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Migratory songbirds carry an inherited capacity to migrate several thousand kilometers each year crossing continental landmasses and barriers between distant breeding sites and wintering areas. How individual songbirds manage with extreme precision to find their way is still largely unknown. The functional characteristics of biological compasses used by songbird migrants has mainly been investigated by recording the birds directed migratory activity in circular cages, so-called Emlen funnels. This method is 50 years old and has not received major updates over the past decades. The aim of this work was to compare the results from newly developed digital methods with the established manual methods to evaluate songbird migratory activity and orientation in circular cages., We performed orientation experiments using the European robin ( Erithacus rubecula) using modified Emlen funnels equipped with thermal paper and simultaneously recorded the songbird movements from above. We evaluated and compared the results obtained with five different methods. Two methods have been commonly used in songbirds' orientation experiments; the other three methods were developed for this study and were based either on evaluation of the thermal paper using automated image analysis, or on the analysis of videos recorded during the experiment., The methods used to evaluate scratches produced by the claws of birds on the thermal papers presented some differences compared with the video analyses. These differences were caused mainly by differences in scatter, as any movement of the bird along the sloping walls of the funnel was recorded on the thermal paper, whereas video evaluations allowed us to detect single takeoff attempts by the birds and to consider only this behavior in the orientation analyses. Using computer vision, we were also able to identify and separately evaluate different behaviors that were impossible to record by the thermal paper., The traditional Emlen funnel is still the most used method to investigate compass orientation in songbirds under controlled conditions. However, new numerical image analysis techniques provide a much higher level of detail of songbirds' migratory behavior and will provide an increasing number of possibilities to evaluate and quantify specific behaviors as new algorithms will be developed. [ABSTRACT FROM AUTHOR]

Simple Summary: The great cormorant has become a model taxon in the study of the ecology and ecotoxicology of fish-eating species. In this study, we used 157 adult and 222 juvenile dead individuals sexed by dissection to provide a method of sexing this species using external measurements. Males were larger than females in all linear body measurements, but there were no significant differences between adults and juveniles. Thus, in further analyses data on juveniles and adults within a sex was combined. The discriminant equations provided, with wing length and bill length, provided high accuracy, with 6.2% of individuals misclassified. The method presented here makes it possible to account for sex-specific patterns in ecological studies of the great cormorant and may be applied to data collected in the past. The possibility of sex identification of birds has substantial importance for studies on different aspects of bird ecology and behaviour. Using discriminant functions is becoming increasingly popular in studies of bird species that are monomorphic in plumage characteristics because they are cheap, hardly invasive and may be applied to data collected in the past. In this paper, we provide a discriminant function to sex great cormorants using external measurements. Males were larger than females in all linear body measurements, but there were no significant differences between adults and juveniles. Thus, data on juveniles and adults within a sex was combined. Discriminant equations with the most commonly used linear measurements, wing length and bill length, were provided. If identifying birds with discriminant function values D2 < −1.256 as females and those with D2 > 0.916 as males, 99% of birds will be correctly sexed. The method presented here makes it possible to account for sex-specific patterns in ecological studies of the great cormorant and may be applied to data collected in the past. The cross-application of discriminant functions developed for other populations of the great cormorant produces a 5.4% and 7.5% misclassification rate for birds from northern Poland using discriminant equations developed for populations in Greece and the Netherlands, respectively. [ABSTRACT FROM AUTHOR]

With the continuous development of science and technology, the state attaches great importance to industry, and the research on materials by researchers is getting more and more in-depth. The steel-wood structure is one of the material structures that has been focused on. The steel-timber composite (STC) structure has the characteristics of good mechanical performance, sustainable attributes, and lightweight. For the steel-timber structure with reinforced layer, its mechanical performance is better, stronger, and more durable. Particle algorithm (PSO for short) is an intelligent search algorithm derived from simulating the foraging behavior of birds. The PSO algorithm uses the information exchange ability of the population to search for the problem to obtain the optimal solution. The purpose of this paper is to study the mechanical properties of steel-timber structural systems with reinforced layers. In this paper, an improved PSO algorithm is proposed, and the algorithm model is used to conduct static tests on steel-timber structures with reinforced layers. The experimental results in this paper show for A and B two different steel-timber specimens with reinforced layers. When the number of reinforced layers of the A specimen is twice that of the B specimen, the stagnation amplitude of the B specimen is twice that of the A specimen. The cumulative energy consumption of A will be relatively more, in every 1 mm of displacement. A specimen is 4.6 kN·mm on average than B specimen, and the damping coefficient of A specimen is 0.028 larger than that of B specimen. This shows that for specimens with more reinforced layers, the higher the ultimate fatigue strength, the stronger the bearing capacity and the better the stability. [ABSTRACT FROM AUTHOR]

The article presents abstracts of several reports on bird ringing and migration including "Oystercatcher Survival and Shell Fishing," by P. W. Atkinson, et al., "Movements and Migration of Colour-ringed Black-tailed Godwits," by J. Gill and "Colour-ringing As a Means of Monitoring Turnstone on the Wash," by J. Smart.

