Northern Goshawks in the Malheur National Forest Eastern Oregon 1992 TO 2011 (original) (raw)
Related papers
2015
We recognize that the Eastside Screens have created an expectation that the goshawk will be protected and managed for, and thus PFAs would be retained during restoration and management activities. While that has not been successful in all projects, it is a requirement counted on by some stakeholders. Under our proposed approach, more wildlife habitat would be retained. Still, we understand that mangers and stakeholders will need assurances that this will work to meet their outlined social and ecological goals. Some stakeholders may need assurances of new wildlife habitat areas being required similar to what PFAs were under the old model. We recommend the creation of new selection criteria for wildlife habitat in the different dry forest types found on the Malheur National Forest. This strategic placement of wildlife habitat areas (for the goshawk and other species) in forest management planning will require close working relationships and trust between each National Forest, stakeholders, and placed-based collaborative groups. We suggest groups of land managers, stakeholders, and trusted scientists work together to develop the new model of wildlife habitat areas within each of the dry forest types. Key Management Considerations 1) The goshawk is not a species with population viability concerns, and thus prioritizing its specific habitat needs on a multi-spatial scale is not warranted. 2) The goshawk occupies varied forest types and does not appear to reliably indicate species composition, diversity and abundance in forest communities; suggesting it may be an inappropriate focal species intended to guide dry forest restoration. 3) New research demonstrates goshawks may be more tolerant of limited timber harvest (in nest stands and post-fledgling areas) than previously assumed. 4) The seasonal restrictions required by the Eastside Screens need not be based on decades old management guides, and instead could be modified to either match the dates proposed in the new Forest Plan or the research contained within this review. Potential Applications 1) Modify goshawk management under the Eastside Screens to better suite diverse wildlife habitat needs in associated forest types (ponderosa, dry mixed conifer, lodgepole pine, moist mixed conifer). 2) Alter timber harvest and seasonal restrictions adopted by the Malheur National Forest from Reynolds et al. (1992) to better reflect the current science on such impacts. 3) Consider alternatives to the goshawk for the new Forest Plan that will better meet current and future wildlife habitat needs. vi 4) Create a working group of managers, stakeholders, and scientists to explore the creation and protection of wildlife habitat areas in lieu of goshawk habitat areas. 5) Work with current science to create new models for selecting wildlife habitat areas based on biophysical characteristics such as soil type, overstory structure, ability to persist in future drought and disturbances, and spatial analysis to surrounding protected areas and planned management activities. Caption: Goshawk nest in pinyon-juniper habitat, southwest Idaho (photo: © Rob Miller). Goshawks were found nesting in pinyon and juniper habitat in Colorado, California, Idaho, Utah, and in Oregon. This adaptability of the goshawk to diverse habitat types that contain appropriate prey base makes it challenging to model for specific forest structure, such as late and old structure or closed canopy.
Large-scale forest composition influences northern goshawk nesting in Wisconsin
The Journal of Wildlife Management, 2013
The northern goshawk (Accipiter gentilis atricapillus) is a woodland raptor that uses a variety of forest types for nesting across its breeding range, but strongly depends on older forests with large trees and open understories. Goshawks may select nesting locations by maximizing the convergence of nesting and foraging habitats. Insights into goshawk responses to heterogeneous landscapes can be gained by examining the location of active nest sites through time and at multiple spatial scales. We examined the landscape-scale forest conditions that influenced the probability of active goshawk nests in the United States Forest Service, Chequamegon-Nicolet National Forest (CNNF) in northern Wisconsin. We used goshawk nest survey and monitoring data from 1997 to 2006 to determine the probability of an active nest site over time in relation to forest composition and road density at 3 scales (200-m, 500-m, and 1,000-m radii). Goshawk nests were located primarily in upland hardwood (64%), conifer (23%), and older aspen-birch (!26 yrs old; 11%) habitat cover types. We used Bayesian temporal autoregressive models of nest locations across multiple spatial scales to analyze these data. The probability of active goshawk nest occurrence increased with increasing conifer cover (1,000 m) and decreased with increasing cover of older aspen-birch and density of primary roads (500 m). In addition, lesser proportions of older aspen-birch at intermediate scales around goshawk nests had a stronger effect on the probability of a nest being active than conifer and primary roads. Thus, the ratio of conifer cover (within 1,000 m) to older aspen-birch cover (within 500 m) in landscapes surrounding nest sites was the key driver in predicting the probability of an active nest site. This finding can be used by forest managers to help sustain the active status of a goshawk nesting area through time (i.e., annually), and foster goshawk nesting activity in areas where active nesting is not currently occurring. ß Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
Goshawk Nest-Site Characteristics in Western Montana and Northern Idaho
