Thelotornis capensis oatesii (Günther, 1881)

For anyone who's taken the time to browse the pictures already up, you'll notice that invertebrates dominate the subject headings - almost as much as they dominate animal diversity...

Today, we're taking a step back to one of my favourite - although taxonomically iffy - groups. Prepare yourselves. Oh, and a word to any herpetophobes - it's only a picture. You'll live. 

Eukaryota

  Animalia

    Eumetazoa (some day soon, I'm going to shock you all and post a picture of a sea sponge. Just not today, evidently). 

      Bilateralia

        Nephrozoa

          Deuterostomia

            Chordata

              Craniata

                Vertebrata (told you so)

                  Gnathostoma

                    Teleostomi

                      Osteichthys

                        Sarcopterygii

                          Tetrapoda

                            Reptiliomorpha

                              Amniota

                                Reptilia 

                                  Romeriida

                                    Diapsida 

                                      Sauria (Includes birds and crocodiles)

                                        Lepidosauromorpha

                                          Lepidosauria (Includes Tuatara)

                                            Squamata

                                              Scleroglossa

                                                Serpentes

                                                  Alethinophidia

                                                    Coenophidia

                                                      Colubroidea

                                                        Colubridae

                                                          Colubrinae

(As always with vertebrate taxonomy, there are three places where uncertainty remains - the higher taxonomy, the lower taxonomy, and the middly bit. 

The areas I particularly want to draw to your attention are the Craniata/Vertebrata, in which this phylogeny would consider the hagfish an invertebrate, but the externally very similar lamprey a vertebrate (although in my opinion, a reasonable distinction), the Amniota/Reptilia/Romeriida/Diapsida/Sauria/Lepidosauria sequence, within which the Mammals (and close relatives), the turtles (Anapsids), and the birds-dinosaurs-and-crocodiles (Archosaurs) are split off, in that order. The precise placement of the mammals (inside or outside reptiles) is a fairly minor point, but the details of the bird/snake/turtle split are not. Turtles (which includes the terrestrial lineage of tortoises) are usually split off first, hence the terms "Anapsid" (Turtles and extinct relatives) and "Diapsid" (Snakes, Lizards, Birds, Tuatara, Crocodiles and friends). However, the features used to seperate them thusly are probably derived, as genetic studies indicate that actually, birds-dinosaurs-and-crocodiles (Archosauria) are more closely related to the turtles (Anapsida) than to the other half of the Diapsida (snakes, lizards and friends). 

Finally, the Colubroidea and every level beneath it are currently under revision, and likely to continue thusly for some time... because lazy taxonomists of the past just chucked any old snake that wasn't particularly venomous, in there, and so most of them don't belong. 

Our species of the day probably does belong, however, and it is:

Thelotornis capensis oatesii

(Günther, 1881)

Thelotornis, the genus to which this rather lovely snake belongs, is native to more-or-less the entirety of sub-Saharan Africa. The species - T. capensis - is predominantly found in non-rainforest areas below the equator, and this subspecies, Thelotornis capensis oatesii, recogniseable by the dull green cap to its head (which is unfortunately not fully visible from this angle, but I assure you, it is there), is centred over south-central Africa. They are known variously as bird, twig or vine snakes, and if you ever see a pair of bulbuls making a fuss, but can't see why, the chances are that one of the sticks near their nest is actually one of these (assuming that you're in sub-Saharan Africa at the time)

It's not a large snake, topping out at under five feet, but, ironically enough for a snake in the taxon previously called "Harmless snakes" (Colubridae), it's quite venomous. Like the related Boomslang, its venom is Haemotoxic, or active on the blood. The specifics of this mean that there's a grace period of around twenty-four hours between envenomation (Getting bitten) and showing any symptoms. When symtoms do show, resulting from the aggregation of blood cells, they aren't pleasant and can potentially be fatal if left untreated.

Before you rush off an start cutting the heads off every well camouflaged snake you see, bear in mind one very important point. 

Across Southern Africa, where this snake is common in gardens, you are more likely to be killed by lightning than bitten by a snake. 

It may sound like a broken record, but most snakes avoid confrontation, and in almost all cases where people are bitten, the person was attempting to handle or harm the snake at the time. 

Also, they're awesome.