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Milnesium Lagniappe, A New Species Of Water Bear (Tardigrada, Eutardigrada, Apochela, Milnesiidae) From The Southern United States, Harry A. Meyer, Juliana G. Hinton, Maria C. Dupré
Milnesium Lagniappe, A New Species Of Water Bear (Tardigrada, Eutardigrada, Apochela, Milnesiidae) From The Southern United States, Harry A. Meyer, Juliana G. Hinton, Maria C. Dupré
Western North American Naturalist
Over 200 species of freshwater and terrestrial water bears (phylum Tardigrada) are known to occur in North America. Of these, 20 species have been recorded in Louisiana. Foliose and fruticose lichen and moss samples collected in 2011 in the city of Lake Charles and in Sam Houston Jones State Park, Calcasieu Parish, Louisiana, USA, were stored in paper envelopes and later soaked in tap water overnight. Tardigrade specimens and eggs were extracted and mounted in polyvinyl lactophenol. The samples contained a new species of tardigrade. Milnesium lagniappe sp. n. has claw formula [2-3]-[3-2] and 9 sculptured bands in the dorsal …
Effects Of Male Size On Searching Behaviors In The Sun Dance Of Bembix, David A. Tanner, James P. Pitts
Effects Of Male Size On Searching Behaviors In The Sun Dance Of Bembix, David A. Tanner, James P. Pitts
Western North American Naturalist
Males of solitary wasp species are faced with the task of locating potential mates, a task made more difficult by inconspicuous females and a landscape seemingly devoid of landmarks. Males may employ a variety of strategies to locate females. In this study, we test for variation among males within the sun dance of Bembix. We show that males ofBembix americana spinolae Lepeletier behave differently within the sun dance and that these differences can be predicted by the size of the male. We show that large males spend more time at “rest” and require a greater number of male–male contacts …
Ecology And Population Dynamics Of Sclerocactus Mesae-Verdae (Boissev. & C. Davidson) L.D. Benson, Janet J. Coles, Karin L. Decker, Tamara S. Naumann
Ecology And Population Dynamics Of Sclerocactus Mesae-Verdae (Boissev. & C. Davidson) L.D. Benson, Janet J. Coles, Karin L. Decker, Tamara S. Naumann
Western North American Naturalist
The population dynamics of Sclerocactus mesae-verdae were documented annually in 3 plots over 20 years in southwestern Colorado. Demographic studies of this duration are rare but they are necessary to gain a more accurate estimate of population trends in long-lived desert species. Sclerocactus mesae-verdae was federally listed as threatened in 1979; this study was initiated in 1986 with the objective of determining whether Colorado populations were growing, declining, or stable. Data collected yearly around 1 May included diameter, vigor, and flower/fruit counts for 1629 stems belonging to 659 plants. We used regression analysis to estimate the mean, variance, and average …
Foliar Ozone Injury On Cutleaf Coneflower At Rocky Mountain National Park, Colorado, Robert Kohut, Colleen Flanagan, James Cheatham, Ellen Porter
Foliar Ozone Injury On Cutleaf Coneflower At Rocky Mountain National Park, Colorado, Robert Kohut, Colleen Flanagan, James Cheatham, Ellen Porter
Western North American Naturalist
Surveys for foliar ozone injury on cutleaf coneflower, spreading dogbane, and quaking aspen were conducted in Rocky Mountain National Park, Colorado, from 2006 through 2010. Foliar injury in the form of ozone stipple was found on coneflower each year. The incidence of injured plants on sites with injury ranged from 5% to 100%. The severity of injury on affected foliage was generally <4% but occurred on some leaves at a level greater than 12% in 3 years and in 1 year on 1 plant at a level >75%. No foliar ozone injury was found on spreading dogbane or quaking aspen in any year of the survey. This is the first documentation of ozone injury on vegetation in Rocky Mountain National Park. While ozone has long …
Antibody Seroprevalence To Hantaviruses In Rodents From Reserva De La Biosfera Sierra De Huatla, Morelos, Elizabeth Arellano, Iván Castro-Arellano, Gerardo Suzán, Francisco X. González-Cózatl, Ricardo Morales Jiménez
Antibody Seroprevalence To Hantaviruses In Rodents From Reserva De La Biosfera Sierra De Huatla, Morelos, Elizabeth Arellano, Iván Castro-Arellano, Gerardo Suzán, Francisco X. González-Cózatl, Ricardo Morales Jiménez
Western North American Naturalist
No abstract provided.
