Seasonal wildlife observations were made along transects on 2 pastures conservatively grazed (36% use of perennial grasses) and 2 pastures moderately grazed (47% use of perennial grasses) in south central New Mexico in non-drought (1997) and drought years (1998). Experimental pastures were similar in soils, terrain, spacing of watering points, and brush cover. Average ecological condition score for the conservatively grazed pastures was 60% compared with 64% for moderately grazed pastures. Throughout the study total standing vegetation understory herbage levels were higher (P < 0.05) on conservatively grazed than moderately grazed pastures. Total wildlife, total gamebird, and total songbird sightings did not differ (P > 0.05) between conservatively and moderately grazed pastures. Black-tailed jackrabbit (Lepus californicus) sightings were higher (P < 0.05) on moderately grazed than conservatively grazed pastures. Sightings of pronghorn (Antilocapra americana), Scaled Quail (Callipepla squamata), Mourning oves (Zenaida macroura), and desert cottontails (Sylvilagus auduboni) showed no differences (P > 0.05) between conservatively and moderately grazed pastures. Dry conditions in 1998 depressed total wildlife sightings by >50% compared to 1997. Both songbird and gamebird (particularly Mourning Dove) sightings were severely reduced in the dry compared to wet year (P < 0.05). Our results are consistent with Nelson et al. (1997) that livestock grazing at intermediate levels had no effect on most Chihuahuan Desert upland wildlife species, and that drought years severely depress wildlife sightings.
Joseph, Jamus; Collins, Michelle; Holechek, Jerry; Valdez, Raul; and Steiner, Robert
"Conservative and moderate grazing effects on Chihuahuan Desert wildlife sightings,"
Western North American Naturalist: Vol. 63
, Article 5.
Available at: http://scholarsarchive.byu.edu/wnan/vol63/iss1/5