Energy metabolism and thermoregulation in hand-reared chukars (Alectoris chukar)

Metabolic rate and colonic temperature were measured in chukars between 1st and 108th day of life (divided into six age groups: 1-3-days old, 1, 2, 3, and 4-weeks old and 3.5-months old) in ambient temperatures set separately for each group and ranging from -12 to 41 degrees C. The Gompertz growth constant for growing chukars (0.042) was close to the value obtained in earlier study for the grey partridge. Similarly as in other species of Galliformes, newly hatched chukar chicks had lower T(b) at TNZ (39.5 degrees C) than that found in older birds (41.3 degrees C in 4-weeks old). The body temperatures taken at TNZ in 2-weeks old chicks and older fitted neatly within allometrically predicted limits of body temperatures for adult birds. The values of RMR at TNZ followed closely a biphasic pattern, with the second phase correlating strongly with the body mass. The value of metabolic scope (the level of metabolic efficiency) for the youngest group was high (3.2) and exceeded the values obtained in earlier studies for other gallinaceous species, including the grey partridge. The obtained values of minimum wet thermal conductance for growing chukar chicks exceeded the predicted values by approximately 40% but the slopes of both lines were very similar. In chukars, the key stage in the expression of fully developed thermoregulatory capacities comes immediately after the first week of life (maintaining somewhat constant body temperature, evident drop in the value of RMR at TNZ and minimal thermal conductance). The model of gradual development of thermoregulation which could be derived from the experiments on chukar chicks was characteristic for typical precocial birds.     

基于RS和GIS技术的河北省鸡形目鸟类分布格局

收集和整理河北省鸡形目鸟类的分布资料,借助GIS的绘图功能,把解译的遥感影像数据数字化为植被类型图和地貌图;根据文献和标本记录的地理位置和野外考察记录,做出河北省鸡形目鸟类的点分布图;根据鸡形目鸟类与其生境之间的相互依赖关系,定义鸡形目鸟类的适宜生境类型,利用GIS技术的分析、提取和叠加功能,提取每种鸡形目鸟类的适宜生境类型图,预测河北省鸡形目鸟类的总体分布格局。结果表明：河北省鸡形目鸟类物种丰富度地区主要集中在坝上高原区和燕山太行山山地区;河北省鸡形目鸟类可分为全省广布种(鹌鹑和雉鸡)、燕山太行山山地和坝上高原分布种(石鸡、斑翅山鹑、勺鸡)和局部地区特征种(黑琴鸡、黑嘴松鸡、花尾榛鸡、褐马鸡)3种类型。     

A force plate study of avian gait

OBJECTIVE: To test the force plate as a gait analysis system for broilers and to determine how the ground reaction force (GRF) patterns change in these birds with growth and administration of analgesia. MATERIALS AND METHODS: Thirty-three male Ross 308 chicks were raised on either an ad libitum or restricted-feeding regime, and subsequently treated with carprofen or a placebo. Vertical, craniocaudal and mediolateral GRFs were measured as the birds walked across a standard force plate. RESULTS: The data were easy to collect, and peak vertical forces of an equivalent percentage of bodyweight as seen in human walking were identified. Mediolateral forces were 2-3 times greater than those demonstrated in other species. GRF patterns showed significant changes during growth, but analgesia did not have a significant effect on the speed of walking, or GRF patterns. CONCLUSIONS AND CLINICAL RELEVANCE: The force plate is a suitable research tool for recording GRFs from avian bipeds. The large mediolateral forces identify a particularly inefficient aspect of avian gait; however, the role of pain remains to be determined.     

Effects of velocity and weight support on ground reaction forces and metabolic power during running

The biomechanical and metabolic demands of human running are distinctly affected by velocity and body weight. As runners increase velocity, ground reaction forces (GRF) increase, which may increase the risk of an overuse injury, and more metabolic power is required to produce greater rates of muscular force generation. Running with weight support attenuates GRFs, but demands less metabolic power than normal weight running. We used a recently developed device (G-trainer) that uses positive air pressure around the lower body to support body weight during treadmill running. Our scientific goal was to quantify the separate and combined effects of running velocity and weight support on GRFs and metabolic power. After obtaining this basic data set, we identified velocity and weight support combinations that resulted in different peak GRFs, yet demanded the same metabolic power. Ideal combinations of velocity and weight could potentially reduce biomechanical risks by attenuating peak GRFs while maintaining aerobic and neuromuscular benefits. Indeed, we found many combinations that decreased peak vertical GRFs yet demanded the same metabolic power as running slower at normal weight. This approach of manipulating velocity and weight during running may prove effective as a training and/or rehabilitation strategy.     

