Filters: Tags: Detection Probability (X) > Categories: Data (X)
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Data set resulting from monitoring the behavior of snakes (n = 62) that had been feed a standardized large meal with transmitter, proportional to their body mass, to make direct comparisons to a control group of snakes that had not been fed a meal (only the transmitter). Transmitters were equipped with a two-position switch that changes pulse rate when the body position of the animal changes more than 10 degrees from the switch's preset orientation. Changes in pulse rate serve as a proxy measurement for snake activity, under the logic that a relatively stationary/sedentary snake would cause the transmitter to tip less frequently that an actively moving/foraging snake would. The experiment took place in the U.S....
Categories: Data;
Tags: Brown Treesnake,
Detection Probability,
Foraging,
Guam,
USGS Science Data Catalog (SDC),
These data are detections of bison in Grand Canyon National Park made during helicopter surveys between 2019 and 2021, and an aerial infrared imagery survey done in February 2020.
Categories: Data;
Tags: Arizona,
Ecology,
North Rim,
Powell Plateau,
USGS Science Data Catalog (SDC),
Feral burros (Equus asinus) and horses (E. ferus caballus) inhabiting public land in the western United States are intended to be managed at population levels established to promote a thriving, natural ecological balance. Like many large ungulate populations, management agencies employ aerial surveys to obtain estimates of horse and burro population sizes. Double-observer sightability (MDS) models perform well for estimating feral horse abundances, yet the effectiveness of these models for use in burro populations is less understood and may be different due to the smaller size, stoic behavior, and cryptic pelage of burros. These models help minimize detection bias, yet bias can be further reduced with models that...
Categories: Data;
Tags: Arizona,
California,
Ecology,
Fort Irwin National Training Center,
Lake Pleasant Herd Management Area,
This dataset contains detection-nondetection data for territorial pairs of Golden Eagles at survey sites randomly selected from a grid of equal-sized (13.9 km2) hexagonal sample cells overlaid across the region of interest in Coastal Southern California during 2016 and 2017. We partitioned surveys within seasons based on approximate transition dates for stages in the breeding cycle of golden eagles in the study region: courtship (15 Dec-28 Feb), incubation (1 Mar-30 Apr), nestling (1 May-15 Jun), and the fledging-dependency period (16 June-Jul 30), totaling 4 possible sampling periods per year. This dataset also describes the proportion of land-cover types from four general categories (urban, open grassland, scrub...
These data represent occupancy estimates for western bumble bee across the western continental United States and the spatial variation in detection probabilities that occur during bumble bee surveys. This product contains five raster layers (appearing as separate bands in a multi-band raster). The first two bands represent the predicted occupancy of western bumble bee in 1998 and 2018. We modeled western bumble bee occupancy as a function of: latitude, longitude, elevation, year, and land cover. The last three bands represent the spatial variation in detection probabilities predicted to occur for surveys conducted across the western United States on three dates (May 15, July 15, and September 15). We modeled detection...
Categories: Data;
Types: Downloadable,
GeoTIFF,
Map Service,
Raster;
Tags: Arizona,
Bombus occidentalis,
California,
Colorado,
Detection Probability,
Occupancy models provide a reliable method of estimating species distributions while accounting for imperfect detectability. The cost of accounting for false absences is that detection and nondetection surveys typically require repeated visits to a site or multiple-observer techniques. More efficient methods of collecting data to estimate detection probabilities would allow additional sites to be surveyed for the same amount of effort, which would support more precise estimation of covariate effects to improve inference about underlying ecological processes. Time-to-detection surveys allow the estimation of detection probability based on a single site visit by one observer, and therefore might be an efficient technique...
Categories: Data;
Tags: California,
Ecology,
Marin County,
Point Reyes National Seashore,
USGS Science Data Catalog (SDC),
This dataset contains count and detection-nondetection data of Barred Owls from 106 historical breeding territories of Northern Spotted Owl territories (i.e. sites) in the Oregon Coast Ranges from 1995 to 2016. Data collected from 1995 to 2014 are partitioned into 2-week periods from 1 March – 31 August each year, totaling 12 possible sampling periods per year. Data collected from 2015 and 2016 are partitioned into 2-month periods from 1 March – 31 August, totaling 3 possible sampling periods each year. This dataset also describes the proportion of total area surveyed per site per sampling period in 2015 and 2016, as well as the proportion of each site with older coniferous forest in each year (1995 – 2016).
A biologist and field crew from Northern Prairie Wildlife Research Center visited sites nine times throughout the breeding season (late May to mid-July) to record counts of grassland birds. Surveyors applied North American Breeding Bird Survey methodology to obtain counts at On-, Near-, and Off-road Stops, but unlike the North American Breeding Bird Survey, which features a single survey at each site, three replicate surveys were conducted on back-to-back-to-back days during each survey period to facilitate estimation of detection and occupancy probabilities. Assignment of surveyors to individual sites followed a design protocol that allows observer effects to also be estimated. The biologist visited each site once...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Ecology,
Land ownership,
Montana,
North American Breeding Bird Survey,
North Dakota,
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