WITS – African Rock Python Research

Prof Graham Alexander – University of the Witwatersrand

Graham has also launched a collaborative project: 

“During 2010, May was the month when things got really
frantic. We were finding mating pairs every few days,
and we expect more of the same this year.” During this
time, male Puff Adders move great distances searching
for mates and are thus more likely to be seen. They are
also more likely to be found by predators and many end
up as food for other animals. “And because of this, a Puff
Adder is more likely to try and bite you if you step on it
while it is moving. You’ll see them crossing roads, and
they can move at any time of the day or night.” After
mating, pregnant females gestate until February when
the babies are born. “That means that pregnancy i

about the same duration as in humans.” During the last
months of pregnancy, mothers become especially
sedentary and bask much more than usual. They can lose
almost half their body mass by the time they give birth and
breed only every second year because it takes time to
recover.
Graham has also launched a collaborative project with
Professor Andrew McKechnie from the University of Pretoria.
“We are measuring the metabolic expenditure of Puff
Adders using the ‘Doubly labeled Water Technique’. This
high-tech method measures changes in the
concentrations of different isotopes of hydrogen and
oxygen to calculate the rates of carbon dioxide excretion at
the lung surface. From this, we can calculate how long a
Puff Adder can last on a meal, and thus how many meals
they need to survive.” Puff Adders are important rodent
predators and provide a valuable ecosystem service by
keeping rodent populations in check. Graham’s tough
research regime has been made possible only by the help
of others. Bryan Maritz, one of Graham’s PhD students, has
been helping out with tracking. “Other students and loved
ones have mucked in too, and chances are, some will be
doing their own research in Dinokeng next year.”
Graham recently presented a plenary at the
17th Scientific Meeting of the South African
Association for Laboratory Animal Science on
his snake research, and has recently been
invited to present more of his research findings
at the annual Zoological Conference in
Stellenbosch in July. His Puff Adder and Python
fieldwork comes to an end in July this year, but
he intends keeping close links with the Dinokeng
gang.