Seasonality and fidelity in roost use of the Mexican free-tailed bat, Tadarida brasiliensis , in an urban setting

We studied 7 urban roosts occupied by Mexican free-tailed bats ( Tadarida brasiliensis ) in downtown Waco, Texas, from August 2001 to September 2002. We examined frequency of roost use, colony sizes, and roost fidelity in relation to gender. Use of roosts and colony sizes were highest in the fall and lowest in the winter, but fluctuated widely during the study. These roosts were not used by maternity colonies, and patterns of occupancy suggested that they served as stopover sites during migratory seasons. Individual bats exhibited high fidelity to discrete roosts included in the study. However, the bats commonly left the study area, suggesting that populations are defined at greater spatial scales than we included in this study. Male bats were recaptured more often and spent more days in the study area than female bats, suggesting a sexual difference in roosting behavior.     

Multiple-scale roost habitat comparisons of female Merriam’s Wild Turkeys in the southern Black Hills, South Dakota

Because quantity and quality of roosting habitat can affect Merriam’s Wild Turkey ( Meleagris gallopavo merriami ) distribution, we described habitat characteristics of Merriam’s turkey roost sites in the southern Black Hills of South Dakota. Varying proportions of Merriam’s turkeys in the southern Black Hills depended on supplemental feed from livestock operations during the 2 winters of our study, whereas the remainder wintered in forested habitat away from supplemental feed. We compared characteristics of roost habitat occupied by female turkeys from both groups. We located turkeys with radio-transmitters in the early morning and late evening to find roost sites. Female Merriam’s turkeys in the southern Black Hills roosted exclusively in ponderosa pine trees, primarily on the upper portions of ridges on easterly aspects. Generally, trees >30 cm diameter at breast height (dbh) were chosen for roosting, but turkeys also roosted in trees with smaller dbh. During winter months, turkeys that relied on supplemental feeding roosted adjacent to the ranch-farmstead where the supplemental food was located. Generally, these turkeys used the same roost site(s) throughout the winter, whereas turkeys that remained in the forest during winter used multiple roost sites. We suggest maintaining stands of trees >30 cm dbh on the upper portions of easterly aspects to provide suitable roosting habitat for female Merriam’s Wild Turkeys in the southern Black Hills.     

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.     

Springtime movements, boost Use, and foraging activity of Townsend's big-eared bat ( Plecotus townsendii ) in central Oregon

Seasonal movements, roost-site fidelity, and foraging activity patterns are largely unknown for western populations of Townsend's big-eared bat ( Plecotus townsendii ). We used miniature radiotelemetry units to track springtime movements of six bats inhabiting forested lava flows in central Oregon, and found that bats moved up to 24 km from hibernacula to foraging areas. Individual bats returned to the same foraging area on successive nights but shifted to different areas in presumed response to changes in insect availability. Both sexes apparently use a series of interim roost sites between emergence from hibernation and the time females enter into maternity colonies, with little individual fidelity to these sites. In regions characterized by extensive lava-flow topography, suitable daytime roosts are numerous and dispersed over a large area, allowing bats to move relatively great distances to locate foraging ranges. Hence, the actual area of concern for effective management of individual populations can be considerably larger than indicated solely by locations of hibernacula and maternity caves of this declining species.     

Dwarf mistletoe-pandora moth interaction and its contribution to ponderosa pine mortality in Arizona

The interaction between Southwestern dwarf mistletoe, Arceuthobium vaginatum subspecies cryptopodum , infestation and defoliation by the pandora moth, Coloradia pandora pandora , on the Kaibab Plateau in Arizona was evaluated. Heavy defoliation of ponderosa pine, Pinus ponderosa , in 1979 and 1981 resulted in mortality of individual trees in areas of heavy dwarf mistletoe infestation. Postmortem evaluation of ponderosa pines indicated that dead trees had a significantly higher dwarf mistletoe rating than did nearby paired live trees. Of 25 tree pairs evaluated, only two live trees had higher dwarf mistletoe ratings than the paired dead tree. Mean dwarf mistletoe ratings were: live trees 2.9, dead trees 4.6 (6 class dwarf mistletoe rating system). Implications for management of the pandora moth are discussed.        

