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Managing the risk of wildfires is a growing concern in the western United States. Targeted grazing, or managing livestock grazing to achieve specific vegetation goals, is one possible tool to treat fuels, but few studies have evaluated its efficacy. The goal of this study was to test the effect of targeted grazing on herbaceous fuel loads and fire behavior by 1) implementing targeted grazing in a field experiment and 2) using a fire model (BehavePlus) to evaluate changes in fire behavior resulting from treatments. We applied targeted cattle grazing using low-stress herding and strategic placement of low-moisture block supplement on rugged rangelands in southwestern Arizona using a herd of 58 Red Angus cows and two bulls. Six of the cows were initially fitted with global positioning system collars. We tested two grazing treatments: 1) herding and supplement versus 2) no herding and no supplement on two pairs of study sites and replicated this for 2 years. Herding and supplement affected both the distribution of cattle and herbaceous fuel loads. Despite light utilization (26%) in treated sites, the BehavePlus fire model predicted that herding and supplement reduced fire rate of spread by more than 60% in grass communities and by more than 50% in grass/shrub communities. Fuel treatments dropped flame lengths below a 1.2-m critical threshold under the moderate fuel moisture scenario in grass communities and below a 2.4-m critical threshold in grass/shrub communities under both moderate and extreme fuel moisture scenarios. These results suggest that targeted grazing could reduce the potential cost of fighting fires in conditions similar to this study site. However, implementing this type of treatment on other sites will require careful calibration of animal numbers, supplement amounts, and length of herding periods relative to the specific context and goals.

Beef cattle grazing patterns are influenced by topography in that cattle generally select grazing sites near water while avoiding steep, rugged terrain; therefore, forage is often left ungrazed in the mountainous uplands whereas lowland riparian zones can be heavily grazed. Improving uniformity in beef cattle terrain-use provides opportunities to increase forage harvest and sustain sensitive ecosystems. Studies suggest that terrain-use by cattle may be improved using genomic selection as combinations of single nucleotide polymorphisms (SNP) explained approximately 35% of the phenotypic variation in terrain-use indices that combined slope, elevation, and distance traveled from water. The objective of this study was to perform genome-wide association studies (GWAS) for six terrain-use traits (slope, elevation, vertical climb, distance traveled from water, rolling index, and rough index) in which we explored single-SNP associations, surveyed the genome in consecutive, one mega-base windows and examined quantitative trait loci (QTL) and underlying positional and functional candidate genes using bioinformatic tools to identify possible pleiotropic effects with other traits. Global positioning system (GPS) collars were used to track terrain-use patterns for 330 beef cows across 14 rangeland operations located in the western U.S. and Illumina BovineHD and BovineSNP50 SNP arrays were used to collect genomic data. Genotype quality control was conducted using PLINK software and association analyses were performed using BOLT, implementing a BayesC model. Quantitative trait loci detection was based upon the posterior inclusion probability (PIP) for individual loci and the proportion of total genetic variance explained by individual genomic windows. Analyses revealed 19 QTL that have been previously associated with health and production traits in dairy and beef cattle as well as 8 positional putative candidate genes that function in oxygen homeostasis, feed efficiency, and growth. These results suggest that beef cattle terrain-use traits are polygenic and may be pleiotropic with other production traits.

Vigilant behavior in wild ungulates is critical to guard against predation. However, few studies have examined vigilant behavior in domesticated ungulates. Considering the expansion of large predator populations, understanding vigilant behavior and factors that influence it will help with the management of livestock. We observed adult female cattle (Bos taurus L.) in open-range conditions where large predators (wolves [Canis lupus L.] and mountain lions [Puma concolor (L.).]) were common threats during summers of 2005 and 2006 in eastern Arizona. This study was designed to determine 1) to what extent cattle exhibit vigilant behavior compared to published data on wild ungulates, 2) whether predation events influence vigilance rates of cattle, and 3) whether social and environmental factors affect vigilance of cattle. Cattle exhibited vigilant behavior (3% ± 0.19%) during peak foraging periods, but at a lower rate than wild ungulates. Cows with calves were more than twice as vigilant (4.5% ± 0.46%)...

