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Vigilance and activity time-budget adjustments of wintering hooded cranes, Grus monacha, in human-dominated foraging habitats.

Li C, Zhou L, Xu L, Zhao N, Beauchamp G - PLoS ONE (2015)

Bottom Line: Our results showed striking differences in the behavior of the cranes when foraging in the highly disturbed rice paddy fields found in the buffer zone compared with the degraded natural wetlands in the core area of the NNR.Time spent vigilant decreased with flock size and cranes spent more time vigilant in the human-dominated buffer zone.We recommend habitat recovery in natural wetlands and community co-management in the surrounding human-dominated landscape for conservation of the hooded crane and, generally, for the vast numbers of migratory waterbirds wintering in the middle and lower reaches of the Yangtze River floodplain.

View Article: PubMed Central - PubMed

Affiliation: School of Resources and Environmental Engineering, Anhui University, Hefei, China; Anhui Biodiversity Information Center, Hefei, China.

ABSTRACT
Due to loss and degradation of natural wetlands, waterbirds increasingly rely on surrounding human-dominated habitats to obtain food. Quantifying vigilance patterns, investigating the trade-off among various activities, and examining the underlying mechanisms will help us understand how waterbirds adapt to human-caused disturbances. During two successive winters (November-February of 2012-13 and 2013-14), we studied the hooded crane, Grus monacha, in the Shengjin Lake National Nature Reserve (NNR), China, to investigate how the species responds to human disturbances through vigilance and activity time-budget adjustments. Our results showed striking differences in the behavior of the cranes when foraging in the highly disturbed rice paddy fields found in the buffer zone compared with the degraded natural wetlands in the core area of the NNR. Time spent vigilant decreased with flock size and cranes spent more time vigilant in the human-dominated buffer zone. In the rice paddy fields, the birds were more vigilant but also fed more at the expense of locomotion and maintenance activities. Adult cranes spent more time vigilant and foraged less than juveniles. We recommend habitat recovery in natural wetlands and community co-management in the surrounding human-dominated landscape for conservation of the hooded crane and, generally, for the vast numbers of migratory waterbirds wintering in the middle and lower reaches of the Yangtze River floodplain.

No MeSH data available.


Percentage time spent vigilant as a function of flock size of the hooded crane in the core area A) and the buffer zone B) of the Shengjin Lake NNR, China.
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pone.0118928.g002: Percentage time spent vigilant as a function of flock size of the hooded crane in the core area A) and the buffer zone B) of the Shengjin Lake NNR, China.

Mentions: The percentage time spent vigilant ranged from 0 to 95.1% (Table 2). The final linear mixed model revealed a statistically significant effect of year (F1,207 = 7.84, p = 0.006), age (F1,412 = 71.31, p<0.001), area (F1,219 = 10.87, p = 0.001), flock size (F1,205 = 6.76, p = 0.010) and the two-way interaction between area and flock size (F1,204 = 4.80, p = 0.030). The hooded crane spent more time vigilant in 2012–13 winter (25.8% ± 2.6%) than in 2013–14 winter (18.9% ± 0.8%). Adult cranes spent more time vigilant than juveniles in both the buffer zone (24.4% ± 1.4% vs 15.5% ± 2.2%) and the core area (20.3% ± 1.2% vs 12.8% ± 1.7%) in the two winters. Both adult and juvenile cranes spent more time vigilant in the buffer zone than those in the core area. Individual vigilance decreased with flock size (β = −0.158 ± 0.036, t = −4.36, p<0.001) in the buffer zone but not in the core area (β = −0.050 ± 0.044, t = −1.13, p = 0.260) (Fig. 2).


Vigilance and activity time-budget adjustments of wintering hooded cranes, Grus monacha, in human-dominated foraging habitats.

Li C, Zhou L, Xu L, Zhao N, Beauchamp G - PLoS ONE (2015)

Percentage time spent vigilant as a function of flock size of the hooded crane in the core area A) and the buffer zone B) of the Shengjin Lake NNR, China.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4359144&req=5

pone.0118928.g002: Percentage time spent vigilant as a function of flock size of the hooded crane in the core area A) and the buffer zone B) of the Shengjin Lake NNR, China.
Mentions: The percentage time spent vigilant ranged from 0 to 95.1% (Table 2). The final linear mixed model revealed a statistically significant effect of year (F1,207 = 7.84, p = 0.006), age (F1,412 = 71.31, p<0.001), area (F1,219 = 10.87, p = 0.001), flock size (F1,205 = 6.76, p = 0.010) and the two-way interaction between area and flock size (F1,204 = 4.80, p = 0.030). The hooded crane spent more time vigilant in 2012–13 winter (25.8% ± 2.6%) than in 2013–14 winter (18.9% ± 0.8%). Adult cranes spent more time vigilant than juveniles in both the buffer zone (24.4% ± 1.4% vs 15.5% ± 2.2%) and the core area (20.3% ± 1.2% vs 12.8% ± 1.7%) in the two winters. Both adult and juvenile cranes spent more time vigilant in the buffer zone than those in the core area. Individual vigilance decreased with flock size (β = −0.158 ± 0.036, t = −4.36, p<0.001) in the buffer zone but not in the core area (β = −0.050 ± 0.044, t = −1.13, p = 0.260) (Fig. 2).

Bottom Line: Our results showed striking differences in the behavior of the cranes when foraging in the highly disturbed rice paddy fields found in the buffer zone compared with the degraded natural wetlands in the core area of the NNR.Time spent vigilant decreased with flock size and cranes spent more time vigilant in the human-dominated buffer zone.We recommend habitat recovery in natural wetlands and community co-management in the surrounding human-dominated landscape for conservation of the hooded crane and, generally, for the vast numbers of migratory waterbirds wintering in the middle and lower reaches of the Yangtze River floodplain.

View Article: PubMed Central - PubMed

Affiliation: School of Resources and Environmental Engineering, Anhui University, Hefei, China; Anhui Biodiversity Information Center, Hefei, China.

ABSTRACT
Due to loss and degradation of natural wetlands, waterbirds increasingly rely on surrounding human-dominated habitats to obtain food. Quantifying vigilance patterns, investigating the trade-off among various activities, and examining the underlying mechanisms will help us understand how waterbirds adapt to human-caused disturbances. During two successive winters (November-February of 2012-13 and 2013-14), we studied the hooded crane, Grus monacha, in the Shengjin Lake National Nature Reserve (NNR), China, to investigate how the species responds to human disturbances through vigilance and activity time-budget adjustments. Our results showed striking differences in the behavior of the cranes when foraging in the highly disturbed rice paddy fields found in the buffer zone compared with the degraded natural wetlands in the core area of the NNR. Time spent vigilant decreased with flock size and cranes spent more time vigilant in the human-dominated buffer zone. In the rice paddy fields, the birds were more vigilant but also fed more at the expense of locomotion and maintenance activities. Adult cranes spent more time vigilant and foraged less than juveniles. We recommend habitat recovery in natural wetlands and community co-management in the surrounding human-dominated landscape for conservation of the hooded crane and, generally, for the vast numbers of migratory waterbirds wintering in the middle and lower reaches of the Yangtze River floodplain.

No MeSH data available.