Howling Wolf Cub #1
Jean-Louis Klein & Marie-Luce Hubert
Timber Wolf Cub, Canis Lupus #1
M. Watson
Common Yellowthroat
Steve and Dave Maslowski
Siamang Calling Using Gular Sac
Mark Newman
Golden-crowned Sparrow Singing
Paul J. Fusco
Houston Toad
Dante Fenolio
Howling Wolf Cub #2
Jean-Louis Klein & Marie-Luce Hubert
Olympic Marmot
Thomas And Pat Leeson
Golden Eagle #1
Jean-Louis Klein & Marie-Luce Hubert
Siberian Husky Howling
Jean-Michel Labat
Howling Wolf Cub
Jean-Louis Klein & Marie-Luce Hubert
Young Woman Waving Scarf, C.1950-60s
H Armstrong Roberts and ClassicStock
Pro Baseball Game, C.1950s
H. Armstrong Roberts/ClassicStock
Acorn Woodpecker #1
Anthony Mercieca
Uinta Ground Squirrel
D & L Klein
Mccowns Longspur #1
James Zipp
Winter Wren #2
James Zipp
Courtship Of Laughing Gulls #3
Ivan Kuzmin
Illustration Of Two Ravens
Ikon Images
Red Deer Stag Bugling
Nhpa
Red-winged Blackbird #1
John Shaw
Common Loon Calling
Thomas And Pat Leeson
Red Grouse Calling
Patrick Frischknecht
American Goldfinch Male Calling
Marie Read
Little League Umpire Calling Safe
Debrocke/ClassicStock
Bluejay Calling
John S. Dunning
Black-tailed Prairie Dog Calling #1
Thomas And Pat Leeson
Siamang Calling Using Gular Sac #1
Mark Newman
Siamang Calling Using Gular Sac #2
Mark Newman
Brandts Cormorant Calling
Anthony Mercieca
Eastern Meadowlark Calling
Anthony Mercieca
Wood Duck Male Calling
Anthony Mercieca
Gadwall Drake Calling
Anthony Mercieca
Blue Jay Calling
Marie Read
Barn Swallow Calling
Marie Read
Snow Monkey Calling
Jean-Louis Klein & Marie-Luce Hubert
Woman In Bell Hop Outfit Calling Out
H. Armstrong Roberts/ClassicStock
Womah Calling Out, C.1950s
Debrocke/ClassicStock
Rock Squirrel Calling
Anthony Mercieca
Dark-sided Frog Calling
Fletcher & Baylis
Emperor Penguin Calling
M. Watson
Chimpanzee Calling
M. Watson
Black-tailed Prairie Dog Calling
Thomas And Pat Leeson
Eastern Spadefoot Calling
Jeffrey Lepore
Tree Frog Calling
Carleton Ray
Gray Treefrogs Calling
James Zipp
Common Gallinule Calling
Ivan Kuzmin
Male American Toad Calling
Ivan Kuzmin
Hookers Sealion Female Calling
Nhpa
Puffin Calling Fratercula Arctica
Nhpa
Gentoo Penguin Calling
John Shaw
Peacock Pavo Cristatus Perched, Calling
Phillip Hayson
Florida Crow Calling
Ken Brate
Rufous-naped Lark Calling
David Hosking
Male American Toad Calling #1
Ivan Kuzmin
American Bison Bull Calling
Ivan Kuzmin
African Lion Calling
Millard H. Sharp
Male American Toad Calling #2
Ivan Kuzmin
Tungara Frog Vocalizing #1
Gregory G. Dimijian, M.D.
White-tailed Kite Young
Anthony Mercieca
Southern Skuas
Jean-Louis Klein & Marie-Luce Hubert
Salmon-crested Or Moluccan Cockatoo #2
Gerard Lacz
Domestic Chicken Crowing
Gary K. Smith/FLPA
Harp Seal Pagophilus Groenlandicus #2
Gerard Lacz
Zebra Finch Taeniopygia Guttata
Gerard Lacz
Border Collie Dog Singing
John Daniels
Roseate Spoonbill #1
Ivan Kuzmin
Green Treefrog Vocalizing
Dante Fenolio