(Authors: Dr. Boripat Siriaroonrat and Kaset Sutasha; Photo: Lip Kee; )
It’s the most dramatic bird decline ever recorded – faster even than those that robbed our planet of the Passenger Pigeon Ectopistes migratorius or the Dodo Raphus cucullatus. Since the 1990s, a staggering 99% of the vulture population in Asia have disappeared – a drop from several million to just a few thousand.
As a result of these steep declines, four species of Asian vulture – White-rumped Vulture Gyps bengalensis, Red-headed Vulture Sarcogyps calvus, Slender-billed Vulture Gyps tenuirostris and Indian Vulture Gyps indicus – are now assessed as being Critically Endangered – the highest threat category of all, and a status that indicates that if we do not continue to act, they will disappear from Asia’s skies within our lifetimes.
The main driver for the decline of vultures on the Indian subcontinent is well-publicised – the use of the veterinary drug Diclofenac to control pain and muscle fatigue in sick and aging cattle. Unfortunately, the drug proved lethal to vultures, who were unwittingly killed in large numbers in South Asia when they feasted on the poisoned carcasses of cattle who were left out in the open to die by herders.
Fortunately, the use of Diclofenac is now banned in India, Nepal and Pakistan, and thanks to the introduction of initiatives such as Safe Zones (areas in which threats are controlled within a 100kn radius, allowing viable populations to develop), vulture numbers are now finally stabilising on the Indian subcontinent. But why have vultures all but disappeared from other parts of Asia where Diclofenac isn’t an issue – as just as importantly, can we bring them back?
In Thailand, as in other parts of South-East Asia, Diclofenac isn’t an issue for vultures. Although the drug is widely available in pharmacies, it comes in cream and tablet forms, and is intended for human use – not for cattle. Despite this, the situation for vultures is even worse than it is in India – although two migratory species Cinereous Vulture Aegypius monachus and Himalayan Griffon Gyps himalayensis, can still be spotted every winter, all three of the species that were once resident in the country (Red-headed Vulture White-rumped Vulture and Slender-billed Vulture) are now extinct in Thailand.
Of the three, the Red-headed Vulture was the most abundant and could be found right in the center of Bangkok until the late 1960s-early 1970s, when burials were not widely practiced and dead bodies were left in the open waiting to be burned. A cholera outbreak in Bangkok in the 19th Century is immortalised by sculptures of vultures feeding on corpses at the Golden Mountain (Wat Saket), which are still standing for us to see today even if the birds themselves are not. Vultures took advantage of the dead bodies until the modernization of the country in the 20th Century. With cemeteries now becoming normal practice, vultures have struggled in the face of the reduced food availability
(Patrick O’Donnell, March 4, 2017)
What birder doesn’t get excited about raptors? Sort of like the mega birds, these aren’t your average worm-eating, seed-feeding, chirping guys with brightly colored plumage. Instead of being “little brown jobs”, most are large, in charge, and always ready to sink their talons into prey. By merit of their dimensions and fierce appearance, even non-birders throughout history have taken note of the raptors.
In Costa Rica, we have more than our fair share. In keeping with high diversity in other aspects of the avian kingdom, including falcons and excluding owls, this small country has a raptor list that tops fifty species. It’s a fine selection of birds for a place the same size as West Virginia but it also comes with a catch commonly found in tropical forest ecosystems. There might be a lot of species, but competition and other factors result in fewer individuals of each species. This basically means that it’s not easy being a raptor in Costa Rica. While there’s a lot of protected habitat, with so many other raptors and birds to compete with, each species has a pretty small population. In fact, because the numbers are so small, I bet we could get a fair estimate about the numbers of every raptor species in Costa Rica with a bit of effort.
To throw another monkey wrench into the raptor situation, clime change isn’t doing them any favors. The hotter, drier weather in Costa Rica might be helping the caracaras and a few other open country species, but the ones that rely on healthy humid forest environments are being seriously challenged. As with so many other bird species in Costa Rica that require humid tropical forest, various raptors seem to also be in decline. A few, like the Ornate Hawk-Eagle, are probably out-competing other species and thus on the increase but the numbers for most seem to be going down.
So, to make a long story short, it’s getting even harder to see raptors in Costa Rica and thus that much more pertinent to know about the best places for seeing them. In general, the best spots aren’t going to be wide open fields because those are recent, human-made habitats much more suited for cattle than forest birds. Instead, spend more time in protected areas with humid forest where you can see the sky and canopy. This way, you can spot that White Hawk making a bright exclamation point against the green wall of forest.
But don’t take my word for it, come to Costa Rica to check out the raptor situation for yourself. You’ll see a few hundred other bird species while looking for hawks, hawk-eagles, and kites anyways.