Barred Owls (Strix varia) expanded their range to include western North America and have been competing with federally threatened Northern Spotted Owls (S. occidentalis caurina) for the past few decades. To help protect Spotted Owls, the US Fish and Wildlife Service is considering conducting a 3- to 10-y study in which as many as 2150 to 4650 Barred Owls would be killed and, possibly, conducting long-term management of Barred Owls. To help give these considerations a global perspective, I gathered information concerning instances of negative effects between native (non-introduced) birds worldwide (n  =  194) and how managers address these effects. I found reports for 15 species of native birds of concern negatively affected by hybridization, 22 by brood parasitism, 58 by competition, and 99 by predation. Control commonly is used to address brood parasitism by cowbirds (Molothrus spp.), and predation by gulls (Larinae) and corvids (Corvidae), whereas control rarely is used to address competition and is never used to address hybridization. Globally, very few raptors are killed for any of these threats. If the precedent-setting removal study as described here is implemented, it would, during its 1st year, result in the death of 36 times more raptors than in all other conservation-based projects combined in the United States and its territories, and 84 times more raptors than in the largest ongoing effort worldwide. This study could cost $1 million annually; simplifying the cost to dollars per Barred Owl killed approximates $700 per Barred Owl for the 1st year and $2800 per Barred Owl for each subsequent year.

We investigated population characteristics, microhabitat use, and activity patterns of Phrynosoma (Tapaja) douglasii (Pygmy Short-horned Lizard) within shrub-steppe habitat in Washington. Females were significantly larger (and more commonly encountered) than were males. Overall, lizards preferred lithosol microhabitat, which is characterized by rocky soils and sparse vegetation. Age, sex, and season, however, affected how lizards used lithosol, loamy, and ecotone microhabitats. Lizard age also affected daily, monthly, and seasonal activity. Adult activity peaked in June, yearling activity in April, and neonate activity in July. During spring and fall, adult activity peaked when daytime temperatures were highest, whereas in summer, the activity peak occurred in early morning and evening. In contrast, neonates remained active during temperature maximums in summer and throughout the day in fall. Although lizards preferred relatively open terrain, they were found closer to shrubs than expected, based on comparisons with random sites. Our results underscore the importance of seasonal variation and age in habitat use and activity patterns of P. (Tapaja) douglasii.

From 2002 to 2007 we measured breeding territory, nest patch, and nest shrub characteristics for Yellow-breasted Chats (Icteria virens auricollis) in the northern edge of their distribution in British Columbia, Canada. Surveys were done at 94 breeding territories, 238 nest patches, 246 nest shrubs, and at random locations for comparison. Habitat selection by chats was not random, and territories were selected for specific vegetation characteristics. Chat breeding territories were located in lower elevation riparian zones consisting mainly of dense shrubs and early successional water-tolerant trees, with the dominant shrub species being wild rose (Rosa spp.). Chats nested in 12 plant species and 72% of nests were within wild rose, which was also the dominant species in 5 m and 11.3 m radius nest patch plots centered at the nest shrub. Based on georeferenced locations of male chat singing or perching locations, chat breeding territories were on average 0.37 ha (s  =  0.27 ha) in size (n  =  66).

The macfarlanei subspecies of the Western Screech-owl (Megascops kennicottii) resides in the dry southern interior of British Columbia and is federally endangered in Canada. We captured and radio-tagged 11 adult screech-owls (6M, 5F) between July 2005 and January 2008 to collect ecological information needed to direct effective conservation. We collected point radiolocations from tagged owls to estimate seasonal and year-round home ranges with the 95% isopleth of the utilization distribution calculated using fixed kernel methods. Screech-owl home ranges averaged 64.5 ha (s  =  10.6, n  =  5), with no substantial difference in size between males and females. Owls used considerably smaller areas during the breeding season (x ¯  =  20.4 ha, s  =  15.3, n  =  7) than the non-breeding season (x ¯  =  88.6 ha, s  =  44.5, n  =  6). During the breeding season, males and females of a single pair overlapped extensively, whereas outside the breeding season very little overlap occurred within pairs. We did not detect overlap between neighbouring pairs. Home ranges of Western Screech-owls were highly associated with riparian forests; most screech-owls had ≥10 ha of riparian forested habitats within their home ranges. These results have implications for habitat conservation for this endangered species.