Winter habitat selection patterns of Merriam's turkeys in the southern Black Hills, South Dakota

In northern areas of their expanded range, information on Merriam's turkeys ( Meleagris gallopavo merriami ) is lacking, specifically pertaining to wintering behavior and factors associated with winter habitat selection. Forest managers need detailed quantification of the effects of logging and other management practices on wintering habitats needed by Wild Turkeys and other wildlife. Therefore, we examined winter habitat selection patterns within ponderosa pine ( Pinus ponderosa ) forests and determined factors associated with use of farmsteads by Merriam's turkeys in the southern Black Hills, South Dakota. We radio-marked 86 female Merriam's turkeys (70 adults and 16 yearlings) and monitored them during winter (1 December–31 March), 2001–2004. Female Wild Turkeys used recently burned pine forest less than expected but selected farmsteads and stands of mature ponderosa pine ( 22.9 cm diameter at breast height [DBH] trees) for foraging sites. Within forests, female Wild Turkeys selected foraging sites with less understory vegetation and visual obstruction, and larger-diameter ponderosa pine. Ponderosa pine seed abundance varied among years, and pine seeds were most abundant in stands of 30–35 cm DBH with basal area of 22–28 m2 ? ha–1. Abundance of pine seeds may have influenced use of farmsteads by Wild Turkeys, more so than ambient temperatures or snow depth. In the southern Black Hills, management should emphasize open- to mid-canopy and mature-structural-stage pine stands, where seed production was greatest. During winters when mast from pine is unavailable, farmsteads likely provide nutritional supplementation and may be important for maintaining Merriam's turkey populations.     

Nest site characteristics and reproductive success of the Western Tanager ( Piranga ludoviciana ) on the Colorado Front Range

From 1999 through 2001 we located and monitored Western Tanager ( Piranga ludoviciana ) nests in public open-space properties in Boulder County, Colorado. Fifty-four of 58 nests were located in ponderosa pine and the remainder in Douglas-fir. Nests were generally placed near the midpoint of branches in areas of high canopy cover (> 50%) in the middle section of nest trees. Nest height varied as a function of nest tree height, and nests were oriented randomly in relation to trunks of nest trees. Tanager nesting success varied annually, with estimates using the Mayfield method ranging from 11.3% in 2000 to 75.3% in 2001. At least 8 nests were predated, and predation was the primary cause of nest failure. Parasitism by Brown-headed Cowbirds ( Molothrus ater ) occurred in 7 of 17 (41%) nests found during egg-laying or incubation. Clutch size averaged 3.8 in 10 unparasitized nests, but only 2.4 in 8 parasitized nests. Brood parasitism dramatically reduced the number of tanager fledglings produced per nest.     

Roosting behavior of the Mexican free-tailed bat ( Tadarida brasiliensis ) in a highway overpass

A colony of Mexican free-tailed bats ( Tadarida brasiliensis ) roosting in an interstate highway overpass in Belton, Bell County, Texas, was studied weekly from 28 June to 21 November 1996 (except for the week of 4 July). We examined 2 aspects of roosting behavior: site-specific fidelity to locations within the roost and gender-related segregation within the roost. Colony estimates based on guano production showed a marked decrease in the number of bats from 19 to 26 July; many of these departing bats were adult females. No female bats sampled after this interval were pregnant. Male bats outnumbered females on nearly all sampling occasions. Throughout the study, one section of the roost was dominated by males, ranging from 83% to 100% of total bats. The majority of bats recaptured at least once were faithful to specific locations within the roost, and more than 70% of bats recaptured multiple times were faithful to specific roost locations.     

Response of understory species to changes in ponderosa pine stocking levels in the Black Hills

The objective of this study was to test the hypothesis that there are no differences in understory production, by species, due to stocking levels of Pinus ponderosa (ponderosa pine). Understory production was estimated, by species, on 3 replicates each of 8 growing stock levels, ranging from clearcuts to unthinned stands, in both sapling- and pole-sized pine stands (48 plots) over 3 nonconsecutive years. All stands were approximately 70 yr old when thinning treatments were applied. Production of many herbaceous species, especially Agropyron spp. (wheatgrasses) and Carex spp. (sedges), declined as growing stock levels (measured in terms of basal area) of ponderosa pine increased. While trends in total production were similar, there were specific differences between sapling and pole stands. Sedges and Oryzopsis asperfolia (roughleaf ricegrass) produced more in sapling stands, whereas Danthonia intermedia (timber oatgrass) was more abundant in pole stands. Shrub production, dominated by Acrtostaphylos uva-ursi (bearberry), was relatively consistent across all stocking levels except unthinned. Although the total number of species declined as pine basal area increased, a few species, such as Linnaea borealis (twinflower) and Shepherdia canadensis (buffaloberry), were found only under relatively dense pine canopies. While floristic species richness was greater at lower stocking levels of ponderosa pine, the total number of species would be greater if all stocking levels were present.     