Precocial development of locomotor performance in a ground-dwelling bird (Alectoris chukar): negotiating a three-dimensional terrestrial environment

Developing animals are particularly vulnerable to predation. Hence, precocial young of many taxa develop predator escape performance that rivals that of adults. Ontogenetically unique among vertebrates, birds transition from hind limb to forelimb dependence for escape behaviours, so developmental investment for immediate gains in running performance may impair flight performance later. Here, in a three-dimensional kinematic study of developing birds performing pre-flight flapping locomotor behaviours, wing-assisted incline running (WAIR) and a newly described behaviour, controlled flapping descent (CFD), we define three stages of locomotor ontogeny in a model gallinaceous bird (Alectoris chukar). In stage I (1–7 days post-hatching (dph)) birds crawl quadrupedally during ascents, and their flapping fails to reduce their acceleration during aerial descents. Stage II (8–19 dph) birds use symmetric wing beats during WAIR, and in CFD significantly reduce acceleration while controlling body pitch to land on their feet. In stage III (20 dph to adults), birds are capable of vertical WAIR and level-powered flight. In contrast to altricial species, which first fly when nearly at adult mass, we show that in a precocial bird the major requirements for flight (i.e. high power output, wing control and wing size) convene by around 8 dph (at ca 5% of adult mass) and yield significant gains in escape performance: immature chukars can fly by 20 dph, at only about 12 per cent of adult mass.     

Interspecific interactions between feral pigs and native birds reveal both positive and negative effects

In tropical Australian rainforests, predators and scavengers aggregate beneath emergent trees that house large colonies of metallic starlings (Aplonis metallica), feeding in the nutrient‐rich open areas below. Analysis of camera‐trap records shows that the presence of feral pigs (Sus scrofa) is associated with an absence of birds (cockatoos and brush turkeys), presumably reflecting behavioural avoidance (pigs pose a direct danger to birds). However, bird numbers increase as soon as pigs depart, then fall if pigs are absent for long periods. Feral pigs thus displace native birds from these resource hotspots; but by turning over the soil and enhancing the birds' access to food, the pigs also have a positive impact on food availability for the avifauna. Thus, although invasive species have caused irreparable environmental damages worldwide, they may also provide positive benefits for certain species. The net benefit of such interspecific interactions will depend on the outcome of both positive and negative effects.     

The relationships between physical capacity and biomechanical plasticity in old adults during level and incline walking

Old compared to young adults exhibit increased hip and decreased ankle mechanical output during walking – a phenomenon known as biomechanical plasticity. Previous comparison studies suggest that low compared to high capacity old adults exhibit larger magnitudes of this plasticity, however the precise relationship between capacity and plasticity magnitude remains unclear. The purpose of this study was to quantify the relationships between physical capacity and biomechanical plasticity magnitude during level and incline walking. Data were collected for 32 old adults walking over level and inclined (+10°) surfaces at self-selected, comfortable speeds. Physical capacity was measured using the Short-Form Health Survey Physical Component (SF-36 PC) and biomechanical plasticity was quantified by ratios of hip extensor to ankle plantarfexor peak torques, angular impulses, peak positive powers, and positive work (larger ratios indicate larger magnitudes of plasticity). SF-36 PC scores correlated positively with all four biomechanical plasticity ratios during level walking and three of the four ratios during incline walking. Some of the biomechanical plasticity ratios correlated positively with comfortable walking speeds and stride frequencies, indicating better walking performance with larger magnitudes of plasticity. Additionally, all four biomechanical plasticity ratios were larger during incline compared to level walking, suggesting the need for larger magnitudes of plasticity during the more difficult task. These results indicate that larger magnitudes of biomechanical plasticity afford functional benefits such as increased level and incline walking performance for old adults. Increased walking performance has the potential to increase quality of life in the growing population of old adults.     

