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Articles 1 - 7 of 7

Full-Text Articles in Life Sciences

Mobbing Behavior In Wild Steller's Jay (Cyanocitta Stelleri), Kelly Anne Commons Jan 2017

Mobbing Behavior In Wild Steller's Jay (Cyanocitta Stelleri), Kelly Anne Commons

Cal Poly Humboldt theses and projects

Mobbing is a widespread anti-predator behavior with multifaceted functions. Mobbing behavior has been found to differ with respect to many individual, group, and encounter level factors. To better understand the factors that influence mobbing behavior in wild Steller’s jays (Cyanocitta stelleri), I induced mobbing behavior using 3 predator mounts: a great horned owl (Bubo virginianus), common raven (Corvus corax), and sharp-shinned hawk (Accipiter cooperii). I observed 90 responses to mock predators by 33 color-marked individuals and found that jays varied in their attendance at mobbing trials, their alarm calling behavior, and in …


Distribution Of The North American Porcupine (Erethizon Dorsatum) In Northern California, Cara L. Appel, William J. Zielinski, Frederick V. Schlexer, Richard Callas, Tim Bean Jan 2017

Distribution Of The North American Porcupine (Erethizon Dorsatum) In Northern California, Cara L. Appel, William J. Zielinski, Frederick V. Schlexer, Richard Callas, Tim Bean

Open Educational Resources

Western Wildlife 4:17–28, 2017: The North American Porcupine (Erethizon dorsatum) is one of the most widely distributed mammals in North America, but recent reports have suggested declines in parts of its range in the West. In California, little is known about the historical or current status of the porcupine, and maps of its distribution conflict considerably. Nevertheless, the species is of interest to natural resource managers. For much of the 1900s, foresters and others primarily treated porcupines as pests because of the undesirable damage they inflict feeding on trees and gnawing on manmade items in search of salt. …


Abundance, Growth, And Predation By Non-Native Brown Trout In The Trinity River, Ca, Justin S. Alvarez Jan 2017

Abundance, Growth, And Predation By Non-Native Brown Trout In The Trinity River, Ca, Justin S. Alvarez

Cal Poly Humboldt theses and projects

Brown Trout were introduced to the Trinity River in Northern California in the 1890’s. Since 1932, Brown Trout have sustained their population without additional stocking. Over the last 15 years, fisheries managers have been concerned that predation by piscivorous Brown Trout may impede efforts to restore native salmonids, in particular endangered Coho Salmon. I investigated predation by Brown Trout on native fish in the 64 km of the main stem Trinity River below Lewiston Dam. Using a bioenergetics approach parameterized with field measurements of Brown Trout abundance and growth, I estimated the amount of energy needed to sustain the 2015 …


The Bee Fauna Of The Horse Mountain And Grouse Mountain Region, Humboldt County, California, Carrie Lopez Jan 2017

The Bee Fauna Of The Horse Mountain And Grouse Mountain Region, Humboldt County, California, Carrie Lopez

Cal Poly Humboldt theses and projects

Recent concerns about the ecological well-being of bee communities in California and elsewhere have increased the need for monitoring programs and studies that evaluate the impact of habitat loss and alteration on bee diversity and abundance. Such studies depend critically on the expertise of people trained in taxonomy, but their numbers have declined in recent years. My primary goal was to gain a comprehensive first-hand experience with bee identification by documenting the fauna of a previously unstudied area in the mountains of northwestern California and by writing an identification key, intended for dedicated non-specialists, to the area’s 35 species of …


Multiscale Habitat Suitability Modeling For Canary Rockfish (Sebastes Pinniger) Along The Northern California Coast, Portia N. Saucedo Jan 2017

Multiscale Habitat Suitability Modeling For Canary Rockfish (Sebastes Pinniger) Along The Northern California Coast, Portia N. Saucedo

Cal Poly Humboldt theses and projects

Detailed spatially-explicit data of the potential habitat of commercially important rockfish species are a critical component for the purposes of marine conservation, evaluation, and planning. Predictive habitat modeling techniques are widely used to identify suitable habitat in un-surveyed regions. This study elucidates the predicted distribution of canary rockfish (Sebastes pinniger) along the largely un-surveyed northern California coast using data from visual underwater surveys and predictive terrain complexity covariates. I used Maximum Entropy (MaxEnt) modelling software to identify regions of suitable habitat for S. pinniger greater than nine cm in total length at two spatial scales. The results of …


Population Characteristics And Trophic Interactions Between Pacific Mole Crabs And Redtail Surfperch On Northern California Sandy Beaches, Michelle Lynn Succow Jan 2017

Population Characteristics And Trophic Interactions Between Pacific Mole Crabs And Redtail Surfperch On Northern California Sandy Beaches, Michelle Lynn Succow

Cal Poly Humboldt theses and projects

A network of marine protected areas (MPAs) was established to protect northern California coastal habitats in December 2012. Populations of two indicator species, Amphistichus rhodoterus (redtail surfperch) and Emerita analoga (pacific mole crabs) were characterized within MPAs and reference sites to provide baseline ecological information for this region. Data were gathered using a series of simple field surveys (hook and line fishing surveys for A. rhodoterus along with core and transect surveys for E. analoga). Relative abundance, lengths, and sex ratios of A. rhodoterus did not differ between MPAs and their respective reference sites, whereas condition (overall health) increased …


Propensity Of Predator Mimicry In Wild Steller's Jays, Trinity C. Tippin Jan 2017

Propensity Of Predator Mimicry In Wild Steller's Jays, Trinity C. Tippin

Cal Poly Humboldt theses and projects

Avian vocal mimicry has been described in a variety of contexts, suggesting its function is multifaceted within and across species; however, basic empirical data describing mimetic signal prevalence and context is lacking for numerous species. I examined occurrence and context of mimicked red-shouldered hawk (Buteo lineatus) calls over a 12-month period in a wild population of 49 individually color-marked Steller’s jays (Cyanocitta stelleri) and reviewed the occurrence of the behavior in historic re-sight data. I documented mimicry of red-shouldered hawk calls in 14 of 49 (28.6%) jays during the study. Hawk mimicry occurred more often during …