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Managing forests for biodiversity conservation while maintaining economic output is a major challenge globally and requires accurate and timely monitoring of imperiled species. In the Pacific Northwest, USA, forest management is heavily influenced by the status of northern spotted owls (Strix occidentalis caurina), which have been in continued population decline for the past four decades. The monitoring program for northern spotted owls is transitioning from mark–resight surveys to a passive acoustic framework, requiring development of alternative analysis approaches. To maintain relevance for conservation and management, these analyses must accurately track underlying population changes, identify responses to disturbance, and estimate occupancy of owl pairs. We randomly selected and surveyed 5‐km2 hexagons for 6 weeks using passive acoustic monitoring in the Olympic Peninsula of Washington and the Oregon Coast Range during the 2018 spotted owl breeding season. We used a convolutional neural network to identify spotted owl calls, followed by logistic regression to determine the sex of vocalizing owls to assign pair status. We implemented multistate occupancy models to estimate probabilities of detection, species‐level landscape use, and pair occupancy of spotted owls. We also quantified detections of barred owls (Strix varia), a congeneric competitor and important driver of spotted owl population declines. The overall rate of hexagon use by spotted owls was estimated at 0.21 (SD 0.04) after adjusting for imperfect detection, and pair occupancy was 0.07 (SD 0.02). The probability of detecting a pair (i.e., both female and male) during a weekly occasion was relatively low (0.03, SD 0.01), indicating that true pair occupancy was between 1.3 and 4.1 times greater than the proportion of hexagons with observed pair detections. Barred owls were ubiquitous, with a naïve occupancy rate of 0.97. The intensity of calling by barred owls had a weak, negative effect on the probability of spotted owls being paired when present but had little measurable effect on their detectability. This work establishes a framework that may be effective for spotted owl population monitoring and illustrates that pairs have very low detection probability, which—combined with increasingly low numbers of spotted owl pairs—is an important consideration for conservation and management. [ABSTRACT FROM AUTHOR]

Forest management affects conditions for both early‐ and late‐seral organisms, and managers and conservationists require information for balancing the ostensibly opposing habitat needs of both these guilds. We conducted meta‐analyses that examined silvicultural systems with a range of postharvest retention and their impacts on mature‐forest and shrubland bird species densities in eastern North America during the breeding season. Densities of mature‐forest bird species generally declined as canopy tree retention and basal area decreased, although some mature‐forest species had similar densities among unharvested and partially harvested (e.g., first‐entry shelterwood) stands, and others had their highest densities in shelterwoods. We conducted a previous meta‐analysis study, which showed most shrubland bird species in the region increase with harvest intensity, but some shrubland species had similar densities in clearcuts and shelterwoods. Given the contrasting effects of harvest intensity on the two avian guilds, we used Partners‐in‐Flight conservation values to generate objective community‐wide conservation indices relative to postharvest tree retention. Clearcuts and shelterwoods typically had the highest conservation values, and unharvested and lightly thinned stands (70%–100% tree retention) had the lowest conservation scores. Many declining shrubland bird species of conservation concern are abundant in low‐retention stands, thus elevating the conservation value of these stands. Additionally, high conservation values of harvested stands with 40%–70% tree retention represent the presence of both shrubland and mature‐forest species; the latter are potentially responding to enhanced understory structure needed for avian nesting or foraging. In contrast, contemporary closed‐canopy forests in eastern North America are generally characterized by low structural diversity and are mid‐seral stands due to historical patterns of land use and tree harvesting. Although avian community conservation values were lowest in high‐retention stands and many other threatened, non‐avian taxa depend on open‐canopy, managed forests, managers should note that late‐seral, unharvested stands can provide important habitat for old‐growth‐dependent taxa and any intensive forestry should also take into account other factors. Considering the growing interest in using postharvest retention of canopy trees to meet ecological objectives, our novel synthesis can assist managers in assessing species‐specific and community‐wide avian responses to tree retention levels along the entire gradient of canopy treatments. [ABSTRACT FROM AUTHOR]

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