Age at sexual maturity of males and timing of the mating season of polar bears (Ursus maritimus) in Greenland

摘要: Age at sexual maturity among male polar bears (Ursus maritimus) and timing of the mating season were studied by microscopic macroscopic analysis reproductive organs from 165 92 female Greenland bears. Males became sexually mature in spring following their fifth birthday. Testes sampled during reached 95% asymptotic length 5.8 years. Some spermatozoa found 2- to 4-year-old spring, but only low concentrations a mixture other cell types. The first corpus luteum was on 1 April most ovulations estimated occur before mid-May which indicate that peak begins late March ends May. These findings are somewhat different similar study Svalbard, where is later become earlier. We hypothesize these differences because adolescent males have testicular activity after main breeding period therefore appear be fully summer not spring.