Category Archives: Raptor Talk

Tweeddale morph? Origins of the name for a uniquely plumaged Oriental Honey Buzzard (Pernis ptilorhyncus)

stray feathers jou 10 1887 hume_0544

19th century painting of “Pernis tweeddalii” by J. G. Keulemans

This post was triggered by an avid birder who asked the above question.

In the late 19th century, an Oriental Honey Buzzard Pernis ptilorhyncus with an (until then) never seen before blackish-and-white plumage was collected in the southeast of Sumatra, Indonesia. This specimen was described by British ornithologist Arthur Hay in 1877, under Pernis ptilorhyncus, apparently hesitating to separate it from the very variable Oriental Honey Buzzard.

Subsequently, another two specimens of similar plumage were collected, and the distinct plumage of these birds led ornithologists to treat them as a new species of Honey Buzzard. In 1880, this new species was christened Pernis tweeddalii, in honour of Arthur Hay, who was also known as Lord Tweeddale.

Along the way, it was lumped back into Oriental Honey Buzzard Pernis ptilorhyncus as it breeds with the normal brownish-plumaged OHBs resident in the tropics. Therein lies the origin of the name “Tweeddale morph” of the torquatus subspecies of the OHB.  

NSS Bird Group live on 938 radio’s Singapore Today program – discussing the Oriental Honey Buzzard in the heartlands that got netizens excited

OHB flying

An Oriental Honey Buzzard, similar to this one, got the resident of Bedok & netizens excited

The Nature Society (Singapore) Bird Group, represented by Alan OwYong and Dr. Yong Ding Li, was live on 938 radio’s Singapore Today program on 24 May 2021 to discuss the Oriental Honey Buzzard, which appeared in the HDB heartlands at Bedok, exciting residents and netizens.

A Bedok resident looked out of her 5th floor window and saw a large bird perched on top of a tree. She shared a photo of the raptor (bird of prey) on Facebook, and netizens suggested various identifications such as White-bellied Sea Eagle, Changeable Hawk-Eagle, Oriental Honey Buzzard, and even eliciting comments such as Godzilla! Maybe there is some semblance to the mystic creature as the raptor has a long neck and held an upright posture.

These are the abridged responses to the radio hosts numerous queries:

“What is it, and did it just arrive?” – Alan clarified that the raptor was an Oriental Honey Buzzard, a migratory species from the north that arrives during the autumn to spend the winter here, in this part of the world.

“Are they common and where do they come from?” – Dr. Yong shared that the Oriental Honey Buzzard is a common migratory raptor to Singapore and they come from north Asia, breeding in the temperate forests of China, the Korean Peninsula, and Japan. Satellite-tracked birds from Japan show that they migrate through China, Southeast Asia, with many passing through Singapore to Indonesia, but some birds also spend the winter in Singapore.

“It’s a buzzard, but it’s also an eagle right?” – Dr. Yong shared that ‘raptor’ is a broad term that refers to eagles, hawks, buzzards, goshawks, and other birds of prey.

“Would they pose a threat to our birds here?” – Alan commented that the Oriental Honey Buzzards feed on the larvae of bees, wasps, and hornets and that they do not pose a threat to other wildlife. Dr. Yong added that these raptors are part of our ecosystem.

“Does the public have to be careful around them?” – Alan said that the Oriental Honey Buzzards do not pose a threat to people. On the other hand, these raptors are often harassed by crows. Dr. Yong added that should someone be lucky enough to witness the Oriental Honey Buzzard feeding at a bee hive or hornet nest, that they should keep clear, as the insects may attack anything that they perceive to be a threat to their hive/nest.

“Has migration patterns of raptors to Singapore changed?” Dr. Yong responded that there is no clear trend of change for raptors but that for many migratory birds other than raptors, there has been a decline. These declines may be due to the loss of habitat in other places along their migration route. Nevertheless, it would be good to keep an eye out for migratory birds as we would like to know more about what’s going on and how best to help them.

The Common Buzzard conundrum for Singapore gone full circle?

Field Guides compare

In the earlier days, popular bird publications such as field guidebooks treat the Buteo buzzards occurring in Singapore simply as Common Buzzard Buteo buteo.

Three publications do not list any subspecies:

  1. Birds of Singapore (Lim & Gardner, 1997)
  2. Birds of West Malaysia & Singapore (Jeyarajasingam, 1999)
  3. Annotated Checklist of the Birds of Singapore (Wang & Hails, 2007)

Birds of Thai-Malay Peninsula vol 1 (Wells, 1999) and Birds of Southeast Asia (Robson, 2000) also treated these buzzards as Common Buzzard Buteo buteo, listing vulpinus and japonicus as the subspecies. The Avifauna of Singapore (Lim, 2009) treated these buzzards as Common Buzzard Buteo buteo, listing japonicus as the subspecies for Singapore.

Now, for the splits.

Birds of Southeast Asia, 2nd edition (Robson, 2008) split the buzzards into two species:

  1. The Common Buzzard Buteo buteo, with vulpinus as the subspecies occurring in Southeast Asia.
  2. The east Asian population as Himalayan Buzzard Buteo burmanicus, as the other species occurring in Southeast Asia.

Birds of Singapore (Yong, et al, 2013) also split the buzzards into two species, but in a different manner:

  1. The Common Buzzard Buteo buteo, with vulpinus as the subspecies occurring in Singapore.
  2. The east Asian population is given a different treatment, as Eastern Buzzard Buteo japonicus, as the other species occurring in Singapore.

Confused?

No worries, Birds of the Indonesian Archipelago (Eaton, et al, 2016) lumped the buzzards back into Buteo buteo, using the name Eurasian Buzzard. They listed vulpinus, refectus & burmanicus as the subspecies occurring in Southeast Asia, commenting that “Species taxonomy confused, but substantial overlap in morphological characters and extremely limited mtDNA divergence advocate subspecific status of these allopatric breeding forms.”

DSC_4310-Common-Buzzard-600

A Common Buzzard perched on a lamp post at Changi.