males

Scientists let swordtail fish choose their mates for nine generations; males kept picking larger females while female preferences varied

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Scientists let swordtail fish choose their mates for nine generations; males kept picking larger females while female preferences varied

Green swordtail fish have taken part in a digital dating game to help scientists understand how animals choose their mates. Researchers from the University of Exeter placed individual fish in tanks with screens showing virtual partners. The fish could then spend time near the partner they preferred.Those choices were used to create new virtual fish … Read more

Burmese python males undergo a dramatic seasonal hormone shift before breeding; scientists tracked testosterone and corticosterone in Florida snakes

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Burmese python males undergo a dramatic seasonal hormone shift before breeding; scientists tracked testosterone and corticosterone in Florida snakes

Burmese python coiled in the grass in the Everglades. Image Credit: Wikipedia Burmese python males in South Florida undergo a marked seasonal change in testosterone as the breeding period approaches, while another hormone linked to stress and energy use follows a less predictable pattern. A study published in General and Comparative Endocrinology tracked testosterone and … Read more

Colorado had more than 80,000 lesser prairie-chickens in 1975 but counted only 89 breeding males in 2024; a land trust has now spent nearly $2 million on a 2,100-acre ranch to help bring them back

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Colorado had more than 80,000 lesser prairie-chickens in 1975 but counted only 89 breeding males in 2024; a land trust has now spent nearly $2 million on a 2,100-acre ranch to help bring them back

The birds live in the Sand Sagebrush Ecoregion, which stretches across southeastern Colorado, southwestern Kansas and a small part of western Oklahoma. (American Bird Conservancy photo) Colorado’s lesser prairie-chicken population has fallen from more than 80,000 birds in 1975 to just 89 breeding males, according to a 2024 data. To restore the population of the … Read more