Vegetation reduces the foraging efficiency of desert ants Cataglyphis urens, and they prefer unvegetated microhabitats

Cataglyphis urens desert ants use olfaction to locate their dead arthropod food, and we conducted trials to determine if vegetation interfered with their foraging ability. In each trial, two dead crickets were placed 1m apart and 1m upwind of the entrance to an ant colony. One cricket had a ring of dead vegetation, 40 cm in diameter, placed around it and the other did not (open). We traced 50 cm diameter circles in the sand around the open cricket and also outside of the vegetation ring. Ants touched the 50 cm circle around the open cricket first significantly more often (23) than they touched the circle outside the vegetation ring first (10 times). They touched the open cricket first significantly more times (27) than they touched the cricket surrounded by vegetation first (6 times). We also deployed 47 pairs of pit traps. Traps of a pair were placed 1 m apart from each other, one in open sand and the other in the interior of a short shrub. There were significantly more unvegetated traps of a pair with more ants (18) than vegetated traps of a pair with more ants (6). Cataglyphis urens shows higher activity levels in open sand compared with vegetated microhabitats, and vegetation interferes with their foraging efficiency, and possibly their ability to find food.