Obituary: Wilmer Webster Tanner, 1909–2011, Stanley L. Welsh
Obituary: Wilmer Webster Tanner, 1909–2011, Stanley L. Welsh
Western North American Naturalist
Wilmer Webster Tanner, 1909–2011
Greater Sage-Grouse Movements And Habitat Use During Winter In Central Oregon, Jennifer R. Bruce, W. Douglas Robinson, Steven L. Petersen, Richard F. Miller
Greater Sage-Grouse Movements And Habitat Use During Winter In Central Oregon, Jennifer R. Bruce, W. Douglas Robinson, Steven L. Petersen, Richard F. Miller
Western North American Naturalist
Greater Sage-Grouse (Centrocercus urophasianus) depend on sagebrush habitat for food and cover during winter, yet few sage-grouse winter ecology studies have been conducted. During January and February 2007, we monitored 22 radio-collared sage-grouse (7 females and 15 males) in central Oregon to characterize winter habitat use and movement patterns. We estimated distances traveled between locations on a weekly basis and quantified habitat characteristics at locations used by male and female sage-grouse. The birds we collared moved extensively across the landscape, using approximately 1480 km2. Sagebrush canopy height in sites used by sage-grouse varied from 0.25 to …
The Relationships Among Plant Cover, Density, Seed Rain, And Dispersal Of Bromus Tectorum In High-Elevation Populations, Andrew R. Kanarek, Rebecca Hufft Kao
The Relationships Among Plant Cover, Density, Seed Rain, And Dispersal Of Bromus Tectorum In High-Elevation Populations, Andrew R. Kanarek, Rebecca Hufft Kao
Western North American Naturalist
The invasive species Bromus tectorum L. is recognized as one of the most ecologically and economically devastating weeds in the western United States. Although B. tectorumhas been studied extensively, few studies have examined its dispersal and spread. We collected data from sites with B. tectorum in and around Rocky Mountain National Park to quantify the relationships between plant cover/density and seed rain and dispersal distance. Results suggest that there is a positive relationship between density within a patch and local seed rain and that B. tectorum exhibits relatively limited short-distance dispersal (where seeds fell in close proximity to plants …
Rabbit Abundance Relative To Rainfall And Plant Production In Northern Chihuahuan Desert Grassland And Shrubland Habitats, David C. Lightfoot, Ana D. Davidson, Christopher M. Mcglone, Dara G. Parker
Rabbit Abundance Relative To Rainfall And Plant Production In Northern Chihuahuan Desert Grassland And Shrubland Habitats, David C. Lightfoot, Ana D. Davidson, Christopher M. Mcglone, Dara G. Parker
Western North American Naturalist
No abstract provided.
