Rani Kiran, Babbar B K, Dhillon Amanpreet Kaur
Department of Zoology, Punjab Agricultural University, Ludhiana, 141004, Punjab, India.
Punjab Remote Sensing Centre, Ludhiana, Punjab, India.
Sci Rep. 2025 Jul 5;15(1):24005. doi: 10.1038/s41598-025-08623-w.
Blue bull (Boselaphus tragocamelus) is one of the largest antelope species and native to the Indian subcontinent. The blue bull population is surplus in some Indian states, and has attained pest status. The information regarding animal population ecology helps in understanding the ecosystem health, climate change impact and plays a pivotal role in devising conservation policies, mitigating human-animal conflict, and resource management. Herd size and composition of blue bull were recorded in forest and agrarian lands of district Ludhiana. Scan sampling method was used to record data during 24 fortnightly visits in 30 clusters from June 2022 to May 2023. The mapping of the blue bull population density highlights the critical spots of animal density. Its population density and encounter rate ranged from 0.318 to 5.79 animals/km and 0.145-1.316 animals/km respectively. The herd composition (χ2 = 167.9396, P = < 0.0001, df = 15) and animals of different age groups and sexes (χ2 = 69.7284, P = < 0.0001, df = 20) changed significantly with season. The habitat types, forest and agrarian land, had no effect on the herd composition. Non-harem groups were observed in summer and monsoon, while harem groups were observed throughout autumn, pre-winter, winter, and spring, indicating long breeding season. The overall sex ratio adult female to adult male ratio is 1:0.18, skewed towards females, indicating the potential for population growth over time. Calving events were most prominent during the pre-winter season. Animal sightings and group size fluctuations were found to be closely correlated with extrinsic factors like food and shelter availability. This study marks the first comprehensive exploration of blue bull population ecology in agrarian land in Punjab and can provide valuable insights for policymakers to focus on managing blue bull populations in areas with high density, particularly during critical breeding seasons, to prevent overpopulation and mitigate human-animal conflicts. Additionally, strategies should be developed to ensure the preservation of their natural habitat.
蓝牛羚（Boselaphus tragocamelus）是最大的羚羊物种之一，原产于印度次大陆。在印度的一些邦，蓝牛羚数量过剩，已达到有害生物的地位。有关动物种群生态学的信息有助于了解生态系统健康、气候变化影响，并在制定保护政策、缓解人兽冲突和资源管理方面发挥关键作用。在卢迪亚纳地区的森林和农田中记录了蓝牛羚的种群规模和组成。在2022年6月至2023年5月期间，对30个集群进行了24次每两周一次的访问，采用扫描抽样法记录数据。蓝牛羚种群密度图突出了动物密度的关键点。其种群密度和相遇率分别为每公里0.318至5.79只动物和每公里0.145 - 1.316只动物。种群组成（χ2 = 167.9396，P = < 0.0001，df = 15）以及不同年龄组和性别的动物（χ2 = 69.7284，P = < 0.0001，df = 20）随季节变化显著。栖息地类型，即森林和农田，对种群组成没有影响。在夏季和季风季节观察到非妻妾群，而在整个秋季、初冬、冬季和春季都观察到妻妾群，表明繁殖季节较长。成年雌性与成年雄性的总体性别比为1:0.18，偏向雌性，表明随着时间推移种群有增长的潜力。产犊事件在初冬季节最为突出。发现动物目击情况和群体大小波动与食物和庇护所可用性等外部因素密切相关。这项研究标志着对旁遮普邦农田中蓝牛羚种群生态学的首次全面探索，可为政策制定者提供有价值的见解，以便他们专注于管理高密度地区的蓝牛羚种群，特别是在关键繁殖季节，以防止种群过剩并缓解人兽冲突。此外，应制定策略以确保其自然栖息地的保护。
