 species of grasses and herbs including three species of bamboo.
On the plant community at PNR, Dr Alek said it is quite diverse and the most abundant fruit tree is the vitex pubescens or ‘leban’ tree, followed by figs and oil palm.
These plants provide fruits, seeds and nectar in flowers, even housing insects ants, termites, bugs and other small animals like lizards for the birds to feed on.
They also function as nesting material, nest holes and perches for the birds.
During the survey, 80 ficus or fig plants were recorded in 2013, with at least two bearing fruit. The most abundant fruit plant is vitex pubescens followed by oil palms, ficus and mango.
Green pigeons, Asian glossy starlings and yellow-vented bulbuls were the most common bird seen on this plant when the fruits are ripe.
Future studies should consider monitoring the fruiting and flowering phenology, the type of birds that feed on them and analyse the nutrient content of fruits and flowers that are likely to be eaten by animals.
Asked on the existing works on dismantling some 200 houses at PNR, Dr Alek hoped that the work would not damage the trees and plants in the nature reserve.
He said that if fruit trees and nesting trees were cleared as part of the works, it would have a negative impact on bird diversity and abundance.
“In our report we have recommended planting native trees, especially those that birds and mammals feed on. My observation when they remove the buildings in the reserve is that the site will be quickly overgrown with weeds and shrub and this is good for wildlife. I hope all those ficus trees are still alive.
“They didn’t seem to be healthy when we were there last July; perhaps their root system was affected by development,” he said.
(From second left) Braken, Dr Alek and others take a closer look at a nesting site.
An aerial shot of the ongoing dismantling works at PNR.