Gabriel Rojo / Bay-winged cowbird,(Agelaioides badius) chicks begging for food, La Pampa, Argentina

David Welling / Brown-headed Cowbird (Molothrus ater) male perched on Cattail, Anahuac National Wildlife Refuge, Texas, USA, June

Rolf Nussbaumer / Northern Cardinal (Cardinalis cardinalis) male feeding young Brown-headed Cowbird (Molothrus ater) New Braunfels, San Antonio, Hill Country, Central Texas, USA

Rolf Nussbaumer / Bronzed cowbird {Molothrus aeneus} chick in nest of Bewick's wren, Texas, USA

Chase Dekker / American Bison (Bison bison) with female Brown-headed Cowbirds (Molothrus ater), Grand Teton National Park, Wyoming

Lucas Bustamante / Capybara (Hydrochaeris hydrochaeris) with a Giant Cowbird (Scaphidura oryzivora). on back, Tambopata National Reserve, Madre de Dios, Peru.

Agustin Esmoris / Screaming Cowbird (Molothrus rufoaxillaris) male, Bahia Blanca, Argentina

Agustin Esmoris / Shiny Cowbird (Molothrus bonariensis) male, Argentina

Gabriel Rojo / Shiny cowbird (Molothrus bonariensis) Calden Forest, La Pampa, Argentina

Gabriel Rojo / Bay-winged cowbird (Agelaioides badius) Calden forest, La Pampa, Argentina

Rolf Nussbaumer / Bronzed Cowbird (Molothrus aeneus), male displaying, Rio Grande Valley, South Texas, Texas, USA. May

Rolf Nussbaumer / Bronzed Cowbird (Molothrus aeneus), male displaying in flight, Rio Grande Valley, South Texas, Texas, USA. May

Rolf Nussbaumer / Bronzed Cowbird (Molothrus aeneus), male perched on berry laden Elbow bush (Forestiera pubescens), Rio Grande Valley, South Texas, Texas, USA. May

Tim Fitzharris / American Bison (Bison bison) bull with landing female Brown-headed Cowbird (Molothrus ater), Grand Teton National Park, Wyoming

Tim Fitzharris / American Bison (Bison bison) bull with landing female Brown-headed Cowbird (Molothrus ater), Grand Teton National Park, Wyoming

Gabriel Rojo / Shiny cowbird (Molothrus bonariensis) Calden Forest, La Pampa, Argentina

Gabriel Rojo / Bay-winged cowbird (Agelaioides badius) Calden forest, La Pampa, Argentina

Melvin Grey / Brown-headed cowbird (Molothrus ater) male. Fort De Soto Pk, Florida, USA, April.

Gabriel Rojo / Shiny cowbird (Molothrus bonariensis) rear view, Calden Forest, La Pampa, Argentina

Gabriel Rojo / Bay-winged cowbird (Agelaioides badius) pair, one bringing food to nest hole, La Pampa, Argentina

Gabriel Rojo / Bay-winged cowbird (Agelaioides badius) rear view, Calden forest, La Pampa, Argentina

Gabriel Rojo / Shiny cowbird (Molothrus bonariensis) perched on branch in the rain, Calden Forest, La Pampa, Argentina

Gabriel Rojo / Bay-winged cowbird (Agelaioides badius) two perched on branch in rain, one calling and another feeding, Calden forest, La Pampa, Argentina

Gabriel Rojo / Bay-winged cowbird (Agelaioides badius) pair, one bringing food to nest hole, La Pampa, Argentina

Gabriel Rojo / Bay-winged cowbird,(Agelaioides badius) feeding begging chicks at nest, La Pampa , Argentina

Gabriel Rojo / Bay-winged cowbird (Agelaioides badius) feeding young at nest hole, La Pampa, Argentina

Alan Murphy / Brown-headed Cowbird (Molothrus ater) male, Texas

Alan Murphy / Bronzed Cowbird (Molothrus aeneus) male, Texas

Alan Murphy / Bronzed Cowbird (Molothrus aeneus) male, Texas

Pete Oxford / Brown-headed cowbird (Molothrus ater) Little St Simon's Island, Barrier Islands, Georgia, USA, April.

Ben Cranke / Giant Cowbird (Molothrus oryzivorus) perched on a palm tree frond, Mato Grosso, Pantanal, Brazil. August.

Pete Oxford / Giant Cowbird (Molothrus oryzivorus), Pantanal, Mato Grosso, Brazil

Luiz Claudio Marigo / Giant Cowbird (Molothrus oryzivorus) at Pixaim River, Pantanal of Mato Grosso, Mato Grosso State, Western Brazil.