Estimating dynamic external hand forces during manual materials handling based on ground reaction forces and body segment accelerations

Direct measurement of hand forces during assessment of manual materials handling is infeasible in most field studies and some laboratory studies (e.g., during patient handling). Therefore, this study proposed and evaluated the performance of a novel hand force estimation method based on ground reaction forces (GRFs) and body segment accelerations.     

Extended parental care and delayed dispersal: northern, tropical, and southern passerines compared

Using modern comparative methods, we found that both time toindependence and time with parents were significantly longerin southern hemisphere and tropical birds than in northern hemisphereones. These differences held even after removing Australianpasserines or cooperatively breeding species, and they do notdepend on habitat, diet, or migration pattern. In southern hemisphereand tropical regions, both cooperative breeding and non-cooperativeparents continue to feed their young for a similar length oftime, but cooperative breeders allow them to stay longer intheir natal territory after they become nutritionally independent.Nevertheless, the young of non-cooperative species stay longerwith their parents than do the young of non-cooperative speciesin the temperate northern hemisphere. The fact that extendedperiods of post-fledging parental care are widespread amongpasserines provides further empirical support for the view thatlife histories of southern and tropical birds are ‘slow,’with small clutches, extended parental care, and long lifespan;parents take care of fewer young for longer. These results supportrecent theoretical models that predict that high adult survivaland low turnover of territory owners generally favor natal philopatry.We suggest that the reasons why some species (with or withoutcooperative breeding) exhibit natal philopatry and others donot lie in the balance between productivity and survival ofadults and of retained or dispersing offspring.     

Vasoactive properties of urotensins I and II in a columbiform and three galliform birds, and a bioassay for urotensin I

Summary Crude extracts ofGillichthys urophyses and chromatographically purified urotensin I (UI) and urotensin II (UII) (fromCatostomus urophyses) were injected intravenously intoCoturnix coturnix japonica, Colinus virginianus, Alectoris graeca (Galliformes) andColumba livia (Columbiformes). Changes in arterial blood pressure were monitored. UI elicited dose-dependent vasodepressor responses in all birds. Thioglycollate treatment abolished the depressor action of arginine vasotocin but not that of UI (in all birds). UII was a pressor agent inCoturnix andColinus, both members of the Galliformes. However, the hormone had no pressor activity inColumba, a member of the Columbiformes, and in another member of the Galliformes,Alectoris. The pressor effect of UII was also dose-dependent. Injection of crude urophysial extract intoColinus andCoturnix, therefore, elicited biphasic responses. UII effects can be abolished by prior incubation with carboxypeptidase A. Intravenous injection of the -adrenoceptor blocker, phenoxybenzamine, prior to urotensin injections had no effect on the responses to urotensins. As the chukar,Alectoris graeca, is sensitive to UI and resistant to anesthesia and surgery, and does not readily develop tachyphylaxis to repeated UI injections, its use is recommended as a routine bioassay animal for UI.     

A mitogenomic perspective on the ancient,rapid radiation in the Galliformes with an emphasis on the Phasianidae

Background  

The Galliformes is a well-known and widely distributed Order in Aves. The phylogenetic relationships of galliform birds, especially the turkeys, grouse, chickens, quails, and pheasants, have been studied intensively, likely because of their close association with humans. Despite extensive studies, convergent morphological evolution and rapid radiation have resulted in conflicting hypotheses of phylogenetic relationships. Many internal nodes have remained ambiguous.     

Molecular characterization and phylogenetic analysis of Eimeria from turkeys and gamebirds: implications for evolutionary relationships in Galliform birds

In order to determine the evolutionary relationships among Eimeria species that parasitize birds of the Galliformes, the 18s rDNA gene and a portion of the cytochrome oxidase subunit 1 (cox-1) were amplified from Eimeria species isolated from turkeys, chukars, and pheasants. The phylogenetic analysis of these sequences suggests that species infecting chickens are polyphyletic and, therefore, do not all share a direct common ancestor. Both the 18s rDNA and the cox-1 sequences indicate that Eimeria tenella and Eimeria necatrix are more closely related to Eimeria of turkeys and pheasants than to other species that infect the chicken. It is, therefore, likely that the chicken Eimeria spp. represent 2 separate ancestral colonizations of the gut, one of which comprises E. tenella and E. necatrix that infect the ceca, while the other includes Eimeria acervulina, Eimeria brunetti, Eimeria maxima, and Eimeria mitis, which infect the upper regions of the intestine.     

