Seasonal Migration of Sika Deer in the Oku-Chichibu Mountains, Central Japan

Movements and seasonal home ranges of 6 GPS collared sika deer were investigated at the Oku-Chichibu Mountains, central Honshu, from April 2009 to March 2010. All deer migrated between discrete summer and winter home ranges. The linear migration distance ranged from 2.5 to 31.9 km. Mean elevation during the summer and the winter ranged from 980 to 1,782 m, and from 1,204 to 1,723 m, respectively. Two deer were upward migrants and 4 deer were downward migrants. Taking into consideration of the relatively small snow accumulation in the summer home range, the possibility of autumn migration to avoid deep snow is low. The percentage of steep slope in the winter home range was higher than that in the summer. Bamboo grass was not found in the summer home range, but was predominant in the winter home range. Road density decreased in the winter home range compared to the summer. Only 2 out of 6 deer stayed mainly in the wildlife protection area during the winter. Our results indicate that the autumn migration was affected by winter forage and human disturbance, thereby assured the survival of the deer during winter.ArticleMAMMAL STUDY. 37(2):127-137 (2012)journal articl

The Relationship Between GPS Sampling Interval and Estimated Daily Travel Distances in Chacma Baboons (Papio ursinus)

Modern studies of animal movement use the Global Positioning System (GPS) to estimate animals’ distance traveled. The temporal resolution of GPS fixes recorded should match those of the behavior of interest; otherwise estimates are likely to be inappropriate. Here, we investigate how different GPS sampling intervals affect estimated daily travel distances for wild chacma baboons (Papio ursinus). By subsampling GPS data collected at one fix per second for 143 daily travel distances (12 baboons over 11–12 days), we found that less frequent GPS fixes result in smaller estimated travel distances. Moving from a GPS frequency of one fix every second to one fix every 30 s resulted in a 33% reduction in estimated daily travel distance, while using hourly GPS fixes resulted in a 66% reduction. We then use the relationship we find between estimated travel distance and GPS sampling interval to recalculate published baboon daily travel distances and find that accounting for the predicted effect of sampling interval does not affect conclusions of previous comparative analyses. However, if short-interval or continuous GPS data—which are becoming more common in studies of primate movement ecology—are compared with historical (longer interval) GPS data in future work, controlling for sampling interval is necessary

Step by step: reconstruction of terrestrial animal movement paths by dead-reckoning

Background: Research on wild animal ecology is increasingly employing GPS telemetry in order to determine animal movement. However, GPS systems record position intermittently, providing no information on latent position or track tortuosity. High frequency GPS have high power requirements, which necessitates large batteries (often effectively precluding their use on small animals) or reduced deployment duration. Dead-reckoning is an alternative approach which has the potential to ‘fill in the gaps’ between less resolute forms of telemetry without incurring the power costs. However, although this method has been used in aquatic environments, no explicit demonstration of terrestrial dead-reckoning has been presented.Results: We perform a simple validation experiment to assess the rate of error accumulation in terrestrial dead-reckoning. In addition, examples of successful implementation of dead-reckoning are given using data from the domestic dog Canus lupus, horse Equus ferus, cow Bos taurus and wild badger Meles meles.Conclusions: This study documents how terrestrial dead-reckoning can be undertaken, describing derivation of heading from tri-axial accelerometer and tri-axial magnetometer data, correction for hard and soft iron distortions on the magnetometer output, and presenting a novel correction procedure to marry dead-reckoned paths to ground-truthed positions. This study is the first explicit demonstration of terrestrial dead-reckoning, which provides a workable method of deriving the paths of animals on a step-by-step scale. The wider implications of this method for the understanding of animal movement ecology are discussed

Thurber needlegrass: Seasonal defoliation effects on forage quantity and quality

Although Thurber needlegrass (Stipa thurberiana Piper) is an important component of Palouse, sagebrush:steppe, and pine:forest rangelands, little is known of its qualitative and quantitative responses to defoliation. At 14-day intervals one of 7 cohorts of Thurber needlegrass plants was defoliated to a 2.5-cm stubble to describe initial growth rates, determine defoliation effects on subsequent regrowth accumulations, relate regrowth potential to available soil moisture, and determine the nutritional value of initial growth and regrowth for livestock. The study was conducted in 1985 and 1986 with a different group of plants used each year. Although crop-year precipitation for the 1985-86 treatment years was 77 and 111%, respectively, of the long term mean (25.2 cm), growth rates of tussocks were similar between years (P > 0.05). Seasonal yield of regrowth varied between years, however, and was well correlated (r2 = 0.76 to 0.80 P < 0.05) with soil moisture content when treatments were applied. Among 7 defoliation dates (24 April-17 July) only the first 5 yielded regrowth in 1985, and all produced regrowth in 1986. Among treatments regrowth averaged 22% of total herbage yield in 1985 and 50% of total yield in 1986. In both years total herbage accumulations were most suppressed (47-63% reduction) by defoliation during the early-boot stage of phenology. In 1985 when conditions were drier, any defoliation before mid-June depressed (P < 0.05) total herbage yield. Crude protein (CP) of needlegrass herbage was high (19-22%) when growth began in April but declined (P < 0.05) to marginal levels for cattle (6.7-7.7%) by mid-July. Regrowth harvested on 31 July ranged from 7 to 9% CP for the earliest (24 April) treatments and as high as 17% for the latest (17 July). Although Thurber needlegrass can produce highly nutritious regrowth for late-season use, managers face diminishing levels of regrowth as the initial cropping date is delayed later into the growing season. Managers contemplating 2-crop grazing regimes for Thurber needlegrass should base scheduling on plant phenology, soil moisture considerations and historic use rather than specific calendar dates. Further work is needed, however, to definitively determine Thurber needlegrass responses to long-term manipulative grazing regimes.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Defoliation of Thurber needlegrass: herbage and root responses

