Keith Swindle - Academia.edu (original) (raw)

Papers by Keith Swindle

I have often wondered what this nation would look like without the efforts of those whom have car... more I have often wondered what this nation would look like without the efforts of those whom have cared about and for its natural heritage. Having had the honor and pleasure to know and work with the following individuals and organizations I now know what the nation would look like without their stewardship and citizenship. All too often those of us concerned about our cultural heritage forget that it is inextricable from our natural heritage. I know that the following people and organizations have served the people of this nation for years to come through their love for and dedication to our natural resources and their stewardship. In their regard, I put forward this document, knowing that it cannot serve justice to their efforts that are, however, realized on the landscape. I do hope that this study will provide some further assistance to understanding the northern spotted owl; a fascinating and remarkable component of the world we belong to that would be inexcusable and unforgivable to lose. This study was made possible by and greatly benefitted from over 25 years of work and research on the northern spotted owl conducted by the Oregon Cooperative Wildlife Research Unit under the original leadership of Dr. Howard M. Wight, then Dr. E. Charles Meslow and now by Dr. Robert G. Anthony. Under the auspices of the Unit, Dr. Eric D. Forsman began studying the owl in the early 1970's in the vicinity of the H.J. Andrews Experimental Forest. Dr. Forsman's initial investigations were of the owls' life-history and habits, home-range size and composition, and habitat use. In the early 1980's Gary S. Miller studied juvenile owl dispersal and survival and then began the density and demography study that still continues today under Jim Thrailkill's leadership. Many of the owl territories and owls that Eric and Gary originally identified were part of this study and I am indebted to them. Funding for these studies was provided through several grants by the U. S.

Canadian Journal of Zoology, Oct 1, 2003

The hypothesis that high temporal variability of northern spotted owl (Strix occidentalis caurina... more The hypothesis that high temporal variability of northern spotted owl (Strix occidentalis caurina) reproductive success is a response to prey abundance remains largely untested. We evaluated this relationship in the Oregon Cascade Mountains. Despite similar biomass of northern flying squirrels (Glaucomys sabrinus) (169 ± 13.9 g/ha) and deer mice (Peromyscus maniculatus) (160 ± 18.8 g/ha), flying squirrels dominated the breeding season diet based on both biomass (49%) and numbers (40%). Abundance of flying squirrels and western red-backed voles (Clethrionomys californicus) was more variable spatially (≥38% of process variation) than temporally (15%-24%), whereas abundance of deer mice was more similar across stands (12% spatial variation) than among years (68% temporal variation). Spotted owl reproductive success was statistically associated only with the abundance of deer mice (number of young per territory: r 2 = 0.68). However, deer mice comprised only 1.6 ± 0.5% of the biomass consumed. The low temporal variability of the dominant prey species provided evidence that simple prey relationship models were not likely to explain the highly synchronous and temporally dynamic patterns of spotted owl reproductive performance. Reproductive success was likely a result of the interaction of both weather and prey and the life history strategy of this long-lived owl. Résumé : L'hypothèse qui veut que l'importante variabilité temporelle du succès reproducteur de la chouette tachetée du nord (Strix occidentalis caurina) s'explique par les variations d'abondance des proies reste à vérifier. Nous avons évalué cette relation dans les monts Cascades de l'Oregon. Bien que les grands polatouches (Glaucomys sabrinus) (169 ± 13,9 g/ha) et les souris sylvestres (Peromyscus maniculatus) (160 ± 18,8 g/ha) aient des biomasses semblables, les polatouches prédominent dans le régime alimentaire de la chouette durant la saison de reproduction, tant par la biomasse (49 %) que par la densité (40 %). L'abondance des grands polatouches et celle des campagnols-à-dos-roux de l'Ouest (Clethrionomys californicus) varient plus dans l'espace (≥38 % de la variation de processus) que dans le temps (15 %-24 %), alors que celle des souris sylvestres est plus semblable d'une parcelle à l'autre (12 % de variation spatiale) que d'une année à l'autre (68 % de variation temporelle). Le succès de la reproduction de la chouette tachetée est en corrélation statistiquement significative seulement avec l'abondance des souris sylvestres (nombre de petits pour territoire: r 2 = 0,68). Cependant, les souris sylvestres ne représentent que 1,6 ± 0,5 % de la biomasse ingérée. La faible variabilité temporelle de l'espèce prédominante de proies indique que des modèles simples de prédation sont peu susceptibles d'expliquer les patterns très synchronisés et la dynamique temporelle de la performance reproductive de la chouette tachetée. Le succès de la reproduction s'explique probablement par l'interaction du climat et des proies, ainsi que par la stratégie démographique de cette chouette à grande longévité. [Traduit par la Rédaction] Rosenberg et al. 1725