Free-grazing ruminants forage in environments containing multiple levels of complexity; the forage selection process operates at the landscape scale, when selecting feeding sites, and at the plant part level when selecting actual bites. Pen trials have shown that livestock associate visual cues with feeding sites, however, no field study has shown that animals generalise from training with visual cues in pens in order to choose feeding sites in the field. Our study tested nine beef heifers’ ability to generalise a learned visual cue association to select feeding sites in a rangeland setting offering a novel forage, Lehmann lovegrass (LL). Initially, animals were trained to associate high quality feed with a visual cue during pen trials. We then tested animal response to the cue before and after they gained 14-day grazing experience with LL. Two identical field experiments (i.e., novel, before animals had experienced foraging LL versus familiar, after the animals had 14-day grazing experience with LL) were conducted over 3-day periods. Each experiment consisted of 27, 10-min trials. Animals were tested in plots containing high quality (HQ) and low quality (LQ) LL patches. For each trial, one of three randomly selected scenarios was presented: (1) the visual cue was placed in the HQ patch, (2) the visual cue was placed in the LQ patch, or (3) no visual cue was placed in either patch. Dependent variables were first patch-type chosen, bite rate in each patch, and number of observations of grazing in each patch. Cue presence influenced initial patch choice, bite rate, and grazing tallies within patch type. Heifers took 212 more HQ bites than LQ bites when the cue was placed in the HQ patch ( P P P

Social learning can be of critical importance to cattle grazing rangeland environments with high variability of food resources across space and time. Experienced individuals can greatly facilitate foraging decisions (what to eat and where to eat) of naïve peers in such settings. We conducted an experiment with cattle to investigate strength and persistence of socially induced food and feeding site avoidance behaviours. Sixteen naïve yearling steers were paired with 16 social models that had either not been trained (control) or been trained with an emetic (LiCl), electrical shock or both to avoid: (a) an unsafe high-quality food (LiCl); (b) an unsafe high-quality feeding site (shock); or (c) both the unsafe high-quality food and the unsafe high-quality feeding site (LiCl + shock). Ten-minute trials were conducted in an experimental arena containing three artificial feeding sites each consisting of groups of bowls with either high- (HQ) or moderate-quality (MQ) foods (HQ = barley and oat grain; MQ = Bermuda grass hay). Unsafe high-quality (UHQ, surrounded by traffic cones) and safe moderate-quality (SMQ) feeding sites consisted of nine rubber bowls containing either HQ or MQ foods. The safe high-quality (SHQ) feeding site consisted of two groups of eight bowls containing HQ food, which surrounded the UHQ and SMQ feeding sites. Social models did not induce diet and feeding site avoidance behaviours in naïve steers; they exerted small and transient changes in the feeding behaviour of their naïve counterparts. Consequences to the individual outweighed social influences; when naïve animals experienced the same punishment contingencies as their social models, their behavioural patterns closely resembled those of their social model. Conditioned food and location aversions via LiCl were apparently influenced by prior exposure to target foods and the experimental arena. Conversely, conditioned feeding site avoidance via shock was apparently not influenced by prior exposure to target foods or the experimental arena.

In the southwestern United States, local weed management programs are increasingly important in weed prevention and control; however, little is known about the effectiveness of different local approaches to weed management. We surveyed coordinators of 53 local weed management programs in Arizona, Colorado, New Mexico, and Utah to determine how 4 key program attributes (interagency coordination, volunteer participation, regulatory authority and enforcement, and the state in which the program was located) were related with 4 performance measures: weed control, public education and outreach, weed monitoring, and integrated weed management. Based on the responses of 42 program coordinators (79%) we found that 1) weed programs that coordinated their activities with other organizations and those with citizen volunteers conducted more monitoring, but programs that did not coordinate or use volunteers treated more of their infested acreage; 2) programs that used a light-handed regulatory approach conducted more weed control than those with more punitive enforcement regimes or no enforcement authority; and 3) Colorado programs conducted more outreach and education than did programs in the other 3 states. Thus, although volunteer involvement and interagency coordination contributed to the performance of the local weed programs studied, particularly in monitoring, they have not compensated for the lack of locally enforceable weed regulations or adequate funding. Successful weed management in southwestern United States will require adequately funded, locally adapted approaches supported by locally enforceable weed regulations.

