The Diadem Snake Spalerosophis
diadema is named for its distinctive head markings, consisting of a dark
band, which runs across the head between the eyes, behind which several irregular,
dark spots may be present. The background colouration of the head and body
varies between individuals but is usually greyish, yellowish, sandy-beige or
reddish and measures up to 180 centimeters in length. A series of dark brown,
olive or reddish blotches runs down the middle of the spine, which fuse into a
dark stripe at the neck. In addition, the flanks are marked on either side with
a row of smaller dark spots. The head is elongated and slightly triangular,
with a rounded snout and large eyes featuring circular pupils. An active
predator, it predominantly feeds on rodents, throwing a loop of its body over
its prey to immobilise it, before delivering a suffocating bite with its
powerful jaws and also produces chemical secretions from an oral gland, which are
highly toxic to small mammals, but pose no danger to humans. In addition to
rodents, the Diadem Snake is also known to prey upon lizards such as agamas, and
occasionally on small birds. When threatened this species is known to inflate
and thrash its body, hiss and make rapid strikes. Theses snakes change their
activity period according to the season, being diurnal during the winter,
autumn and spring, and nocturnal and crepuscular during the summer. They often
rest amongst stones, loose rocks, desert plant roots or in rodent burrows
during the day to avoid the extreme heat. The Diadem Snake has a large
distribution, occurring throughout northern Africa from Mauritania to Egypt,
the Arabian Peninsula including Saudi Arabia, and southwest and central Asia,
as far as Kazakhstan, Pakistan and India. They are found in arid and semi-arid
areas, including stony and sandy desert, and frequently occur in cultivated
areas and palm groves surrounding oases. It can be found from lowland regions
to elevations of up to 2,000 metres.
It was about 1.5 meters in length and aggressive. Cliff
sent me the following details of his encounter with this snake. We had camped
in Wadi Nisah during the winter when air temperatures fall rapidly with
approaching sunset. We were driving back to our campsite just as the sun was on
the horizon when I spotted the snake and drove towards it stopping well short
assuming it would flee the approaching vehicle. The 3 of us hopped out and
proceed toward the snake. I had parked in a sliver of sunlight and a deep
shadow cast by some rock separated us from the snake which occupied another
sliver of sunlight. As we approached the snake, it turned and aggressively started
directly toward us. I have never encountered such aggression in a snake. Amazingly,
as it tried to cross the shaded area in pursuit of us, the temperature had
already dropped enough that the snake's forward progress to be stopped. I
emptied my Pelican case and ever so carefully collected it into the case where
it spent the freezing night. We broke camp the next morning, posed the snake
for its photo session, then departed before it had warmed in the sun.