Filters: Tags: die-off (X)6 results (7ms)
This data set maps sagebrush mortality in Utah delineated by Utah Division of Wildlife Resources personnel during the summer of 2003.
Mechanisms of plant survival and mortality during drought: why do some plants survive while others succumb to drought?
Severe droughts have been associated with regional-scale forest mortality worldwide. Climate change is expected to exacerbate regional mortality events; however, prediction remains difficult because the physiological mechanisms underlying drought survival and mortality are poorly understood. We developed a hydraulically based theory considering carbon balance and insect resistance that allowed development and examination of hypotheses regarding survival and mortality. Multiple mechanisms may cause mortality during drought. A common mechanism for plants with isohydric regulation of water status results from avoidance of drought-induced hydraulic failure via stomatal closure, resulting in carbon starvation and a cascade...
Common murres collected in Alaska from January 1, 2015 through December 31, 2016 and shipped to USGS National Wildlife Health Center for cause of death determination
About 62,000 dead or dying common murres (Uria aalge), the trophically dominant fish-eating seabird of the North Pacific, washed ashore between summer 2015 and spring 2016 on beaches from California to Alaska. Most birds were severely emaciated and, so far, no evidence for anything other than starvation was found to explain this mass mortality. Three-quarters of murres were found in the Gulf of Alaska and the remainder along the West Coast. Total mortality was estimated at 0.54 to 1.2 million birds. About two-thirds of murres killed were adults, a substantial blow to breeding populations. Additionally, 22 complete reproductive failures were observed at multiple colonies region-wide during (2015) and after (2016-2017)...
Mortality of shadscale (Atriplex confertifolia [Torr. & Frem.] Wats.) was severe in Great Basin valley bottoms between 1983 and 1988. Puddle Valley, Utah, just west of the Great Salt Lake, typifies areas of extensive shrub loss in which density decreased from over to less than . We analyzed vegetation along a radial transect established in the bottom of Puddle Valley in 1987. Mortality was greatest at the lowest elevations where shrubs were initially most dense. These sites occurred where soil moisture, fine-textured soils, and bulk density were greatest of all sites evaluated. Soil was most saline at the margins of the valley bottom. Higher densities of live shadscale occurred where slopes are greater, soil is...
USGS National Wildlife Health Center necropsy results to determine cause of illness/death for seabirds collected in Alaska from January 1, 2017 through December 31, 2021
Summary of Bering and Chukchi Seas seabird necropsies, 2017-2021. More than 14,000 dead seabirds were reported and a total of 117 carcasses were examined. 92 cases had emaciation identified as the Cause Of Death (COD), seven cases where COD was undetermined, and 17 cases where COD was determined as "Other", which included predation, trauma, encephalitis, peritonitis, and bacterial infection. Low Pathogenic Avian Influenza (n=4) and saxitoxin (n=15) were also detected; however, the virus and biotoxin were not determined to be the COD except for one case in 2020 where saxitoxin toxicosis was suspected.
Improving the quality of habitat for western big-game species, such as elk and mule deer, was identified as a priority by the Department of the Interior in 2018. Maintaining healthy herds not only supports the ecosystems where these species are found, but also the hunting and wildlife watching communities. For example, in Wyoming, big game hunting contributed over $300 million to the state’s economy in 2015. Yet as climate conditions change, the quantity, quality, and timing of vegetation available to mule deer, elk, and other ungulates, known as forage, could shift. It’s possible that these changes could have cascading impacts on the behavior and population sizes of many species. A key strategy used by managers...