Filters: Tags: Population dynamics (X)
141 results (15ms)|
Filters
Date Range
Extensions Types Contacts
Categories Tag Types
|
Lake Erie Biological Station (LEBS), located in Sandusky, Ohio, is a field station of the USGS Great Lakes Science Center (GLSC). LEBS is the primary federal agency for applied fisheries science excellence in Lake Erie. Since 2004, LEBS has participated in a collaborative, multiagency effort to assess forage fish populations in the western basin of Lake Erie. Assessing the distribution and abundance of both predator and prey (forage) fish species is a cornerstone of ecosystem-based based fishery management, and supports decision making that considers food-web interactions. The objectives of this survey were to provide estimates of densities of key forage and predator species in the western basin of Lake Erie, to...
Categories: Data;
Types: Citation;
Tags: Field sampling,
Freshwater ecosystems,
Lake Erie,
Michigan,
Ohio,
Locations of two types of hair collection stations for sampling the grizzly and black bear populations in the Glacier National Park region of the Northern Continental Divide Ecosystem, Montana, USA. Sampling was conducted during June-October, 2004.
Categories: Data;
Tags: Crown of the Continent,
Glacier National Park,
Montana,
Northern Continental Divide,
bears,
Two independent sampling methods were used to collect genetic samples from grizzly bears (Ursus arctos): (i) hair traps—corrals of barbed wire with lure in the center systematically distributed using an 8 x 8 km (1998, 2000) or 7 x 7 km (2004) grid and (ii) bear rubs—naturally occurring trees or other objects that bears rub on fitted with barbed wire (1998–2000, 2004, and 2009–2012). From 1998 to 2000, sampling occurred on 8000 km2 in the northern extent of the Northern Continental Divide Ecosystem (NCDE), whereas systematic and consistent, ecosystem-wide sampling occurred in 2004 and 2009–2012. In total, there were 6160 confirmed grizzly bear detections, leading to the identification of 1115 unique individual genotypes...
Categories: Data;
Types: Citation;
Tags: Glacier National Park,
Northern Continental Divide Ecosystem,
USGS Science Data Catalog (SDC),
genetic diversity,
genotype,
This dataset contains demographic data pertaining to Hesperocyparis forbesii on Otay Mountain in San Diego County, California, USA, over a 14-year study period from 2004 to 2017 following the 2003 Otay/Mine Fire. Site variables including elevation, incline, and slope were collected as well as pre-fire tree density and stand age for 16 study site locations. Tree density, height, and cone production was then monitored over the study period with data collection occurring in 2004, 2005, 2009, 2011, 2014, and 2017. These data support the following publication: Brennan, T.J. & Keeley, J.E., 2019, Postfire population dynamics of a fire-dependent cypress, Plant Ecology, 220(6): 605. https://doi.org/10.1007/s11258-019-00939-8
Snowshoe hare populations fluctuate over a period of several years and are thought to send the cats on migration routes in what’s known as the “travelling wave” theory. In a changing boreal region, scientists want to know where and how lynx move across the landscape to better understand how the larger system is connected.Researchers will build on on-going research in national wildlife refuges by placing satellite tracking collars on cats to better understand the dynamics across the region. Isotypes in the cats’ teeth as well as genetic markers give more clues about lynx movement. This project involves collaboration with local trappers.The project is a collaboration among the University of Alaska Fairbanks, Yukon...
The application of ecological modeling can demonstrate robust, objective, and transparent biological analysis. The Austin Ecological Service Field Office has a multitude of challenging Species Status Assessments (SSA) to complete to support upcoming ESA classification decisions. Previously the Service has invested in development and use of a range of quantitative analytical tools to use in population analysis for SSAs culminating in a recent training class, Species Status Assessment 200 – Strategic use of data: describing population trends for Species Status Assessments. We now seek to apply these tools for more generalized use for a variety of species situations. With this proposed research, population-modeling...
Assessing the distribution and abundance of both predator and prey (forage) fish species is a cornerstone of ecosystem-based based fishery management, and supports decision making that considers food-web interactions. In support of binational Great Lakes fishery management the objectives of this survey were to: provide estimates of densities of key forage and predator species in the western basin of Lake Erie, to assess seasonal and spatial distributions of fishes, and to assess year class strength. A systematic grid sampling approach with 41 stations was sampled during June (Spring) and September (Autumn), starting in 2013. This data release adds 2017 data to the set – making it five years of continuous observation.
Categories: Data;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Field sampling,
Freshwater ecosystems,
Lake Erie,
Michigan,
Ohio,
The database on shell-skeletal remains from 1980 through 2012 was collected as part of a monograph covering the desert tortoise populations inside and outside the fenced Desert Tortoise Research Natural Area during a period of population decline. The principal objectives of the study were to compare trends in demographic and habitat data inside the protective fence with those outside the fence. Populations and habitat outside the fence were unprotected from recreational vehicle use and sheep grazing. Data for each shell-skeletal remain found on the long-term, 7.77 square kilometers plot, included carcass number, previous number as a live tortoise, date of collection, date last observed if marked; known or estimated...
A long-term research project was conducted on Agassiz’s desert tortoises (Gopherus agassizii) at a 7.77 square kilometer plot at the Desert Tortoise Research Natural Area, Western Mojave Desert, California, USA. The plot included tortoise populations and habitat both inside and outside the protective fence at the Research Natural Area. Databases used in the research and publications from the research project are assembled here and include: census (survey) database used for the demographic analysis and Bayesian modeling of the desert tortoise population; shell-skeletal remains of desert tortoises; clinical signs of health, disease, and trauma in desert tortoises; perennial (shrubs, perennial grasses) and annual plant...
