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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.


Scan rate A) and mean scan duration B) of the hooded crane wintering in the Shengjin Lake NNR, China: A1, adult cranes in the buffer zone; A2, adults in the core area; J1, juveniles in the buffer zone; J2, juveniles in the core area.
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pone.0118928.g003: Scan rate A) and mean scan duration B) of the hooded crane wintering in the Shengjin Lake NNR, China: A1, adult cranes in the buffer zone; A2, adults in the core area; J1, juveniles in the buffer zone; J2, juveniles in the core area.

Mentions: Mean scan duration ranged from 0.4 s to 80.0 s. The final linear mixed model indicated no significant effect of year (F1,187 = 0.45, p = 0.506), age (F1,388 = 0.49, p = 0.486), area (F1,183 = 1.31, p = 0.253) or flock size (F1,184 = 1.51, p = 0.220) on mean scan duration. Scan rates ranged from 0 to 5.44 min−1. The final negative binomial regression model showed a statistically significant effect of year (χ2 = 6.56, p = 0.010), age (χ2 = 94.26, p<0.001), area (χ2 = 80.90, p<0.001) and flock size (χ2 = 16.10, p<0.001). The hooded crane scanned more frequently in 2012–13 winter (1.35 ± 0.09 min−1) than in 2013–14 winter (1.16 ± 0.04 min−1). Adult cranes scanned more frequently than juveniles in both the buffer zone (1.68 ± 0.06 min−1 vs 0.90 ± 0.07 min−1) and the core area (1.11 ± 0.05 min−1 vs 0.66 ± 0.07 min−1). Scan rate decreased with the flock size (β = −0.007 ± 0.002) and the cranes scanned more frequently in the buffer zone than in the core area (Fig. 3).


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)

Scan rate A) and mean scan duration B) of the hooded crane wintering in the Shengjin Lake NNR, China: A1, adult cranes in the buffer zone; A2, adults in the core area; J1, juveniles in the buffer zone; J2, juveniles in the core area.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0118928.g003: Scan rate A) and mean scan duration B) of the hooded crane wintering in the Shengjin Lake NNR, China: A1, adult cranes in the buffer zone; A2, adults in the core area; J1, juveniles in the buffer zone; J2, juveniles in the core area.
Mentions: Mean scan duration ranged from 0.4 s to 80.0 s. The final linear mixed model indicated no significant effect of year (F1,187 = 0.45, p = 0.506), age (F1,388 = 0.49, p = 0.486), area (F1,183 = 1.31, p = 0.253) or flock size (F1,184 = 1.51, p = 0.220) on mean scan duration. Scan rates ranged from 0 to 5.44 min−1. The final negative binomial regression model showed a statistically significant effect of year (χ2 = 6.56, p = 0.010), age (χ2 = 94.26, p<0.001), area (χ2 = 80.90, p<0.001) and flock size (χ2 = 16.10, p<0.001). The hooded crane scanned more frequently in 2012–13 winter (1.35 ± 0.09 min−1) than in 2013–14 winter (1.16 ± 0.04 min−1). Adult cranes scanned more frequently than juveniles in both the buffer zone (1.68 ± 0.06 min−1 vs 0.90 ± 0.07 min−1) and the core area (1.11 ± 0.05 min−1 vs 0.66 ± 0.07 min−1). Scan rate decreased with the flock size (β = −0.007 ± 0.002) and the cranes scanned more frequently in the buffer zone than in the core area (Fig. 3).

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.