Biology

Biology of DDRS

 Flora

The diversity of flora on the DDRS reflects the steep gradient in elevation between the uplands and canyon lands.  On the uplands, the Chihuahuan desert indicator species lechuguilla (Agave lechuguilla) and tarbush (Florensia cernua) are associated with creosotebush (Larrea tridentata), ocotillo (Fouquieria splendens), plume tiquilia (Tiquilia greggii), yucca (Yucca spp.), sotol (Dasylirion leiophylla) and an array of cacti. In 2005 a 26-month survey of an upland 10,000 m2 plot identified 86 species from 29 families, excluding grasses (Killion and Cook submitted).  In the canyons, oak (Quercus grisea), walnut (Juglans spp.), juniper (Juniperus pinchotii) and woody legumes (Mimosa spp. and Acacia spp.) form dense pockets of woodland along intermittent waterways. Throughout the site, a variety of annual and perennial wildflowers mark the milder seasons and decorate more sheltered areas throughout much of the year.

Fauna

Desert fauna of the site includes a variety of specialized invertebrates.  Because of the remoteness of the area, very little invertebrate collecting has been done.  A preliminary survey of the ground-dwelling spiders, using pitfall traps have yielded 66 species distributed in 46 genera and 24 families.  Several species are new to science and one may well be a new family to science (Broussard and Horner 2006, Platnick and Horner 2007).  Identified solifugids include six different species from five genera and two families. Vertebrates are the typical Chihuahuan Desert animals such as the cactus mouse (Peromyscus eremicus), desert cottontail (Sylvilagus audobonii), black-tailed Jackrabbit (Lepus californicus) , javelina or collared peccary (Taxidea taxus)  mule deer (Odocoileus hemionus), kit fox (Vulpes macrotis), coyote (Canis latrans), mountain lion (Puma concolor), etc.  Approximately 90 species of birds, mostly migrants, have been identified at the DDRS by a current study (Holbert in prep).  Numerous bats, lizards, snakes, and insects are present, but are yet to be identified.