Birds, Wagler's Pit Viper etc - November 2021

When you go around looking for birds, be mindful of other creatures which may be lurking along your favourite trails. Some of them can be really special especially a nice but venomous looking snake like a Wagler's Pitviper (Tropidolaemus wagleri).

This is a female Wagler's Pit Viper 

Venomous terrestrial species of snakes in Malaysia are basically divided into 2 families, the elapidae which include cobras and kraits and viperidae which include viper and pit vipers. There are 3 subfamilies within this family of vipers: the Fea's viper (Azemiopinae), Pit vipers (Crotalinae) and Pitless vipers or true vipers (Viperinae), Iman D. Johan Arief, et al (2021). 

According to their research, Iman D. Johan Arief, et al (2021) argued that Wagler's pit viper (Trimeresurus wagleri) is among the commonest species of pit vipers found in Malaysia. Due to its highly differentiated morphological characteristics, it has now been categorised in a different subgenus known as "Tropidolaemus".

In another earlier research, Choo Hock Tan et al (2017) reported that Tropidolaemus is mainly distributed in Southeast Asia. There are currently at least four species of Tropidolaemus been recognised in the literature and media including the most commonly described, the "Temple pit viper" (Tropidolaemus wagleri), also known as speckled pit viper and Wagler's pit viper.

While variations in coloration do exist, generally the adult females have a black or dark green base coloration with yellow cross-banding while the males basically retain most of the external characteristics from the juvenile phase; they are typically slender and much smaller than the females, says Iman D. Johan Arief, et al (2021) and as can be seen from the above photo. 

The male body is generally light green in color, ornamented with red and white post-auricular stripes, as well as red and white spots on the dorsum. According to Iman D. Johan Arief, et al (2021), despite the high reports of snake bites due to pit vipers in Malaysia, most envenomation does not result in fatality. From 1965-1971, there were 1136 cases with 4 fatalities involving the Malayan pit viper (Calloselasma rhodostoma). 

Choo Hock Tan et al (2017) argues that unlike most other pit vipers, T. wagleri venom does not possess hemorrhagic or anticoagulant properties. Hypothetically, the venom of female T. wagleri would be one that is streamlined for the predation of larger warm-blooded animals such as rodents or birds, while the smaller male adults and juveniles feed mainly on amphibians and reptiles.

Addressing the qualitative and quantitative details of the venom proteins, Choo Hock Tan et al (2017) research surprisingly, revealed highly similar chromatographic profiles of both the male and female venoms. Despite their drastic sexual dimorphism, their findings imply that the venom contents of T. wagleri are consistent regardless of the sex and body size of the snake. Predation is accomplished with the venom neurotoxic activity mediated through the waglerins.

According to Iman Dr. Johan Arief et al (2021) the potency of the haemorrhagic and thrombin-like activity varies depending on the species, which may result in thrombocytopenic syndrome and haemorrhage.

Although the bites of members of this genus rarely result in serious envenomation, nevertheless, their bites can be excruciatingly painful with local blistering, tissue necrosis, and haemorrhage, Iman Dr. Johan Arief et al (2021).

References:

i) Choo HockTan, KaeYiTan, Michelle Khai KhunYap, & Nget HongTan,  "Venomics of Tropidolaemus wagleri, the sexually dimorphic temple pit viper: Unveiling a deeply conserved atypical toxin arsenal" (Feb 2017).

ii) Iman D. Johan Arief, Xin Y Er, Rafiq Shajahan, Faiz Johan Arief, Naganathan Pillai, "Venomous Terrestrial Snakes in the Tropics of Malaysia: Review", (Mar 2021).

Here are some of the birds seen along the way.

This is our very own "Tweety Bird" - Common Tailorbird.

Pin-striped Tit Babbler - together with the above tailorbird, they can easily manoeuvre along the thick vines and bushes in the jungle. Have seen them picking up caterpillars, etc in those areas. 

I believe this should be a Spectacled Spiderhunter.

Quite a large bird and their calls can be heard quite a distance away. 

Blue-throated Bee-eater

Its tail streamer is usually longer as compared to the Blue-throated Bee-eater.

Indian Cuckoo

This could just be a sub-adult.

At a glance, it looks like a Peregrine Falcon.

This is a medium size migrant cuckoo with a unique call which sounds repeatedly like this: "bo-ka-ta-ko" 

I rarely see three falconets in a tree.

Black-thighed Falconet

Eating its prey which I later found out that it was a dragonfly.

Scaly-breasted Bulbul

It is smaller than other bulbuls - the olive-winged, the Red-eyed etc but their calls are more melodious.

 

They can be quite friendly too and they definitely like a cool shower.

Enjoying a cool splash by itself.

It was then joined by its partner.

Another two other members decided to joined in the fun.

Suddenly more joined in.

Finally the whole gang of six decided to gate-crashed the party.

This could be a juvenile Spectacled Bulbul

Here's a funny looking 'cicak" (lizard)

This is an earless agamid lizard (Aphaniotis fusca). Can only be found in this region.

A spider with a designer web.

Finally a unique pair of insect - they look like some small cicadas.

THAT'S ALL FOLKS !

MUCHAS GRACIAS ! FOR DROPPING IN. ADIOUS !