Images

These two American toads (Anaxrus americanus) are in amplexus, or mating position. In this position, the male toad grasps the female toad behind her front legs and does not let go.

This adolescent chick, hatched and raised at the USGS Patuxent Wildlife Research Center, is one of ten whooping cranes being released in Louisiana in February 2011. It is a milestone for the state and for the birds, which have not lived in the state since the 1950s.

This adolescent chick, hatched and raised at the USGS Patuxent Wildlife Research Center, is one of ten whooping cranes being released in Louisiana in February 2011. It is a milestone for the state and for the birds, which have not lived in the state since the 1950s.

This adolescent chick, hatched and raised at the USGS Patuxent Wildlife Research Center, is one of ten whooping cranes being released in Louisiana in February 2011. It is a milestone for the state and for the birds, which have not lived in the state since the 1950s.

This adolescent chick, hatched and raised at the USGS Patuxent Wildlife Research Center, is one of ten whooping cranes being released in Louisiana in February 2011. It is a milestone for the state and for the birds, which have not lived in the state since the 1950s.

A class photo! The entire gang of adolescent whooping crane chicks appear to be ice skating at the USGS Patuxent Wildlife Research Center in Laurel, Md.

A class photo! The entire gang of adolescent whooping crane chicks together at the USGS Patuxent Wildlife Research Center in Laurel, Md. The chicks, hatched and raised by USGS caretakers, are being released into the wild in Louisiana in February 2011.  It is a milestone for the state and for the birds, which have not lived in the state since the 1950s.

This adolescent chick, hatched and raised at the USGS Patuxent Wildlife Research Center, is one of ten whooping cranes being released in Louisiana in February 2011. It is a milestone for the state and for the birds, which have not lived in the state since the 1950s.

This adolescent chick, hatched and raised at the USGS Patuxent Wildlife Research Center, is one of ten whooping cranes being released in Louisiana in February 2011. It is a milestone for the state and for the birds, which have not lived in the state since the 1950s.

This adolescent chick, hatched and raised at the USGS Patuxent Wildlife Research Center, is one of ten whooping cranes being released in Louisiana in February 2011. It is a milestone for the state and for the birds, which have not lived in the state since the 1950s.

This adolescent chick, hatched and raised at the USGS Patuxent Wildlife Research Center, is one of ten whooping cranes being released in Louisiana in February 2011. It is a milestone for the state and for the birds, which have not lived in the state since the 1950s.

This adolescent chick, hatched and raised at the USGS Patuxent Wildlife Research Center, is one of ten whooping cranes being released in Louisiana in February 2011. It is a milestone for the state and for the birds, which have not lived in the state since the 1950s.

This adolescent chick, hatched and raised at the USGS Patuxent Wildlife Research Center, is one of ten whooping cranes being released in Louisiana in February 2011. It is a milestone for the state and for the birds, which have not lived in the state since the 1950s.

EESC research engineers and technicians build a full-scale prototype of a fishway entrance in the S.O. Conte Research Laboratory's flume facility

This is an adult wood frog (Lithobates sylvaticus). Wood frogs are most commonly found in the early spring, when they gather in vernal pools to breed and lay eggs. This species can be easily identified by the dark 'mask' markings behind the eye.

Wood frogs (Lithobates sylvaticus) lay their eggs in large clusters in the early spring. They prefer to lay their eggs in vernal pools, which hold water for only part of the year.

Melanoma in brown bullhead from Lake Memphremagog, Vermont          

Three field staff assessing trail conditions at one of more than 3000 trail transects along the Appalachian Trail.  This transect sampled a rare mudhole in Vermont.

Redhead, Aythya americana, are one of many species of waterfowl regularly seen as part of the Christmas Bird Count at Patuxent Research Refuge. This male redhead was observed at Knowles Marsh on the central tract of the refuge.

A flock of Eastern Bluebirds at the Patuxent Research Refuge. Species Population Dynamics & Surveillance Capability Team.

Brown tree snake (Boiga irregularis) is an invasive species originally from Australia but arrived in Guam accidently on imported cargo.