The Condor, 1989
Descriptions of Northern Goshawk (Accipiter gentilis) nest sites are limited to Oregon (Moore 1980, Reynolds et al. 1982) California (Hall, unpubl.), South Dakota (Bartelt, unpubl. report), Colorado (Shuster 1980), Alaska (McGowan 1975) New York/New Jersey (Speiser and Bosakowski 1987), and West Germany (Dietzen 1978). In these studies, nesting habitat varied from conifer to deciduous forest and from even-aged to multi-storied stands. Within any region, however, the literature suggests goshawk nest-site selection is predictable and depends on available habitat and local climate. No one has examined nest-site characteristics in the northern Rocky Mountains. We surveyed goshawk nesting habitat in western Montana and northern Idaho to compare nest-site use with characteristics reported in the literature. STUDY AREA The geographic area considered in this report is restricted to western Montana and northern Idaho. This broad region encompasses a wide variety of climatic regimes and forest types on east and west sides of the Continental Divide, but can be divided into two zones based on the relative influence of maritime climate. The panhandle of Idaho and northwest Montana experience abundant rain and snowfall and moderate temperatures from maritime air masses, resulting in growth of large trees and many coastal plant species (e.g., Thuja plicata, Tsuga heterophylla, Pinus monticola, and Larix occidentalis) (Amo 1979). This area corresponds to Bailey' s (1976) Cedar-Hemlock subdivision and Crowley' s (1972) Columbian Rockies. Hereafter we will refer to this region as Columbian Highlands. Our second region includes portions of Bailey' s (1976) Douglas-fir and grama-needlegrass-wheatgrass subdivisions. Here, the colder, drier continental climate east of the Continental Divide, and substantially modified Pacific influence in west-central Montana and central Idaho, supports forest stands of smaller trees and poor-I
Does forest structure affect reproduction of northern goshawks in ponderosa pine forests?
Journal of Applied Ecology, 2007
1. Many management prescriptions are based on ecological hypotheses; evaluating empirical support for these hypotheses can improve management. There has been considerable dispute about the potential response of the northern goshawk to three management-driven forest structures in ponderosa pine forests of the southwestern United States: (i) the structure recommended by US Forest Service's goshawk guidelines, designed to increase the abundance of 14 goshawk prey species and thus benefit goshawks; (ii) preferred foraging habitat as suggested by empirical evidence that goshawks forage selectively in areas with abundant large trees and dense canopy closure, rather than areas of highest prey abundance; and (iii) presettlement (i.e. prior to Euro-American settlement) structure characterized by clumps of large trees, canopy closure < 40% and dense herbaceous understorey, which could have negative effects on goshawks. 2. To evaluate empirical support for hypotheses that goshawk reproduction is affected by each of these three forest structures, we measured forest structure in a 1215-ha nest-centred circular area in each of 13 goshawk breeding areas on the Apache-Sitgreaves National Forest, Arizona. The breeding areas were selected to span the full range of productivity (fledglings per year monitored) over the previous 9-year period. 3. Forest structure had a moderate effect on goshawk productivity (r 2 ≤ 0•46). Contrary to expectation, goshawk productivity decreased with increasing similarity to the goshawk guidelines. 4. Goshawk reproduction was not correlated with resemblance of the breeding area to preferred foraging habitat or resemblance to presettlement forest conditions. 5. Synthesis and applications. Because the goshawk guidelines may not improve goshawk reproduction, the Forest Service should reconsider its decision to apply the guidelines to most forested lands in Arizona and New Mexico. Managers should evaluate empirical support routinely for the major ecological hypotheses that underlie forest prescriptions.
DOES SURVEY METHOD BIAS THE DESCRIPTION OF NORTHERN GOSHAWK NEST-SITE STRUCTURE
Abstmrr: Past str~dies on the nesting habitat of northern goshawks (Accipiter gentilis) often relied on nests fomid opportunistically, either during timber-sale operations, by searching apparently "good goshawk habitat, or 1)y other search methods where areas were preselected based on known forest conditions. Therefore, a bias in the characterimtion of habitat surrounding northern goshawk nest sites may exist toward late-forest structure (large trecs, high canopy closure). This potential problem has confo~~nded interpretation of data on nesting habitat of northern gosl~a\vks and added to uncertainty in the review process to consider the species for fcderal listing as threatened or endangcred. Systematic srtnley methods. which strive for complete coverage of an area and often llse broadcasts of conspecific calls, have been developed to overcome these potential biases, but no str~dy has compared habitat characteristics around nests foi~nd opport~~nistically with those found systematic~~llv. We compared habitat characteristics in a 0.4-ha area aror~nd nests found systematically (n = 27) versus those found opporti~nistically (11 = 22) on 3 national forests in eastern Oregon. \Ve found that both density of large trees (systematic: r = 16.4 + 3.1 trees/ha; r t SE; opportunistic: f = 21.3 2 3.2; P = 0.56) and canopy elosi~re (systematic: .t = 72 2 2%; opportunistic: .f = 70 + 2%; P = 0.61) \xlere similar around nests found wit11 either search method. Our results diminish concern that past survey methods mischaracterized northern goshawk nest-site s t~~i c t u r e .
