March 2020
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79 Reads
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8 Citations
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March 2020
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79 Reads
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8 Citations
March 2020
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26 Reads
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5 Citations
January 1998
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9 Reads
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22 Citations
The Birds of North America Online
January 1998
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4 Reads
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1 Citation
January 1998
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3 Reads
January 1998
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2 Reads
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2 Citations
The Birds of North America Online
February 1995
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59 Reads
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196 Citations
To address recent criticisms of the recovery process of the U.S. Endangered Species Act and to search for ways to improve recovery efforts, we evaluated all recovery plans approved by the U.S. Fish and Wildlife Service and the National Marine Fisheries Service as of August 1991. As expected with rare species, we found an overall lack of detailed biological information presented in recovery plans. Information on species’ distributions was most common, being mentioned in 88% of the original recovery plans, while information on species’ abundance, population demographics, and dynamics (in descending order) was much less available. Biological information tended to be sparsely distributed among taxonomic groups. We found that threatened and endangered species were at risk of extinction, yet differentiation between threatened and endangered species’ status in the wild and their recovery goals was not evident. Based on criteria developed by Mace and Lande (1991) (and depending on choice of minimum criteria), population-based recovery goals set in recovery plans, if achieved, would not improve the level of endangerment for 60–73% of vertebrate species. With few exceptions, a taxonomic bias was detected in the recovery process that favored animals over plants, vertebrates over invertebrates, and birds and mammals over fish and herpetofauna. The average time in years between listing and original recovery plan approval, however, was significantly shorter for plants (4.1) than animals (11.3), and for invertebrates (6.3) than vertebrates (9.4). It took an average of at least five years between each step in the recovery plan process (from listing to recovery plan approval and subsequent revision). Only 3.5% of the species in recovery plans were identified as keystones, and little recent emphasis has been placed on recovery plans covering multiple species. Finally, though public education was recommended frequently (92%) in recovery plans, public attitude assessment was virtually ignored (<2%). We suggest possible explanations for some of these findings, discuss the implications in light of the Endangered Species Act reauthorization, and present recommendations for future recovery plans and conservation strategies. Evaluamos todos los planes de recuperación aprobados por el Servicio de Pesca y Vida Silvestre de los Estados Unidos y por el Servicio Nacional de Pesquerías Marinas hasta Agosto de 1991, a efecto de referirnos a las recientes críticas al proceso de recuperación propuesto por el Acta de Especies en Peligro de Extinción y para buscar caminos que mejoren los esfuerzos de recuperación. Tal como se esperaba con las especies raras, encontramos una falta generalizada de información biológica detallada en los planes de recuperación. La información sobre la distribución de las especies fue la más común, siendo mencionada en el 88% de los planes de recuperación originales, mientras que la información sobre la abundancia de las especies, la demografía y la dinámica poblacional (en orden descendente) estuvieron mucho menos disponibles. La información biológica tendió ha estar distribuída en forma esparcida entre los grupos taxonómicos. Encontramos que especies amenazadas y en peligro estaban en riesgo de extinción, sin embargo la diferenciación entre el estado silvestre de las especies amenazadas y en peligro y sus objetivos de recuperación no era evidente. Basados en el criterio desarrollado por Mace y Lande (1991) (y dependiendo de la elección de un criterio mínimo), los objetivos de recuperación poblacional formulados en los planes de recuperación no mejorarían el nivel de riesgo de extinción para un 60–73% de las especies de vertebrados. Con pocas excepciones, se detectó un sesgo taxonómico en los procesos de recuperación que favoreció a los animales por sobre las plantas, a vertebrados por sobre los invertebrados y a los pájaros y mamíferos por sobre los peces y la herpetofauna. Sin embargo, el tiempo promedio en años entre el listado y la aprobación del plan de recuperación original fue significativamente más corto para las plantas que para los animales (11.3), e invertebrados (6.3) que vertebrados (9.4). Llevó un promedio de por lo menos 5 años entre cada paso en el proceso del plan de recuperación (desde el listado hasta la aprobación del plan de recuperación y subsecuente revisión). Sólo un 3.5% de las especies en los planes de recuperación fueron identificadas como especies “clave” y se ha puesto poco énfasis en los planes de recuperación que cubran especies múltiples. Finalmente, si bien la educación pública fue recomendada frecuentemente (92%) en los planes de recuperación, la evaluación de la actividad pública fue virtualmente ignorada (<2%). Sugerimos posibles explicaciones para algunos de estos hallazgos, discutimos las implicaciones para de la reautorización del Acta de Especies en Peligro de Extinción y presentamos recomendaciones para planes de recuperación y estrategias de conservación futuros.
January 1995
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15 Reads
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23 Citations
December 1993
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77 Reads
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165 Citations
Science
January 1993
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22 Reads
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23 Citations
The Birds of North America Online
... warblers are known to hybridize regularly where their geographic ranges meet in Washington and Oregon (Wright et al. 2020). Although there has been extensive research in their hybrid zone, there is limited information on hybrid migration ecology and wintering grounds. ...
