鄱阳湖区稻田生境中灰鹤越冬行为的时间分配与觅食行为

2013年11月—2014年2月,采用瞬时扫描和焦点动物法研究了鄱阳湖区稻田生境中灰鹤越冬行为的时间分配、活动节律与觅食行为。结果显示,觅食(64.09%)行为所占比例最大,其次为警戒(15.97%)、飞行(8.67%)和修整(7.37%)行为。4种主要行为中,觅食行为时间分配随越冬前期(11月)、中期(12月—翌年1月)、后期(2月)逐渐增加,其余行为时间均逐渐减少。各环境因子对主要行为的影响存在显著交互效应,修整行为随各环境因子变化最为明显,日最低温度升高、日最高温度降低、日照长度增加及湿度降低都会使修整行为增加;日照长度增加和湿度降低时,觅食行为增加;日照长度增加时,警戒行为减少。环境因子对成鹤影响效果与总体相同。环境因子仅对幼鹤的觅食行为影响显著,即日照长度增加和湿度降低,幼鹤觅食行为增加。环境因子对行为的影响为非线性关系,致使其影响趋势在不同范围内有所变化。行为节律上,灰鹤昼间各时段觅食行为保持较高水平,觅食高峰出现在11:00—11:59和17:00—17:30。灰鹤觅食生境与其夜宿地分离,致其上午觅食高峰有所推后。幼鹤昼间各时段行为节律与成鹤有较大差异,且各时段觅食行为比例均高于成鹤。灰鹤越冬期在稻田生境的平均啄食频率为(32.06±0.47)次/min,平均步行频率为(6.55±0.35)步/min。啄食频率与步行频率呈极显著负相关。时段和集群类型对啄食频率的影响存在显著交互效应。稻田中食物资源的可利用性逐渐下降,灰鹤的啄食频率随时间逐渐降低,为保证越冬期间获取足够的能量供应,灰鹤采取逐渐增加步行频率和觅食时间的策略。有觅食间隔的抽样单元中,平均警戒次数为(1.37±0.04)次/单元,平均警戒持续时间为(6.02±0.37)s/单元。成鹤花费在警戒的时间多于幼鹤,家庭群中的个体警戒持续时间多于聚集群中的个体。     

丹顶鹤与白枕鹤的领域比较

有７种濒危鹤类受到现代人的威胁［２０］,丹顶鹤（Ｇｒｕｓｊａｐｏｎｅｎｓｉｓ）和白枕鹤（Ｇｒｕｓｖｉｐｉｏ）是其中两种,分别为我国的Ⅰ、Ⅱ级保护动物。在中国丹顶鹤主要在黑龙江省的乌裕尔河下游和三江平原等地繁殖,数量在４８２～５０２之间［７］。吉林省的向海也有４０余只繁殖鹤［８,９］。它们在长江中下游的江苏盐城、高邮湖、洪泽湖,安徽省的城东湖、石臼湖、菜子湖越冬［５］。白枕鹤繁殖区在中国东北的乌裕尔河下游、向海、达里诺尔湖以及乌苏里江以东俄罗斯的沿海边区［２０］。我国已知的繁殖区内数量不多［１］,…     

丹顶鹤越冬栖息地数学模型的建立

利用地理信息系统及遥感卫片通过建立数学模型的方法来模拟及预测盐城自然保护区丹顶鹤越冬栖息地的分布。经验证,模型的正确预测率为７２．６３％,认为模型基本上能够反映丹顶鹤栖息地的分布情况。     

Genetic differentiation in a captive population of the endangered Siberian crane (Grus leucogeranus Pall.)

DNA fingerprinting, followed by multivariate analysis of data, was used to characterize genetic heterogeneity in captive populations of the endangered Siberian and sandhill cranes. The genetic structure revealed reflected the natural population and species distributions. The relevant groups differed not only from each other, but also from interspecies and inter-population hybrids bred in captivity. In this study we have tested an approach to the analysis of population structure based on individual genotypes. Interpretation of fingerprinting data by means of the analytical system applied here is a useful and reliable procedure for the estimation of genetic relationships between individuals.     