Fire history of Paunsaugunt Plateau in southern Utah

A fire history of the Pausaugunt Plateau in southern Utah was developed using dendrochronological methods. Fire frequencies of individual ponderosa pine trees from three sites on the plateau varied from 19.5 to 47 years. Composite fire intervals for the three sites ranged from 15.2 to 18.4 years. The last recorded fires in these study areas occurred in 1892, 1902, and 1911, corresponding to the initiation of fire suppression policies in the West. The absence of fire since 1911 may be contributing to a recently documented decrease in ponderosa pine regeneration within the high-elevation, mixed-coniferous forests of the Paunsaugunt Plateau.     

A seed chalcid ( Eurytoma squamosa Bugbee) parasitizes buckbrush ( Ceanothus fendleri Gray) seeds in a ponderosa pine forest of Arizona

Predispersal seed parasitism rates were quantified for buckbrush ( Ceanothus fendleri Gray) in 3 Arizona ponderosa pine ( Pinus ponderosa Laws.) forest units that had been thinned for ecological restoration objectives. The chalcidoid wasp Eurytoma squamosa Bugbee (Eurytomidae) was responsible for 35% of total seed loss in a single year. These findings represent an expansion of the known range and host list for E. squamosa and increase our understanding of factors that may constrain regeneration of C. fendleri in Southwest ponderosa pine forests.     

Selection of dwarf mistletoe-infected ponderosa pines by Ips species (Coleoptera, Scolytidae) in northern Arizona

Following an Ips bark beetle outbreak in 2002, mortality of ponderosa pine ( Pinus ponderosa Douglas ex C. Lawson) was evaluated in 2 study areas infested with southwestern dwarf mistletoe ( Arceuthobium vaginatum [Willd.] Presl subsp. cryptopodum [Engelm.] Hawksw. & Wiens) in the Coconino and Tonto National Forests, Arizona. A pairwise comparison of dwarf mistletoe ratings for live and dead ponderosa pines was conducted to determine whether dead ponderosa pines had higher dwarf mistletoe ratings than pines that were not attacked. In both study areas, dead ponderosa pines had significantly higher dwarf mistletoe ratings, indicating an association between the severity of dwarf mistletoe infection and susceptibility to attack by Ips spp. We suggest that the probability of ponderosa pine mortality is greater in stands severely infested with southwestern dwarf mistletoe in northern Arizona.     

Physical characteristics of Blue Grouse winter use-trees and roost sites

Physical characteristics of winter use-trees and roost sites of Blue Grouse ( Dendragapus obscurus ) were studied in northeastern Utah. Blue Grouse selectively roosted in the largest Douglas-fir ( Pseudotsuga menziesii ) trees during the day and subalpine fir ( Abies lasiocarpa ) trees at night. Diurnal and nocturnal roosts were typically adjacent to tree trunks in the lower two-thirds of trees. Nocturnal roosts provided greater canopy and denser shelter than diurnal roosts. Roost site selection was consistent with occupation of favorable microhabitat, particularly at night, and foraging strategy during the day. Timber management strategies should perpetuate large trees within Douglas-fir-subalpine fir habitat in areas occupied by wintering Blue Grouse.     

Roosting behavior of male Euderma maculatum from Utah

Eight spotted bats ( Euderma maculatum ) were captured and released along the Fort Pierce Wash, Washington County, Utah, in August 1974. Observations indicated that Euderma roosts in cracks and crevices.       

Ponderosa pine conelet and cone mortality in central Arizona

Ponderosa pine conelets in 10 stands on the Coconino and Kaibab national forests were observed periodically from July 1982 until they matured in September 1983. Abortion, ponderosa pine cone beetles ( Conophthorus ponderosae Hopkins), and ponderosa pine coneworms ( Dioryctria sp., probably Auranticella [Grote]) were the significant mortality factors. Cattle, tip moths, and squirrels rarely destroyed conelets or cones.     

