Sexual differences in vigilance of paired Ruddy Shelduck in winter

The effect of distance between members of pairs of the Ruddy Shelduck (Tadorna ferruginea) during vigilance behavior was studied during winter at Lijiang Lashihai Lake Reserve, southwest China. The distance between the paired birds while feeding was grouped into three categories: <1 m, 1-3 to and >3 m. Nearly 90% of the distances recorded between paired males and females were within three meters. The degree of vigilance increased with distance apart for females, but not for males. The scanning rate of males was significantly, higher than that of females at <1 m and at 1-3 m respectively, but no significant difference occurred when the distance between them was >3 m. These results are discussed in relation to mate competition and wintering strategy; it is suggested that staving close together is the optimal strategy for members of Ruddy Shelduck pairs.

Group size effects on foraging and vigilance in migratory Tibetan antelope

Large group sizes have been hypothesized to decrease predation risk and increase food competition. We investigated group size effects on vigilance and foraging behaviour during the migratory period in female Tibetan antelope Pantholops hodgsoni, in the Kekexili Nature Reserve of Qinghai Province, China. During June to August, adult female antelope and yearling females gather in large migratory groups and cross the Qinghai-Tibet highway to calving grounds within the Nature Reserve and return to Qumalai county after calving. Large groups of antelope aggregate in the migratory corridor where they compete for limited food resources and attract the attention of mammalian and avian predators and scavengers. We restricted our sampling to groups of less than 30 antelopes and thus limit our inference accordingly. Focal-animal sampling was used to record the behaviour of the free-ranging antelope except for those with lambs. Tibetan antelope spent more time foraging in larger groups but frequency of foraging bouts was not affected by group size. Conversely, the time spent vigilant and frequency of vigilance bouts decreased with increased group size. We suggest that these results are best explained by competition for food and risk of predation. (C) 2007 Elsevier B.V. All rights reserved.

云南大山包黑颈鹤(Grus nigricollis)越冬行为和保护研究

从2006 年10 月24 日至2007 年4 月9 日，采用固定样线法和瞬时扫描法， 对在大山包国家级自然保护区（N27°18′38″～27°29′15″，E103°14′55″～103°23′49″） 内越冬的黑颈鹤种群进行了越冬行为、日间活动节律和越冬栖息地利用的详细调 查，同时对黑颈鹤的春季迁徙行为和冬季黑颈鹤的死亡现象进行了观察和分析。 这些研究有助于我们了解黑颈鹤是采取何种行为模式和栖息地利用模式来适应高 海拔、低温度的环境，同时对如何有效地保护越冬黑颈鹤和合理规划保护区功能 区域有重要的指导作用。 将黑颈鹤的越冬行为分为：取食（Feeding）、搜寻（Searching）、警戒（Vigilance）、 争斗（Fight）、行走（Walk）、飞行（Flight）、休整（Maintenance）和其它（Others） 八种，越冬期间最主要的行为是取食（53.05±4.93）％，其它行为依次为：搜寻 （10.38±1.34）％、警戒（18.75±2.65）%、休整（10.32±4.93）％、行走（4.90±1.59） ％、飞行（1.70±0.38）％、争斗（0.36±0.25）％、其它（0.55±0.41）％。单因素 方差分析（One-Way ANOVA）分析表明越冬期间黑颈鹤日间各时间段（1h）和各 月份间行为差异极显著（P<0.05），并呈现出规律的变化。黑颈鹤的取食、警戒、 搜寻行为具明显的早（10:00-11:00）、晚（17:00-18:00）两个活动高峰，中午 13:00~14:00 最低；而休整行为正好相反，呈现出中午高峰、上午和下午低谷的趋 势；另外几种行为节律性表现不明显。黑颈鹤越冬期主要行为的节律变化是受环 境温度变化影响的，温度高时黑颈鹤增加了修整时间减少了取食时间，而温度低 时则减少了修整时间增加了取食时间以维持能量需求，湿度是通过温度对黑颈鹤 产生影响的。每天黑颈鹤都随着太阳的升起开始觉醒，于07:18±0:15 飞离夜栖地， 大雾的天气影响了黑颈鹤的外出觅食，与之相适应的是黑颈鹤相应的推迟了出飞 时间。黑颈鹤所采取的所有行为都表现出了对大山包特殊环境的适应。 在大山包黑颈鹤所利用的栖息共有耕地（farmland）、草地（grassland）、沼泽 （marsh）和浅水水域（water area）四类。选择指数分析表明黑颈鹤对水域有极大 的偏好，其次为沼泽湿地，再次为耕地，而对草地表现为负选择，并且在越冬期 间的各月份之间，对不同栖息利用比率保持一致。这提示我们在进行保护区规划 的时候应该适当增加前三种栖息地的面积以满足黑颈鹤的越冬需求。主成份因子 分析表明黑颈鹤倾向于选择距夜栖地和水源较近、人流较少、干扰较小、无坡或缓坡的低海拔栖息地。处于不同越冬地的越冬黑颈鹤根据当地的实际情况采取不 同的栖息地利用，说明黑颈鹤具有较强的环境适应能力。 调查期间记录到了三只带有彩环的黑颈鹤个体，其中有两只佩戴有卫星发射 器，发射器编号分别为64309 和64311。大山包黑颈鹤种群数量变动的春季和秋季 高峰是由于处于不同越冬地的黑颈鹤迁徙造成的，同时也说明了大山包是在滇东 北和黔西北越冬的黑颈鹤的集散地。黑颈鹤的春季迁徙一般集中在3 月下旬至4 月上旬，在晴朗、微风的上午10:00-11:00 迁徙的黑颈鹤数量最多，说明了天气条 件对黑颈鹤迁徙的重要性。 大山包保护区内的高压输电电线和通信电缆对越冬黑颈鹤构成了极大的威 胁。观察期间共有7 只黑颈鹤因撞上输电电线而死亡，除去一只没有外伤的成体 之外，成幼比例为1:1，大都发生在天气较为恶劣的12 月-2 月之间。发生撞死黑 颈鹤的时候保护区内都有不同程度的大雾笼罩，由于大雾的影响造成可视条件下 降，加之黑颈鹤飞行的机动性差（翼载量大、展弦比不大），造成了黑颈鹤的伤亡.

