@article {JRN55292, title = {Shrub encroachment, landscape restoration, and intraguild predation}, journal = {Journal of Arid Environments }, volume = {193}, year = {2021}, month = {July 10, 2021}, abstract = {Shrub encroachment into arid grasslands occurs globally with the potential to affect vertebrates and their interactions. In the Chihuahuan Desert of southern New Mexico, shrub encroachment has prompted intensive efforts by land management agencies to remove shrubs and restore historical grassland habitats. We asked if restoration actions involving shrub removal affected dynamics of intraguild predation (IGP) including an IGP predator (coyote, Canis latrans), an IGP prey (kit fox, Vulpes macrotis), plus their shared lagomorph prey. We used camera traps on 14 sites with paired treated and untreated areas to examine spatial and temporal niche partitioning of coyotes and kit foxes. Shrub removal did not produce straightforward effects on abundances of coyotes, kit foxes, or their prey resources. Instead, abundances of kit foxes were constrained when coyote abundance reached a threshold. Below this threshold, kit foxes were more common on areas with low shrub cover, possibly due to lack of hiding cover for lagomorph prey that increased their predation risk. Our system included two alternative states: IGP predator dominated and coexistence of IGP predator and prey. Coexistence may have been facilitated by temporal niche partitioning as diel activity patterns differed for coyotes and kit foxes. Future research on intraguild predation should integrate spatial and temporal niches to understand species coexistence including on dynamic landscapes undergoing restoration.}, keywords = {Canis latrans, Chihuahuan Desert, Diel activity, Intraguild predation, shrub encroachment, Valupes microtis}, doi = {10.1016/j.jaridenv.2021.104588}, url = {files/bibliography/21-026.pdf}, author = {Robert L. Schooley and Brandon T Bestelmeyer and John M. Coffman and Casey Wagnon} } @article {JRN54901, title = {Shrub encroachment, productivity pulses, and core-transient dynamics of Chihuahuan Desert rodents}, journal = {Ecosphere}, volume = {9}, year = {2018}, month = {07/2018}, pages = {Article e02330}, abstract = {

Drylands worldwide are experiencing shrub encroachment into grasslands with potential consequences for biodiversity and ecosystem services. Climate change could increase the rate of shrub encroachment, amplify precipitation variability, and thus alter bottom-up processes for animal communities. Desert rodents are important biodiversity elements of arid grasslands and shrublands that exert strong effects on soil, vegetation, and other animal species. We used long-term data from the Jornada Basin Long Term Ecological Research site in the Chihuahuan Desert of southern New Mexico to ask whether bottomup control of desert rodents changes across shrub encroachment gradients. Our design included spatial blocks with replicated ecological states representing transitions from black grama (Bouteloua eriopoda) to honey mesquite (Prosopis glandulosa). Grassland-to-shrubland transitions did not produce degraded ecosystems, on average, with reduced net primary production or decreased rodent biomass. However, more rodent biomass was supported on unencroached grasslands following droughts whose frequency and severity may increase in southwestern United States. Hence, the observed evenness in rodent biomass across ecological states should be sensitive to climate change. The best predictors of rodent biomass also differed markedly for two trophic groups. This outcome was explained by considering core-transient dynamics. Granivores were mostly core species that regularly occurred on sites and responded to lagged net primary production at local scales, whereas folivores included transient species (especially Sigmodon hispidus) that responded to lagged precipitation at broader scales via spillover dynamics. Bottom-up processes for desert rodents across shrub invasion gradients were understood by integrating lagged responses to productivity pulses with core-transient structuring of communities.

