A new record of Picidae in China:the Brown-fronted Woodpecker (Dendrocopos auriceps)

A female Brown-fronted Woodpecker (Dendrocopos auriceps) was first observed and photographed in the Jilong Valley of the Mount Qomolangma Region,China,on 21 May 2012.The coordinates of the site are 28°19′25.03″N,85°20′29.70"E at an elevation of 2150 m.A few months later,a male was observed at 28°20′02.49"N,85°20′46.30"E on 8 August at an elevation of 2197 m.The habitat is a mountain temperate coniferous and dry broadleaved mixed forest of the warm temperate zone.

Foraging behavior of the Eurasian Three-toed Woodpecker subspecies Picoides tridactylus funebris in southern Gansu, China

The Three-toed Woodpecker subspecies Picoides tridactylus funebris is endemic to the Qinghai-Tibet plateau in China. No part of its life history was ever reported since its discovery in 1870. To close this gap, we observed foraging behavior of a pair between April and August 2007. A total of 117 observations (28 for male and 89 for female) were obtained by following the birds within their home-ranges using radio-tracking. P. t. funebris preferred foraging on live spruces and snags bigger than available with an average diameter of breast height (DBH) of 32.7 ± 9.2 cm. The most frequent foraging technique was pecking (39.8% of foraging time) and peeling (13.2%). Moreover, sap-sucking was observed more often in P. t. funebris than in P. t. alpinus, suggesting that P. t. funebris was more dependent on the tree sap than the other subspecies. We found distinct niche partitioning between the sexes with respect to use of three out of four investigated parameters of the foraging substrates. These differences were likely related to sexual dimorphism pronounced by slightly larger bill of the male. We concluded that the subspecies P. t. funebris displayed foraging behavior which was very similar to that of other subspecies of the Three-toed Woodpecker.

Nest-cavity characteristics of the Great Spotted Woodpecker Dendrocopos major in shelter plantations of west Inner Mongolia

The Great Spotted Woodpecker Dendrocopos major （L.）, one of the natural predators of Anoplophora glabripennis （Motsch.） （Coleoptera： Cerambycidae）, is resident to Wulate Qianqi County of the Inner Mongolia and widely found in shelter plantations. In August 2005 and 2006, 174 and 153 nest-cavities of Great Spotted Woodpeckers were found respectively in Wulate Qianqi County and 22 breeding nest-cavities were investigated in 2007. The results showed that mostly willow species were selected for nesting by the Great Spotted Woodpecker, but mature poplar trees also could be chosen. Nest cavities were often found with a protuberance above the cavity entrance or with a downward sloping gradient, or both. The selection of the height of the nest-cavity height was not significant. The vertical diameter of the nest-cavity entrance （VDE） and the horizontal diameter of the nest-cavity entrance （HDE） ranged from 5.0 to 5.8 cm. The results also indicated that the compass orientation of more than 60% of nest-cavities were towards the north, northeast and east. This study suggests a convergence of some nest-cavity characteristics of the Great Spotted Woodpecker in shelter plantations and will help us to make artificial nest for conserving the woodpecker and, as well, use the bird for controlling pests.

How does a woodpecker work? An impact dynamics approach

To understand how a woodpecker is able accelerate its head to such a high velocity in a short amount of time,a multi-rigid-segment model of a woodpecker＇s body is established in this study.Based on the skeletal specimen of the woodpecker and several videos of woodpeckers pecking,the parameters of a three-degree-of-freedom system are determined.The high velocity of the head is found to be the result of a whipping effect,which could be affected by muscle torque and tendon stiffness.The mechanism of whipping is analyzed by comparing the response of a hinged rod to that of a rigid rod.Depending on the parameters,the dynamic behavior of a hinged rod is classified into three response modes.Of these,a high free-end velocity could be achieved in mode II.The model is then generalized to a multihinge condition,and the free-end velocity is found to increase with hinge number,which explains the high free-end velocity resulting from whipping.Furthermore,the effects of some other factors,such as damping and mass distribution,on the velocity are also discussed.

