Brown, D. E., R. D. Babb, C. Lorenzo, and M. M. Altemus. 2014. Ecology of the antelope jackrabbit (Lepus alleni). The Southwestern Naturalist 59:575-587.

thackerk1 — Thu, 20 Jun 2019 22:39:48 +0000

Authors

David E. Brown

Randall D. Babb

Consuelo Lorenzo

Maria M. Altemus

The antelope jackrabbit (Lepus alleni) is a lagomorph indicative of Neotropic savanna and thornscrub in south-central Arizona, west-central Sonora, and western Sinaloa <1,200 m elevation. We found populations in Arizona are most abundant in tropic–subtropic areas of low relief, characterized by velvet mesquite (Prosopis velutina) with an herbaceous understory (= Sonoran savanna grassland), and receiving a mean annual rainfall of between 200 and 450 mm, >90 mm of which falls as summer precipitation. In Mexico, this hare most commonly occurred in savanna grasslands or thornscrub interrupted by open areas receiving between 200 and 450 mm of precipitation per annum. Cacti were important habitat components for the hares and mean annual temperatures were >18°C with <60 d a year having temperatures below 0°C. Although sympatric with Lepus californicus over portions of its range, the two species preferred different habitats and rarely occurred together, and L. alleni was more prone to occur in groups than was L. californicus. We calculated the distributional range of L. alleni as ca. 102,000 km2 in Arizona and Mexico.

Additional Information

Ecology of the antelope jackrabbit

Date of publication:

2014

Topics

antelope jackrabbit

annual rainfall

lagomorph

habitat

cacti

distributional range

Native lagomorphs suppress grass establishment in a shrub-encroached, semiarid grassland

mmerrick — Wed, 05 Jun 2019 18:23:28 +0000

Authors

Abercrombie, S. T.

Koprowski, J. L.

Nichols, M. H.

Femhi, J. S.

Shrub encroachment into arid grasslands has been associated with reduced grass abundance, increased soil erosion, and local declines in biodiversity. Livestock over‐ grazing and the associated reduction of fine fuels has been a primary driver of shrub encroachment in the southwestern United States, but shrublands continue to persist despite livestock removal and grassland restoration efforts. We hypothesized that an herbivory feedback from native mammals may contribute to continued suppression of grasses after the removal of livestock. Our herbivore exclusion experiment in southeastern Arizona included five treatment levels and allowed access to native mammals based on their relative body size, separating the effects of rodents, lago‐morphs, and mule deer. We included two control treatments and replicated each treatment 10 times (n = 50). We introduced uniform divisions of lawn sod (Cynodon dactylon) into each exclosure for 24‐hr periods prior to (n = 2) and following (n = 2) the monsoon rains and used motion‐activated cameras to document herbivore visita‐ tions. In the pre‐monsoon trials, treatments that allowed lagomorph access had less sod biomass relative to other treatments (p < 0.001), averaging 44% (SD 36%) and 29% (SD 45%) remaining biomass after the 24‐hr trial periods. Following the onset of monsoons, differences in remaining biomass among treatments disappeared. Desert cottontails (Sylvilagus audubonii) were detected more frequently than any of the other 11 herbivore species present at the site, accounting for 83% of detections dur‐ ing the pre‐monsoon trials. Significantly more (p < 0.001) desert cottontails were de‐ tected during the pre‐monsoon trials (2,077) compared to the post‐monsoon trials (174), which coincided with biomass removal from lagomorph accessible treatments. We conclude that desert cottontails are significant consumers of herbaceous vegeta‐ tion in shrub‐encroached arid grasslands and they, along with other native herbi‐ vores, may act as a biotic feedback contributing to the competitive advantage and persistence of shrubs.