| Black-necked crane is a national-level key protected wildlife,widely distributed in the Tibetan Plateau and its surrounding areas.Selincuo National Nature Reserve to alpine lakes as the main,while covering rivers,swamps and other wetland types,is an important breeding habitat of the black-necked crane.However,due to the remote location of most of the breeding sites of black-necked cranes,inconvenient transportation,and harsh climate,there are few studies on the behavior of black-necked cranes in the breeding season in the Selincuo Reserve.In this study,we focus on the behavior of black-necked cranes during the breeding season by sampling the behavior of black-necked cranes in different family structures(F2 for 2-adult families;F3-S1 for 2-adult and 1-young families;F4-S2 for2-adult and 2-young families)using video cameras from June to August 2021 and from May to July 2022 to understand the behavioral rhythms and temporal distribution of black-necked cranes in different family structures and habitat types during the breeding season.The results were obtained as follows:1.Feeding behavior was the most dominant behavior of black-necked cranes during the breeding season,accounting for more than half of their daytime activity time.The proportions of daytime time allocation for breeding season were: feeding behavior(59.45± 25.02)%,walking behavior(14.73±12.59)%,alert behavior(12.35±9.35)%,maintenance behavior(11.02±14.41)%,resting behavior(1.56±4.92)% and social behavior(0.89±1.68)%.The time allocation of daytime behaviors varied among different family structures of black-necked cranes,but feeding behavior was still the predominant daytime behavior.The analysis of the proportion of time spent on walking behavior among different family structures showed that there was a significant difference between F3-S1 and F4-S2(p < 0.05),and a highly significant difference between F2 and F4-S2(p < 0.01),and F4-S2(20.13%)was significantly higher than F3-S1(12.82%)and F2(11.3%);The time share of maintenance behaviors was significantly different between F2 and F3-S1(p < 0.05),and the time share of F2(15.89%)was higher than that of F3-S1(7.61%).The time allocation of each other behavior did not differ significantly among different family structures of black-necked cranes.2.In four different habitats of black-necked crane activities,including meadow,grassland,open water,and aquatic vegetation,feeding behavior was still the most dominant behavior of black-necked cranes during daytime.The analysis of the proportion of time spent on each behavior in different habitats showed that the proportion of time spent on vigilance behavior was significantly different between open water and aquatic vegetation habitats(p < 0.05),and the time spent on vigilance was significantly higher in aquatic vegetation(14.34%)than in open water(9.23%),while the proportion of time spent on each other behavior was not significant in different habitats.3.The results of the analysis of the differences in the time allocation of each behavior of black-necked cranes in different family structures in the same habitat showed that there were significant differences(p < 0.05)between F3-S1 and F4-S2 in the percentage of time spent on vigilance and walking behavior in the meadow habitat,and the vigilance behavior was greater in F3-S1(20.73%)than in F4-S2(6.28%),and the walking behavior was greater in F4-S2(29.95%)was greater than F3-S1(9.13%).In aquatic vegetation,there were significant differences(p < 0.05)between F2 and F3-S1 and between F3-S1 and F4-S2 in terms of the percentage of alert behavior hours,and F2(14.85%)was greater than F3-S1(8.56%)and F4-S2(18.08%)was greater than F3-S1(8.56%).In contrast,there was no significant difference in the proportion of time spent on each behavior by Black-necked Cranes in grassland and open water habitats with different family structures.The analysis of the difference in the proportion of time spent in each behavior within the same family structure of black-necked cranes in different habitats showed that there was no significant difference in the proportion of time spent in each behavior in F2 and F3-S1 in different habitats.the proportion of time spent in vigilance behavior in F4-S2 was significantly different between meadow and aquatic vegetation(p < 0.05),and also between open water and aquatic vegetation(p < 0.05),and the proportion of time spent in vigilance behavior was higher in F4-S2 than in meadow(6.28 ± 3.88%)and open water(9.01 ± 5.80%).),and alerting behavior was higher in aquatic vegetation(18.08 ± 12.14%)than in meadows(6.28 ± 3.88%)and open water(9.01 ± 5.80%).4.In this study,we found that in addition to the two feeding peaks in the morning and evening,there was also a peak in the afternoon from 15:00 to 16:00,which was mainly to better adapt to the low temperature environment at high altitude.Alerting behavior,a kind of anti-predatory behavior,has no obvious troughs during the daytime,and the alerting peak shows a certain rhythm of "morning,midday and evening".The peaks of walking behavior were scattered in the morning,afternoon and evening;the peaks of resting and maintenance usually occurred before and after the peak of feeding,when the black-necked cranes usually completed a certain amount of energy accumulation,while the community behavior was small and did not change significantly during the daytime.5.The results of the correlations between the time share of various behaviors of black-necked cranes showed that there were highly significant negative correlations between feeding behavior and walking behavior(r=-0.44,p<0.01),alert behavior(r=-0.73,p<0.01),maintenance behavior(r=-0.76,p<0.01),and resting behavior(r=-0.31,p<0.01).There was a highly significant positive correlation between vigilance behavior and maintenance behavior(r=0.51,<0.05).A significant positive correlation was shown between maintenance and community(r=0.22,p<0.05)and maintenance and resting(r=0.20,p<0.05).This behavioral correlation is usually a trade-off between limited daytime time for black-necked cranes based on themselves and the external environment.6.Analysis of the relationship between three behavioral indicators,namely frequency of black-necked crane behavior,percentage of time spent on behavior and duration of single behavior,and the number of family cranes showed that the frequency of walking behavior increased as the number of family cranes increased(r = 0.21,p = 0.039);the duration of single behavior for maintenance behavior decreased as the number of family cranes increased(r =-0.11,p < 0.001);the time spent on walking behavior increased as the number of family cranes increased(r = 0.30,p =0.0019);the percentage of time spent on walking behavior The percentage of walking behavior time increased with the increase of the number of household cranes(r=0.30,p=0.0019).Analysis of the relationship between the duration of a single vigilance and the frequency of vigilance activities and the main behaviors such as maintenance,feeding and walking revealed that the time allocation between vigilance behaviors and other behaviors such as feeding did not support the hypothesis of time allocation for predation risk in black-necked cranes.During the breeding season,black-necked cranes mainly feed,and the time allocation of each behavior varies due to the differences in food resources and disturbance in different habitats and the different food requirements of black-necked cranes in different family structures.Different habitats provide different nutritional requirements and habitat characteristics for black-necked cranes,and the focus of each behavior time allocation varies within different habitats,so that retaining diverse habitat types is more beneficial to the survival of black-necked cranes.Since the total time of day is certain,regulation between different behaviors is needed to meet the balance of time allocation during the day.The behavioral rhythms of black-necked cranes can be affected by family structure,habitat type,food resources,and human disturbance.In this paper,we study the behavior of black-necked cranes during the breeding season to clarify the daytime behavior patterns and activity patterns of blacknecked cranes during the breeding season,to understand the behavioral differences of black-necked cranes with different family structures,and how they adapt to changes in their habitat through behavioral pattern changes,in order to provide a scientific basis for the management and conservation of black-necked cranes... |
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