Polar Bear Cubs: Denning, Birth, and the First Year of Life
Polar bear cubs are born at 500-700 g inside a snow den while their mother has fasted for months. Here is how they survive the first Arctic year.
April 2026
December 2024
Why Is Panda Reproduction So Hard? The 24-Hour Fertile Window and the Science of Breeding Pandas
Panda females ovulate once a year for 24-72 hours. The breeding challenge, AI breakthroughs, and why captive survival jumped from 10% to 90%.
Panda Cubs: From 100 Grams to 100 Kilograms in Two Years
Panda cubs weigh 85-130 g at birth, one of the smallest mother-to-cub ratios in mammals. Here is how they grow from pink blind newborn to independent adult.
November 2024
Grizzly Bear Cubs and Family Life: Birth, Growth, and the 2-Year Bond
Grizzly cubs weigh 400-500 g at birth inside a winter den. The first 3 years of life, the mother-cub bond, and why male infanticide shapes family survival.
Brown Bear Cubs and Mothers: Winter Births, the 2-Year Bond, and Male Infanticide
Brown bear cubs weigh 350-500 g at birth mid-hibernation. The mother-cub bond, infanticide risk from boars, and how maternal care shapes survival.