Heredity, Mar 21, 2012

Seabirds are highly vagile and can disperse up to thousands of kilometers, making it difficult to... more Seabirds are highly vagile and can disperse up to thousands of kilometers, making it difficult to identify the factors that promote isolation between populations. The endemic Hawaiian petrel (Pterodroma sandwichensis) is one such species. Today it is endangered, and known to breed only on the islands of Hawaii, Maui, Lanai and Kauai. Historical records indicate that a large population formerly bred on Molokai as well, but this population has recently been extirpated. Given the great dispersal potential of these petrels, it remains unclear if populations are genetically distinct and which factors may contribute to isolation between them. We sampled petrels from across their range, including individuals from the presumably extirpated Molokai population. We sequenced 524 bp of mitochondrial DNA, 741 bp from three nuclear introns, and genotyped 18 microsatellite loci in order to examine the patterns of divergence in this species and to investigate the potential underlying mechanisms. Both mitochondrial and nuclear data sets indicated significant genetic differentiation among all modern populations, but no differentiation was found between historic samples from Molokai and modern birds from Lanai. Populationspecific nonbreeding distribution and strong natal philopatry may reduce gene flow between populations. However, the lack of population structure between extirpated Molokai birds and modern birds on Lanai indicates that there was substantial gene flow between these populations and that petrels may be able to overcome barriers to dispersal prior to complete extirpation. Hawaiian petrel populations could be considered distinct management units, however, the dwindling population on Hawaii may require translocation to prevent extirpation in the near future.

Wildlife Monographs, 2002

2 Wildlife Monographs Abstract: We studied the dispersal behavior of 1,475 northern spotted owls ... more 2 Wildlife Monographs Abstract: We studied the dispersal behavior of 1,475 northern spotted owls (Strix occidentalis caurina) during banding and radio-telemetry studies in Oregon and Washington in 1985-1996. The sample included 324 radio-marked juveniles and 1,151 banded ...

This file contains data for 15 microsatellite loci genotyped in modern Hawaiian petrel (Pterodrom... more This file contains data for 15 microsatellite loci genotyped in modern Hawaiian petrel (Pterodroma sandwichensis) samples from the islands of Hawaii, Maui, Lanai, and Kauai in the Hawaiian Islands, USA. The file is in the three digit Genepop format. See the ReadMe file for additional details

Seabirds are highly vagile and can disperse up to thousands of kilometers, therefore it can be di... more Seabirds are highly vagile and can disperse up to thousands of kilometers, therefore it can be difficult to identify the factors that promote isolation between populations. The endemic Hawaiian petrel (Pterodroma sandwichensis) is one such species. Today it is endangered, and known to breed only on the islands of Hawaii, Maui, Lanai, and Kauai. Historical records indicate that a large population formerly bred on Molokai as well, but this population has recently been extirpated. Given the great dispersal potential of these petrels it remains unclear if populations are genetically distinct and which factors may contribute to isolation between them. We sampled petrels from across their range, including individuals from the extirpated Molokai population. We sequenced 524 bp of mitochondrial DNA, 741 bp from three nuclear introns, and genotyped 18 microsatellite loci in order to examine patterns of divergence in this species and to investigate the potential underlying mechanisms. Mitochondrial and nuclear data sets indicated significant genetic differentiation among all modern populations, but no differentiation was found between historic samples from Molokai and modern birds from Lanai. Population-specific non-breeding distribution or perhaps strong natal philopatry may reduce gene flow between populations. However, the lack of population structure between extirpated Molokai birds and modern birds on Lanai suggests that petrels may be able to overcome these barriers and disperse prior to complete extirpation. Hawaiian petrel populations should be managed as distinct units, except potentially for the dwindling population on Hawaii, which may require translocation to prevent extirpation in the near future