Very little is known about the social behavior of Heather Voles (Phenacomys intermedius), mainly because they are difficult to trap and maintain in captivity. We were able to maintain individuals in the laboratory and observe dyadic interactions among adult males and females, as well as related and unrelated juveniles, in a neutral arena. Overall, Heather Voles were very docile compared to other microtine species observed in captivity. There were no amicable behaviors observed, and the majority of encounters consisted of neutral egocentric actions. Males and females showed very similar levels of aggression in intrasexual encounters, although encounters between males contained more overt fighting behaviors. Male-female encounters contained the most aggressive behaviors (especially chasing), with a large proportion of those behaviors likely being the male attempting to copulate with the female, and the female resisting. No differences in aggressive behaviors were observed between related and unrelated juveniles.

Townsend's Big-eared Bat (Corynorhinus townsendii) is a species of conservation concern for many states and provinces. However, little is known about key demographic parameters, such as survival, for this species due to its sensitivity to human disturbance. This species can also be vulnerable to injuries from wing bands; the most commonly applied marking technique used in the past to estimate survival in bats. During the US Fish and Wildlife Service's Bat Banding Program (1932–1972), CM Senger banded 1,346 Townsend's Big-eared Bats at 3 major cave systems in Washington during 1964–1975, and continued to recapture banded bats until 1980. I applied current mark-recapture techniques to retrospectively estimate survival of hibernating Townsend's Big-Eared Bats banded by CM Senger. I also investigated sex, time, and trend effects on survival and capture probabilities of these 3 populations of bats using Cormack-Jolly-Seber (CJS) open models and the modeling capabilities of program MARK. For each location, estimates of annual survival and capture probabilities varied somewhat by sex and ranged from 0.54 to 0.68 for males and 0.60 to 0.67 for females. During the banding study, band injuries were noted and populations declined at all locations potentially violating assumptions of the CJS model. However, the dataset from which these estimates were derived is likely to be the most complete and well-maintained dataset in the Bat Banding Program files. Resulting annual survival estimates from these data were relatively precise and modeling provided evidence of time and trend effects and differences in survival between the sexes. These results provide historical, post hoc estimates of an important life-history parameter for this species of bat wintering in caves in 3 localized areas of Washington State.

We examined key factors thought to influence Mourning Dove (Zenaida macroura) nest density (nests/ha) in Blue Oak woodlands (Quercus douglasii), riparian woodlands (Salix spp., Populus fremontii), and commercial walnut (Juglans spp.) orchards in northern California (north of UTM: Zone 51N, 324397E, 4207703N, datum WGS84). We hypothesized that nest density could be used to characterize the suitability of habitats for breeding Mourning Doves because nest success has often been shown to not vary predictably by habitat type. Because weather does affect nest success, we examined the influence of spring rainfall and ambient temperature, as well as habitat on nest density. We recorded all Mourning Dove nests found in surveys conducted every 3rd wk from mid-April to mid-August, which encompassed the nesting season, in each of 6 to 10 randomly placed survey plots in each of 4 study areas during 1992–1995, with a supplemental survey during September 1994. Survey date, habitat type, and spring weather affected period nest density (PND; mean number of all active nests/ha present during any given survey); and habitat type and weather affected cumulative nest density (CND; total number of different nests produced annually/ha). Seasonally, PND was relatively low in April, high from May to July, lower in August, and zero by September. Riparian woodlands tended to support higher PND and CND compared to walnut orchards and Blue Oak woodlands in that order. This effect was pronounced during the warm-dry springs of 1992 and 1994, but was not always evident during the relatively cool-wet springs of 1993 and 1995 (weather characterized relative to April mean high temperature and March to May mean rainfall). The best predictive model (lowest AIC_C) for PND contained a quadratic trend with survey timing, and effects due to habitat type, high temperature and rainfall deviations from long-term average, number of rain-days, and tree density. The best model for CND contained habitat, temperature, rainfall, rain-days, and tree density. Nest success increased at a declining rate as nest density increased in Blue Oak and riparian woodlands, demonstrating probable density-dependent resource or mortality limits on nest success that did not affect nest density within the ranges we recorded. Nest density measures should be useful to land managers in assessing responses of nesting Mourning Doves to available nesting habitats and local spring weather.