Richard Reynolds

We used radiotelemetry to determine habitat use by Flammulated Owls (Otus flammeolus) during the breeding season on 452 ha of montane conifer forest in central Colorado in 1982-1983. Mean size and SD of home ranges was 11.1±1.9 ha (range= 8.5-12.5 ha, n= 4) in ...

Developing and displaying forest structural targets are crucial for sustaining the habitats of the northern goshawk, a sensitive species in Southwestern forests. These structural targets were described in Management Recommendations for the Northern Goshawk in the Southwestern United States (MRNG) (Reynolds, et al., 1992). The MRNG were developed in a unique food-web approach that identified desired forest conditions for the goshawk. These desired conditions were based on syntheses of the habitats of both goshawks and the diverse suite of plants and animals in their food web. Not surprisingly, implementing these structural targets results in forests restored to conditions similar to our understanding of pre-European settlement forests. Silviculturists are responsible for:

We used field data, topographical information (elevation, slope, aspect, landform), and Landsat Thematic Mapper imagery to model forest vegetative types to a lO-m resolution on the Kaibab National Forest in northern Arizona. Forest types were identified by clustering the field data and then using a decision tree based on the spectral characteristics of a Landsat image and topographical information to predict the forest types. Significant variables in the models included raw basal area and proportion of basal area by species. Use of additional variables (canopy closure, understory vegetative height, seedling/sapling presence, and proportion of ground covered by vegetation) did not improve the model. Forest types described by the model included pinyon-juniper, ponderosa pine, ponderosa pine-fir mixes, spruce-dominated mixes, deciduous-dominated mixes, and clearings. Sample-based accuracy assessment accounted for 92.9 % of the variability in the vegetation model. Error rates (post-stra...

Northern goshawks interact with each other and their environment in a spatially dependent manner. However, finding the location of active goshawk nests (e.g. where eggs are laid) in a given year is difficult due to the secretive nature of the hawks in their forest environment, their annually variable attempts at nesting, and the extent of the area within a home range where they will nest. We used a Gibbsian pairwise potential model to describe the spatial dependency (1) among nest locations influenced by territoriality and (2) between nest locations and the environment for a large population of goshawks on the Kaibab National Forest’s (NNF) North Kaibab Ranger District (NKRD). Nest locations in a given year were regularly distributed at a minimum distance of 1.6 km between active nests; however, as the spatial scale increased (i.e. as distance between the nests increased), the degree of regularity decreased. Important forest predictors for nest locations included canopy closure, tot...

Annual territory occupancy by Flammulated Owls (Otus flammeolus) in Colorado was evaluated from 1981-1996. Fourteen territories occurred within a 452 ha study area. Each year, three to six territories were occupied by breeding pairs and three to seven were occupied by unpaired males. Territories were occupied by breeding pairs a mean of 5.1 years (not necessarily consecutive) and by unpaired males a mean of 3.9 years (not necessarily consecutive). Territories most consistently occupied by breeding pairs contained the highest percentage of old (200-400 years) ponderosa pine/ Douglas-flr, whereas territories least occupied by breeding pairs contained the least amount of this vegetation type.

We used mark-recapture methods to monitor Northern Goshawks (Accipiter gentilis) and their nests over 12 yr in an increasing sample of breeding territories (37 in 1991 to 121 in 2002) in northern Arizona. As many as 8 yr of repeated nest searching were required to identify the population of breeders, as individuals skipped egg-laying on territories for up to 7 consecutive yr. Extensive temporal (within territory) and spatial (among territory) variation in reproduction and a high annual frequency of movements among dispersed alternate nests in territories made finding and monitoring goshawks problematic. Low detectability of nonbreeding goshawks (combined with uncertainties stemming from variations in breeding and use of alternate nests) made it difficult to categorize territories unequivocally as ‘‘unoccupied’’ by goshawks in non-egg-laying years. Temporal and spatial variation in reproduction required large numbers of territories to attain reliable estimates of reproduction of gosh...

Advances in molecular techniques have facilitated use of genetic data in demographic wildlife studies. An important first step in genetic mark-recapture is selecting markers that uniquely ‘‘mark’’ and reliably ‘‘recapture’’ individuals. Markers should be tested on reliable DNA from known individuals (blood) before being used on non-invasively sampled DNA (hair, scat, or molted feathers). To evaluate whether Northern Goshawks (Accipiter gentilis) can be uniquely identified by genotyping, 113 known (banded, sexed) goshawks from the Kaibab Plateau, Arizona, were genotyped using DNA from blood and five microsatellite markers and a sex-linked gene. We used mean relatedness to test whether adults in the population were related and probability of identity (P(ID) = probability that two random individuals from the population have the same genotype) to test the ability of multi-locus genotyping for uniquely identifying goshawks. We used genetic data to assess inbreeding and demographic data t...