Thurber needlegrass (Stipa thurberiana Piper) is an important component of both forested and shrub-steppe communities of the Pacific Northwest and Great Basin regions, and little is known of its tolerance to defoliation. A study was conducted on the Squaw Butte Experimental Range to determine the response of containerized Thurber needlegrass to single defoliations (2.5-cm stubble) throughout the growing season. Dates of treatment spanned vegetative through quiescent stages of phenology. Response variables included: summer regrowth, number of reproductive stems, fall growth, and subsequent spring herbage production, change in basal area, and root mass. Vigor of Thurber needlegrass was reduced most by defoliation during the early-boot stage of development. Impacts were successively less severe from vegetative, late-boot, and anthesis treatments, respectively. Cumulative herbage production the year of treatment was reduced from 38 to 64% by defoliation at the early-boot stage. The same treatment reduced subsequent spring growth by 46 to 51% and root mass the next spring by 34 to 45%. Treatment effects were somewhat reduced when temperature and moisture regimes allowed substantial regrowth after defoliation. Defoliation during or after anthesis had little effect on plant response. Managers should be aware that a single defoliation, particularly during the boot stage, can significantly reduce subsequent herbage production and root mass and possibly lower the competitive ability of Thurber needlegrass.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Tolerances of Sagebrush, Rabbitbrush, and Greasewood to Elevated Water Tables

Knowledge of the effects of saturated soils and flooding on Wyoming big sagebrush (Artemisia tridentata wyomingensis), green rabbitbrush (Chrysothamnus viscidiflorus), and black greasewood (Sarcobatus vermiculatus) can enhance our understanding of their distribution. The responses of these 3 species to elevated water tables were studied on 4 contours bordering an expanding lake in southeast Oregon during the 1983 and 1984 growing seasons. When plants were initially selected for study, contours were 0, 10, 20, and 40 cm above the lake surface. Continued expansion of the lake flooded the lower contours and elevated the water tables under the upper contours. Wyoming big sagebrush rapidly succumbed to surface flooding and elevated water tables within 10 cm of the surface. Green rabbitbrush behaved similarly, but responses lagged about 1 week behind sagebrush. Black greasewood tolerated surface flooding for 40 days before effects were apparent. Water tables within 25 to 30 cm of the surface had no effect on greasewood. Given adequate topography and water supplies, water spreading techniques could be used to control Wyoming big sagebrush and green rabbitbrush.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Bunchgrass basal area affects selection of plants by cattle

Cattle are selective foragers in response to several plant attributes. We tested hypotheses that caespitose plants of various basal areas were equally susceptible to herbivory and were defoliated with equal intensity by cattle. Five-hundred crested wheatgrass (Agropryon desertorum (Fischer ex Link) Schultes) plants, distributed among 10 basal area classes, were monitored for frequency and level of utilization after approximately 74% of all plants in pastures were grazed by cattle. Plants with < 25-cm2 basal area were less likely, and plants between 65 and 105-cm2 more likely to be grazed than other classes. Ninety-one percent of the 65 to 85-cm2 basal area plants were defoliated, while only 48% of those < 2 .5 cm2 were grazed. The fact that mid-size plants occurred least often but were defoliated most often lends further credence to the selective grazing hypothesis. Less frequent use by cattle of plants < 2 5-cm2 basal area may enhance chances of seedling establishment and survival of smaller established plants or remnants of deteriorating tufts. Among grazed plants, however, smaller plants endured higher utilization by weight than the overall population. Utilization was equal among other size classes. Because forage yield per unit of basal area declined as plant size increased, cattle probably forage most efficiently by selecting bite-size plants. Researchers using single plants, tiller, or leaves as experimental units should note that varying sized tufts are not equally likely to be defoliated, and plants less than 25-cm2 basal area may receive greater than average levels of utilization from free-ranging cattle under light to moderate utilization levels. These aspects of livestock grazing behavior and research objectives should be considered in selection of experimental units.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Habitat Use by Federal Horses in the Northern Sagebrush Steppe

Distribution patterns of feral horses (Equus caballus) relative to plant communities, herbaceous production, and perennial water sources were studied from April 1979 to March 1981 in Oregon's Owyhee Breaks. Repeated observations of radio-collared and easily identified horses allowed estimation of home range sizes and documentation of the plant communities utilized. A map of plant communities was constructed, and composition and herbaceous production of key communities sampled. Time-lapse cameras monitored the daylight watering patterns of horses. One hundred thirty-three horses were initially censused and identified on the study area with the total population subsequently increasing at an annual rate of 13%. Home ranges averaged 12 km2 with the minimum convex polygon procedure and 27 km2 with the 90% confidence ellipse method. No seasonal shifts in home ranges occurred, and no correlations were detected between home range size and number of horses per band, densities of perennial water sources, or levels of forage production within home ranges. Six distinct herds were identified on the area. Only one band of horses moved from one herd to another during the 2-year study. Animals in each herd made greatest use of the most prevalent plant community, with no community being universally preferred to over another. Watering activities were most intense during the first and last periods of daylight. Horses rapidly vacated the watering areas after drinking. A seasonal trend was observed in which horses remained slightly closer to perennial water sources during warm, dry summer months than during spring periods when additional seasonal sources were available. Seasonal differences were not statistically significant, however.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202