Seasonality, habitat type and locality influenced bird assemblage structure in Nigeria

This is the first report of the avian assemblage in the study area of Dutse, Nigeria. In addition to recording bird species, the effects of season, dominant vegetation structure, locality and anthropogenic activities on bird abundance, species richness and diversity were investigated. Using the point transect method, 264 points on 48 km of transect were used to count birds between 06:30 and 11:00 from August 2015 to February 2016. A total of 122 bird species of 41 families were recorded. Highest bird species richness was recorded in Warwade, highest abundance in Model, and highest diversity in Malamawa. The dry season and woodland habitat showed higher bird species richness, abundance and diversity than the wet season and shrubland habitat. Tree density was more important in increasing bird abundance than shrub density. Small-scale anthropogenic activities and habitat modification, such as farming, grazing, wood removal and human interference did not appear to have impacted the birds; however, loss of high tree-density woodland habitats may pose a major threat to the bird community in Dutse. The presence of birds of concern in the area suggests the need for conservation efforts of avifauna and as well as the forested habitats in Dutse.

本研究首次报道了尼日利亚杜策（Dutse）研究区域的鸟类群落组成。本研究在记录鸟类物种的同时，还探究了季节、优势植被结构、采样点位以及人为活动对鸟类种群丰度、物种丰富度与多样性的影响。本研究采用点样线法（point transect method），于2015年8月至2016年2月期间，在每日06:30至11:00的时段内，沿48公里样线上的264个采样点开展鸟类计数工作。本次调查共记录到隶属于41个科的122种鸟类。物种丰富度最高的区域为Warwade，种群丰度最高的区域为Model，多样性指数最高的区域为Malamawa。旱季与林地栖息地的鸟类物种丰富度、种群丰度及多样性指数均高于雨季与灌丛栖息地。相较于灌丛密度，乔木密度对提升鸟类种群丰度的促进作用更为显著。小型人为活动与栖息地改造（如农耕、放牧、伐薪及人类干扰似乎并未对当地鸟类产生显著影响；但高密度乔木林地栖息地的丧失，可能对杜策区域的鸟类群落构成重大威胁。该区域存在受关注鸟类，这表明需针对杜策区域的鸟类区系及森林栖息地开展保护工作。