Fledging success is often assumed to be a reliable index of reproductive success (i.e., fitness) in the ornithological literature. We examined the validity of this assumption in a large population of Northern Goshawks (Accipiter gentilis) on the Kaibab Plateau, Arizona, at both the population and individual levels. We used mark-recapture data from 558 fledglings produced at 494 nests over a 10-yr period to assess the hypothesis that the number of fledglings returning to breed from an annual fledgling cohort is positively correlated with the size of the cohort. Natal philopatry was low and recruitment was gradual: only 48 fledglings (8.6%) returned to breed between 2?8 yr of age (x = 3.5 yr). We found no evidence that the breeding population produced more local recruits in years of high fledgling production than in years of low fledgling production. At the individual level, however, fledgling production for 290 breeding adults was related to their contributions to the future breeding...

Current management guidelines for the Northern Goshawk (Accipiter gentilis) in the Southwest call for a mosaic habitat consisting of approximately 10 percent of the forest area in grass-forb/ shrubs, 10 percent in 2.5-12.7 cm trees, 20 percent in 12.7-30.5 cm trees, 20 percent in 30.5-45.7 cm trees, 20 percent in 45.7-61.0 cm trees, and 20 percent in 61.0 cm and greater trees. This habitat mosaic was conceived as convenient categories to describe a generally balanced, ecologically sustainable, forest ecosystem. In reality, however, the vegetative structural percentages vary. We describe how differences in site quality and stand density affect vegetative structural stage percentage and forest age.

The Flammulated Owl (Otus flammeolus) is widely distributed in the montane forests of western North America (Bent 1938). The owl is insectivorous (Ross 1969) and is presumed to be migratory in the northern part of its range (Balda et al. 1975). Little is known of the nesting behavior of this species, especially during the postfledging period. Here, we present the postfledging behavior of adults and young and describe the occurrence of brood division in Flammulated Owls.

We studied 347 nesting attempts on 107 nesting territories of northern goshawks (Accipiter gentilis) on 1,732 km2 of the Kaibab Plateau, Arizona from 1991-1996. Mark and recapture methodology was used to estimate survival probabilities, territory and mate fidelity, turnover on territories, and dispersal. Territories were regularly spaced at a mean nearest neighbor distance of 3.88 krn (n = 100, P = 0.98, Cramer-von-Mises). An estimate of the total breeding population on the study area (146 territories) suggested that about 73 percent of the breeding population was located during the study. Annual proportion of pairs that laid eggs, production of fledglings, nesting success, fecundity, and recapture rates varied from highs in 1991-1993 to a low in 1994; there was partial recovery in these parameters in 1995 and 1996. Declines appeared to be associated with variation in abundance of several prey species, especially the red squirrel (Tamisciurus hudsonicus).

In Colorado, nesting flammulated owls ( Otus flammeolus) showed a preference for old trees and stands of ponderosa pine and Douglas-fir. Owls more often settled in areas dominated by older forests then young forests when they returned in the spring to nest. Flammulated owls used old trees and forest stands more often for forag- ing and for defending territories. Individual owls returned more often to territories that were in old stands of ponderosa pine mixed with Douglas-fir compared to territories composed of mosaics of stands of other tree species and ages.

... will be used as covariates in a logistic model to evaluate relationships between goshawk presence and ... Where forest habitats are continuous, the spacing between the nests of breeding pairs ... a combination of changes in habitat, food, predators, competitors, disease, or weather. ...

Developing and displaying forest structural targets are crucial for sustaining the habitats of the northern goshawk, a sensitive species in Southwestern forests. These structural targets were described in Management Recommendations for the Northern Goshawk in the Southwestern United States (MRNG) (Reynolds, et al., 1992). The MRNG were developed in a unique food-web approach that identified desired forest conditions for the

To investigate whether Northern Goshawk (Accipiter gentilis) reproduction is food-limited, we evaluated the reproductive output from 401 goshawk breeding opportunities on the Kaibab Plateau, Arizona during 1999-2002. Concurrently, we estimated densities of 10 goshawk prey species (seven birds, three mammals) using distance sampling. We then assessed the relationship between goshawk productivity (number of fledglings produced) and prey density within and among years by relating the contribution of individual prey species and total prey density to goshawk productivity. We also estimated the proportion of total diet and biomass for each species that contributed > or = 3% of all prey items. Total prey density was highly correlated with variation in goshawk productivity (r2 x 0.98, P x 0.012). Red squirrel (Tamiasciurus hudsonicus) density explained more variation in goshawk productivity than any other species (r2 x 0.94, P x 0.031), but density could not be estimated for every predom...

