Composition of forest stands used by White-headed Woodpeckers for nesting in Washington

In this study, I examined the composition of managed ponderosa pine ( Pinus ponderosa ) forests used by nesting White-headed Woodpeckers ( Picoides albolarvatus ) along the eastern slope of the Cascade Range in Washington. I sampled trees and snags using the point-centered quarter method to assess species composition, tree and snag density, and stand basal area in 16 forest stands containing White-headed Woodpecker nests. All stands had a history of timber management and 2 had been burned and salvage-logged. Mean live-tree density (≥10.16 cm dbh) was 182.3 trees · ha –1 (SE = 13.52), mean snag density (≥10.16 cm dbh) was 11.5 snags · ha –1 (SE = 1.92), and mean stand basal area was 17.2 m 2 · ha –1 (SE = 1.58). Ponderosa pine had the highest importance value (mean = 220.9, SE = 17.25) of any tree species in all but 2 stands. Mean dbh of ponderosa pines was 33.0 cm (SE = 0.26) and ranged from 26.1 to 50.2 cm within stands. Mean density of ponderosa pine was greatest in the 20.3–30.5 cm dbh size class and lowest in the 50.8–61.0 cm and >61.0 cm dbh size classes. Tree density was up to 5.3 times greater than densities believed to be typical of ponderosa pine forests prior to fire suppression. Snag densities were within the range estimated for historical dry forests of the eastern Cascades, yet only 50% of all snags sampled had a dbh >25.4 cm. Although White-headed Woodpeckers are considered strongly associated with old-growth ponderosa pine, my results suggest that they may be more adaptable to using forests dominated by smaller diameter trees. En este estudio, examiné la composición de los bosques manejados de pino ponderosa ( Pinus ponderosa ), utilizados para anidamiento por el pájaro carpintero cabeciblanco ( Picoides albolarvatus ), a lo largo de la vertiente oriental de la cordillera Cascade del Estado de Washington. Muestreé árboles vivos y muertos usando el método de cuadrantes al punto central en 16 rodales con nidos del pájaro carpintero cabeciblanco para evaluar la composición de especies, la densidad de árboles vivos y muertos y el área basal del rodal. Todas las áreas tenían una historia de manejo maderable y 2 habían sido quemadas y taladas para recuperar madera. La densidad promedio de árboles vivos (≥10.16 cm DAP) fue 182.3 árboles · ha –1 (DE = 13.52), la densidad promedio de árboles muertos (≥10.16 cm DAP) fue 11.5 árboles muertos · ha –1 (DE = 1.92) y el área basal promedio de los rodales fue 17.2 m 2 · ha –1 (DE = 1.58). El pino ponderosa tuvo el valor de importancia más alto (promedio = 220.9, DE = 17.25) de las especies de árboles en todos, menos 2 rodales. El DAP promedio de los pinos ponderosa fue 33.0 cm (DE = 0.26) y variaba de 26.1 a 50.2 cm dentro de rodales. La densidad promedio del pino ponderosa fue la mayor en la clase de 20.3–30.5 cm DAP y menor de las clases de 50.8–61.0 cm y >61.0 cm DAP. La densidad de árboles fue hasta 5.3 veces mayor que las consideradas típicas para bosques de pino ponderosa antes de la intervención para prevenir incendios. Las densidades de árboles muertos estuvo dentro del rango estimado para los bosques secos históricos del oriente de la cordillera Cascade, no obstante sólo 50% de los árboles muertos muestreados tuvieron un DAP >25.4 cm. Aunque se considera que los pájaros carpinteros cabeciblancos están estrechamente asociados con bosques primarios de pino ponderosa, mis resultados sugieren que podrían ser más adaptados a usar bosques donde predominan árboles de diámetro menor.     

Cryptogams, vascular plants, and soil hydrological relations: some preliminary results from the semiarid woodlands of eastern Australia

Grazed and ungrazed sites were examined in a semiarid woodland in eastern Australia to determine relationships within various types of cryptogams, and the role of cryptogams in pasture dynamics, infiltration, and water erosion. Strong relationships were found between vascular plant cover and cover of cryptogams for nine rangeland sites over an 18-month period. In the absence of vascular plants, sites with low cover of cryptogams were dominated by algae. The presence of a cryptogamic crust had no significant effect on infiltration at ungrazed sites but significantly increased infiltration at some grazed sites. Splash erosion was very low on soils with at least 50% cryptogam cover. Below this level splash erosion increased markedly, along with the proportion of fine sediments lost.     

