Issued by the USPS on April 16, 2009, this mint self-adhesive definitive stamp (on original backing paper) features the Polar Bear. The design shows the bear's head, chest, and front paws; in the background is a dark sky dotted with stars.

Featuring a Bottlenose Dolphin leaping from the water, this mint self-adhesive definitive stamp (on original backing paper) was issued by the United States Postal Service on June 12, 2009. The stamp design is intended to portray the playful behavior of these intelligent marine mammals.

Issued by the United States Postal Service on May 14, 2007, this mint self-adhesive stamp (on original backing paper) features a stylized drawing of a bighorn sheep (Ovis canadensis). The Bighorn's range includes the colder, higher elevations of the Rocky Mountains and some of the hottest, most arid regions of the American Southwest and Mexico.

This mint self-adhesive stamp, featuring a Monarch Butterfly, was issued by the United States Postal Service on May 17, 2010. The 64 cents denomination paid the first class letter rate ($0.44) plus a $0.20 non-machineable (square/rigid/thick) envelope surcharge.

This attached block of four mint stamps comprises the 1971 Wildlife Conservation Issue (issued June 12, 1971). Using the Polar Bear, California Condor, Trout, and Alligator as representatives of wildlife, this popular issue promoted wildlife preservation.

Highlighting the need to protect and preserve wildlife resources, this mint stamp portrays the Whooping Crane, which at the time this stamp was issued (November 22, 1957) was almost extinct. This very attractive stamp, depicting two adult cranes and two chicks, was the fourth in the U.S. Wildlife conservation series (the 1956 three-stamp stamp- item USW1- initiated the series).

This sheet of 20 mint stamps, beautifully designed by Steve Buchanan, was issued by the United States Postal Service on Aug. 23, 1981. The sheet includes five copies each of four different stamp designs. The featured carnivorous plants are the Venus Flytrap, the Yellow trumpet, the Cobra Lilly, and the English Sundew. Each stamp depicts the carnivorous plant attacking an insect.

Issued by the United States on October 7, 2003, this attractive mint strip of five self-adhesive postage stamps features the following reptiles and amphibians: Scarlet Kingsnake, Blue-Spotted Salamander, Reticulate Collared Lizard, Ornate Chorus Frog, and Ornate Box Turtle. These stamps were designed for the USPS by artist Steve Buchanan.

This mint self-adhesive stamp was issued by the United States on Mar. 14, 2003, to commemorate the centenary anniversary of the Pelican Island National Wildlife Refuge (1903-2003). The stamp was designed by Carl T. Herrman and features a Brown Pelican.

The U.S. Postal Service issued this sheet of 15 (three copies each of five different designs) deep sea creature stamps on Oct. 2, 2000. This item is the full sheet as issued; to obtain just the five different stamps, please see item# USW20). The bizarre creatures that live in this virtually unknown underworld are represented in this sheet by the Fanfin Anglerfish, the Sea Cucumber, the Fangtooth, the Amphipod, and the Medusa. This beautiful sheet was designed for the USPS by Ethel Kessler.