Effect of traffic noise on black-faced spoonbills in the TaipaColoane Wetland Reserve, Macao

摘要

Context Nearly 20% of black-faced spoonbills (Platalea minor), a globally endangered species, winter along the coasts of the Pearl River Estuary, China. However, these wintering habitats are threatened by urban development. Especially in Macao, road construction for the tourism industry has resulted in habitat deterioration. Aims Our study aimed to assess the effects of traffic noise on the distribution and behaviour of black-faced spoonbills in the TaipaColoane Wetland Reserve, Macao SAR. Methods We built a traffic-noise prediction model for habitat-suitability division. Then we investigated the relationship between traffic noise and diurnal of spoonbill behaviours by collecting traffic-noise data on surrounding roads and observing the activity of black-faced spoonbills in the area over two winters, from 2007 to 2009. Key results The maximum number of individuals present in a single month was 50 in the winter of 200708 (in February) and 52 in the winter of 200809 (in January). Continuous traffic noise was 46.5 and 45.4dB(A), respectively, at roosting sites in two ecological zones. On the basis of the prediction model, only 10.8 of 30.3ha were suitable for spoonbills, with noise levels lower than 47dB(A). Most of the time, the spoonbills were acclimated to the traffic and were not alarmed. However, heavy trucks with a high noise level of 81.82.3dB(A) sometimes disrupted spoonbill behaviour. Conclusions The traffic noise around the TaipaColoane Wetland Reserve did exist but did not substantially affect black-faced spoonbills. For the birds mainly roosting in a quieter area, the small area of suitable habitat may indirectly limit population growth. Implications The fences around Ecological Zone I were successful in minimising visual stimuli from human activities and passing cars. To maintain the suitability of the winter habitat in Macao, restrictions on traffic flow, especially on heavy truck volume, are necessary for spoonbill conservation.