Desiccation Sensitivity And Heat Tolerance Of Prunus Ilicifolia Seeds Dispersed By American Black Bears (Ursus Americanus), Mark Borchert, Claudia M. Tyler
Desiccation Sensitivity And Heat Tolerance Of Prunus Ilicifolia Seeds Dispersed By American Black Bears (Ursus Americanus), Mark Borchert, Claudia M. Tyler
Western North American Naturalist
Carnivore consumption of fruit is a principle means by which many fleshy-fruited plant species achieve long-distance seed dispersal. We examined carnivore dispersal of hollyleaf cherry (Prunus ilicifolia) seeds, specifically assessing the survival, desiccation sensitivity, and germination of seeds found in bear scats. Studies were conducted both in the laboratory and in 2 burn areas in Los Padres National Forest, California. Bear scats containing P. ilicifolia seeds were collected in burned and unburned chaparral. We counted seeds in each scat and noted whether endocarps had tooth punctures or rattled audibly when shaken. For comparative germination trials, we also collected …
Nesting Ecology Of Yellow Warblers (Dendroica Petechia) In Montane Chaparral Habitat In The Northern Sierra Nevada, Diana L. Humple, Ryan D. Burnett
Nesting Ecology Of Yellow Warblers (Dendroica Petechia) In Montane Chaparral Habitat In The Northern Sierra Nevada, Diana L. Humple, Ryan D. Burnett
Western North American Naturalist
The Yellow Warbler (Dendroica petechia) is considered a riparian specialist in much of western North America, but in California it also breeds in a second habitat type: montane chaparral of the Sierra Nevada and southern Cascades. We monitored Yellow Warbler nests in montane chaparral and assessed their poorly known nesting ecology in this habitat. We also conducted point counts in upland habitat throughout the region. We determined habitat associations for Yellow Warblers based on nest site and point-count vegetation data; nests were predominantly in bush chinquapin (Chrysolepis sempervirens) and greenleaf manzanita (Arctostaphylos patula), and …
A Late-Pleistocene/Holocene Biotic Community From Marmot End Alcove, Escalante River Basin, Colorado Plateau, Usa, Manny Kropf
A Late-Pleistocene/Holocene Biotic Community From Marmot End Alcove, Escalante River Basin, Colorado Plateau, Usa, Manny Kropf
Western North American Naturalist
Skeletal remains of the extinct mountain goat Oreamnos harringtoni and Marmota (marmot), an extralimital species, were recovered from Marmot End Alcove along with remains of montane plants that included Pseudotsuga menziesii (Douglas-fir), Picea (spruce), Pinus flexilis (limber pine), and Juniperus communis (common juniper). The alcove is located in Harris Wash, a semiarid tributary in an unstudied portion of the Escalante River Basin on the Colorado Plateau in southern Utah. A Marmota incisor tooth and montane plant needles returned late Pleistocene AMS dates ranging from 12,300 yr BP to 15,600 yr BP.
Present Effects Of Past Wildfires On Leaf Litter Breakdown In Stream Ecosystems, Peter Koetsier, Teresa R. B. Krause, Quenton M. Tuckett
Present Effects Of Past Wildfires On Leaf Litter Breakdown In Stream Ecosystems, Peter Koetsier, Teresa R. B. Krause, Quenton M. Tuckett
Western North American Naturalist
We investigated the present effects from a 10-year-old wildfire on leaf litter breakdown rates in 3 headwater streams in central Idaho. These systems experienced a massive debris flow one year after the fire. Based on soil instability and burn patterns, we identified 3 stream conditions: unburned, burned only, and burned/scoured. We placed leaf bags containing willow leaves (Salix sp.) in each stream type and removed bags at various time intervals until all bags were collected 100 days after their introduction. Leaf material was dried and weighed, and decay rate coefficients were calculated. Macroinvertebrates colonizing the bags were enumerated and …
Pollen Evidence Of Historical Forest Disturbance On The Wasatch Plateau, Utah, Jesse L. Morris, Andrea R. Brunelle, A. Steven Munson
Pollen Evidence Of Historical Forest Disturbance On The Wasatch Plateau, Utah, Jesse L. Morris, Andrea R. Brunelle, A. Steven Munson