基于多源遥感的贵州草海国家级自然保护区黑颈鹤生境适宜性评价

生境适宜性评价是保护和管理濒危物种的重要途径。已有研究中用于物种生境适宜性评价的环境变量数据多存在分辨率低精度不高的问题,在研究小尺度物种生境适宜性时误差较大。为解决这一问题,本文根据黑颈鹤的出现点数据与光学、雷达遥感数据及地形辅助数据得出栖息地与觅食地特征,利用最大熵(MaxEnt)模型对草海越冬黑颈鹤细尺度的生境适宜性进行评价。结果显示：(1)运用多源遥感和地形辅助数据生成的环境变量结合MaxEnt预测黑颈鹤的栖息地与觅食地效果都较为优秀,两者受使用者工作特征曲线下的面积值(AUC)值均大于0.94;(2)距耕地距离、距水域距离、水深及距建筑距离是影响黑颈鹤栖息地主要环境因子,而影响觅食地分布的主要环境因子则是距耕地距离、优势植被、距建筑物距离和水深。(3)草海自然保护区黑颈鹤栖息地与觅食地的最适宜区和次适宜区面积较小,栖息地与觅食地最、次适宜区总和分别为6.404km~2与12.644 km~2,占比仅为研究区的6.43%和12.69%。通过调查发现,当前自然保护区的人为干扰源主要是游客和当地的居民,潜在地威胁着黑颈鹤的栖息地和觅食地。因此,为了避免保护区黑颈鹤栖息地与觅食地的退...     

Decision analysis for conservation breeding: Maximizing production for reintroduction of whooping cranes

Captive breeding is key to management of severely endangered species, but maximizing captive production can be challenging because of poor knowledge of species breeding biology and the complexity of evaluating different management options. In the face of uncertainty and complexity, decision-analytic approaches can be used to identify optimal management options for maximizing captive production. Building decision-analytic models requires iterations of model conception, data analysis, model building and evaluation, identification of remaining uncertainty, further research and monitoring to reduce uncertainty, and integration of new data into the model. We initiated such a process to maximize captive production of the whooping crane (Grus americana), the world's most endangered crane, which is managed through captive breeding and reintroduction. We collected 15 years of captive breeding data from 3 institutions and used Bayesian analysis and model selection to identify predictors of whooping crane hatching success. The strongest predictor, and that with clear management relevance, was incubation environment. The incubation period of whooping crane eggs is split across two environments: crane nests and artificial incubators. Although artificial incubators are useful for allowing breeding pairs to produce multiple clutches, our results indicate that crane incubation is most effective at promoting hatching success. Hatching probability increased the longer an egg spent in a crane nest, from 40% hatching probability for eggs receiving 1 day of crane incubation to 95% for those receiving 30 days (time incubated in each environment varied independently of total incubation period). Because birds will lay fewer eggs when they are incubating longer, a tradeoff exists between the number of clutches produced and egg hatching probability. We developed a decision-analytic model that estimated 16 to be the optimal number of days of crane incubation needed to maximize the number of offspring produced. These results show that using decision-analytic tools to account for uncertainty in captive breeding can improve the rate at which such programs contribute to wildlife reintroductions. © 2011 The Wildlife Society.     

Location and agricultural practices influence spring use of harvested cornfields by cranes and geese in Nebraska