Biomechanical differences between incline and plane hopping

Kannas, TM, Kellis, E, and Amiridis, IG. Biomechanical differences between incline and plane hopping. J Strength Cond Res 25(12): 3334-3341, 2011-The need for the generation of higher joint power output during performance of dynamic activities led us to investigate the force-length relationship of the plantar flexors during consecutive stretch-shortening cycles of hopping. The hypothesis of this study was that hopping (consecutive jumps with the knee as straight as possible) on an inclined (15°) surface might lead to a better jumping performance compared with hopping on a plane surface (0°). Twelve active men performed 3 sets of 10 consecutive hops on both an incline and plane surface. Ground reaction forces; ankle and knee joint kinematics; electromyographic (EMG) activity from the medial gastrocnemius (MG), soleus (Sol) and tibialis anterior (TA); and architectural data from the MG were recorded. The results showed that participants jumped significantly higher (p < 0.05) when hopping on an inclined surface (30.32 ± 8.18 cm) compared with hopping on a plane surface (27.52 ± 4.97 cm). No differences in temporal characteristics between the 2 types of jumps were observed. Incline hopping induced significantly greater ankle dorsiflexion and knee extension at takeoff compared with plane hopping (p < 0.05). The fascicle length of the MG was greater at initial contact with the ground during incline hopping (p < 0.05). Moreover, the EMG activities of Sol and TA during the propulsion phase were significantly higher during incline compared with that during plane hopping (p < 0.05). It does not seem unreasonable to suggest that, if the aim of hopping plyometrics is to improve plantar flexor explosivity, incline hopping might be a more effective exercise than hopping on a plane surface.     

Muscle work is biased toward energy generation over dissipation in non-level running

This study tested the hypothesis that skeletal muscles generate more mechanical energy in gait tasks that raise the center of mass compared to the mechanical energy they dissipate in gait tasks that lower the center of mass despite equivalent changes in total mechanical energy. Thirteen adults ran on a 10° decline and incline surface at a constant average velocity. Three-dimensional (3D) joint powers were calculated from ground force and 3D kinematic data using inverse dynamics. Joint work was calculated from the power curves and assumed to be due to skeletal muscle–tendon actuators. External work was calculated from the kinematics of the pelvis through the gait cycle. Incline vs. decline running was characterized with smaller ground forces that operated over longer lever arms causing larger joint torques and work from these torques. Total lower extremity joint work was 28% greater in incline vs. decline running (1.32 vs. −1.03 J/kg m, p<0.001). Total lower extremity joint work comprised 86% and 71% of the total external work in incline (1.53 J/kg m) and decline running (−1.45 J/kg m), which themselves were not significantly different (p<0.180). We conjectured that the larger ground forces in decline vs. incline running caused larger accelerations of all body tissues and initiated a greater energy-dissipating response in these tissues compared to their response in incline running. The runners actively lowered themselves less during decline stance and descended farther as projectiles than they lifted themselves during incline stance and ascended as projectiles. These data indicated that despite larger ground forces in decline running, the reduced displacement during downhill stance phases limited the work done by muscle contraction in decline compared to incline running.     

The wild turkey as a host for Heterakis gallinarum and Histomonas meleagridis.

Freshly embryonated eggs of Heterakis gallinarum gathered from naturally infected domestic turkeys and chickens developed the first 4 weeks essentially as well in young wild turkeys as in domestic poults, but then became progressively retarded and failed in most birds to result in females with fertile eggs. There was no significant difference in the prevalence or progress of infections with Histomonas meleagridis in the two kinds of turkeys, both of which differed from chickens only in that the latter had neither liver involvement nor mortality. In a second test, heterakids hatched from eggs stored 5-6 months at 4 C (comparable to overwintering) sustained very heavy losses in all birds, with greatly accelerated liberations of H. meleagridis, Few worms reached maturity and still fewer produced fertile eggs. In turkeys, and especially in wild turkeys, replacement of infective stages was so poor, that these birds were of no importance in contaminating the soil.     