Western North American Naturalist
Environmental indicators from lake sediments provide excellent opportunities to improve understanding of forest disturbance processes and corresponding changes in forest composition. Our research provides a methodology for assessing recent, historic, and prehistoric disturbances using lacustrine sediment records. We collected sediment cores from Blue Lake, a small subalpine lake on the Wasatch Plateau in central Utah. These cores record environmental changes caused by both spruce beetle (Dendroctonus rufipennis Kirby) and human (logging and livestock grazing) modification. We observed deteriorated insect remains in the lake sediments. These remains correspond temporally with a historic spruce beetle outbreak, though alkaline conditions in the …
Large-Scale Effects On Bird Assemblages In Desert Grasslands, Giselle Block, Michael L. Morrison
Large-Scale Effects On Bird Assemblages In Desert Grasslands, Giselle Block, Michael L. Morrison
Western North American Naturalist
During winter 1996–1997 and summer 1997, we surveyed birds at 26 study sites in desert grasslands of Arizona and New Mexico to determine tolerance of birds to variability in plant composition and structure. The relationship between bird abundance and vegetative characteristics might be an important consideration in the development of management and restoration plans. Of the 49 bird species we observed, we examined 13 and 16 species in detail for winter and summer seasons, respectively. A noticeable shift in species composition occurred between 3% and 10% woody plant cover. During winter, Chestnut-collared Longspurs (Calcarius ornatus) and Horned Larks …
Avian Use Of Harvested Crop Fields In North Dakota During Spring Migration, Alegra M. Galle, George M. Linz, H. Jeffrey Homan, William J. Bleier
Avian Use Of Harvested Crop Fields In North Dakota During Spring Migration, Alegra M. Galle, George M. Linz, H. Jeffrey Homan, William J. Bleier
Western North American Naturalist
Broad-spectrum herbicide applications and improved harvesting efficiency of crops have reduced the availability of weed seeds and waste grains for game and nongame wildlife. Over the last decade, corn and soybean plantings have steadily increased in the Prairie Pothole Region (PPR) of North Dakota, while sunflower plantings have declined. The PPR is an important corridor for migratory birds, and changes in food availabilities at stopover habitats may affect how food resources are used. In early spring 2003 and 2004, we compared bird use of harvested fields of sunflower, soybeans, small grains, and corn in the PPR of North Dakota. Across …
Arthropod And Plant Communities As Indicators Of Land Rehabilitation Effectiveness In A Semiarid Shrubsteppe, Eric T. Gardner, Val J. Anderson, Robert L. Johnson
Arthropod And Plant Communities As Indicators Of Land Rehabilitation Effectiveness In A Semiarid Shrubsteppe, Eric T. Gardner, Val J. Anderson, Robert L. Johnson
Western North American Naturalist
We describe a case study evaluating the ecological impact of Bromus tectorum L. (cheatgrass) invasion following fire disturbance and the effectiveness of revegetation as a means of rehabilitation in a degraded semiarid shrubsteppe system. The effectiveness of rehabilitation efforts was assessed relative to arthropod richness, vegetation and arthropod community composition, and ground-cover characteristics in 3 habitats: undisturbed, burned and weed infested (B. tectorum), and burned then rehabilitated with native and nonnative vegetation. Arthropods were collected in each habitat using pitfall traps. Differences in arthropod richness were compared using rarefaction curves. Nonmetric multidimensional scaling and nonparametric multivariate statistical procedures, …
Population Ecology And Reproduction Of The Mexican Mud Turtle (Kinosternon Integrum) In Tonatico, Estado De México, Rodrigo Macip-Ríos, Maria De Lourdes Arias Cisneros, Xochitl S. Aguilar-Miguel, Gustavo Casas-Andreu