This dataset contains information from capture-mark-recapture sampling of Oregon spotted frogs (Rana pretiosa) conducted 2016-2019 by USGS as part of a study relating R. pretiosa survival and abundance to wetland inundation in the upper Deschutes River. Data consist of site, survey, habitat, and species detection covariates, as well as 10 years of hydrological and drought metrics used to establish relationships between river flow and area of inundation at survey sites. Remotely sensed and model predicted area wet estimates for the sites are also given.
These data are in two tables relating to fall age ratios (number of juvenile birds : total birds aged) of Black Brant (Branta bernicla nigricans) staging in Izembek Lagoon, Alaska, since 1963. The first table is observation data for the age classes of Black Brant during surveys, and associated survey characteristics. The second table contains model-based estimates of age ratios by year along with Standard Error (SE), and 95% Bayesian credible intervals around estimates.
This dataset includes records of captures of San Francisco gartersnakes (Thamnophis sirtalis tetrataenia) collected at five sites from 2007 to 2020. The data include measurements of snake snout-vent length to estimate growth patterns, snake sex, and the record of all captures of individual snakes for estimating capture probability, availability for capture, and survival. These data support the following publication: Rose, J.P., Kim, R., Schoenig, E.J., Lien, P.C. and Halstead, B.J., 2022. Integrating growth and survival models for flexible estimation of size-dependent survival in a cryptic, endangered snake. Ecology and Evolution, 12(4), https://doi.org/10.1002/ece3.8799.
The Great Lakes Research Vessel Catch (RVCAT) database is managed at the Great Lakes Science Center (GLSC). RVCAT has been used as the primary data collection tool aboard the GLSC’s research vessel operations across the Great Lakes. Content: The data set has been collected on various vessel operations on all the Great Lakes and select connecting waterways between the years 1930-2021. Data collection begins in early spring and ends in late fall. Each vessel operation was completed for a specific purpose, or target mission. Data Structure: These data are collected at the GLSC in the RVCAT Oracle database. This database has been broken down into comma separated value (csv) spreadsheets in order to facilitate greater...
This data release includes Lake Ontario prey fish data including species captured, relative abundance, spatial distribution, size structure, and age data from the April or spring prey fish bottom trawl survey, 1997 and 2021. Data from 1997 - 2015 are from U.S. waters of Lake Ontario while data from 2016 - 2021 include both U.S. and Canadian waters of Lake Ontario. Details about the vessel and gear descriptions, sampling protocols, and catch processing protocols can be found in the Process sections of this metadata. Portions of this data release follows the data model of the USGS Great Lakes Science Center Research Vessel Catalog (RVCAT). The trawl data included in this data release are a subset of the larger RVCAT...
This dataset identifies lead (Pb) concentration found in the blood of waterfowl sampled in western and northern Alaska and eastern Russia between 1993 and 2022. Data include age, sex, body measurement, capture location, presence or absence of lead shot on x-rays, and blood lead levels. Because the study took place over a number of years at the same study sites, many of the same birds were sampled in multiple years.
The Cape Sable Seaside Sparrow (CSSS; Ammospiza maritima mirabilis) is an endangered species that has experienced population declines of more than 60% since the 1990s. The CSSS is restricted in geographic extent to a relatively small area of remaining marl prairie in the southern Florida Everglades and remains in six subpopulation areas (named A-F). There has been over two decades of field research conducted on the CSSS across its six subpopulations, but a statistically robust analysis of the bird’s demographic parameters utilizing all data has yet to be completed. To address this gap, we conducted demographic analysis of the CSSS population using an integrated population model (IPM). The IPM provides a flexible...
This dataset consists of one table with egg predation data from Common Murres at two seabird nesting colonies on Gull and Chisik Islands in lower Cook Inlet, Alaska.
These data have been collected on various vessel operations on the Great Lakes and select connecting waterways. This vessel operations data set is part of and connected to a larger database of Great Lakes research that includes trawl and gillnet catch data, sample information of fish species caught, as well as effort applied, operation conditions, and location details. The larger database also contains data on hydroacoustics, ichthyoplankton, zooplankton, zebra mussel, and benthos samples collected. Multiple operations were conducted on all Great Lakes each year (1958-2016) beginning in early spring and ending in late fall. Each vessel operation was completed for a specific purpose, or target mission, which are...
Due to its range expansion and potential ecological effects, Corbicula fluminea is considered one of the most important non-indigenous species (NIS) in aquatic ecosystems. Its presence since 2003 in the upstream area of Mondego estuary (oligohaline and mesohaline sectors) was studied during thirteen months, from December 2007 to December 2008. Monthly mean abundance and biomass ranged from 542 to 11142 individuals m−2 and 13.1–20.4 g Ash Free Dry Weight m−2, respectively. Populations of C. fluminea were composed mostly of juveniles, always present in extremely high densities compared to other estuarine ecosystems (e.g. Minho estuary) suggesting a continuous recruitment pattern. The hydraulic regime of the River...
Categories: Publication;
Types: Citation;
Tags: Corbicula fluminea,
Mondego estuary,
mesohaline,
non-indigenous invasive species,
oligohaline,
Climate often drives ungulate population dynamics, and as climates change, some areas may become unsuitable for species persistence. Unraveling the relationships between climate and population dynamics, and projecting them across time, advances ecological understanding that informs and steers sustainable conservation for species. Using pronghorn (Antilocapra americana) as an ecological model, we used a Bayesian approach to analyze long-term population, precipitation, and temperature data from 18 subpopulations in the southwestern United States. We determined which long-term (12 and 24 months) or short-term (gestation trimester and lactation period) climatic conditions best predicted annual rate of population growth...
Categories: Data;
Types: Citation;
Tags: Antilocapra americana,
Arizona,
Drought,
Drought, Fire and Extreme Weather,
Mammals,
|
|