Many grazing-management challenges stem from poor livestock distribution resulting in overuse of some areas and low utilization of others. Managing livestock-distribution patterns requires knowledge of pasture characteristics and animal behavior patterns. Behavioral patterns result from recognizable processes that include inherited attributes, individual and social learning systems, cue-consequence specificity, predispositions toward novel stimuli, and spatial memory. Through these behavioral mechanisms, animals form and revise preferences and aversions for specific locations in their foraging landscape. To accomplish habitat selection, domestic herbivores use sight and sound cues to seek and return to high-quality foraging locations. Nested within habitat selection are learned diet preferences and aversions by which ungulate herbivores associate taste with positive or negative postingestive feedback. The deliberate and careful modification of animal attributes and habitat characteristics could yield options for adaptive rangeland management. In this article, we describe the basic principles that underlie how animals make decisions about where to forage and how long to stay in a particular habitat. We also suggest management practices designed to modify animal behavior and alter habitat-use patterns.

Animals possess an external or skin-defense system that protects them from aggressions inflicted by predators, and an internal or gut-defense system that deters them from over-ingesting toxins. We conducted a study with cattle to investigate the relation between skin- and gut-defense systems and their influence on diet and habitat selection. Sixteen yearling steers were randomly assigned to one of four treatment groups and were exposed individually to an experimental arena during multiple 10 min trials during which they were allowed to select between an unsafe high quality habitat (UHQ) surrounded by traffic cones (visual cues), a safe, uncued high quality habitat (SHQ), or a safe, uncued moderate quality habitat (SMQ). Experimental habitats were made up of groups of bowls containing barley and oat grain (UHQ and SHQ habitats) or Bermuda grass hay (SMQ habitat). Treatments consisted of no aversions (control group), or of averted groups using: (a) electric shock; (b) lithium chloride (LiCl); or (c) both LiCl and electric shock. Steers in the shock group avoided UHQ almost completely, spending significantly less time there than control steers ( P< 0.05), but consumed as much HQ forage from SHQ habitat as control steers. Thus, steers in this group did not become averted to the HQ food in uncued locations. Moreover, location avoidance of steers in this group did not extinguish after shock collars were removed or when location of the UHQ habitat was switched. Steers in the LiCl group consumed significantly less HQ forage than control steers, both in UHQ habitat and SHQ habitat, and spent significantly less time than control steers in UHQ and SHQ habitats. Whereas food aversion remained unchanged during experimentation and extinction trials, location avoidance of steers in the LiCl group rapidly extinguished when location of habitats was switched. Thus, steers averted with LiCl avoided HQ food irrespective of its location or association with visual cues. Steers in the LiCl + shock group almost completely avoided HQ forage in UHQ and SHQ habitats and spent less time than the control steers in both of these

We determined the cattle distribution patterns of dams (and foster dams) and their offspring while grazing a 1030 ha (about 3 km by 5 km) allotment during the summers of 1990–1993. Our primary objective in this 4-year field study was to determine whether yearling and adult offspring (and foster offspring) would return to the initial locations and associated habitat types that they were exposed to by their dams (or foster dams) early in life. We observed the dams' offspring for four consecutive summers (1990–1993) and the foster-dams' offspring for 3 consecutive summers (1991–1993). Cross-fostering was conducted to learn the relative importance of natural dams vs. foster dams as social models in influencing distribution patterns of offspring. Offspring were reared mostly in two different locations on the allotment by their dams or foster dams. Centroid analyses indicated that offspring in all 4 groups remained near the general location where they were reared as calves when they returned to the allotment as older animals (mean 0.5 to 1.2 km from dams' or foster dams' centroid). Peers apparently attenuated the dams' (and foster dams') influence on location and habitat use when offspring were yearlings. The effect of peers was manifested by an increase in distance from dams' or foster dams' centroid, and by a higher association index among yearlings, both of which reflected the collective experiences of offspring in the peer groups. Drought weakened the dams' and foster dams' influence on location and habitat use as water became scarce near their centroids, but drought amplified the dams' and foster dams' influence when water was not limited near their centroids. By the final year of the study, offspring in 3 of the 4 groups monitored were within 0.7 km from the dams' or foster dams' centroid (offspring in the fourth group were within 1.1 km from the foster dams' centroid). Collectively, our results suggest that experiences early in life affected cattle distribution, and that distribution at any point in time was a ‘snapshot’ of ongoing behavioral changes that were developing according to each individual's antecedent experiences and current environmental and social conditions. These results support the ‘working hypotheses’ that herding, selective culling, and water and shade development are important management techniques that can enhance dispersion and decrease use of sensitive areas on rangelands (e.g., riparian areas).