Journal of Wildlife Management, 2010
The northern goshawk (Accipiter gentilis) has been the subject of considerable interest because of the impact of logging on this species' nesting habitat. However, few studies have examined movements of fledgling birds around the nest prior to independence, and even fewer have described resource requirements of young birds during their postfledging period. Over 3 years, we followed 31 radiotagged goshawk fledglings from 15 nests in southeastern British Columbia, Canada. Of these birds, 26 survived to disperse. Between fledging and dispersal 95% of fledgling relocations (n 5 1,148) were within 450 m of the nest. Fledglings primarily remained within 298 m of the nest during the first 21 days postfledging and within 525 m of the nest between 21 days postfledging and dispersal. Fledglings' movements were highly directional, with individual and sibling movements away from any particular nest tending out in one direction. Postfledging areas averaged 36.7 ha in size (median 5 23.1, inter-quartile range 5 20.8-39.7 ha). Fledglings strongly avoided forest ,40 years old and weakly selected young forests (40-80 yr), mature forests (.80 yr), and stands with .40% canopy cover during the first 21 days and after. We suggest forest managers wishing to conserve goshawk postfledging areas in the interior montane forests of British Columbia maintain forests .40 years old with high crown closure covering an area L 21 ha and preferably .40 ha. This area should contain all identified occupied and alternative nest trees in a nest area. At least half this area should be forest .80 years old and contain existing nests and potential for future nest trees.
Journal of Wildlife Management, 2005
We used radiotelemetry to examine foraging habitat preferences of 17 breeding, male northern goshawks (Accipiter gentilis) in Minnesota from 1998-2000. We assessed habitat preference using radio relocation points and 50m radius buffers of radio relocation points. Our data suggested that foraging male goshawks used early-successional upland conifer stands (≥25 yrs old), early-successional upland deciduous stands (≥50 yrs old), late-successional upland conifer stands (≥50 yrs old), and late-successional upland deciduous stands (≥50 yrs old) more frequently than expected based on the abundance of these vegetation types in the landscape. The 2 most available stand types, early-successional upland deciduous (<25 yrs old) and all ages of late-successional lowland conifer stands, were used less than expected by foraging goshawks. Late-successional lowland deciduous stands (≥50 yrs old) were used in proportion to availability. Although analysis of relocation points suggested early-successional upland deciduous stands (25-49 yrs old) and late-successional upland conifer stands (≥50 yrs old) were used in proportion to availability, analysis of buffers around relocation points indicated that these stand types were also used more than expected by foraging goshawks. Regardless of vegetation community type, stands used by goshawks were structurally similar with high canopy and understory stem densities, high canopy closure, substantial shrub cover, and large amounts of woody debris. Nest stands consisted of taller and larger diameter canopy trees and fewer understory trees than foraging stands, but stands were otherwise similar in structural features, suggesting goshawks used similar stands for nesting and foraging but that they tended to select the most mature stands for nesting. A commonality among nesting and foraging stands was the presence of open spaces between the canopy and understory foliage, and between understory and shrub layer foliage. In our study area, these spaces may have served as relatively unobstructed flight paths where foraging and nesting stands possessed stem densities at the upper end of that reported for goshawk habitat.
Comparison of Nest Defense Behaviors of Goshawks (Accipiter gentilis) from Finland and Montana
Animals
As human impacts on wildlife have become a topic of increasing interest, studies have focused on issues such as overexploitation and habitat loss. However, little research has examined potential anthropogenic impacts on animal behavior. Understanding the degree to which human interaction may alter natural animal behavior has become increasingly important in developing effective conservation strategies. We examined two populations of northern goshawks (Accipiter gentilis) in Montana and Finland. Goshawks in Finland were not protected until the late 1980s, and prior to this protection were routinely shot, as it was believed that shooting goshawks would keep grouse populations high. In the United States, Goshawk were not managed as predator control. Though aggressive nest defense has been characterized throughout North America, goshawks in Finland do not show this same behavior. To quantify aggression, we presented nesting goshawks with an owl decoy, a human mannequin, and a live human...