Resin Production in Natural and Artificial Red-Cockaded Woodpecker Cavity Trees

Resin flow was measured in red-cockaded woodpecker (Picoides borealis Vieillot) clusters in longleaf pine (Pinus palustris Mill.) in the southern region of the Angelina National Forest, Texas. Resin flow (ml) at 1.4 m height over 24 hrs was measured from one 2.5 cm punch through the phloem between 0700 and 1000 hrs from March 1999 to September 2000, for a total of 9 measurements per tree. Resin was sampled in naturally active cavity trees, artificial (insert) active, natural inactive, artificial inactive and control pines (84 sample trees). Resin flow pattern was significantly different during the year, but not significantly different in the cavity tree type resin flow. Cavity trees in the 90th percentile (>33.0 ml resin in 24 hrs) were defined as super resin producing. High average resin flows in August 1999 and September 2000 indicate when to sample resin for potential cavity trees. Regression equations were produced to estimate future resin production.

Comparative study of the mechanical properties,micro-structure,and composition of the cranial and beak bones of the great spotted woodpecker and the lark bird

Woodpeckers are well able to resist head injury during repeated high speed impacts at 6-7 m s-1 with decelerations up to 1000 g.This study was designed to compare the mechanical properties,microstructures and compositions of cranial bone and beak bone of great spotted woodpecker(Dendrocopos major) and the Mongolian sky lark(Melanocorypha mongolica).Microstructures were observed using micro-computed tomography and scanning electron microscopy and their compositions were characterized by X-ray powder diffraction and Fourier-transform infrared spectroscopy.Under high stress,the cranial bone and the beak of the woodpecker exhibited distinctive mechanical features,which were associated with differences in micro-structure and composition,compared with those of the lark.Evolutionary optimization of bone micro-structure has enabled functional adaptation to the woodpecker's specific lifestyle.Its characteristic micro-structure efficiently avoids head impact injury and may provide potential clues to the prevention of brain injury using bio-inspired designs of shock-absorbing materials.

Biomechanism of impact resistance in the woodpecker's head and its application

The woodpecker does not suffer head/eye impact injuries while drumming on a tree trunk with high acceleration （more than 1000xg） and high frequency. The mechanism that protects the woodpecker＇s head has aroused the interest of ornithologists, biologists and scientists in the areas of mechanical engineering, material science and electronics engineering. This article reviews the literature on the biomechanisms and materials responsible for protecting the woodpecker from head impact injury and their applications in engineering and human protection.

Frequency Analysis and Anti-Shock Mechanism of Woodpecker＇s Head Structure

The mechanical properties of the skull and the anti-shock characteristics of woodpecker＇s head were investigated by ex- periment and numerical simulation. We measured the micro-Young＇s modulus of the skull by nano-indentation method and calculated the macro-equivalent Young＇s modulus of the skull at different positions using homogenization theory. Based on the Computerized Tomography （CT） images of woodpecker head, we then built complete and symmetric finite element models of woodpecker＇s skull and its internal structure and performed modal analysis and stress spectrum analysis. The numerical results show that the application of pre-tension force to the hyoid bone can increase the natural frequency of woodpecker＇s head. The first natural frequency under the pre-tension force of 25 N reaches 57 Hz, which is increased by 21.3% from the non-pre-tension state and is more than twice the working frequency of woodpecker （20 Hz 25 Hz）. On the application of impact force to the tip of beak for 0.6 ms, high magnitudes of stress component occur at around 100 Hz and 8,000 Hz, far away from both the working frequencies and the natural frequencies of woodpecker head. The large gaps among the natural, working and stress response frequencies enable the woodpecker to effectively protect its brain from the resonance injury.

Energy conversion in woodpecker on successive peckings and its role on anti-shock protection of brain

To investigate the mechanism of brain protection of woodpecker,we built a finite element model of a whole woodpecker using computed topography scanning technique and geometry modeling.Dynamic analyses reveal:(i)99.7%of the impact energy is converted into strain energy in the bulk of body and 0.3%is converted into strain energy in the head after three successive peckings,indicating the majority of the impact energy is stored in the bulk of body;(ii)the strain energy in brain is mainly converted into the dissipated energy,alleviating the mechanical injury to brain;(iii)the deformation and the effective energy dissipation of the beaks facilitate the decrease of the stress and impact energy transferred to the brain;(iv)the skull and dura mater not only provide the physical protection for the brain,but also diminish the strain energy in the brain by energy dissipation;(v)the binding of skull with the hyoid bone enhances the anti-shock ability of head.The whole body of the woodpecker gets involved in the energy conversion and forms an efficient anti-shock protection system for brain.