Density, distribution, and habitat of Flammulated Owls in Idaho

From 1990 to 1992 we surveyed for Flammulated Owls ( Otus flammeolus ) in 3 areas in Idaho: Salmon National Forest (SNF), Payette National Forest and adjacent Hells Canyon National Recreation Area (PNF-HCNRA), and Nez Perce National Forest (NPNF). We also collected and summarized information on all historic and modern records of Flammulated Owls in Idaho. Flammulated Owls were detected on 65% of 68 routes (2-16 km in length) surveyed at densities ranging from 0.04 to 1.25 singing males/40 ha. Owls were detected on survey routes as early as 10 May and as late as 23 July. Mean percent canopy cover estimated at owl locations on the PNF-HCNRA and NPNF study sites ranged from 52% to 64%, while shrub cover ranged from 16% to 21% and ground cover was 39% to 49%. Our surveys and summary of distributional records indicated that Flammulated Owls occur throughout the montane forests of Idaho in old or mature stands of open ponderosa pine ( Pinus ponderosa ), Douglas-fir ( Pseudotsuga menziesii ), and stands co-dominated by those 2 species. Fire suppression and timber harvest activity in ponderosa pine forests represent 2 main threats to the species' future security in Idaho. More research on the effects of various silvicultural treatments on Flammulated Owl populations is warranted.     

Bats of the White and Inyo Mountains of California-nevada

We surveyed bats throughout the White and Inyo Mountains of California and Nevada. From December 1990 to November 1996, we surveyed hibernating bats, and foraging bats from June 1992 to September 1996. The White-Inyo Range rests in a unique biogeographical junction between the Sierra Nevada, Mojave Desert, and Great Basin Regions. Elevational gradients of 305-4340 m, combined with limited human development, further enhance the interest of natural history and faunal distributions in this range. We found 13 bat species in the course of 2668 observations. Three of these species, the spotted bat ( Euderma maculatum ), silver-haired bat ( Lasionycteris noctivagans ), and hoary bat ( Lasturus cinereus ), have no previous records from the White-Inyo Range. We found bats in all vegetation zones except alpine, 3500-4342 m. Despite an abundance of mines in this range, only Townsend's big-eared bat ( Corynorhinus townsendii ) and western small-footed myotis ( Myotis ciliolabrum ) used them routinely. Our data also indicated the importance of surface water to bat populations in arid regions.     

Home range size of Black-backed Woodpeckers in burned forests of southwestern Idaho

We examined home range size of Black-backed Woodpeckers ( Picoides arcticus ) in burned ponderosa pine ( Pinus ponderosa ) / Douglas-fir ( Pseudotsuga menziesii ) forests of southwestern Idaho during 2000 and 2002 (6 and 8 years following fire). Home range size for 4 adult males during the post-fledging period was 115.6–420.9 ha using the 95% fixed-kernel method, and 150.4–766.1 ha using the 100% minimum convex polygon method. Smoothed bootstrap estimates (95%) were 130.0–521.9 ha. Home range sizes were significantly smaller 6 years after fire than 8 years after fire. Each male had from 2 to 8 areas of concentrated use within his home range. We provide recommendations for estimating area requirements of Black-backed Woodpeckers in post-fire ponderosa pine / Douglas-fir forests.     

A comparison of the spherical densiometer and ocular methods of estimating canopy cover

Percent tree canopy cover in a ponderosa pine ( Pinus ponderosa ) forest of northeastern California was estimated by the point intercept spherical densiometer and ocular methods. Estimates derived by the two methods were similar (P > .05). The ocular method is recommended when understory vegetation is tall or clumped instead of randomly distributed, or if available field time limits sample size.     

A disjunct ponderosa pine stand in southeastern Oregon

An isolated stand of ponderosa pine ( Pinus ponderosa ) is surviving on an extremely harsh site in southeastern Oregon. Seed production is low because of insects, primarily pine coneworm ( Dioryctria auranticella ), feeding in developing cones. Seedling establishment is infrequent and difficult because of drought and coarse, rocky soils. A rock-mulch soil surface probably reduces interspecific competition. Because stand size is small (