弯曲姿态蛾类幼虫的自动识别方法研究

【目的】为害态幼虫现场识别时, 幼虫常出现姿态弯曲情况, 使提取的特征向量失真, 影响幼虫的匹配识别结果。本文提出了一种基于扇形变换的姿态不变胡氏矩特征向量提取方法, 提取的病害幼虫特征向量具有平移、 比例、 旋转和姿态不变性, 可以实现粗短弯曲姿态幼虫的自动识别。【方法】首先在幼虫图像细化的基础上采用最优一致逼近法确定了幼虫的弯曲区域和非弯曲区域。然后, 幼虫的弯曲区域采用扇形变换实现校正变直, 非弯曲区域经旋转和平移与扇形变换后的区域拼接组成完整虫体; 采用八邻域均值法填充变换后虫体区域中的空白点, 实现幼虫像的弯曲自动校正; 在此基础上提取胡氏不变矩具有姿态不变性, 采用最小距离分类器实现了多姿态幼虫的自动识别。最后, 以多种弯曲姿态的斜纹夜蛾Prodenia litura、 棉铃虫Heliocoverpa armigera、 甜菜夜蛾Spodoptera exigua、 玉米螟Ostrinia nubilalis等病害蛾类幼虫为识别对象进行了识别验证。【结果】对于24种不同姿态的幼虫图像, 在80%的识别阈值条件下, 基于经典胡氏不变矩的幼虫识别率为25%, 基于姿态不变胡氏矩的识别率为100%。【结论】实验结果表明该方法对多种弯曲姿态的粗短幼虫具有较高的识别率。     

斑背大尾莺的白色型

2007年5月20日于辽宁省东港市孤山镇苇田——鸭绿江口湿地国家级自然保护区核心区,在冬季未收割的残留枯草斑块中发现一只白色的雀鸟(封4图片),不鸣叫,飞行姿态及尾部展示与大尾莺(Megalurus)颇为相似。经多次观察发现有雄性大尾莺追随之。23日设网将其捕获,并拍照、称重、度量。最后确定该鸟为雌性斑背大尾莺(Megalurus pryeri sinensis)的白色型(white morph)。该鸟羽色以白色为主,两肋及肛羽沾黄,头顶略现灰,右翼前侧第二枚飞羽前缘距羽端0.2cm有一长0.5cm的黑褐斑。上喙黑褐、下喙肉黄、跗跖肉色等特征与正常大尾莺无异。测量数据如下:…     

基于高分辨率网络的大熊猫姿态估计方法

对圈养大熊猫 (Ailuropoda melanoleuca) 开展长期行为监测能及时了解其所处生理周期和健康状况,有助于繁殖饲养机构迅速采取相应繁育保护措施提高饲养管理水平,但目前无法对大熊猫进行24 h监控并及时地获得相应的行为信息。准确的动物姿态估计是动物行为研究的关键,也是诸多下游应用的基础。了解大熊猫的姿态可以促进大熊猫行为研究并提升保护管理水平。为了提高复杂环境下大熊猫姿态估计的准确率,本文以高分辨率网络 (High resolution net, HRNet) 为基础网络架构提出了一种大熊猫姿态估计方法：针对大熊猫不同部位尺度差异较大的问题,在HRNet-32中引入了空洞空间金字塔池化 (Atrous spatial pyramid pooling, ASPP) 模块,在提升特征感受野的同时捕获多尺度信息;同时对大熊猫身体关键点进行分组,引入基于部位的多分支结构来学习特定于每个部位组的表征。多次对比实验结果表明本文所用模型具有较高的检测精度：在PCK@0.05中所用模型精度达到了81.51%。本文提出的方法可为大熊猫的行为分析和健康评估提供技术支撑。     

Does defensive posture increase mimetic fidelity of caterpillars with eyespots to their putative snake models？