Nest boxes have been used as artificial cavities for decades to attract cavity-nesting birds that rely on such structures to roost and breed. Nest boxes aid research efforts to understand the biology and behaviour of birds and may increase breeding success, thereby contributing to the conservation of a species. The type and dimension of nest boxes and the survey design used in the tropics vary, depending on the targeted species. This paper reviewed 30 published in-situ works using nest boxes and their survey design in Malaysia. Most studies were done on Barn Owls (Tyto alba javanica) (25), followed by hornbills (5), where they were conducted in oil palm plantations (50%), rice fields (20%), forest habitats (16.7%), urban landscapes (10%), and different habitat matrices (3.3%). Attempts to enhance/manage the local populations were the main research purpose. Unlike studies from other tropical countries, studies involving nest boxes in Malaysia are still in their infancy. This review suggests future research focus on forest species, especially those requiring immediate conservation attention, and delineate parameters highlighted in published works to counter literature inconsistency. Such research involving nest boxes may also be further expanded to the study and/or conserve other interconnected fauna species. [ABSTRACT FROM AUTHOR]

Simple Summary: We report on the occurrence of parasitic quill mites of the family Syringophilidae on the well-known avian group birds-of-paradise. Our investigation resulted in the discovery of two new species of mites belonging to the subfamily Picobiinae, which has never before been recorded on birds-of-paradise. We hypothesise that the interspecific sexual behaviour of paradisaeids, which involves copulation with non-closely related host species, may have facilitated the spread of syringophilid mites between different and unrelated host species. These findings highlight the potential role of sexual behaviour in the distribution and transmission of parasitic quill mites among avian hosts. While birds-of-paradise (Passeriformes: Paradisaeidae) are a well-known group of birds, our understanding of their parasites is still limited. This study reports on parasitic quill mites of the subfamily Picobiinae (Acariformes: Syringophilidae), which have never before been recorded on this group of birds. The mite specimens presented in this paper were collected from birds-of-paradise that had been captured in Papua New Guinea and Indonesia in the years 1910–1911 and are now deposited in the Bavarian State Collection of Zoology, Munich, Germany. Two syringophilid species are described as new to science: (i) Picobia frankei sp. n. from the magnificent riflebird Lophorina magnifica, the glossy-mantled manucode Manucodia ater, and the crinkle-collared manucode Manucodia chalybatus, and (ii) Gunabopicobia garylarsoni sp. n. from the twelve-wired bird-of-paradise Seleucidis melanoleucus and the lesser bird-of-paradise Paradisaea minor. We hypothesise that the presence of both picobiine species on phylogenetically unrelated paradisaeids may be caused by the sexual behaviour of these birds, where interspecific copulations may play a role in the switching of parasites between non-closely related host species. [ABSTRACT FROM AUTHOR]

Black kites of the nominal subspecies Milvus migrans migrans breed in Europe and winter regularly in sub-Saharan Africa and the Middle East. As a new phenomenon, black kites with morphological characteristics of the subspecies Milvus migrans lineatus are observed in Europe. Based on observations of black kites in winter 2020/2021 summarized in this paper, based on other recent reports about wintering black kites in Europe and based on juvenile black kite tagged on Crete and tracked for two years, we conclude that hundreds to thousands of black kites are now regularly wintering in south of Europe, and in smaller numbers in other parts of Europe as well as in northern Africa. The growing number of wintering black kites in Europe is apparently caused by members of the population from a hybrid zone between M. m. migrans and M. m. lineatus breeding east of the Urals, i.e. from the area of the European part of Russia. This is consistent with the hypothesis of the spreading of M. m. lineatus and a subsequent hybridization zone between M. m. migrans and M. m. lineatus in a westerly direction from Siberia across continental Europe. Moreover, two black kites found dead on Crete were attributed to M. m. lineatus and M. m. migrans by cytochrome B gene sequence analyses. The juvenile black kite with lineatus features tagged on Crete and telemetrically tracked during the next two years moved to the south-western part of Russia during the next two summers, but did not breed. It spent the following two winters at the same landfill in south-western Turkey. It seems that an adaptation to food sources provided by municipal waste landfills is important for black kites wintering in Europe, the Middle East and Morocco. Highlights • Hundreds to thousands of black kites are now regularly wintering in Europe. • The growing number of wintering black kites is caused by birds from a hybrid zone between Milvus migrans migrans and M. m. lineatus in eastern Europe. • Municipal waste landfills are important as food sources for black kites wintering in Europe. [ABSTRACT FROM AUTHOR]

