Skip to main content
Advanced Search

Filters: Tags: empidonax traillii extimus (X)

13 results (58ms)   

View Results as: JSON ATOM CSV
Characterizing avian diet is complex, especially for generalist insectivores, as food resources can vary over space and time, and individuals of different sexes and ages may consume different food. We examined diet of a generalist insectivore, the Southwestern Willow Flycatcher (Empidonax traillii extimus), at Roosevelt Lake in central Arizona from 2000 to 2004, determined from 344 fecal samples. We found that five prey categories accounted for 70% of the proportional abundance in flycatcher diet: Hymenoptera, Diptera, Cicadellidae, Coleoptera, and Formicidae, although the relative amounts of these and other taxa differed significantly among years. We detected no differences in diet between sexes of adults, but...
thumbnail
These data identify, in general, the areas of FINAL critical habitat for Empidonax traillii extimus (southwestern willow flycatcher).
thumbnail
These data are statistical model outputs for Willow flycatcher (ssp. Southwestern willow flycatcher) (Empidonax traillii extimus )  species distribution, completed by Frank Davis’ Biogeography Lab at UC Santa Barbara. Based on examination of species observation data and consultation with biologists, CBI used the model's broad extent output masked to within 10 km of the Colorado River and the following USFS ecoregion subsections: 322Aa, M261Er, M261Es, 322Ag, M262Bi, M262Bh, M262Bg, 322Cc.  The UCSB Biogeography Lab used Maxent to generate predictions of habitat occupancy for ~70 species for the CA Energy Commission’s project “Cumulative Biological Impacts Framework for Solar Energy in the CA Desert”,...
The southwestern willow flycatcher (SWFL; Empidonax traillii extimus) is an endangered songbird whose habitat has declined dramatically over the last century. Understanding habitat selection patterns and the ability to identify potential breeding areas for the SWFL is crucial to the management and conservation of this species. We developed a multiscaled model of SWFL breeding habitat with a Geographic Information System (GIS), survey data, GIS variables, and multiple logistic regressions. We obtained presence and absence survey data from a riverine ecosystem and a reservoir delta in south-central Arizona, USA, in 1999. We extracted the GIS variables from satellite imagery and digital elevation models to characterize...
thumbnail
This dataset represents current terrestrial intactness values (estimated at the 1km level) within the modeled distribution of the Southwestern willow flycatcher (Empidonax traillii extimus).Terrestrial intactness is high in areas where development is low, vegetation intactness is high, and fragmentation is low. Consequently, this dataset serves as a general* indication of habitat quality within the distribution of this conservation element. Estimates of current terrestrial intactness were generated by an EEMS fuzzy logic model that integrates multiple measures of landscape development and vegetation intactness, including agriculture development (from LANDFIRE EVT v1.1), urban development (from LANDFIRE EVT v1.1...
An understanding of individuality in animal vocalizations can assist in tracking individuals spatially and temporally, and is particularly useful for species of conservation concern. We determined whether fitz bew vocalizations of the endangered Southwestern Willow Flycatcher (Empidonax traillii extimus) showed vocal individuality, assessed the differences in vocal individuality among three populations, and tested the ability of predictive vocalization models to reidentify individuals. Fitz bew vocalizations were recorded from two populations in Arizona (Roosevelt Lake and San Pedro River) and one in California (Kern River). Individuality was determined using discriminant function analysis (DFA) and trained artificial...
Exotic vegetation has become a major habitat component in many ecosystems around the world, sometimes dramatically changing the vegetation community structure and composition. In the southwestern United States, riparian ecosystems are undergoing major changes in part due to the establishment and spread of the exotic Tamarix (saltcedar, tamarisk). There are concerns about the suitability of Tamarix as habitat for birds. Although Tamarix habitats tend to support fewer species and individuals than native habitats, Arizona Breeding Bird Atlas data and Birds of North America accounts show that 49 species use Tamarix as breeding habitat. Importantly, the relative use of Tamarix and its quality as habitat vary substantially...
thumbnail
These data are statistical model outputs for southwestern willow flycatcher (Empidonax traillii extimus) species distribution, completed by Frank Davis’ Biogeography Lab at UC Santa Barbara. The UCSB Biogeography Lab used Maxent to generate predictions of habitat occupancy for ~70 species for the CA Energy Commission’s project “Cumulative Biological Impacts Framework for Solar Energy in the CA Desert”, 500-10-021. Species distribution models were produced at 270 m resolution using a subset of 22 environmental variables. Models were evaluated with 10-foldcross validated AUC scores. Results are preliminary and have notyet been reviewed by expert biologists. Both continuous probability surfaces and binary...
thumbnail
To provide the user with a general idea of areas where final critical habitat for Southwestern willow flycatcher (Empidonax traillii extimus). The geographic extent includes counties in Arizona, California, Colorado, New Mexico, Nevada and Utah.
    map background search result map search result map Southwestern willow flycatcher - UCSB Species Distribution Model, CA Desert Southwestern willow flycatcher - Habitat Intactness, DRECP Southwestern willow flycatcher - Species Distribution Model, DRECP FINAL Critical Habitat for Empidonax Traillii Extimus (Southwestern Willow Flycatcher) Southwestern Willow Flycatcher: Current Habitat Suitability Consensus of All Models Southwestern Willow Flycatcher: 2030 Habitat Suitability Consensus of All Models Southwestern Willow Flycatcher: 2060 Habitat Suitability Consensus of All Models Southwestern Willow Flycatcher: 2090 Habitat Suitability Consensus of All Models BLM REA SOD 2010 Southwestern Willow Flycatcher Critical Habitat, Final 2005 BLM REA SOD 2010 Southwestern Willow Flycatcher Critical Habitat, Final 2005 Southwestern Willow Flycatcher: Current Habitat Suitability Consensus of All Models Southwestern Willow Flycatcher: 2030 Habitat Suitability Consensus of All Models Southwestern Willow Flycatcher: 2060 Habitat Suitability Consensus of All Models Southwestern Willow Flycatcher: 2090 Habitat Suitability Consensus of All Models Southwestern willow flycatcher - Habitat Intactness, DRECP Southwestern willow flycatcher - Species Distribution Model, DRECP Southwestern willow flycatcher - UCSB Species Distribution Model, CA Desert FINAL Critical Habitat for Empidonax Traillii Extimus (Southwestern Willow Flycatcher)