Organisms often evolve behaviours that increase or reinforce the protection from predators afforded by their morpho- logical defences. For example, mimetic animals may adopt postures or locomotory behaviours that emulate a characteristic fea- ture of their model to increase predator deception. Caterpillars with eyespots are thought to mimic snakes, and when threatened many of these caterpillars adopt a posture that appears to enhance this resemblance. Herein we evaluate the quantitative strength of evidence of behavioural mimicry in the caterpillars of 14 species by comparing how closely a series of putative snake-mimicking caterpillars resemble snakes while at rest and when threatened. Specifically, we quantified the head morphology and eye position of a range of snake species, as well as the shape of the apparent head （i.e. anterior body segments） and position of eyespots in caterpillars resting or in their defensive posture. This allowed us to objectively examine evidence for an increased resemblance to either snakes generally, or to Viperidae snakes specifically, upon adopting the defensive posture. Widening the anterior body segments during the defensive posture typically made caterpillars appear more viper-like as opposed to more snake-like in general. Enhanced resemblance to vipers upon mounting the defensive posture was apparent only from the dorsal view. Laterally, caterpillars more closely resembled snakes in the resting posture and shifting to the defensive posture instead reduced mimetic fidelity, Overall we found evidence for behavioural mimicry in all 14 species examined. We highlight that objectively quantifying mimetic fidelity can help identify key features involved in deception .     

猕猴不同性别年龄组个体时间分配和姿态行为的差异分析

2005 年11 月至2006 年10 月,对生活在广西桂林七星公园内的一群半野生猕猴进行观察,采用瞬时扫描取样法收集不同性别-年龄组个体的活动时间分配、活动高度和姿态行为的数据。研究结果表明:七星公园猕猴属半地栖性灵长类动物,花费较多的时间休息(41.5% );坐是猕猴最主要的休息姿态
(85. 5% )和觅食姿态(85. 4% ),四足行走是最主要的移动模式(64.5% )。成年个体的活动时间分配表现出明显的性别差异,主要表现为成年雌猴花费更多的时间相互理毛。不同年龄组个体的活动时间分配也表现出显著差异。休息时间随年龄的增长而增加,而玩耍时间则表现出相反的趋势。猕猴的活动高度和移动模式也表现出明显的年龄差异。成年个体花费更多的时间在地面活动。在移动过程中,成年个体采用四足行走的频率明显高于其它年龄组个体;亚成年个体跳跃最多;少年个体采用攀爬和架桥的频率明显高于成年个体。这些差异可能与个体在不同发育阶段的体型和活动水平差异以及林冠的不连续性有关。本研究结果将有助于了解猕猴不同性别年龄组个体对其栖息的社会和自然环境的行为适应机制。     

Prototype Design and Experimental Study on Locust Air-Posture Righting

Locust has the capacity to maintain a righting posture and glide through attitude adjustment after leaping. A prototype inspired by the dynamic mechanism of attitude adjustment of locusts was developed. The prototype consists of a pair of wings driven by a four-bar mechanism, and a 2 Degree of Freedom （DOF） tail to imitate the movement of the locust abdomen. The power source, microcontroller, wireless data transmission module, and attitude sensors are contained in the fuselage. Experiments imitating the flight of locust were conducted to determine the mechanism of locust Subsequent Attitude Adjustment （SAA）. The tethered prototype was driven by the movement of the tail and the flapping of the wings. Results show that the pitch and yaw of the tail, and the asymmetric action of the flapping wings significantly influence the posture of the prototype. These findings suggest that both the wiggling abdomen and flapping wings contribute to the locust SAA in the air. This research lays the groundwork and technical support for the probable design and development of practical jumping robots with attitude adjustment function.     

用聚氨酯泡沫塑料为假体制作鸟类姿态标本

简要介绍用聚氨酯泡沫塑料为主要填充材料制作鸟类姿态标本的技术,包括设计、测量、剥皮、用聚氨酯泡沫塑料制作躯干部内模、用捆绑法制作翅膀和腿,以及缝合和塑形等技术。     

江苏鸟类一个科的新记录———贼鸥科

2016年9月16日,笔者于江苏东台沿海的方塘河口北侧观察并拍摄到1只贼鸥。当日南方有台风活动,又近天文大潮,海边风浪极大,即便中午光线也较暗。在高潮时,该鸟与其他鸥、燕鸥、鸻鹬等鸻形目Charadriiformes鸟类飞行于空中,目视其飞行姿态轻盈。     

中外科学家研究发现恐龙个体发育中行走姿态发生改变

大多数爬行动物的行走姿态是四足匍匐前进的，而恐龙中有不少类群是两足行走的。中国科学院古脊椎动物与古人类研究所的赵祺博士等人在6月28日的《自然通讯》中发表了他们最新的研究成果，