The present paper elaborates on the morphological features of limestone birds depicted on the famous Al-Ubaid frieze, dated to c. 2400 B.C. and discovered in southern Mesopotamia in the vicinity of the ancient city of Ur. The main purpose of this paper is to identify wild bird species that could have been the original sources of inspiration for the birds depicted on the Al-Ubaid frieze. The popular belief identifying the Al-Ubaid birds with ducks has to be abandoned due to the vivid differences in the varied morphologies of the body, head, and neck of the investigated birds. The research presented suggests that some of the Al-Ubaid birds have traits characteristic of short-neck geese or coots, both waterfowl species. Some of the Al-Ubaid birds may be also be regarded as pigeons or doves. This idea was developed by analyzing some selected traits of the Columbidae encountered on the Al-Ubaid bird frieze. The findings confirm that there exists a demonstrable problem with a proper identification of geese, ducks, swans and pigeons in ancient Mesopotamian art, a challenge that likely results from the lack of ornithological approach in the historical and archaeological discourse. [ABSTRACT FROM AUTHOR]

The Pigeon-Inspired optimization (PIO) algorithm is a novel intelligent optimization algorithm inspired by birds' behavior as their travel. This; behavior modeled to be used for solving many optimization problems in different fields. However; it always suffers from unstable behavior when used with nonlinear; time-varying systems. In; this paper, this algorithm is adapted to calculate the optimum controller gains for roll and pitch channels in a guided tactical missile. The; vehicle model is presented in a nonlinear; form and then shown in a linearized form for the sake of an autopilot design. The PIO; algorithm is supported and accompanied by an adaptive algorithm to determine the initial states and constraints for the PIO algorithm to enhance the behavior of the optimization algorithm to speed up the convergence rate to reach an optimum and feasible solution. Also; an estimation function is incorporated to estimate model parameters variation such as dynamic pressure, stability derivatives, and mass properties. Meanwhile; a comparative analysis is carried out with original PIO and particle swarm optimization algorithms, utilizing a non-linear; model with the presence of noise source and disturbance to ensure the ability of the algorithm to make the autopilot robust and stable against several sources of uncertainties. [ABSTRACT FROM AUTHOR]

Interspecific brood or nest parasitism is a relatively common breeding behavior in birds. Through this reproductive tactic, brood-parasites avoid the costs associated with raising and maintaining chicks by laying their eggs in the nests of the host species in which they are specialized. The common cuckoo (Cuculus canorus) follows this brood parasite strategy. Female cuckoos lay their eggs in the nests of other bird species, mimicking egg shape, size, and color of the host species. In this paper we report the first documented case of parasitism of tawny pipit nests by the common cuckoo in Spanish steppe habitats, where no record of parasitism on this species has been reported to date. [ABSTRACT FROM AUTHOR]

Intelligent manufacturing is an important part of Industry 4.0; artificial intelligence technology is a necessary means to realize intelligent manufacturing. This requires the exploration of pattern recognition, computer vision, intelligent optimization, and other related technologies. Particle swarm optimization (PSO) algorithm is an optimization algorithm inspired by the foraging behavior of birds. PSO was an intelligent technology and an efficient optimization algorithm verified by a lot of research and experiments. In this paper, the traditional PSO algorithm is compared with genetic algorithms (GA) to illustrate the performance of the traditional PSO algorithm. By analyzing the advantages and disadvantages of the traditional PSO algorithm, the traditional PSO algorithm is improved through introducing into the sharing information mechanism and the competition strategy, called information sharing based PSO (IPSO). The novel algorithm IPSO was the rapid convergence speed similar to the traditional PSO and enhanced the global search capability. Our experimental results show that IPSO has better performance than the traditional PSO and the GA algorithm on benchmark functions, especially for difficult functions. [ABSTRACT FROM AUTHOR]

