How does Targeted Grazing with Small Ruminants Influence Subsequent Patch Use by
Mule Deer and Cattle?
Utsumi, S.A.1, A.F. Cibils1, R.E., Estell2, J., Boren3, B. Cooper1, S. Cox4 and D.,
VanLeeuwen5
1 ,3, 4, 5
New Mexico State University, 1 Department of Animal and Rangeland Sciences, 3
Department of Wildlife Sciences, 4 Corona Range and Livestock Research Center, 5
Agricultural Biometrics Service and 2 USDA/ARS-Jornada Experimental Range
We measured mule deer and cattle selection of one-seed juniper infested patches (30 x 20
m) which were untreated (Control ) or that had been grazed with goats or goats + sheep at
either high (10m2/AU/day; Small patches) or low (60 m2/AU/day; Large patches)
stocking densities., Mule deer and cattle presence during the winter, spring, summer, and
fall following a summer targeted grazing treatment was determined using automated
cameras with infrared motion sensors. Camera counts were used to predict selection
indices (SI) and to model the probability of deer presence in patches as a function of
cattle counts. Both deer (SI: 0.00) and cattle (SI: 0.40; P < 0.001) avoided large patches
which had been grazed by goats + sheep. These were also the patches that had received
heaviest utilization of herbaceous vegetation (73.5%) during the previous summer. Deer
selected small patches that had been grazed by goats + sheep (SI: 2.24; P = 0.001);
whereas cattle selected large patches (SI: 1.50; P = 0.058) and avoided small patches
grazed by goats alone (SI: 0.59; P = 0.052). Cattle showed highest preference for grazed
patches in summer (SI: 3.18; P = 0.001), while deer avoided grazed patches in summer
(SI: 0.21; P = 0.034) and spring (SI: 0.13; P = 0.016). The probability of mule deer
presence on a given patch (y) was significantly reduced by cattle (x) presence (y= e-0.128x;
R2=0.40; P < 0.001). Targeted grazing programs with small ruminants could be used to
create contrasting patches of different sizes to improve habitat for multiple rangeland
ungulates.
Key words: Juniperus monosperma, restoration, cattle-deer interactions