Posted by Carmela Espanola & Stuart Marsden
First, the whole group would like to congratulate Carmela
Espanola on her recent PhD
conferment. Her PhD, funded by Loro Parque Fundacion, focused
on parrots and other large frugivores in the dwindling forests of Luzon. There
are several important aspects to this PhD which we hope to publish in the
future. This potentially very important paper has just been published.
Large frugivorous (fruit-eating) birds are incredibly important.
People know them, eat them, and keep them as pets. A huge number are threatened
worldwide. Crucially, most provide irreplaceable ecosystem function by
dispersing the seeds of tropical trees.
Carmela and her team surveyed 25 frugivore species using ‘distance
sampling’ along nearly 500 km of line transects at 14 sites across the island
of Luzon. Most frugivores seemed at least to be hanging on at most forested
sites – although one species, the Green Racquet-tail, a lowland parrot has been
recorded at only seven sites in the last ten years. Still more alarming was the
absence of large parrots from most sites with apparently intact habitat
surveyed. Worryingly, even where present, large parrots occurred at much lower
densities than related species in similar habitat elsewhere in Southeast
Asia.
She estimated population sizes for species in five reserves selected from the current
protected area network. For six species, including
four of six parrots, largest populations in any reserve in Luzon numbered
<1,000 individuals, and nearly one-third of all populations in reserves were
less than 100. If we consider that animals might have a minimum viable population
(MVP) below which they are likely doomed to extinction, then we can try to look
into the future to see which frugivores will still be around in which reserves.
At MVPs of 500, frugivore communities in all but 2–3 of the largest reserves on
Luzon are not expected to survive.
Although many frugivores are good fliers that can disperse between
widely separated sites, we nevertheless predict that without stricter species
and site protection a major collapse of frugivore communities will occur across Luzon. This will have
very serious implications for ecosystem functioning of the forests themselves
and for indigenous communities dependent on the island’s forests to live.
A grant that Carmela recently secured from the National Science
Research Institute of the University of the Philippines will allow further work
on cavity-nesting frugivores where breeding ecology will be investigated and
nest availability/competition will be assessed at two adjoining reserves in
western Luzon. These are the only reserves in Luzon where a thriving population
of the Green Racquet-tail, a threatened Luzon-endemic parrot, is still found.
Volunteers with experience in tropical ecological research and training in
tree-climbing are welcome to join the fieldwork from April-May 2014 (email carmela.espanola@up.edu.ph).Thanks to Adrian Constantino of Birding Adventure Philippines (parrot photos), Chris Johns (hornbill photo) and Arnel Telesforo (tree photo) for letting us use their stunning images.
Carmela Espanola's PhD was funded by Loro Parque Fundacion
I have often seen these small green birds with yellow beak (that looks like a parrot) together with other birds eating the fruits of our Rambotan tree every morning. Our family loves to watch them feasting on the fruits every morning. My father would always leave ripe fruits for the birds to eat (like rambotan and bananas). He never harvest all the fruits. He always remember to give the birds share.
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