Numerous studies suggest some cows use certain areas (e.g. riparian habitats) more than others (e.g. uplands), but the research generally has been based on observations of small numbers of animals or on general inspections of entire herds. Consequently, it is not known if individual animals differ in home range (HR) and habitat use (HU) or if behavioral characteristics are a valid selection tool to decrease cattle use of riparian habitats. We conducted field observations of the differences in HR and HU among adult cows on summer range in Idaho. We located 116 cows on 4970 occasions during 1990, and 87 cows on 3995 occasions during 1991. Individual cows occupied one of four HR areas, and the majority (78%) showed high consistency in HR, despite drought, ad hoc management procedures and occasional herding. Thirty-three percent (n = 29) of the 87 animals monitored during 1990 and 1991 exhibited total HR fidelity between years, whereas 45% (n = 39), 18% (n = 16) and 3% (n = 3) of the animals differed slightly, moderately and substantially in HR use. All cows tended to shift their activities (i.e., centroid) to the south, apparently in response to decreasing water availability between 1990 and 1991. Cows in the four HR groups differed in the degree to which they foraged and rested in riparian and upland habitats, largely depending on the physical characteristics of the HR area. Given the high degree of home range fidelity in our study and those of others, we submit that selective culling may effectively change cattle distribution and decrease the use of riparian areas.

Wild and domestic ungulates modify their behaviour in the presence of olfactory and visual cues of predators but investigations have not exposed a domestic species to a series of cues representing various predators and other ungulate herbivores. We used wolf (Canis lupus), mountain lion (Puma concolor), and mule deer (Odocoileus hemionus) stimuli (olfactory and visual), and a control (no stimuli) to experimentally test for differences in behaviour of cattle (Bos taurus) raised in Arizona. We measured (1) vigilance, (2) foraging rates, (3) giving up density (GUD) of high quality foods and (4) time spent in high quality forage locations in response to location of stimuli treatments. In general, we found a consistent pattern in that wolf and deer treatments caused disparate results in all 4 response variables. Wolf stimuli significantly increased cattle vigilance and decreased cattle foraging rates; conversely, deer stimuli significantly increased cattle foraging rate and increased cattle use of high quality forage areas containing stimuli. Mountain lion stimuli did not significantly impact any of the 4 response variables. Our findings suggest that domestic herbivores react to predatory stimuli, can differentiate between stimuli representing two predatory species, and suggest that cattle may reduce antipredatory behaviour when near heterospecifics.

A study was conducted in an eight-arm radial maze to determine if cattle with various foraging experiences could facilitate location of feeding sites by other cattle. Heifers assigned as “followers” (n=24) were initially trained to expect straw at the end of each arm. Initial training of heifers assigned as “leaders” (n=12) differed based on the three following treatments:(1) no-experience, (2) barley in the same two arms, and (3) barley in two arms but locations changed daily. During training, leaders with barley in fixed locations foraged more efficiently by traveling to fewer (P

