“On 31st August 2017, I witnessed a joint mobbing by 4 bird species on a male Wrangler Pit Viper (Tropidolaemus wagleri) at Dairy Farm Nature Park (below). The 4 bird species were the Crimson Sunbird (Aethopyga siparaja), Olive-backed Sunbird (Cinnyris jugularis), Scarlet-backed Flowerpecker (Dicaeum cruentatum) and the Pin-striped Tit Babbler (Macronus gularis).
![WranglerPitViper-mobbed [ThongChowNgian]](http://www.besgroup.org/wp-content/uploads/WranglerPitViper-mobbed-ThongChowNgian.jpg)
“The mobbing lasted for about 10 minutes. During that time, the birds were observed calling loudly and making a ruckus. Each bird took turns to stage a mock attack, dive bombing at times before retreating to a nearby branch to perch. Strangely, the viper did not react in any way to the mobbing and remained at the same location long after the mobbing.
“I was only able to video the Olive-backed sunbird and Crimson Sunbird mobbing the viper as I had a telephoto lens on my camera and therefore could not zoom out (below).
“The photo below shows the Pin-striped Tit-babbler perched about half a meter away from the viper, ready to launch another attack.
![TitBabblerPS [ThongChowNgian]](http://www.besgroup.org/wp-content/uploads/TitBabblerPS-ThongChowNgian.jpg)
“It was interesting to see 4 bird species having a common objective, taking turns mobbing a common enemy. Unfortunately it was a futile effort by these birds.”
Thong Chow Ngian
Singapore
12th September 2017
Lee Chiu San
Wagler’s Pit Viper is an arboreal snake relatively common in Singapore. Though not aggressive, it is nevertheless venomous, so treat it with respect. However, it generally minds its own business.
It is remarkably inactive, especially when digesting a meal, so it comes as no surprise that the mobbing by the birds elicited no reaction.
It is also the classic ambush predator of rodents, and birds that land too close.
This species displays marked sexual dimorphism. Juveniles and males are green, like the one in the photo. Females are somewhat larger, and are cream coloured speckled irregularly with black.
The Wagler’s Pit Viper is displayed at the Snake Temple in Penang.