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Keyword: demography

Response of a remnant marmot population to habitat enhancement yields insights into marmot ecology

Publications Posted on: January 04, 2021
We evaluated the response of a remnant population of yellow-bellied marmots (Marmota flaviventris) to targeted habitat enhancement in an ecological system that had been degraded during ~100 years of intensive livestock management, including marmot eradication. We used capture-recapture data and a novel use of a multistate framework to evaluate geographic expansion of the marmot population pre- and post-habitat enhancement.

Population dynamics of Rana sierrae at Dusy Basin: influence of non‐native predators, drought, and restoration potential

Publications Posted on: September 28, 2020
The Sierra Nevada yellow‐legged frog (Rana sierrae) was once an abundant and widely distributed amphibian in California's alpine ranges. Rana sierrae is adapted to high‐elevation, fishless habitats. Its adaptions are reflected in a unique life cycle that involves a flexible, extended juvenile phase due to the short growing season typical of its alpine habitat.

Multispecies conservation planning on U. S. federal lands [Chapter 3]

Publications Posted on: March 04, 2020
Numerous laws directly, or indirectly, mandate the conservation of all species on public lands in the United States (Goble and Freyfogle 2002, Nagle and Ruhl 2002). Key laws relevant to the management of biodiversity on federal lands include the National Forest Management Act (NFMA; Noon et al. 2003) and the Federal Endangered Species Act (ESA; 1973).

Demography of Northern goshawks in northern Arizona, 1991-1996

Publications Posted on: March 04, 2020
We studied 282 nesting attempts on 107 territories of Northern Goshawks (Accipiter gentilis) on the Kaibab Plateau in northern Arizona from 1991–1996. Mark-recapture methods were used to estimate recruitment, turnover of adults on territories, fi delity to territories by adults, and apparent annual survival of breeding adults. Territories were regularly spaced at a mean nearest-neighbor distance of 3.9 km.

100 years of vegetation change at the Sierra Ancha Experimental Forest

Projects Posted on: March 08, 2019
This project incorporates historical data collected at the Sierra Ancha Experimental Forest nearly 100 years ago to determine how plant communities have changed over that period of time.

Sprawling and diverse: The changing U.S. population and implications for public lands in the 21st Century

Publications Posted on: June 29, 2018
Public lands are typically established in recognition of their unique ecological value, yet both ecological and social values of public lands change over time, along with human distribution and land use. These transformations are evident even in developed countries with long histories of public land management, such as the United States.

Managing emerging threats to spotted owls

Publications Posted on: May 10, 2018
The 3 spotted owl (Strix occidentalis) subspecies in North America (i.e., northern spotted owl [S. o. caurina], California spotted owl [S. o. occidentalis], Mexican spotted owl [S. o. lucida]) have all experienced population declines over the past century due to habitat loss and fragmentation from logging.

Long-term demography of the Northern Goshawk in a variable environment

Publications Posted on: May 17, 2017
The Nearctic northern goshawk (Accipiter gentilis atricapillis) is a resident of conifer, broadleaf, and mixed forests from the boreal to the southwestern montane regions of North America.

Northern goshawks on the Kaibab Plateau: A 20-year investigation into factors affecting their demography

Science Spotlights Posted on: August 26, 2016
The elusive northern goshawk, its forest habitats, and the habitats of its bird and mammal prey are significant conservation issues related to the management of forests throughout the hawk’s North American range.  The Rocky Mountain Research Station has been enumerating the population size and documenting the population ecology and demography of individual goshawks on Arizona’s Kaibab Plateau for 20 years with the objective of identifying the vegetation composition and structure of forests habitats that best supports their survival and reproduction.

A longevity record for Canada lynx, Lynx canadensis, in western Montana

Publications Posted on: January 22, 2016
The Canada lynx (Lynx canadensis) was listed as a threatened species under the Endangered Species Act (USDI Fish and Wildlife Service 2000) in 2000 and is a species of conservation concern in the United States. New insights into the basic demography of southern lynx populations are needed.