Millions of ducks, geese, and sandhill cranes (Grus canadensis; hereafter cranes) stop in the Central Platte River Valley (CPRV) of Nebraska to store nutrients for migration and reproduction by consuming corn remaining in fields after harvest. We examined factors that influence use of cornfields by cranes and geese (all mid-continent species combined; e.g., Anser, Chen, and Branta spp.) because it is a key step to efficient conservation planning aimed at ensuring that adequate food resources are available to migratory birds stopping in the CPRV. Distance to night-time roost site, segment of the CPRV (west to east), and agricultural practices (post-harvest treatment of cornfields: idle, grazed, mulched, mulched and grazed, and tilled) were the most important and influential variables in our models for geese and cranes. Probability of cornfield use by geese and cranes decreased with increasing distance from the closest potential roosting site. The use of cornfields by geese increased with the density of corn present there during the early migration period, but field use by cranes appeared not to be influenced by early migration corn density. However, probability of cornfield use by cranes did increase with the amount of wet grassland habitat within 4.8 km of the field. Geese were most likely to use fields that were tilled and least likely to use fields that were mulched and grazed. Cranes were most likely to use fields that were mulched and least likely to use fields that were tilled, but grazing appeared not to influence the likelihood of field use by cranes. Geese were more likely to use cornfields in western segments of the CPRV, but cranes were more likely to use cornfields in eastern segments. Our data suggest that managers could favor crane use of fields and reduce direct competition with geese by reducing fall and spring tilling and increasing mulching. Moreover, crane conservation efforts would be most beneficial if they were focused in the eastern portions of the CPRV and in fields as close as possible to both known roosting and large amounts of wet grassland habitats. © 2011 The Wildlife Society.     

灰鹤在迁徙途中撞击高压线 伤亡分析与视觉盲区初探

广布于欧亚大陆的灰鹤(Grusgrus)又叫普通鹤、欧亚鹤。采用直接计数法,观测灰鹤的迁徙活动。依据2019至2021年在乌鲁木齐郊区连续3年搜集灰鹤迁徙期遭遇高压线(220kV)挂碰遇难的数据,简单介绍伤亡案例的特点。可能是因为灰鹤前端有一个视觉盲区,致49只灰鹤碰撞了高压线,统计到伤亡率达5.4%。伤亡者多是1龄以上4龄以内的亚成鸟(占94%),成鸟占6%,尚未见1龄内幼鸟。现场解剖,伤亡者的断翅率最高,达到53%;腿被撞折的比率也很高,达51%;腹部或背部擦伤占24%;头或颈部碰伤约为14%。因为碰挂后落地(≥30 m架空线),造成二次受伤,结果有41%的灰鹤身体是多处受伤(复合伤)。最后,对视野盲区进行了初步分析,探讨伤亡的原因,并介绍和推荐几种行之有效的解决办法。     

滦河上游——白枕鹤西部种群的重要停歇地

白枕鹤(Grus vipio)为国家II级重点保护野生动物, 被IUCN列为易危(VU)物种。白枕鹤西部种群繁殖于中蒙俄交界处的达乌尔地区, 数量呈下降趋势。我们于2017-2018年在蒙古国东部给白枕鹤西部种群的50只个体佩戴了GPS-GSM跟踪设备。截至2019年5月, 获得春季和秋季迁徙路径各48条。分析结果显示: 春季91.67%和秋季72.91%的跟踪个体在滦河上游(河北省沽源-内蒙古正蓝旗-多伦区域)停歇, 春季停留时间36.16 ± 15.00天、秋季20.26 ± 11.08天, 分别占春季和秋季迁徙时间的75%和67%, 确定了这一区域是西部种群迁徙途中最重要的停歇地。迁徙路线栖息地选择模型结果显示, 白枕鹤常在距离湖泊较近(< 210 km)、海拔1,200-1,500 m, 且坡度小(< 1°)的区域停歇。而滦河上游和整条迁徙路线停歇位点比较的模型结果显示, 滦河上游停歇地的海拔1,200-1,500 m与整条迁徙路线栖息地选择模型的结果一致; 此外这个区域离河流更近(< 70 km), 不仅有湿地和水体的栖息环境, 还有草地和农田可供觅食和栖息。保护空缺分析发现滦河上游现有四处保护地, 但在保护地内的迁徙停歇点不超过总位点的1.63%。综上, 我们建议将滦河上游整体纳入保护地体系进行管理, 为这一受胁物种及其栖息地管理和保护提供可靠保障。