Spatial ecology of little egret (Egretta garzetta) in Hong Kong uncovers preference for commercial fishponds

Abstract

Many natural wetlands have been converted to human-influenced wetlands. In some instances, human-influenced wetlands could provide complementary habitats for waterbirds, compensating for the loss of natural wetlands. Inner Deep Bay in Hong Kong is composed of both natural and human-influenced wetlands and is under immense development pressure. From an ecology perspective, we need to understand if different wetland types play the same ecological role. To achieve this, we tracked nine little egrets (Egretta garzetta) using GPS loggers for 14 months to study their spatial ecology, home range, movement and habitat use. We found that over 88% of the home range of all individuals comprised of wetlands (commercial fishponds, mangrove, gei wai, channel, and intertidal mudflat). Among these wetland types, nearly all (seven of nine) individuals preferred commercial fishponds over other habitats in all seasons. Little egrets exhibited seasonal movement and habitat use among seasons, with largest home range, greatest movement, and most frequent visits to commercial fishponds in winter compared to spring and autumn. Our results highlight the significant role of commercial fishponds, providing a feeding ground for little egrets. However, other wetland types cannot be ignored, as they were also used considerably. These findings underscore the importance of maintaining a diversity of wetland types as alternative foraging and breeding habitats.

Seasonal space use and habitat selection in magpie geese: implications for reducing human‐wildlife conflicts

“…We selected the MCP method because it is a direct, non‐probabilistic estimator of space use (Jorge et al 2020). Following similar habitat selection studies (Mallord et al 2018, Jorge et al 2020, Pang et al 2020), we used all GPS detections (MCP 100%) to be most representative of the habitat available to geese within their range. We calculated MCP from individual trajectories using the as.ltraj and mcp functions (Calenge 2006), and exported them as shapefiles using the R package raster (Hijmans 2020) to clip the habitat layer in ArcGIS 10.4 (Esri, Redlands, CA, USA).…”

Penggunaan Ruang Terbuka Hijau Pabrik PT Polytama Propindo, Indramayu, Sebagai Habitat Burung dan Herpetofauna

“…Hal ini dikarenakan lingkungan pabrik dikeliling oleh lahan basah yang disukai oleh jenis kuntul kecil. Kuntul kecil merupakan jenis spesialis lahan basah dan jarang memanfaatkan habitat yang bukan lahan basah (Pang et al, 2020). Penggunaan habitat oleh komunitas herpetofauna berdasarkan ruang secara horizontal menunjukkan sebaran dan luas wilayah jelajah.…”

Ecological Correlates of 20-Year Population Trends of Wintering Waterbirds in Deep Bay, South China

“…Since 1998, the Hong Kong Government began to fund the monitoring of waterbirdssystematic, monthly surveys have been carried out in the Deep Bay area, which encompasses two regions: (1) the northwest New Territories, Hong Kong Special Administrative Region China, and (2) Futian Mangrove National Nature Reserve, Shenzhen, Guangdong Province, China. The study area contains a mixture of different wetland types, including commercial aquaculture ponds, mangroves, and intertidal mudflats (more details in Pang et al, 2020). Synchronized surveys were conducted along 16 fixed, non-overlapping transects distributed across the study areas by trained surveyors.…”