Images

The Agassiz's desert tortoise, a native of the Mojave Desert.

A pocketbook mussel (Lampsilis cardium). Native freshwater mussels are among the most fascinating, widespread, and endangered animals in fresh waters. They play important ecological roles in our lakes and rivers and their shells are used to produce cultured pearls.

This image of a live silver carp egg specimen was taken with a microscope camera at the USGS Columbia Environmental Research Center. Asian carp are invasive species that could pose substantial environmental risks and economic impacts if they become established.

This image of a live silver carp larva was taken with a microscope camera at the USGS Columbia Environmental Research Center. Asian carp are invasive species that could pose substantial environmental risks and economic impacts if they become established.

A photomicrograph depicting the siliceous frustules of fifty species of diatoms arranged within a circular shape. The image has been inverted to white on black to bring out details. Diatoms form the base of many marine and aquatic foodchains and upon death, their glassy frustules form sediments known as diatomaceous earth.

A USGS biological science technician releases an adult golden eagle (Aquila chrysaetos) near Barrett Reservoir in southern California.

Location: Near Barrett Reservoir, San Diego County, California. Photo provided courtesy of photographer. Contact photographer for use.

A USGS biological science technician holds an adult golden eagle (Aquila chrysaetos) ready for release. The USGS uses solar-powered GPS tags and special 3-D mapping techniques to track the eagles' movements across the landscape.

A USGS biological science technician holds an adult golden eagle (Aquila chrysaetos) ready for release. The USGS uses solar-powered GPS tags and special 3-D mapping techniques to track the eagles' movements across the landscape.

Taking a break in the fog on the San Joaquin River while trawling aboard the USGS Research Vessel Munson II.

Ecosystems are changing at a rapid pace. It can be difficult to determine if a landscape is in need of restoration. In this photo of the spring wildflower bloom in the Sonoran desert, an invasive annual grass, Bromus rubens (red brome), is pervasive. Land managers have to make decisions about when, where, and how to intervene in a system.

Image of whitebark pine cone and seeds.

A monarch butterfly (Danaus plexippus) resting and sunning at an overwintering site in the Piedra Herrada Monarch Butterfly Sanctuary in Mexico. This individual is a male, identifiable by the black spot on each hindwing.

A group of monarch butterflies (Danaus plexippus) covers an oyamel fir tree (Abies religiosa) at an overwintering site in the Piedra Herrada Monarch Butterfly Sanctuary in Mexico.

Biologists place a culvert trap in locations that they need data from.  Field crews will set up the culvert trap and check it daily, usually in the morning, to determine if a bear has been captured.  Additionally, trap doors are checked via radio telemetry. 

A biologist measures a grizzly bear’s head length.

Biologists with IGBST and the National Park Service fit a grizzly bear with a radio collar.  Once a bear is radio collared, biologists can track its movements with telemetry.

Biologists use road-killed ungulates such as deer, elk, or bison as bait in the traps. 

Biologists have immobilized the bear and prepare to lift it out of the trap and onto the tarp for data collection.  Once on the tarp the bear is easier to move. 

The kerchief over the grizzly bear’s eyes protects it from dust and debris and reduces visual stimulation. The small tubing in its nose, known as a nasal cannula, delivers oxygen to the animal while it is tranquilized.  

One of the first measurements taken is the bear’s weight using a quadpod and electronic scale. 

Field personnel use bioelectrical impedance to assess body fat percentage of captured bears.  The procedure is similar to how body fat is measured in humans and is based on the resistance of body tissues to the flow of a small, harmless electrical signal.