USGS Science⌕ Search

SEARCH · USGS Science

Results for “Americas”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 955 records · Page 53Linked to original sources
USGS1994

Shorebirds in western North America: Late 1800s to late 1900s

Only anecdotal information is available to assess whether populations of the 47 shorebird species that breed or winter west of the Rocky Mountains changed in size or distribution during the past century. Unregulated hunting from 1870 to 1927 reduced populations of several species, at least temporarily, and was a factor in bringing the Eskimo Curlew ( Numenius borealis ) close to extinction. Large scale transformation of native grasslands and wetlands for agriculture and other purposes resulted in population declines and nesting range contractions of several temperate-zone breeders. In general, upland species were affected more than wetland species, breeding ranges contracted westward, and alteration of breeding habitat was the factor most responsible for range contractions and population declines. A ranking system assessing shorebird susceptibility to habitat alteration also predicted temperate breeders to be among the most vulnerable species to environmental change. The few estimates for current population sizes of western North American shorebirds range from fewer than 50 Eskimo Curlews to a few million Western Sandpipers ( Calidris mauri ), the most abundant species. Concentrations of at least 1000 shorebirds occur on migration at over 120 western North American sites and of 100,000 to 1,000,000 shorebirds at 18 sites. Whether populations are limited by conditions on breeding, wintering or migration ranges is unknown for most species. Expansion of ongoing programs coupled with economical new census efforts could be useful for monitoring the majority of western North American shorebirds during the next century.

Studies in Avian Biology↗
USGS1995

Ecology and conservation of the Marbled Murrelet in North America: An overview

Over the past decade, the Marbled Murrelet has become a focus of much controversy. It was listed as threatened in Washington, Oregon, and California by the U.S. Fish and Wildlife Service in February 1993. In order to aid the various agencies with management, the Marbled Murrelet Conservation Assessment was formed to bring together scientists, managers, and others to gather all the available data on this small seabird. This volume of research is the culmination of that effort. In this chapter, we integrate the results of the investigations and summaries on the past history, present status, and possible future of the species, based on the data presented in this volume and other published research. We also propose what we consider the most important research needs. Then, based on the findings of this volume, we suggest actions for management to help ensure the survival of the species.

Book chapter↗
USGS2020

Discovery of a reproducing wild population of the swamp eel Amphipnous cuchia (Hamilton, 1822) in North America

We report discovery of an established population of the Asian swamp eel Amphipnous cuchia (Hamilton, 1822) in Bayou St. John, an urban waterway in New Orleans, Louisiana, USA. This fish, commonly referred to as cuchia (kuchia), is a member of the family Synbranchidae and is native to southern and southeastern Asia. Recently-used synonyms include Monopterus cuchia and Ophichthys cuchia . We collected both adult and young-of-year cuchia from dense mats of littoral vegetation at several locations in Bayou St. John. Presence of multiple age and size classes is the first documented evidence of reproduction of this species outside of its native range. Establishment of this air-breathing, burrowing, salt-tolerant, opportunistic predator is of concern given that Bayou St. John is a tributary of Lake Pontchartrain, which provides a direct pathway for dispersal into the Mississippi River basin and coastal wetlands of the Gulf of Mexico.

Louisiana↗