听力障碍与听力正常群体视觉注意发展及其机制的比较

One of the most important functions in the individual development is the interaction and integration of each sensory input. There exist two competing theories, i.e. the deficiency theory and the compensatory theory, regarding the origin and nature of changes in visual functions observed after auditory deprivation. The deficiency theory proposed that integrative processes are essential for normal development. In contrast, the compensatory theory stated that the loss of one sense may be met by a greater reliance upon, therefore an enhancement of the remaining senses. Given that hearing impaired children’s learning depends primarily on visual information, it is important to recognize the differences of visual attention between them and their hearing age-mates. Differences among age groups could exist in either selectivity or sustained attention. Study 1 and study 2 explored the selective and sustained attention development of hearing impaired and hearing students with average cognitive ability, aged from 7 years to college students. The analysis and discussion of the results are based on the visual attention development as well as deficiency theory and compensatory theory. According to the results of the study 1 and study 2, the spatial distribution and controlling of the visual attention between hearing impaired and hearing students were also investigated in the study 3 and study 4. The present work showed that: Firstly, both hearing impaired and hearing participants had the similar developmental trajectory of the sustained attention. The ability of children’s sustained attention appeared to improve with age, and in adolescence it reached the peak. The hearing impaired participants had the comparable sustained attention skills to the matched hearing ones. Besides, the results of the hearing impaired participants showed that they could maintain their attention and vigilance on the current task over the observation period. Secondly, group differences of visual attention development were found between hearing impaired and hearing participants. In the childhood, the visual attention developmental speed of the hearing impaired children was slower than that of the hearing ones. The selective attention skill of the hearing impaired were not comparable to the hearing ones, however, their selective skill improved with age, so in the adulthood, hearing impaired students showed the slight advantage in the selective attention skill over the hearing ones. Thirdly, hearing impaired and hearing participants showed the similar spatial distribution in the attention resources. In the low perceptual load condition, both participants were suffered great interference of the distrator at the fixation. In contrast, in the high perceptual load condition, hearing impaired adults were suffered more interference of the peripheral distractor, which suggested that they distributed more attention resources to the peripheral field when faced difficult tasks. Fourthly, both groups showed similar processing in the visual attention tasks. That is, they both searched the target with only the color feature in a parallel way, but in a serial way while processing orientation feature and the features with the combination of the color and orientation. Furthermore, the results indicated that two groups show similar ways in the attention controlling. In summary, the present study showed that visual attention development was dependent upon the integration of multimodal sensory information. Because of the interaction and integration of the input from various sensory, it has a negative impact on the intact sensory at the early stage of one sensory loss, however, it can better the functions of other intact sensory gradually with development and practice.