Luiz Claudio Marigo / Giant Cowbird (Molothrus oryzivorus) at Pixaim River, Pantanal of Mato Grosso, Mato Grosso State, Western Brazil.

Glenn Bartley / Bronzed Cowbird (Molothrus aeneus) male, Costa Rica

Alan Murphy / Bronzed Cowbird (Molothrus aeneus) male, Texas

Alan Murphy / Brown-headed Cowbird (Molothrus ater) female, Texas

Alan Murphy / Brown-headed Cowbird (Molothrus ater) female, Texas

Alan Murphy / Brown-headed Cowbird (Molothrus ater) male, Texas

Glenn Bartley / Brown-headed Cowbird (Molothrus ater), British Columbia, Canada

Glenn Bartley / Brown-headed Cowbird (Molothrus ater), Texas

Cyril Ruoso / Bronzed Cowbird (Molothrus aeneus) bathing, southern Texas

Tui De Roy / Turquoise jay (Cyanolyca turcosa) raising parasitic Giant cowbird chick, Bellavista cloud forest private reserve, 1700m altitude, Tandayapa Valleyk, Andean cloud forest, Ecuador

Loic Poidevin / Brown headed cowbird (Molothrus ater) Pointe Pelee, Ontario, Canada, May

Rolf Nussbaumer / Bronzed cowbird (Molothrus aeneus) two males perched together on branch, Dinero, Lake Corpus Christi, South Texas, USA.

Rolf Nussbaumer / Bronzed cowbird (Molothrus aeneus) pair sitting on branch, Dinero, Lake Corpus Christi, South Texas, USA.

Donald M. Jones / Brown-headed Cowbird (Molothrus ater) in flowering tree, Troy, Montana

Donald M. Jones / Brown-headed Cowbird (Molothrus ater) in flowering tree, Troy, Montana

Rolf Nussbaumer / Bronzed Cowbird (Molothrus aeneus). Laredo, Webb County, Texas, USA, April.

Sebastian Kennerknecht / Brown-headed Cowbird (Molothrus ater) juvenile on Domestic Cattle (Bos taurus), Moss Landing, Monterey Bay, California

David Welling / Bronzed Cowbird (Molothrus aeneus) male visiting a garden pond to drink and bathe. Rio Grande Valley, Texas, USA, April.

Luiz Claudio Marigo / Giant Cowbird (Molothrus oryzivorus) feeding on parasitic ticks from Capybaras (Hydrochaeris hydrochaeris). The Pantanal wetlands of Mato Grosso State, Brazil, October.

Luiz Claudio Marigo / Giant Cowbird (Molothrus oryzivorus) feeding on parasitic ticks from a Capybara (Hydrochoeris hydrochaeris). The Pantanal wetlands of Mato Grosso State, Brazil, October.

David Welling / Bronzed Cowbird (Molotrhus aeneus) male bathing in smalll pond, Rio Grande Valley, Texas, USA, May

Pete Oxford / Shiny Cowbird (Molothrus bonariensis), Pantanal, Brazil

Steve Gettle / Brown-headed Cowbird (Molothrus ater) female, Crane Creek State Park, Ohio

Donald M. Jones / Brown-headed Cowbird (Molothrus ater) male in flowering crab-apple tree, Troy, Montana

Doug Wechsler / Mixed flock of Red-winged Blackbird (Agelaius phoeniceus) and Brown-headed Cowbird (Molothrus ater) Texas, Floyd County, USA

Donald M. Jones / Brown-headed Cowbird (Molothrus ater) in flowering tree, North America

Roy Mangersnes / Bay-winged Cowbird (Molothrus / Agelaioides badius) perched, Buenos Aires, Argentina, South America. November.

Donald M. Jones / Brown-headed Cowbird (Molothrus ater) female, western Montana

Donald M. Jones / Brown-headed Cowbird (Molothrus ater) male in flowering tree, western Montana

Donald M. Jones / Brown-headed Cowbird (Molothrus ater) male in flowering tree, western Montana

David Welling / Brown-headed Cowbird (Molothrus ater) female singing on thorn bush, Rio Grande Valley, Texas, USA

David Welling / Brown-headed Cowbird (Molothrus ater) male perched, Rio Grande Valley, Texas, USA

Rolf Nussbaumer / Brown-headed Cowbird {Molothrus ater} male bathing, Hill Country, Texas

Rolf Nussbaumer / Male Bronzed Cowbird (Molothrus aeneus) Welder Wildlife Refuge, Sinton, Texas, USA. June 2005

Rolf Nussbaumer / Male Bronzed Cowbird (Molothrus aeneus) Welder Wildlife Refuge, Sinton, Texas, USA, June 2005

Tom Vezo / Bronzed Cowbird (Molothrus aeneus) perched on a stick, Costa Rica

Tom Vezo / Male Brown headed cowbird {Molothrus ater} Long Island, NY, USA.