Biomechanism of resistance to retinal injury in woodpecker’s eyes

Retinal injury is the most common ocular impairment associated with shaken baby syndrome(SBS), which could lead to vision loss and blindness. However, a woodpecker does not develop retinal hemorrhages or detachment even at a high acceleration of 1,000×g during pecking. To understand the mechanism of retinal injury and its resistance strategy, we put insight into the special ability of the woodpecker to protect the retina against damage under acceleration–deceleration impact. In this study, the structural and mechanical differences on the eyes of the woodpecker and human were analyzed quantitatively based on anatomical observation. We developed finite element eye models of the woodpecker and human to evaluate the dynamic response of the retina to the shaking load obtained from experimental data. Moreover, several structural parameters and mechanical conditions were exchanged between the woodpecker and human to evaluate their effects on retinal injury in SBS. The simulation results indicated that scleral ossification, lack of vitreoretinal attachment, and rotational acceleration–deceleration impact loading in a woodpecker contribute to the resistance to retinal injuries during pecking. The above mentioned special physical structures and mechanical behavior can distribute the high strain in the posterior segment of the woodpecker’s retina, which decrease the risk of retinal injury to SBS.

Biological analysis of woodpecker’s brain after impact experiments

Woodpeckers can withstand a fierce impact during pecking.Previous studies have focused on the biomechanical analysis of the pecking process,the properties of the beak and hyoid bone of woodpecker;however,the biological characteristics of the woodpecker brain are also important in resisting impact injuries.We employed impact experiments and biological analysis in normal and injured brains to reveal the impact-resistant biological characteristics of woodpecker brains,as well as the impact energy’s biological effects on the woodpecker brain.The hoopoe,which has a similar size but only a slight pecking behavior,was selected as the control group to compare brain morphology and neuronal cells differences in normal brains between woodpecker and hoopoe by sectioning and staining.A loading device was designed to conduct a quantifiable impact energy to the woodpeckers’head.Four groups of woodpeckers were impacted with the same energy on the forehead,beak,tempus and occiput,respectively.Biological changes in the injured brains were evaluated by Nissl staining and enzyme-linked immunosorbent assay.The results showed that:(1)woodpeckers had a larger cerebellum and a higher density of Nissl bodies than hoopoe;(2)Nissl apoptosis appeared in the brain samples after the forehead and the occiput impact experiments,but no obvious Nissl body apoptosis was observed after impact on the tempus and the beak;(3)β-amyloid protein accumulated in the normal status woodpecker brain.This study reveals that:woodpecker brain morphology is well-adapted to impact,woodpecker heads display location-dependent protective performance,with beak and tempus regions having a better protective performance than the forehead and occiput,Nissl apoptosis appears in injured woodpecker brains,and that the accumulation ofβ-amyloid protein does not show a direct relationship with the injury state of woodpecker’s brain tissue in our study.

Mechanical Performance of Cranial Bone in Impact Protection of Woodpecker Brain:A Finite Element Study

Human head impact injuries caused by a sudden impact force are very common in aviation lifesaving,car crash accident,war or sports activities. Yet,an intriguing example of nature is woodpecker which is free from head injury even it drums trunk continually at a speed of about 6-7 m/s and a deceleration of about 1000 g.Woodpecker must have special characteristics to attenuate repetitive impact force to sustain rapid pecking without brain injury. In this study,the effect of mechanical property of cranial bone on the brain during impact was investigated using the finite element(FE)approach. It was demonstrated that the pressure,Von-Mises stresses and shear stress at the same point on the posterior of woodpecker's brain were decreased greatly compared with hoopoe and lark. It was stated that the higher strength of woodpecker's cranial bone might play an important role for preventing woodpecker's head injury.

第七届全国机器翻译研讨会机器翻译评测总结

该文介绍了第七届全国机器翻译研讨会(CWMT2011)机器翻译评测的具体情况。本次评测重点关注各种语言到汉语的翻译,除了汉英、英汉、日汉三个语言对以外,评测还新增了五种民族语言(藏语、蒙古语、维吾尔语、哈萨克语、柯尔克孜语)到汉语的翻译评测。共有19家国内外单位的165个系统参加此次评测。除了介绍评测项目的设置、评测数据的准备、评测流程、参评单位等,本文还重点介绍了CWMT2011的评测结果,并对评测结果进行了分析,用实例说明了与评测结果相关的几个因素:源语言与目标语言是否相似、评测领域是否集中、测试集与训练及开发集语料是否相似、训练语料的规模、参评系统的技术和成熟度等。