Tracks and trails

Unlike more vegetated habitats and ecosystems, the dunes and sandsheets of the desert offer endless and unparalleled potential for recording the presence, passage and activities of its wildlife, large and small. From the tracks of a passing viper (watch for the side-winding motion and the loop as the snake changes from left to right-handed progression), the characteristic pug-marks of the jerboa as it jumps along on its hind-legs, or the telltale raised trail of the skink as it ‘swims’ along just below the sand’s surface, the desert records all.

The best time to study tracks and trails is in the early morning before the wind gets up and wipes clean the night’s slate and when the low morning light enhances the profile of the prints. There are even places where the combination of cold nights and high humidity leave the surface of the desert sparkling with frost and its surface almost plastic-like in appearance, recording the tiniest of beetle or gerbil prints with exquisite perfection.

The use of tracks and trails is an important item in the conservation and research toolbox. With rare and mobile species like the addax or the cheetah, the study of tracks helps in census work, the determination of herd composition, and the understanding of migratory routes and patterns. For nocturnal animals, too, the sand is an extraordinary witness to the night’s antics and goings on.

The photos below are just a small sample. There are also some mystery pictures for you to guess the answers to.

   Dorcas Gazelle walking unhurriedly and
   dragging its feet. When startled or about
   to flee, gazelles will often jump vertically.
   This is known as 'stotting' and the marks
   it leaves on the ground are likened by the
   Twareg to the cluster of stars known as
   the Pleiades.




   Can you guess what made these neat
   tracks? The culprit is rarely seen by
   day and often travels over 10 km at a
   time in search for seeds to eat.

   The Hoopoe Lark is one of the real stars of
   the desert. The heavier tracks to the right
   show where it landed before moving off in
   search of small seeds and insects. The
   Twareg call this bird 'the one that
   loses children' because of its habit of
   drawing would be predators away by
   running along the ground in front of them.



   This form of motion is known as 'side-
   winding'; progression is perpendicular to
   the axis of the body, which is raised clear
   of the sand as the animal progresses. Any
   idea what made the track?


 



   Reptiles like this Fringe-toed Lizard are
   common in the desert. The tracks to the
   left were made by an unhurried lizard. At
   midday, however, when ground temp-
   eratures can reach 80°C, the track is
   much. much finer, as the lizard races along
   from tussock to tussock, lifting its body
   clear of the burning sand.



Answers to the mystery pictures can be found here.