Tom Vezo / Male Brown headed cowbird singing {Molothrus ater} Long Island, NY USA

Tom Vezo / Brown headed cowbird female {Molothrus ater} Long Island, NY USA

Tom Vezo / Female Brown headed cowbird {Molothrus ater} Long Island, New York, USA

Larry Michael / Brown headed cowbird {Molothrus ater} rear view of male perching on barbed wire, Wisconsin, USA.

Rolf Nussbaumer / Bronzed cowbird {Molothrus aeneus} female profile, Welder Wildlife Refuge, Sinton, Texas, USA.

Rolf Nussbaumer / Brown headed cowbird {Molothrus ater} male bathing, Welder Wildlife Refuge, Sinton, Texas, USA.

Rolf Nussbaumer / Male Bronzed cowbird {Molothrus aeneus} displaying, Welder Wildlife Refuge, Sinton, Texas, USA.

Rolf Nussbaumer / Bronzed cowbird {Molothrus aeneus} male profile, Welder Wildlife Refuge, Sinton, Texas, USA, June 2005

Rolf Nussbaumer / Bronzed cowbird male {Molothrus aeneus} Texas, USA

Mark Payne-Gill / Song sparrow nest {Zonotrichia melodia} parasitised with 5 Cowbird eggs {Molothrus ater}

Agustin Esmoris / Giant Cowbird (Molothrus oryzivorus), Argentina

Agustin Esmoris / Shiny Cowbird (Molothrus bonariensis) female, Bahia Blanca, Argentina

Agustin Esmoris / Shiny Cowbird (Molothrus bonariensis) female, Argentina

Agustin Esmoris / Shiny Cowbird (Molothrus bonariensis) female, Argentina

Jim Brandenburg / American Bison (Bison bison) with Brown-headed Cowbird (Molothrus ater) group feeding on insects, South Dakota

Jim Brandenburg / American Bison (Bison bison) grazing while Brown-headed Cowbirds (Molothrus ater) feed on grass seed and insects stirred up by the Buffalo, South Dakota

Staffan Widstrand / Capybara (Hydrochoerus hydrochaeris) sitting in wetland vegetation with Giant cowbird (Molothrus oryzivorus) perched on its back, Cuiaba River, Pantanal, Mato Grosso, Brazil.

Joel Sartore / Photo Ark / Grayish baywing (Agelaioides badius) portrait, Zoo Brasilia. Captive, occurs in South America.

Joel Sartore / Photo Ark / Grayish baywing (Agelaioides badius) portrait, Zoo Brasilia. Captive, occurs in South America.

Gabriel Rojo / Bay-winged cowbird (Agelaioides badius) perched on branch of flowering Chanar (Geoffroea decorticans), Calden forest, La Pampa, Patagonia, Argentina.

Gabriel Rojo / Bay-winged cowbird (Agelaioides badius) perched on wild flowers calling, Calden Forest, La Pampa, Patagonia, Argentina.

Joel Sartore / Photo Ark / Brown-headed cowbird (Molothrus ater artemisiae) portrait, Wildlife Rehabilitation Center Northern Utah. Captive, occurs in North America and Mexico.

Joel Sartore / Photo Ark / Brown-headed cowbird (Molothrus ater artemisiae) portrait, Wildlife Rehabilitation Center Northern Utah. Captive, occurs in North America and Mexico.

Charlie Summers / A Brown-headed cowbird (Molothrus ater) chick, a brood parasite, begging to be fed from a Savannah sparrow (Passerculus sandwichensis), North Park, Colorado, USA.

Wendy Shattil / Bronzed cowbird (Crotophaga sulcirostris) in the hand following mist netting and ringing by Texas Parks and Wildlife. Southmost Preserve, The Nature Conservancy reserve, Brownsville, Texas, USA. July...

Wendy Shattil / Bronzed cowbird (Molothrus aeneus) held by wildlife biologist from Texas Parks and Wildlife during ringing. Southmost Preserve, The Nature Conservancy reserve, Brownsville, Texas, USA. July 2019.