In Colorado, nesting flammulated owls ( Otus flammeolus) showed a preference for old trees and stands of ponderosa pine and Douglas-fir. Owls more often settled in areas dominated by older forests then young forests when they returned in the spring to nest. Flammulated owls used old trees and forest stands more often for forag- ing and for defending territories. Individual

We demonstrate approaches to developing conservation strategies for two threatened, endangered, and sensitive predators, the northern goshawk (Accipiter gentilis) and the Mexican spotted owl (Strix occidentalis lucida), which incorporate knowledge,of their habitats and those used by their major prey species. For each predator, a composite of prey habitats is constructed and then synthesized with the predator habitat. This synthesis results in a set of habitats for the predator's food web. Habitats are then projected onto aspatio -temporal scale by referencing them to historic forest conditions. These reference conditions include the composition, struc- ture, and landscape patterns of relevant forest types that existed before intensive management. We focus on forest types because each contains plants and animals that are adapted to local environments; for example, different plant species composi- tions, structures, patterns, and natural disturbances. Projection assures that the d...

ABSTRACT. We demonstrate approaches to developing conservation strategies for two threatened, endangered, and sensitive predators, the northern goshawk (Accipiter gentilis) and the Mexican spotted owl (Strix occidentalis lucida), which incorporate knowledge,of their habitats and those used by their major prey species. For each predator, a composite of prey habitats is constructed and then synthesized with the predator habitat. This synthesis

A female Flammulated Owl (Otus fiammeolus), banded as a breeding adult on 14 J ul. 1981 in central Colorado, was last captured on 9 J ul. 1987. On the same study area, a male Flammulated Owl was banded as a nestling on 15 J ul. 1981 and was last recaptured at a nest 2.5 Ian distant from its natal site

ABSTRACT Ecosystem-based forest management requires long planning horizons to incorporate forest dynamics — changes resulting from vegetation growth and succession and the periodic resetting of these by natural and anthropogenic disturbances such as fire, wind, insects, and timber harvests. Given these dynamics, ecosystem-based forest management plans should specify desired conditions such as tree species composition, age class, tree density and structure, size and density of snags and course woody debris, and the size, shape, and juxtaposition of trees, groups of trees, and stands in order to create and sustain habitats for wildlife. The management recommendations for the northern goshawk (Accipiter gentilis) in the southwestern United States (hereafter, recommendations; Reynolds et al. 1992) is a management plan designed to conserve this top predator by accounting for factors thought to limit their populations: vegetation structures, foods, predators, and competitors. The recommendations combined coarse- and fine-filter approaches to develop desired habitats for goshawks and their prey in landscapes whose compositions, structures, and patterns were conditioned on the aut- and synecologies of over- and understory plant species in forest ecosystems. Management plans that address all stages of a species' life history, the physical and biological factors limiting its populations, the habitats of other members of its ecological community, and the spatial and temporal dynamics of forests it occupies should be robust to failure (Reynolds et al. 2006a, b). The recommendations have been implemented in National Forests in the southwestern United States since 1996 (USDA Forest Service 1996), but their efficacy at conserving goshawk reproduction and survival has yet to be demonstrated. Recently, Beier et al. (2008) conducted a test of the recommendations and concluded that reproduction of goshawks declined as forest structures in their breeding areas became increasingly similar to those described in the recommendations. Here we show that methods they used to determine similarity to the structural conditions described in the recommendations resulted in inappropriate measures of similarity. We also show that their monitoring of goshawk reproduction on the 13 breeding areas used in their study was insufficient, and show how their insufficient monitoring introduced a systematic bias that reduced the precision of their test even if they had correctly measured similarity. We end by suggesting approaches for determining structural similarity to the goshawk recommendations in ponderosa pine and how to achieve adequate sampling for reproduction on breeding areas. © 2012 The Wildlife Society.

We used radiotelemetry to determine habitat use by Flammulated Owls (Otus Jlammeolus) during the breeding season on 452 ha of montane conifer forest in central Colorado in 1982-1983. Mean size and SD of home ranges was 11.1 2 1.9 ha (range = 8.5-12.5 ha, n = 4) in 1982 and 18.3 t 5.1 ha (range = 14.0-24.0 ha, n =