Background:The ideal habitat use of waterbirds can be considered to be fixed,but current habitat use depends on environmental conditions,especially those of food characteristics,considered crucial to their use of habi...Background:The ideal habitat use of waterbirds can be considered to be fixed,but current habitat use depends on environmental conditions,especially those of food characteristics,considered crucial to their use of habitats.Understanding how waterbirds respond to variation in food availability at degraded wetland sites and change their habitat use patterns over spatial and temporal scales should direct future conservation planning.The objectives of this study were to identify these spatial-temporal foraging habitat use patterns of Hooded Cranes(Grus monacha)and their relationship with food characteristics in the severely degraded wetlands of the Shengjin and Caizi lakes along with the Yangtze River floodplain.Methods:We investigated the changes in food characteristics,relative abundance and density of Hooded Cranes in various habitat types across three winter periods from November 2012 to April 2013.We examined the effect of these winter periods and habitat types on the pattern of use by the cranes and explored the relationship between these patterns and food characteristics using linear regression.Results:The food characteristics and habitat use clearly changed over spatial-temporal scales.In the early and mid-winter periods,the most abundant,accessible and frequented food resources were found in paddy fields,while in the late period the more abundant food were available in meadows,which then replaced the paddy fields.There were fewer effects of winter periods,habitat types and their interactions on habitat use patterns except for the effect of habitat types on the relative abundance,determined as a function of food abundance,but independent of food depth and sediment permeability.Conclusions:In response to the degradation and loss of lake wetlands,the cranes shifted their habitat use patterns by making tradeoffs between food abundance and accessibility over spatial-temporal scales that facilitated their survival in the mosaic of these lake wetlands.展开更多
Background: The habitat use and foraging behaviors of waterbirds are closely related to the distribution and abundance of their food resources. Reductions in food supply can cause waterbirds to shift their habitats an...Background: The habitat use and foraging behaviors of waterbirds are closely related to the distribution and abundance of their food resources. Reductions in food supply can cause waterbirds to shift their habitats and adjust their foraging behaviors to meet their nutritional requirements and increase fitness. Seasonal withdraw of the water levels in the river-connected lakes in the middle and lower Yangtze River floodplain provides abundant food resources for the wintering Greater White-fronted Goose(Anser albifrons). Sedge(Carex) meadows are critical foraging habitats for herbivorous waterbirds in the hydro-fluctuation belt, which changes with hydrological conditions and climate. This study aimed to examine the behavioral responses of the Greater White-fronted Goose to temporal-spatial changes of food availability in the Sedge meadows.Methods: Fields surveys were carried out at Shengjin Lake from November 2017 to April 2018. According to the phenology of Shengjin Lake, we divided the wintering season into three periods. The food density, minimum temperature, food items, grass height, and number of foraging geese were surveyed, and samples of the foraging behavior were collected. We analyzed the relationship of the foraging behavior and habitat use relative to the food resources, using correlation and linear regression analyses.Results: Along with the temporal-spatial variation and exploitation of food resources, the food abundance and items varied widely among the foraging sites. Over the whole wintering period, the foraging habitat with the highest utilization rate was the meadows, followed by the paddy fields, and then mudflats. Furthermore, the utilization of the meadows showed a bimodal distribution trend, while the paddy fields showed a unimodal trend, and a decreasing trend was seen in the mudflats over the whole wintering period. The results of the generalized linear model showed that the foraging rate was related to the food density and grass height, with a linearly increasing trend during the winter.Co展开更多
基金supported by the National Natural Science Foundation of China(Grant no.31172117 and 31472020)the Graduate Student Innovation Research Projects of Anhui University(YQ 01001770)
文摘Background:The ideal habitat use of waterbirds can be considered to be fixed,but current habitat use depends on environmental conditions,especially those of food characteristics,considered crucial to their use of habitats.Understanding how waterbirds respond to variation in food availability at degraded wetland sites and change their habitat use patterns over spatial and temporal scales should direct future conservation planning.The objectives of this study were to identify these spatial-temporal foraging habitat use patterns of Hooded Cranes(Grus monacha)and their relationship with food characteristics in the severely degraded wetlands of the Shengjin and Caizi lakes along with the Yangtze River floodplain.Methods:We investigated the changes in food characteristics,relative abundance and density of Hooded Cranes in various habitat types across three winter periods from November 2012 to April 2013.We examined the effect of these winter periods and habitat types on the pattern of use by the cranes and explored the relationship between these patterns and food characteristics using linear regression.Results:The food characteristics and habitat use clearly changed over spatial-temporal scales.In the early and mid-winter periods,the most abundant,accessible and frequented food resources were found in paddy fields,while in the late period the more abundant food were available in meadows,which then replaced the paddy fields.There were fewer effects of winter periods,habitat types and their interactions on habitat use patterns except for the effect of habitat types on the relative abundance,determined as a function of food abundance,but independent of food depth and sediment permeability.Conclusions:In response to the degradation and loss of lake wetlands,the cranes shifted their habitat use patterns by making tradeoffs between food abundance and accessibility over spatial-temporal scales that facilitated their survival in the mosaic of these lake wetlands.
基金the National Natural Science Foundation of China(Grant No.31472020).
文摘Background: The habitat use and foraging behaviors of waterbirds are closely related to the distribution and abundance of their food resources. Reductions in food supply can cause waterbirds to shift their habitats and adjust their foraging behaviors to meet their nutritional requirements and increase fitness. Seasonal withdraw of the water levels in the river-connected lakes in the middle and lower Yangtze River floodplain provides abundant food resources for the wintering Greater White-fronted Goose(Anser albifrons). Sedge(Carex) meadows are critical foraging habitats for herbivorous waterbirds in the hydro-fluctuation belt, which changes with hydrological conditions and climate. This study aimed to examine the behavioral responses of the Greater White-fronted Goose to temporal-spatial changes of food availability in the Sedge meadows.Methods: Fields surveys were carried out at Shengjin Lake from November 2017 to April 2018. According to the phenology of Shengjin Lake, we divided the wintering season into three periods. The food density, minimum temperature, food items, grass height, and number of foraging geese were surveyed, and samples of the foraging behavior were collected. We analyzed the relationship of the foraging behavior and habitat use relative to the food resources, using correlation and linear regression analyses.Results: Along with the temporal-spatial variation and exploitation of food resources, the food abundance and items varied widely among the foraging sites. Over the whole wintering period, the foraging habitat with the highest utilization rate was the meadows, followed by the paddy fields, and then mudflats. Furthermore, the utilization of the meadows showed a bimodal distribution trend, while the paddy fields showed a unimodal trend, and a decreasing trend was seen in the mudflats over the whole wintering period. The results of the generalized linear model showed that the foraging rate was related to the food density and grass height, with a linearly increasing trend during the winter.Co