Population Ecology And Reproduction Of The Mexican Mud Turtle (Kinosternon Integrum) In Tonatico, Estado De México, Rodrigo Macip-Ríos, Maria De Lourdes Arias Cisneros, Xochitl S. Aguilar-Miguel, Gustavo Casas-Andreu
Western North American Naturalist
Ecological data directly from the field are important in understanding the life history strategies of kinosternid species in the tropics. Herein we summarize the basic population ecology and life history of Kinosternon integrum in the municipality of Tonatico (southeastern Estado de México, México). From October 2003 to November 2004, we marked a total of 204 turtles and recaptured 118 of them. Mean population size using the Jolly-Seber model was 197 (95% CI 128–416) individuals, with a sex ratio of 1:1.7, biased to females. Males were larger than females in carapace length and plastron length. The reproductive season starts in late …
Note On The Occurrence Of Siphlonurus Autumnalis (Ephemeroptera: Siphlonuridae) In A Montana Spring Brook, Robert L. Newell, Michelle L. Anderson
Note On The Occurrence Of Siphlonurus Autumnalis (Ephemeroptera: Siphlonuridae) In A Montana Spring Brook, Robert L. Newell, Michelle L. Anderson
Western North American Naturalist
The little-known mayfly Siphlonurus autumnalis McDunnough (Ephemeroptera: Siphlonuridae) was collected from several locations in its floodplain habitats along the Middle Fork of the Flathead River in western Montana. To confirm identification, nymphs were reared along with an associated species, S. occidentalis Eaton (Ephemeroptera: Siphlonuridae). Adults emerged from 6 September until 16 October. Habitats are described and the first photos of the 2 sexes are provided.
Distribution Records And Comments On Mammals In Western South Dakota, Steven G. Platt, Zannita Fast Horse, Thomas R. Rainwater, Stanlee M. Miller
Distribution Records And Comments On Mammals In Western South Dakota, Steven G. Platt, Zannita Fast Horse, Thomas R. Rainwater, Stanlee M. Miller
Western North American Naturalist
The mammal fauna of western South Dakota is imperfectly known; in particular there is a notable paucity of data from Indian reservations in the region. We collected mammals from January 2003 through May 2006 using a variety of standard methodologies, including trapping with snap-traps and Macabee traps, shooting, and salvaging road- and hunter-killed animals. Herein we provide 23 specimen-based county records representing 17 species of mammals. In addition, a photo record constitutes the first report of Dasypus novemcinctus from South Dakota and the northernmost record in the United States. The possible local extirpation of Marmota flaviventris in the southern Black …
Ectoparasites Of The Occult Bat, Myotis Occultus (Chiroptera: Vespertilionidae), Ernest W. Valdez, Christopher M. Ritzi, John O. Whitaker Jr.
Ectoparasites Of The Occult Bat, Myotis Occultus (Chiroptera: Vespertilionidae), Ernest W. Valdez, Christopher M. Ritzi, John O. Whitaker Jr.
Western North American Naturalist
Only a single previous study has examined ectoparasites of the occult bat (Myotis occultus), from which only 2 species of fleas were identified. For our study, we examined 202 individuals, 52 fresh hosts and 150 museum specimens, from New Mexico and southern Colorado for ectoparasites. We recorded 2158 ectoparasites, 634 from fresh hosts and 1524 from museum specimens. Ectoparasites belonged to 10 families and 13 genera of insect or acari and represent new host and locality records. In general, ectoparasites collected from fresh hosts and museum specimens were represented by 4 major species of mite: Macronyssus crosbyi, Alabidocarpus …
Large, Wetland-Associated Mayflies (Ephermeroptera) Of Glacier National Park, Montana, Robert L. Newell, Blake R. Hossack
Large, Wetland-Associated Mayflies (Ephermeroptera) Of Glacier National Park, Montana, Robert L. Newell, Blake R. Hossack
Western North American Naturalist