Costs of parental care on hunting behaviour of Helobdella papillornata (Euhirudinea: Glossiphoniidae)

Helobdella papillornata, an Australian freshwater leech, feeds primarily on snails and has a high level of parental care involving brooding eggs and young, with direct feeding of young. Parental costs and offspring benefits from these behaviours are poorly understood. A potential cost of parental care may be a change in the time taken to hunt prey. To test this hypothesis, the hunting behaviour of adults without progeny, parents with eggs, and parents with young were compared. We found that parents brooding eggs had a significantly (P = 0.029) longer lag time to begin hunting than parents brooding young, and spent significantly (P = 0.018) less time actively hunting than non-brooding adults. These costs, which may represent lost potential for the parent’s future reproductive success, should be outweighed by the fitness benefits of improved growth and survival of offspring, if parental care is favoured by selection. The hunting costs of care in Helobdella and other benthic, dorsoventrally flattened leeches in the family Glossiphoniidae may be smaller than the costs of brood tending that would be imposed on other freshwater leeches, and this difference may help explain the restriction of care to a single clade of the Euhirudinea.     

Evolution of parental incubation behaviour in dinosaurs cannot be inferred from clutch mass in birds

A recent study proposed that incubation behaviour (i.e. type of parental care) in theropod dinosaurs can be inferred from an allometric analysis of clutch volume in extant birds. However, the study in question failed to account for factors known to affect egg and clutch size in living bird species. A new scaling analysis of avian clutch mass demonstrates that type of parental care cannot be distinguished by conventional allometry because of the confounding effects of phylogeny and hatchling maturity. Precociality of young but not paternal care in the theropod ancestors of birds is consistent with the available data.     

Prediction of ground reaction forces in level and incline/decline walking from a multistage analysis of plantar pressure data

Knowing the ground reaction forces (GRFs) during walking has various biomechanical applications in injury prevention, gait analysis, as well as prosthetic and footwear design. The current study presents a method for predicting the GRFs in level and incline/decline walking that may be used in various outdoor biomechanics studies geared towards the above applications. The method was developed to predict the complete set of GRFs at walking inclinations of 0°, ±5°, ±10°, ±15°, and ±20°. Plantar pressure insoles were used to obtain inclination-specific, linear regression models based on three periods of gait stance phase, and the model-determined GRFs were compared with those measured from a forceplate. The three periods were determined based on the observed shifting of load-bearing insole sensors from heel to forefoot during walking, i.e., heel-strike, midstance, and toe-off. Six subjects wearing minimalist shoes fitted with plantar pressure insoles containing 99 pressure sensors performed ten walking trials at each of the aforementioned inclinations on an adjustable ramp with an embedded forceplate. Data from contact of the instrumented shoes with the forceplate were used to create linear regressions to transform insole pressure data into a complete set of GRFs. The root mean square error (RMSE) over peak recorded values were on average 10%, 3%, 21% for level walking and 11%, 4%, 23% for ramp walking in the respective anteroposterior, vertical, and mediolateral directions. The multistage linear regression model developed in the current study may be an acceptable option for estimating GRFs during walking in various environments without the restraint of a forceplate.     

中国鸡形目鸟类的现状与保护对策

鸡形目是一个与人类关系非常密切的鸟类类群 ,其保护工作受到国际自然保护组织的广泛关注。作为世界上鸡形目鸟类资源最为丰富的国家之一 ,我国加强该类群鸟类的保护工作不仅是野生动物资源保护的一个重要组成部分 ,而且对全球生物多样性的保护具有特别重要的意义。本文结合国家林业局“十五”期间将要实施的《全国野生动植物及自然保护区建设工程总体规划》 ,对我国鸡形目鸟类的多样性、特有性和分布特点进行了阐述 ,对该类群的濒危状况和致危因素进行了分析 ,从就地保护、易地保护以及科学研究三个方面介绍了我国在该类群研究与保护方面所取得的成就 ,探讨了目前保护管理工作中所存在的问题并提出了相应的保护对策