}, keywords = {bottom-up control, Chihuahuan Desert, net primary production, precipitation variability, prosopis glandulosa, rodent communities, shrub encroachment, Special Feature: Dynamic Deserts}, doi = {e02330. 10.1002/ecs2.2330}, url = {files/bibliography/18-009.pdf}, author = {Robert L. Schooley and Brandon T Bestelmeyer and A. Campanella} } @article {50825, title = {Spatial patterns, density dependence, and demography in the harvester ant, Pogonomyrmex rugosus, in semi-arid grasslands}, journal = {Journal of Arid Environments}, volume = {53}, year = {2003}, note = {//NONE//NONE//}, month = {2003}, pages = {183-196}, abstract = {To evaluate the relationship between the local spacing patterns of ant colonies and the broad-scale heterogeneity typical of real landscapes, we examine the spacing of colonies of harvester ants (Pogonomyrmex rugosus) on 12 1-ha plots in semi-arid grasslands at the Sevilleta National Wildlife Refuge in New Mexico. We linked land use and topography to colony densities and local spacing patterns, tested the theoretical prediction that regularity should be positively correlated with colony density, and determined the spatial scale of density-dependent recruitment. In general, colonies were regularly spaced at a fine scale. We caution that broad-scale aggregation of colonies can conceal fine-scale regularity. The prediction of density-dependent spacing was supported only within a single topographic position, but not across the entire landscape. Recruitment of new colonies was independent of plot-level densities but depended on locations of established colonies within plots. Landscape heterogeneity can influence the fine-scale spacing of ant colonies, both directly and indirectly, complicating predictions regarding density-dependent spacing. {\textcopyright}2002 Elsevier Science Ltd.}, keywords = {ant colony, density-dependent spacing, ant, colony distribution, ant, demography, ant, harvester, ant, Pogonomyrmex, ant, recruitment, article, articles, demography,ants, journal, journals}, author = {Robert L. Schooley and J.A. Wiens} } @article {JRN54298, title = {Dispersion of kangaroo rat mounds at multiple scales in New Mexico, USA}, journal = {Landscape Ecology}, volume = {6}, year = {2001}, pages = {267-277}, author = {Robert L. Schooley and J.A. Wiens} } @article {51118, title = {Influence of small-scale disturbances by kangaroo rates on Chihuahuan Desert ants}, journal = {Oecologia}, volume = {125}, year = {2000}, month = {2000}, pages = {142-149}, abstract = {Banner-tailed kangaroo rats (Dipodomys spectabilis) are prominent ecosystem engineers that build large mounds that influence the spatial structuring of fungi, plants, and some ground-dwelling animals. Ants are diverse and functionally important components of arid ecosystems; some species are also ecosystem engineers. We investigated the effects of patch disturbances created by D. spectabilis mounds on ant assemblages in a Chihuahuan Desert grassland in southern New Mexico by using pitfall traps in a paired design (mound vs matrix). Although the distrubances did not alter species richness or harbor unique ant communities relative to the matrix, they did alter species composition; the abundances of 6 of 26 species were affected. The distrubances might also act to disrupt spatial patterning of ants caused by other environmental gradients. In contrast to previous investigations of large-scale disturbances, we detected no effects of the disturbances on ants at the fucntional-group level. Whether ant communities respond to disturbance at a functional-group or within-functional-group level may depend on teh size and intersity fo the disturbance useful function-group schemes also may be scale-dependent, however, or species may respond idiosyncratically. Interactions between distrubance-generating ammmals and ants may produce a nested spatial structure of patches.}, keywords = {disturbances, ecosystem engineers, formicidae, heteromyidae, spatial scale}, url = {/files/bibliography/00-022.pdf}, author = {Robert L. Schooley and Brandon T Bestelmeyer and J.F. Kelly} } @article {51120, title = {Movements during colony founding by queens of the honeypot ant (Myrmecocystus mimicus Wheeler)}, journal = {American Midland Naturalist}, volume = {144}, year = {2000}, note = {//USDA//LTER IV//}, month = {2000}, pages = {439-444}, abstract = {

Habitat selection by ant queens has been little studied even though it may be a critical component of colony founding. We describe the movement pathways of honey ant queens (Myrmecocystus mimicus Wheeler) searching for sites on the ground to initiate nests. Typical paths may include segments of directional movement that are interrupted by segments of area-restricted search. Mechanisms producing area-restricted search might include variable step lengths and looping behavior. Cues that prompt the switch to local search remain undetected.

}, keywords = {ant community, grazing effects, ant, biodiversity, ant, honeypot, ant, Myrmecocystus mimicus, ants, habitat selection, article, articles, grazing, ant communities, habitat preference, ants, journal, journals}, doi = {10.1674/0003-0031(2000)144[0439:MDCFBQ]2.0.CO;2}, url = {files/bibliography/JRN00306.pdf}, author = {Robert L. Schooley and Brandon T Bestelmeyer} }