We describe species richness and habitat associations of mayflies (Ephemeroptera) collected during amphibian surveys of 355 water bodies in Glacier National Park (NP), Montana, in 2006–2008. We collected 9 taxa (in 7 genera) of mayflies that were identifiable to species. Callibaetis ferrugineus hageni was collected most frequently, followed by Siphlonurus occidentalis, S. phyllis, Ameletus celer, A. similior, Parameletus columbiae, Ephemerella dorothea infrequens, Baetis bicaudatus, and Leptophlebia cupida. Siphlonurus phyllis had not been reported in the western United States prior to our surveys, and P. columbiae is a species of concern in the region. The identifications of 4 additional taxa were …
Camel Spider (Solifugae) Use Of Prairie Dog Colonies, B. D. Duval, W. G. Whitford
Camel Spider (Solifugae) Use Of Prairie Dog Colonies, B. D. Duval, W. G. Whitford
Western North American Naturalist
Solifugids (camel spiders) are widespread throughout arid regions of western North America and are thought to be important in structuring desert arthropod communities. Despite the ubiquity of camel spiders, little is known about their ecology. Black-tailed prairie dogs (Cynomys ludovicianus) are also widespread in western North America and are important ecosystem engineers, but they have been reduced in extent because of human activity. Here we report significantly greater numbers of camel spiders on black-tailed prairie dog colonies in southern New Mexico. The difference in vegetation structure created by prairie dog activity is likely the reason for the increased …
Regional And Seasonal Diet Of The Western Burrowing Owl In South Central Nevada, Derek B. Hall, Paul D. Greger, Jeffrey R. Rosier
Regional And Seasonal Diet Of The Western Burrowing Owl In South Central Nevada, Derek B. Hall, Paul D. Greger, Jeffrey R. Rosier
Western North American Naturalist
We examined diets of Western Burrowing Owls (Athene cunicularia hypugaea) based on contents of pellets and large prey remains collected year-round at burrows in each of the 3 regions in south central Nevada (Mojave Desert, Great Basin Desert, and Transition region). The most common prey items, based on percent frequency of occurrence, were crickets and grasshoppers, beetles, rodents, sun spiders, and scorpions. The most common vertebrate prey was kangaroo rats (Dipodomys spp.). True bugs (Hemiptera), scorpions, and western harvest mice (Reithrodontomys megalotis) occurred most frequently in pellets from the Great Basin Desert region. Kangaroo rats …
Assessing Cheatgrass (Bromus Tectorum) Genetic Diversity And Population Structure Using Rapd And Microsatellite Molecular Markers, Michael C. Ashley, William S. Longland
Assessing Cheatgrass (Bromus Tectorum) Genetic Diversity And Population Structure Using Rapd And Microsatellite Molecular Markers, Michael C. Ashley, William S. Longland
Western North American Naturalist
Two molecular marker systems, random amplified polymorphic DNA (RAPD) and microsatellites, were used to evaluate population diversity and differentiation in 4 northern Nevada Bromus tectorum populations. From 80 RAPD primers, we found 16 (20%) that yielded 165 strong repeatable bands. Of those bands, 60 (35.8%) were polymorphic. Of those, 21 met data-pruning guidelines for final analysis. RAPD variation was moderate (x̄ = 0.363, sx̄ = 0.022), ranging from 0.312 to 0.404. Microsatellite variation was similar (x̄ = 0.234, sx̄ = 0.051) but varied more widely, ranging from 0.009 to 0.551. All populations were out of Hardy-Weinberg …
Relationship Between Cheatgrass Coverage And The Relative Abundance Of Snakes On Antelope Island, Utah, Lucas K. Hall, John F. Mull, John F. Cavitt
Relationship Between Cheatgrass Coverage And The Relative Abundance Of Snakes On Antelope Island, Utah, Lucas K. Hall, John F. Mull, John F. Cavitt
Western North American Naturalist
Cheatgrass (Bromus tectorum) is an invasive annual known to negatively impact many shrub-dependent organisms; however, relatively little research has examined how it affects snake communities. Bromus tectorum is abundant at Antelope Island State Park, Davis County, Utah, and could be a possible threat to snake populations. Study sites representing different B. tectorum coverage percentages were established to measure relative abundance of snakes. Snakes were captured from June to September 2005 primarily by using funnel traps attached to drift-fence arrays. Linear regression revealed a negative relationship between B. tectorum coverage (%) and the relative abundance of the Great Basin …