Journal of Wildlife Management, Oct 1, 1999

Unlike previous spotted owl (Strix occidentalis) habitat association studies, we restricted our i... more Unlike previous spotted owl (Strix occidentalis) habitat association studies, we restricted our inquiry to the old-forest type and thus explored the association of spotted owls with habitat distribution as opposed to habitat type. We compared old-forest distribution around 126 northern spotted owl (S. o. caurina) nests in 70 pair territories, 14 nonreproductive spotted owl activity centers, and 104 points drawn randomly from old forest (closed canopy, >80 yr) in the central Cascade Mountains of Oregon. We quantified the percentage of old forest within 50 concentric circular plots (0.1-5.0-km radii) centered on each analyzed point, and we used logistic regression to make spatially explicit inferences. Owl nests were surrounded by more old forest in plots with 0.2-0.8-km radii (P < 0.05). Results suggested the landscape scales most pertinent to northern spotted owl nest-site positioning in this study were (in descending order) (1) the surrounding 15 ha (approx 200-m radius), (2) the surrounding 30-115 ha (approx 300-600-m radius), (3) the surrounding 200 ha (800-m radius), and (4) possibly the surrounding 700 ha (1,500-m radius). Nests were associated with higher proportions of old forest near the nest, implying that the arrangement of habitat was important for nest-site selection, positioning, or both. The 70 territories of nesting owls had more old forest on average than did the 14 nonreprodu•tive owl sites, and the probability that a pair nested at least once during the study was positively associated with area of old-forest habitat in all radii studied. Because spotted owls in the central Cascade Mountains of Oregon are known to have home ranges that average 1,769 ha, our results apply to nest-site location on the landscape and not to the amount of habitat necessary for pair persistence or successful reproduction.

A landscape plan based on historical fire regimes for a managed forest ecosystem: the Augusta Cre... more A landscape plan based on historical fire regimes for a managed forest ecosystem: the Augusta Creek study. Gen. Tech.

Wildlife Monographs, 2002

PLOS ONE, Mar 24, 2022

Attraction to artificial light at night (ALAN) poses a threat to many fledgling seabirds leaving ... more Attraction to artificial light at night (ALAN) poses a threat to many fledgling seabirds leaving their nests for the first time. In Hawai'i, fledgling wedge-tailed shearwaters disoriented by lights may become grounded due to exhaustion or collision, exposing them to additional threats from road traffic and predation. While the timing and magnitude of shearwater fallout varies from year to year, little is known about how changing lighting and environmental conditions influence the risk of grounding for this species. We analyzed 8 years (2012-2019) of observations of road-killed shearwaters along the Kalaniana'ole Highway on O'ahu to quantify the timing and magnitude of fallout during the fledging season (November-December). Our goal was to compare fallout before (2012-15) and after (2016-19) a transition in highway lighting from unshielded high-pressure sodium (HPS) to full-cutoff light-emitting diode (LED) streetlights. To detect the shearwater response to the lighting regime, we also accounted for three potential environmental drivers of interannual variability in fallout: moon illumination, wind speed, and wind direction. The effects of these environmental drivers varied across years, with moon illumination, wind speed and wind direction significantly affecting fallout in at least one year. Altogether, the interaction between moon illumination and wind speed was the most important predictor, suggesting that fallout increases during nights with low moon and strong winds. The lack of an increase in fallout after the change from HPS to shielded 3000K-4000K LED streetlights suggests the new streetlights did not worsen the light pollution impacts on wedge-tailed shearwaters on Southeast O'ahu. However, due to potential species-specific disparities in the behavior and light attraction of petrels, similar studies are needed before energy saving LED lights are implemented throughout the Hawaiian archipelago.

