Fakarayi Togarasei, Mashapa Clayton, Gandiwa Edson, Kativu Shakkie
Tropical Resource Ecology Programme, University of Zimbabwe, P. O. Box MP 167, Mount Pleasant, Harare, Zimbabwe.
BirdLife Zimbabwe, P. O. Box RVL 100, Runiville, Harare, Zimbabwe.
PLoS One. 2016 Nov 22;11(11):e0166209. doi: 10.1371/journal.pone.0166209. eCollection 2016.
Three species of cranes are distributed widely throughout southern Africa, but little is known about how they respond to the changes in land-use that have occurred in this region. This study assessed habitat preference of the two crane species across land-use categories of the self contained small scale commercial farms of 30 to 40 ha per household (A1), large scale commercial agriculture farms of > 50 ha per household (A2) and Old Resettlement, farms of < 5 ha per household with communal grazing land in Driefontein Grasslands Important Bird Area (IBA), Zimbabwe. The study further explored how selected explanatory (environmental) habitat variables influence crane species abundance. Crane bird counts and data on influencing environmental variables were collected between June and August 2012. Our results show that varying land-use categories had an influence on the abundance and distribution of the Wattled Crane (Bugeranus carunculatus) and the Grey Crowned Crane (Belearica regulorum) across Driefontein Grasslands IBA. The Wattled Crane was widely distributed in the relatively undisturbed A2 farms while the Grey Crowned Crane was associated with the more disturbed land of A1 farms, Old Resettlement and its communal grazing land. Cyperus esculentus and percent (%) bare ground were strong environmental variables best explaining the observed patterns in Wattled Crane abundance across land-use categories. The pattern in Grey Crowned Crane abundance was best explained by soil penetrability, moisture and grass height variables. A holistic sustainable land-use management that takes into account conservation of essential habitats in Driefontein Grasslands IBA is desirable for crane populations and other wetland dependent species that include water birds.
三种鹤广泛分布于非洲南部，但对于它们如何应对该地区土地利用变化知之甚少。本研究评估了两种鹤在不同土地利用类型中的栖息地偏好，这些土地利用类型包括每户30至40公顷的自给自足型小规模商业农场（A1）、每户超过50公顷的大规模商业农业农场（A2）以及位于津巴布韦德里方丹草原重要鸟类区（IBA）的每户小于5公顷且有公共放牧地的旧安置农场。该研究进一步探讨了选定的解释性（环境）栖息地变量如何影响鹤类物种的丰富度。2012年6月至8月期间收集了鹤的数量数据以及影响环境变量的数据。我们的结果表明，不同的土地利用类型对德里方丹草原IBA地区肉垂鹤（Bugeranus carunculatus）和灰冠鹤（Belearica regulorum）的丰富度和分布有影响。肉垂鹤广泛分布在相对未受干扰的A2农场，而灰冠鹤则与A1农场、旧安置农场及其公共放牧地等受干扰较多的土地有关。香附子和裸地百分比是最能解释不同土地利用类型中肉垂鹤丰富度观测模式的重要环境变量。灰冠鹤丰富度的模式最好由土壤渗透率、湿度和草高变量来解释。对于鹤类种群以及包括水鸟在内的其他依赖湿地的物种而言，需要一种全面的可持续土地利用管理方式，该方式要考虑到对德里方丹草原IBA地区重要栖息地的保护。