We tested the hypothesis that cattle aided by visual cues would be more efficient than uncued animals in locating and consuming foods placed in either fixed or variable locations within a 0.64-ha experimental pasture. Eight yearling steers were randomly selected and trained to associate traffic barricades and traffic cones with high- (oat–barley mixture) and low- (straw) quality foods, respectively. Initially steers were randomly assigned to 1 of 4 food location/visual cue treatments: fixed locations/with cues (F/C), variable locations/with cues (V/C), fixed locations/no cues (F/NC), or variable locations/no cues (V/NC). High- and low-quality foods and their respective cue (or no cue) were placed in the experimental pasture. Individual animals were allowed to explore the pasture for 10 min twice per day every other day for 1 week. Minutes until feeding, first feed type consumed (i.e., high-quality, low-quality, or no food consumed), animal location and activity (i.e., feeding, standing, or moving), and total intake of high- and low-quality feed were recorded during each 10-min trial. At the end of each week, location/visual cue treatments were randomly assigned to another 2 steers, which permitted an independent test of each animal in each treatment over a 4-week period. Animals in the F/C and V/C treatments took about 2 min to initially locate and consume a food, compared to F/NC and V/NC animals who took nearly 4 and 6 min, respectively. The high-quality food was the first food located and consumed by F/C, V/C, F/NC, and V/NC animals during 79, 77, 67, and 54% of sampling occasions, respectively. Cued animals typically spent more time feeding (P=0.0004) and less time standing (P=0.005) than uncued animals. Cued animals had a higher mean intake than uncued animals of high- (P=0.001) and low- (P=0.04) quality food. Mean high-quality intake for F/C, V/C, F/NC, and V/NC treatments was 266, 245, 214, and 126 (±22) g, respectively; mean low-quality intake for the same treatments was 36, 32, 12, and 10 (±10) g. Cued animals also consumed more food per distance traveled than uncued animals (P=0.005). Animals located food quicker (P=0.03) and consumed more high-quality food (P=0.02) when food locations were constant than when they were variable. Our data strongly indicate that cattle can learn to associate visual cues with disparate food qualities and use this information to forage more efficiently in both fixed and variable foraging environments.

The Walker Basin Allotment grazing system in central Arizona is designed to allocate resource use under elk (Cervus elaphus L.) and cattle (Bos taurus L.) grazing. The grazing system was designed to promote biologically acceptable levels of forage use on the half of the allotment scheduled for cattle grazing and to rest the other half by attracting elk to pastures recently grazed by cattle. The objectives of our 2-year study were to determine whether the grazing system facilitated proper forage use as defined by recent forage use and residual stubble height guidelines (i.e., 30 to 40% use and an 8- to 10-cm stubble height) and whether the system rested one half of the allotment from elk and cattle grazing. Mean (+/- SEM) total elk and cattle forage use for western wheatgrass (Pascopyrum smithii Rydb.), the key forage species, was 32 and 61% +/- 7 in 1997 and 1998, respectively; corresponding mean (+/- SEM) stubble heights were 11 and 10 cm +/- 0.6. Mean total cattle and elk forage use in 1998 (61%) exceeded the 30 to 40% use guidelines. However, mean end-of-year stubble height was never below 10 cm. The grazing system did not provide half the allotment with complete rest; elk used all study pastures. Elk use was higher in pastures with heavier tree cover and steeper terrain in both years, regardless of where cattle grazing occurred. Elk grazing patterns were apparently more dependent on tree cover and topography than any changes in forage caused by the grazing system. DOI:10.2458/azu_jrm_v55i4_halstead

Forage use data can help rangeland and wildlife managers make informed decisions. However, managers need to know if forage use techniques that are commonly used to estimate ungulate herbivory under field conditions produce comparable results. The objective of this 2-year study was to directly compare forage use measurements obtained via the paired-plot method and 2 height-weight methods (using on-site height-weight curves and the pre-established United States Forest Service height-weight gauge). In June, July, and October of 1997 and 1998, we measured forage use of western wheatgrass (Pascopyrum smithii Rydb.) by cattle (Bos taurus L.) and wild ungulates, mainly elk (Cervus elaphus L.). On-site height-weight curves and the USFS gauge consistently produced lower estimates (overall means = 8 and 7%, respectively) than the paired-plot method (overall mean = 31%). Height-weight estimates did not differ (P > 0.05) when calculated with either on-site curves or the USFS gauge. Within sampling areas, paired-plot estimates were relatively more precise (mean CV = 63%) than on-site curves (mean CV = 238%) or the USFS gauge (mean CV = 271%). Selective grazing likely contributed to higher CVs for height-weight techniques. Our findings are important for rangeland and wildlife managers because the forage monitoring technique they use may influence the results obtained and, consequently, grazing management and wildlife harvest decisions. Managers should ensure that chosen monitoring techniques provide an appropriate evaluation of management goals and objectives. DOI:10.2458/azu_jrm_v53i5_halstead