California rcd-bacLe d t oles (Clet I uionoml s t:ttlifornirtzr) are endernic to lorests i l l we... more California rcd-bacLe d t oles (Clet I uionoml s t:ttlifornirtzr) are endernic to lorests i l l weslcrn Oregorr and norLhtcst ( ial i lornia (Alexander and Verts I992). Some invrist igators uggcsted rhat ( ial i for.nia rccl backcd voles o(.( u[ more frccluentl_v in mature clo-ccd-canopv fcrrests with little undcrstorv de r . l , , pmer ' t . r r ' , 1 "1 " " r f , , r l r . r L i r a r t h . r t i , c . i g nilicant arnounts o[ coarse rvoodv debris (Tevis 1956. Cashwilcr 1959. \ ' lascr i9[ l l" Doyle 1987. Comez 1992). or grcater food resour-ces lnvpogeous frurgi. f l rc and Maser 1982). Othcr inrestigators did not detecL a dif ierence in abundancc of {lnlifrrrnia led,brckr:d voles bch{een voung and nlclcr forests (Aubrev et o1.1991,. Corn and Bury 1991. Cilbclt and Alhl ine 199l). Ho.wever, voung sLands eraminr:d in the lattcr stu. l ics \ \ ,ere natulallv fegcnerated aftcr lire. and the atrthors suggestcd that Calilbrnia rcd backed voles mav respon...

FRISWOLD, B., SWINDLE, K., HYRENBACH, D. & PRICE, M.R. 2020. Wedge-tailed Shearwater Ardenna paci... more FRISWOLD, B., SWINDLE, K., HYRENBACH, D. & PRICE, M.R. 2020. Wedge-tailed Shearwater Ardenna pacifica fallout patterns inform targeted management. Marine Ornithology 48: 245–254. Seabird fledglings are often attracted to artificial, bright lights, leading to their grounding. This phenomenon is termed “fallout” and is associated with an increased risk of mortality from land-based threats. This study evaluated temporal trends and spatial factors, such as fallout clustering near lights and proximity to colonies, to inform targeted management actions. Standardized surveys were conducted from 2002 to 2010 for Wedge-tailed Shearwater Ardenna pacifica (WTSH) fallout on the island of O‘ahu, Hawai‘i, USA. First, yearly fallout counts along the transect showed a two-year cycle and identified 25 November as the date with the highest fallout across years. Second, artificial lights and utility lines were present in 94% and 83% of fallout locations, leading to significantly higher fallout rates a...

Oecologia, 2012

Foraging segregation may play an important role in the maintenance of animal diversity, and is a ... more Foraging segregation may play an important role in the maintenance of animal diversity, and is a proposed mechanism for promoting genetic divergence within seabird species. However, little information exists regarding its presence among seabird populations. We investigated genetic and foraging divergence between two colonies of endangered Hawaiian petrels (Pterodroma sandwichensis) nesting on the islands of Hawaii and Kauai using the mitochondrial Cytochrome b gene and carbon, nitrogen and hydrogen isotope values (d 13 C, d 15 N and dD, respectively) of feathers. Genetic analyses revealed strong differentiation between colonies on Hawaii and Kauai, with U ST = 0.50 (p \ 0.0001). Coalescent-based analyses gave estimates of \1 migration event per 1,000 generations.

The Journal of Wildlife Management, 1999

... US Geological Survey, Biological Resources Division, Department of Fisheries and Wildlife, Or... more ... US Geological Survey, Biological Resources Division, Department of Fisheries and Wildlife, Oregon Cooperative Wildlife Research Unit, 104 Nash Hall, Oregon State University, Corvallis, OR 97331, USA DANIEL SCHAFER, Department of Statistics, 44 ... 1990, Rip-ple et al. ...

Canadian Journal of Zoology, 2003

Introduction Cissel, John H.; Swanson, Frederick J.; Grant, Gordon E.; Olson, Deanna H.; Stanley,... more Introduction Cissel, John H.; Swanson, Frederick J.; Grant, Gordon E.; Olson, Deanna H.; Stanley, Gregory V.; Garman, Steven L.; Ashkenas, Linda R.; Hunter, Matthew G.; Kertis, Jane A.; Mayo, James H.; McSwain, Michelle D.; Swetland, Sam G.; Swindle, Keith A.; Wallin, David O. 1998. A landscape plan based on historical fire regimes for a managed forest ecosystem: the Augusta Creek study. Gen. Tech.

Canadian Journal of Zoology, Oct 1, 2003

Heredity, Mar 21, 2012

Wildlife Monographs, 2002

Journal of Wildlife Management, Oct 1, 1999

Wildlife Monographs, 2002

PLOS ONE, Mar 24, 2022

Oecologia, 2012

The Journal of Wildlife Management, 1999

Canadian Journal of Zoology, 2003