March 2020
... -Sowy mogą wyjątkowo powtarzać lęgi po stracie. Przypadków takich nie notowano nigdy u włochatki na kontynencie amerykańskim (Hayward & Hayward 2020 (Mebs & Scherzinger 2000) -Włochatki mogą gniazdować poza dziuplami wykutymi przez dzięcioły i budkami lęgowymi, co w niektórych populacjach może nie być rzadkie (dane własne niepubl.). W powyższym zestawieniu nie uwzględniono trudności związanych z nasłuchem i stymulacją głosową, które omawiają krajowe prace metodyczne (np. ...
March 2020
... Changes in tree mortality may cause declines in suitable nesting habitats for some species such as northern goshawk (Graham et al. 1999;Kennedy 2003), but an increase in nesting sites for others such as the American three-toed woodpecker and red-breasted nuthatch that use tree snags and down woody debris (Bunnell 2013;Wiggins 2004). Climate-related changes in primary cavity nesters will also influence availability and competition for cavity nest sites (Hayward and Hayward 1993). ...
January 1993
... In addition to aiding in dispersal of mycorrhizal fungi, C. gapperi are also important prey for several carnivores (Hayward & Verner 1994; Ruggiero et al. 1995). Thus, maintenance of C. gapperi in variable retention harvest forests will also have potentially favourable impacts on predator populations (Garton, Hayward & Hayward 1989). The preference of M. longicaudus and M. pennsylvanicus for the early successional habitats of the clearcut and seed-tree sites may be explained by the abundance of herbs and grasses providing food and cover (Reich 1981; Getz 1985). ...
January 1989
... By 3500 years ago, temperate rainforests had emerged (Lacourse 2005;Galloway et al. 2009) as part of the Coastal Western Hemlock Zone . Heather vole is often absent or occurs in low densities within closed-canopy forest habitats (Miller et al. 1985;Walker 1987;Hayward and Hayward 1995;Sullivan et al. 2000;Barnosky et al. 2003;Sullivan and Sullivan 2021). On Vancouver Island and across the North Pacific Coast, the development of coastal western hemlock forests and ultimately of temperate rainforests that are inconsistent with the ecological preferences of the heather vole likely became habitat barriers. ...
January 1995
... The North American subspecies (A. f. richardsoni ) is distributed throughout boreal forests in Canada and Alaska, but its distribution also extends south in high-elevation, subalpine forests in the Rocky Mountains (Hayward et al. 1987). Across the boreal forests in Eurasia, boreal owls vary from dark brown and smaller (mean female wing0/176 mm) in Fennoscandia to light grey and larger (mean female wing 0/187 mm) in Russia, east of the Kolyma River (Dement'ev and Gladkov 1966, Cramp 1985). ...
May 1987
Ornithological Applications
... Likewise, observed changes in kestrel phenology induced by climate change (e.g., Steenhof and Peterson 2009b, Heath et al. 2012, Van Buskirk 2012) may alter the detection rate of kestrels during fixed-date annual surveys, potentially inducing trends in yearly counts (Simons et al. 2007, McClure et al. 2011, Heath et al. 2012. Studies of nestbox occupancy are also potentially problematic because changes in the availability of suitable habitat in surrounding areas may induce false trends in occupancy (VanCamp and Henny 1975, Hayward et al. 1992, McClure et al. 2017. Note that expected trends would be similar regardless of which vital rate is depressed. ...
October 1992
Journal of Wildlife Management
... Particularly concerning are our projections of important reductions in the size of future, individual mapped habitat areas for the boreal owl in New Mexico. Summer home range areas in Idaho were found to average 1182 ± 335 ha for 15 owls, with an observed minimum of 229 ha and an observed maximum of 2386 ha [59]. Although, in Idaho, boreal owls were not restricted to spruce-fir forest (they nested in mixed-conifer forest, where they presumably found more suitable nesting cavities, but roosted and foraged in spruce-fir forest), they also selected cool roosting sites during hot weather periods, when they often exhibited signs of heat stress [59]. ...
January 1993
Wildlife Monographs
... Here we examine macrogeographic variation of these song types displayed by Setophaga townsendi, a species distributed through much of western Canada, Alaska, and the Pacific Northwest of the USA (Wright et al. 1998). Early descriptions of song in Setophaga townsendi noted 2 song types: one beginning with clear, whistled notes and the other beginning with 3-6 vibrato notes, both songs showing a variable ending of whistled notes (Wright et al. 1998). ...
January 1998
The Birds of North America Online
... It has been suggested that female aggression may increase during a period of food scarcity and near caches. For example, frequent staying of Tengmalm's Owls Aegolius funereus near their winter caches has been explained as a cache defence (Hayward & Hayward 1993). However, the behaviour of defence of hoarded food in owls has been poorly documented in the literature. ...
January 1993
The Birds of North America Online