Suitability of shrub establishment on Wyoming mined lands reclaimed for wildlife habitat

Restoring coal mined land to pre-mining shrub cover, density, height, community composition, and diversity to renew wildlife habitat quality is a priority for reclamation specialists. Long-term shrub reestablishment success on reclaimed mined land in Wyoming and suitability of these lands for wildlife habitat are unknown. Fourteen reclaimed study sites, 10 yr old or older, were selected on 8 mines in Wyoming to evaluate shrub reestablishment and wildlife habitat value for antelope ( Antilocapra americana ) and sage grouse ( Centrocercus urophasianus ). Five sites were categorized as fourwing saltbush ( Atriplex canescens ) sites and 9 as fourwing saltbush/big sagebrush ( A. canescens/Artemisia tridentata spp. wyomingensis ) sites. Published data describing antelope and sage grouse-preferred habitat requirements in sagebrush-grassland steppe ecosystems were used to evaluate shrub community value of sampled sites for wildlife habitat. Mean shrub canopy cover, density, and height for fourwing saltbush sites were 5.8%, 0.23 m -2 , and 41.6 cm, respectively, compared to 5.6%, 0.61 m -2 , and 31.1 cm for fourwing saltbush/big sagebrush sites. Two fourwing saltbush and 4 fourwing saltbush/big sagebrush sites provided sufficient cover for antelope, while 2 fourwing saltbush and 4 fourwing saltbush/big sagebrush sites were adequate for sage grouse. Only 1 fourwing saltbush/big sagebrush site provided high enough shrub densities for sage grouse. One fourwing saltbush and 7 fourwing saltbush/big sagebrush sites provided ample shrub heights for antelope, while 1 fourwing saltbush and 8 fourwing saltbush/big sagebrush sites were sufficient for sage grouse. One fourwing saltbush and 1 fourwing saltbush/big sagebrush site provided enough grass, forb, and shrub composition for antelope, while no site in either reclamation type was satisfactory for sage grouse. Shrub diversity was 3 times higher for fourwing saltbush/big sagebrush sites (0.984) than for fourwing saltbush sites (0.328). Individually, sites seeded with multiple shrub species had higher canopy cover, density, and diversity compared with single-species shrub seedings. Achieving premining shrub cover, density, height, community composition, and diversity within existing bond-release time frames is unrealistic, considering that some native shrublands require 30-60 yr to reach maturity.     

Changes in kit fox–coyote–prey relationships in the Great Basin Desert, Utah

Variation in kit fox ( Vulpes macrotis ) population parameters can be influenced by vegetative cover and the distribution and abundance of other predator and prey species. Dramatic changes to Great Basin Desert habitats, which can potentially impact mammalian species, have occurred in some areas in Utah. We examined kit fox demographics and prey populations from 1999 to 2001 on Dugway Proving Ground (DPG), a U.S. Army facility in Utah, and compared some parameters to historical levels (1956–1958, 1966–1969). Adult survival rates were fairly consistent between 1999 and 2000 and between 1999 and 2001; however, survival was greater in 2001 than in 2000. Reproductive rates ranged from 1.0 to 3.8 pups per female in 1999–2000 and were similar to historical numbers (1.0–4.2 pups per female). We found a decrease in pre-whelping kit fox density from the 1960s (0.12 foxes ? km –2 ) to 1999–2001 (0.04 foxes ? km –2 ); however, densities were similar between the current study and the 1950s (0.08 foxes ? km –2 ). Using 9 years of data, we found density dependence between reproductive rates of the current year and annual fox density from the previous year. Using 7 years of data, we found a slight correlation between kit fox annual density and a 1-year lag in leporid abundance, even though leporid abundance was lower during the present study than it was historically. Compared to historical levels, current small mammal abundance and species composition has changed in several habitats. Kit fox breeding density and annual density were inversely correlated with coyote ( Canis latrans ) density. Changes to the landscape at DPG, especially due to invasion of cheatgrass ( Bromus tectorum ) and addition of artificial water sources, have caused a change in available kit fox habitat and prey species, and have increased the abundance of coyotes, the kit fox's major competitor.     

