loading . . . Effect of seasonal climatic changes on fertility in different species of male mammals and birds - The Journal of Basic and Applied Zoology Background Climate is a key environmental factor affecting both human and animal reproductive health. Rising temperatures, altered precipitation patterns, and an increase in extreme weather events are examples of climate change that can upset hormonal balance, impair the quality of sperm and eggs, and decrease fertility rates overall. These shifts also impact the availability of food and water, leading to physical stress that hinders reproduction. Therefore, the current study investigates the effect of seasonal climatic changes on fertility hormones (follicle stimulating hormone (FSH), luteinizing hormone (LH), estrogen, testosterone) in different species of mammals (cow, sheep, and goat) and birds (duck, chicken, and pigeon) and histological study of testes of birds. Results At the end of the experimental period the results showed that climate change adversely affects fertility by decreasing serum levels of FSH, LH, estrogen, and testosterone significantly (P < 0.001) in male (cow, sheep, and goat) in summer and winter compared to spring and autumn., Moreover testosterone and LH levels showed significant decrease (P < 0.001) in male (duck, chicken, and pigeon) in summer and winter compared to spring and autumn. Serum FSH and estrogen showed no significant change in male (duck, chicken, and pigeon) in all seasons. Testes histopathology showed numerous spermatogenic cell layers, with normal-size of seminiferous tubules in spring and autumn in all species. While, reduction in the size of the seminiferous tubules with absence of spermatozoa (azoospermia) in winter and summer occurred in all species. Conclusion Overall, the present study pointed out the negative impacts of climatic changes on the fertility of different species of male mammals and birds, especially in summer and winter. https://link.springer.com/article/10.1186/s41936-025-00501-1