Both black-tailed jackrabbits (Lepus californicus) and antelope jackrabbits (L. alleni) have been reported to prefer less densely vegetated habitats over densely vegetated habitats. Studies comparing trends of antelope jackrabbit numbers in differing habitats are lacking however. From 2012 to 2019 we conducted walking transect surveys in two different grassland types where jackrabbits occur. We found antelope jackrabbit densities to be significantly lower in a semidesert grassland site protected from grazing when compared to a grazed site in Sonoran savanna grassland (p < 0.01). While antelope jackrabbit densities in the temperate, densely vegetated semidesert grassland site declined over time in the absence of fire, and increased after burning, antelope jackrabbit densities fluctuated at a higher level independently without the presence of fire in more sparsely vegetated Sonoran savanna grassland. We attribute these changes in antelope jackrabbit numbers in the two survey sites to the animal′s preference for open annual grasslands in a tropic-subtropic environment as compared to grasslands composed of dense perennial bunch-grasses.