Environmental effects on Common Snipe winnowing and calling (activity)

Our objective was to clarify the effects of 10 identified variables on snipe activity (winnowing and calling) by demonstrating correlations between the variables and snipe activity. We monitored snipe at 2 study areas in southwestern Montana and northwestern Wyoming at all hours of the day and night during the 1996 and 1997 breeding seasons. We measured 10 variables at established points along transects that were situated through the middle of each study site (8 study sites total). A total of 1200 monitoring periods were conducted throughout the course of this study. Effects of each factor on snipe activity were considered by examining general trends in each factor's graphical representation. Our results identified 6 factors (season, time of day, lunar cycle, solar radiation, wind speed, and temperature) that are associated with snipe activity. Snipe were most active early in the breeding season during 2 twilight periods during the first and last quarters of the lunar cycle. Low solar radiation levels, wind speeds, and temperatures were also most ideal conditions for snipe activity. All 6 factors should be considered when attempting to detect, survey, or estimate snipe populations.     

Effects of long-term livestock grazing and habitat on understory vegetation

The herbaceous understory stratum contains most of the plant diversity in ponderosa pine ( Pinus ponderosa P. & C. Lawson var. scopulorum Engelm.) forests of the American Southwest and provides critical food and habitat for many wildlife species. During the last century, this stratum has been affected by livestock grazing and by increased dominance of overstory trees. We sampled a unique grazing exclosure to examine the relative importance of long-term livestock grazing (grazed or ungrazed) and habitat (park or tree) on the understory community. We sampled 3 plots of 192 contiguous quadrats (each quadrat 0.5 m 2 ) in each of the 4 treatment combinations, for a total of 2304 quadrats. Species-area curves were generated by aggregating quadrats into nonoverlapping areas at grain sizes of 0.5 to 576 m 2 . The effects of habitat and grazing on species density were evident at very different scales. Species density was higher in park than tree plots at scales ≤32 m 2 but did not differ between habitats at larger scales. Species density differed minimally between grazed and ungrazed treatments at small grains, but grazed plots contained more species than ungrazed plots at larger grains. Grazing treatments differed at smaller grains (to 4–8 m 2 ) than did habitats (to 32 m 2 ), with respect to density of native species and graminoids. Grazed plots had more exotic species than ungrazed plots at all grain sizes, though few exotics were present. Twenty-two species were identified as indicator species associated with habitats and/or grazing treatments. Evaluations of plant community response to treatments would be improved by accounting for the grain at which data have been collected and analyzed and by identifying indicator species associated with various treatments. These data would enable more-informed conservation and management decisions.     

Plants of Navajo National Monument

The floristic composition of Navajo National Monument is presented. The flora of the monument consists of 293 species of vascular plants, representing 177 genera and 66 families. The species are scattered throughout 12 plant communities found within the monument. The flora is dominated by forbs (60 percent), followed by shrubs (16 percent), grasses (12 percent) and trees (5 percent). Betatakin canyon exhibits the greatest floristic richness with 223 species being represented and 123 species found only in that area. This is due primarily to two factors: (1) the greater variety of habitats available in the area, and (2) the much longer time the area has been protected from grazing and other manmade disturbance.     

Temporal activity patterns of Dipodomys ordii population

Temporal activity patterns for Dipodomys ordii were generally bimodal during the summer, with the highest peak occurring during early predawn hours when conditions were optimum for water conservation. Removal of dominant members in the population resulted in a substantial shift in the activity pattern to increased activity during the evening hours.     

A new sceloporine lizard from Oaxaca, Mexico

Sceloporus megalepidurus halli, subsp. nov., is described from San José Lachiguiri, Oaxaca, Mexico, from one adult male.     

Condition models for wintering Northern Pintails in the Southern High Plains

Three condition models for wintering Northern Pintails ( Anas acuta ) were tested for their ability to predict fat mass, logarithm of fat mass, or a condition index (CI) incorporating fat mass. Equations generated to predict fat mass and the logarithm of fat mass accounted for more than 69% of the variation in these dependent variables. Log transformations of body mass, wing length, and total length explained at least 60% of the variation in CI. All models performed better on an independent data set. Mean prediction error was minimal (≤8% of measured variables) and negative for all models. Regression models apply to live and dead pintails and thus represent tools that have utility in a wide variety of studies on pintail condition.