Influence Of Pocket Gopher Mounds On Nonnative Plant Establishment In A Shrubsteppe Ecosystem, G. Page Kyle, Andrew Kulmatiski, Karen H. Beard
Influence Of Pocket Gopher Mounds On Nonnative Plant Establishment In A Shrubsteppe Ecosystem, G. Page Kyle, Andrew Kulmatiski, Karen H. Beard
Western North American Naturalist
Soil disturbances across a wide range of spatial scales have been found to promote the establishment of invasive plant species. This study addresses whether mounds built by northern pocket gophers (Thomomys talpoides) in the shrubsteppe environment of north central Washington are facilitating plant invasions into native-dominated fields. Research was conducted in native-dominated plant communities adjacent to ex-arable, nonnative-dominated fields. To determine the effect of mounds on plant growth, we recorded new establishment and persistence of all plant species over 2 growing seasons on 10–19 mound and intermound areas in 10 fields. Nonnative plant establishment was not affected by …
Use Of A Mine By Eastern Pipistrelles (Perimyotis Subflavus) In East Central Nebraska, Jason P. Damm, Keith Geluso
Use Of A Mine By Eastern Pipistrelles (Perimyotis Subflavus) In East Central Nebraska, Jason P. Damm, Keith Geluso
Western North American Naturalist
The eastern pipistrelle (Perimyotis subflavus) is relatively common and widespread throughout the eastern United States. In recent decades, the distribution of P. subflavus has expanded westward across the Great Plains, and little information exists on its natural history in this region. In east central Nebraska, we monitored the use of a mine by eastern pipistrelles for >1 year. A few males occupied the roost in summer, but during the period of hibernation (late September–early May), the mine was used by at least 30 individuals composed of both sexes. Most individuals first entered the mine during late September through …
Demography Of The Yarrow's Spiny Lizard, Sceloporus Jarrovii, From The Central Chihuahuan Desert, Héctor Gadsden, José L. Estrada-Rodríguez
Demography Of The Yarrow's Spiny Lizard, Sceloporus Jarrovii, From The Central Chihuahuan Desert, Héctor Gadsden, José L. Estrada-Rodríguez
Western North American Naturalist
The demography of a population of Yarrow's spiny lizard, Sceloporus jarrovii, was examined from 2004 to 2006 in the canyon Las Piedras Encimadas, located in Gomez Palacio, Durango, México. Lizards were studied using a mark-recapture technique. Reproduction in females occurred between November and May, coinciding with dry conditions. Reproductive activity was highest (percent of females with vitellogenic follicles or embryos) in the middle of the dry season (November and December). Thirteen percent of females reached sexual maturity at an average age of 8.5 months. The population structure was similar in spring and fall, but not in summer. A notable …
Geographic Patterns Of Ground-Dwelling Arthropods Across An Ecoregional Transition In The North American Southwest, David C. Lightfoot, Sandra L. Brantley, Craig D. Allen
Geographic Patterns Of Ground-Dwelling Arthropods Across An Ecoregional Transition In The North American Southwest, David C. Lightfoot, Sandra L. Brantley, Craig D. Allen
Western North American Naturalist
We examined the biogeographic patterns of ground-dwelling arthropod communities across a heterogeneous semiarid region of the Southern Rio Grande Rift Valley of New Mexico. Our 3 sites included portions of 5 ecoregions, with the middle site a transition area where all ecoregions converged. We addressed the following 3 questions: (1) Do the species assemblage patterns for ground arthropods across habitats and sites conform to recognized ecoregions? (2) Are arthropod assemblages in distinct vegetation-defined habitats within an ecoregion more similar to each other or to assemblages in similar vegetation-defined habitats in other ecoregions? (3) Is there a detectable edge effect with …