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Gravel bars can be critical for biodiversity conservation: a case study on scaly-sided Merganser in South china.

Zeng Q, Shi L, Wen L, Chen J, Duo H, Lei G - PLoS ONE (2015)

Bottom Line: We then built habitat suitability models (Generalized Linear Models-GLMs) to study the effects of landscape metrics and human disturbance on Scaly-sided Merganser presence probability.We found that 1) the Scaly-sided Merganser tended to congregate at river segments with more gravel patches; 2) the Scaly-sided Merganser preferred areas with larger and more contiguous gravel patches; and 3) the number of houses along the river bank (a proxy for anthropogenic disturbance) had significantly negative impacts on the occurrence of the Scaly-sided Merganser.Our results suggest that gravel bars are vital to the Scaly-sided Merganser as shelters from disturbance, as well as sites for feeding and roosting.

View Article: PubMed Central - PubMed

Affiliation: School of Nature Conservation, Beijing Forestry University, Beijing, 100083, China.

ABSTRACT
Gravel bars are characteristic components of river landscapes and are increasingly recognized as key sites for many waterbirds, though detailed studies on the ecological function of gravel bars for waterbirds are rare. In this study, we surveyed the endangered Scaly-sided Merganser Mergus squamatus along a 40 km river section of Yuan River, in Central China, for three consecutive winters. We derived the landscape metrics of river gravel bars from geo-rectified fine resolution (0.6 m) aerial image data. We then built habitat suitability models (Generalized Linear Models-GLMs) to study the effects of landscape metrics and human disturbance on Scaly-sided Merganser presence probability. We found that 1) the Scaly-sided Merganser tended to congregate at river segments with more gravel patches; 2) the Scaly-sided Merganser preferred areas with larger and more contiguous gravel patches; and 3) the number of houses along the river bank (a proxy for anthropogenic disturbance) had significantly negative impacts on the occurrence of the Scaly-sided Merganser. Our results suggest that gravel bars are vital to the Scaly-sided Merganser as shelters from disturbance, as well as sites for feeding and roosting. Therefore, maintaining the exposure of gravel bars in regulated rivers during the low water period in winter might be the key for the conservation of the endangered species. These findings have important implications for understanding behavioral evolution and distribution of the species and for delineating between habitats of different quality for conservation and management.

No MeSH data available.


Related in: MedlinePlus

The density of estimated coefficients for A) Model 1, B) Model 2 C) Model 3, and D) Model 4 through 50,000 iterations of Gibbs sampling.
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pone.0127387.g004: The density of estimated coefficients for A) Model 1, B) Model 2 C) Model 3, and D) Model 4 through 50,000 iterations of Gibbs sampling.

Mentions: The occurrence of the Scaly-sided Merganser was significantly negatively affected by BLD, and this was consistent for both the GLM estimates (Table 3) and the Bayesian inferred posterior density distribution (Table 3 and Fig 4B). In addition, the GLM estimation of -2.02 was close the medium of -2.88 from MCMC posterior sampling for the model which included BLD as main factor only (i.e. model 2).


Gravel bars can be critical for biodiversity conservation: a case study on scaly-sided Merganser in South china.

Zeng Q, Shi L, Wen L, Chen J, Duo H, Lei G - PLoS ONE (2015)

The density of estimated coefficients for A) Model 1, B) Model 2 C) Model 3, and D) Model 4 through 50,000 iterations of Gibbs sampling.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4440824&req=5

pone.0127387.g004: The density of estimated coefficients for A) Model 1, B) Model 2 C) Model 3, and D) Model 4 through 50,000 iterations of Gibbs sampling.
Mentions: The occurrence of the Scaly-sided Merganser was significantly negatively affected by BLD, and this was consistent for both the GLM estimates (Table 3) and the Bayesian inferred posterior density distribution (Table 3 and Fig 4B). In addition, the GLM estimation of -2.02 was close the medium of -2.88 from MCMC posterior sampling for the model which included BLD as main factor only (i.e. model 2).

Bottom Line: We then built habitat suitability models (Generalized Linear Models-GLMs) to study the effects of landscape metrics and human disturbance on Scaly-sided Merganser presence probability.We found that 1) the Scaly-sided Merganser tended to congregate at river segments with more gravel patches; 2) the Scaly-sided Merganser preferred areas with larger and more contiguous gravel patches; and 3) the number of houses along the river bank (a proxy for anthropogenic disturbance) had significantly negative impacts on the occurrence of the Scaly-sided Merganser.Our results suggest that gravel bars are vital to the Scaly-sided Merganser as shelters from disturbance, as well as sites for feeding and roosting.

View Article: PubMed Central - PubMed

Affiliation: School of Nature Conservation, Beijing Forestry University, Beijing, 100083, China.

ABSTRACT
Gravel bars are characteristic components of river landscapes and are increasingly recognized as key sites for many waterbirds, though detailed studies on the ecological function of gravel bars for waterbirds are rare. In this study, we surveyed the endangered Scaly-sided Merganser Mergus squamatus along a 40 km river section of Yuan River, in Central China, for three consecutive winters. We derived the landscape metrics of river gravel bars from geo-rectified fine resolution (0.6 m) aerial image data. We then built habitat suitability models (Generalized Linear Models-GLMs) to study the effects of landscape metrics and human disturbance on Scaly-sided Merganser presence probability. We found that 1) the Scaly-sided Merganser tended to congregate at river segments with more gravel patches; 2) the Scaly-sided Merganser preferred areas with larger and more contiguous gravel patches; and 3) the number of houses along the river bank (a proxy for anthropogenic disturbance) had significantly negative impacts on the occurrence of the Scaly-sided Merganser. Our results suggest that gravel bars are vital to the Scaly-sided Merganser as shelters from disturbance, as well as sites for feeding and roosting. Therefore, maintaining the exposure of gravel bars in regulated rivers during the low water period in winter might be the key for the conservation of the endangered species. These findings have important implications for understanding behavioral evolution and distribution of the species and for delineating between habitats of different quality for conservation and management.

No MeSH data available.


Related in: MedlinePlus