This paper pertains to the habitats of the Grey Francolin Francolinus pondicerianus with specific reference to populations, habitat type, vegetation, foraging, impact of human dwellings, and probable threats to populations in 20 villages covering four northern districts of Tamil Nadu, India. A total of 252 individuals were enumerated. During the non-breeding season, birds move in small groups of 2–6. Of four habitats identified, the maximum number of 143 birds was observed foraging in grasslands, while 61 were seen in dry fallow agricultural lands, 37 in dry lakes/canals, and 11 in harvested fields. No significant association was observed between habitat type and bird behaviour. They feed on termites and spilled paddy grains. Males have repeated loud calls and fight with each other. Four species of tall grasses, six of stunted trees and two shrubs were identified to provide bird habitat. Birds preferred to live away from human dwellings, with 193 found 1,000 m away from settlements. The study area continues to be a suitable habitat for Grey Francolin populations, hence this habitat needs protection. [ABSTRACT FROM AUTHOR]

Aiming at the inherent problems of swarm intelligence algorithm, such as falling into local extremum in early stage and low precision in later stage, this paper proposes an improved sparrow search algorithm (ISSA). Firstly, we introduce the idea of flight behavior in the bird swarm algorithm into SSA to keep the diversity of the population and reduce the probability of falling into local optimum; Secondly, we creatively introduce the idea of crossover and mutation in genetic algorithm into SSA to get better next-generation population. These two improvements not only keep the diversity of the population at all times but also make up for the defect that the sparrow search algorithm is easy to fall into local optimum at the end of the iteration. The optimization ability of the improved SSA is greatly improved. [ABSTRACT FROM AUTHOR]

Autonomous flight for large aircraft appears to be within our reach. However, launching autonomous systems for everyday missions still requires an immense interdisciplinary research effort supported by pointed policies and funding. We believe that concerted endeavors in the fields of neuroscience, mathematics, sensor physics, robotics, and computer science are needed to address remaining crucial scientific challenges. In this paper, we argue for a bio-inspired approach to solve autonomous flying challenges, outline the frontier of sensing, data processing, and flight control within a neuromorphic paradigm, and chart directions of research needed to achieve operational capabilities comparable to those we observe in nature. One central problem of neuromorphic computing is learning. In biological systems, learning is achieved by adaptive and relativistic information acquisition characterized by near-continuous information retrieval with variable rates and sparsity. This results in both energy and computational resource savings being an inspiration for autonomous systems. We consider pertinent features of insect, bat and bird flight behavior as examples to address various vital aspects of autonomous flight. Insects exhibit sophisticated flight dynamics with comparatively reduced complexity of the brain. They represent excellent objects for the study of navigation and flight control. Bats and birds enable more complex models of attention and point to the importance of active sensing for conducting more complex missions. The implementation of neuromorphic paradigms for autonomous flight will require fundamental changes in both traditional hardware and software. We provide recommendations for sensor hardware and processing algorithm development to enable energy efficient and computationally effective flight control. [ABSTRACT FROM AUTHOR]

Featured Application: The work intends to demonstrate the feasibility of applying different materials and technologies with the aim of performing morphing to different parts of an aerial system for increasing their capabilities and performance. The aim of this work is to present the development of a bio-inspired approach for a robotic tail using Macro Fiber Composites (MFC) as actuators. The use of this technology will allow achieving closer to the nature approach of the tail, aiming to mimic a bird tail behavior. The tail will change its shape, performing morphing, providing a new type of actuation methodology in flapping control systems. The work is intended as a first step for demonstrating the potential of these technologies for being applied in other parts of the aerials robotics systems. When compared with traditional actuation approaches, one key advantage that is given by the use of MFC is their ability to adapt to different flight conditions via geometric tailoring, imitating what birds do in nature. Theoretical explanations, design, and experimental validation of the developed concept using different methodologies will be presented in this paper. [ABSTRACT FROM AUTHOR]

In order to contribute to achieving noise and emission reduction goals, Fraunhofer and Airbus deal with the development of a morphing leading edge (MLE) as a high lift device for aircraft. Within the European research program "Clean Sky 2", a morphing leading edge with gapless chord- and camber-increase for high-lift performance was developed. The MLE is able to morph into two different aerofoils—one for cruise and one for take-off/landing, the latter increasing lift and stall angle over the former. The shape flexibility is realised by a carbon fibre reinforced plastic (CFRP) skin optimised for bending and a sliding contact at the bottom. The material is selected in terms of type, thickness, and lay-up including ply-wise fibre orientation based on numerical simulation and material tests. The MLE is driven by an internal electromechanical actuation system. Load introduction into the skin is realised by span-wise stringers, which require specific stiffness and thermal expansion properties for this task. To avoid the penetration of a bird into the front spar of the wing in case of bird strike, a bird strike protection structure is proposed and analysed. In this paper, the designed MLE including aerodynamic properties, composite skin structure, actuation system, and bird strike behaviour is described and analysed. [ABSTRACT FROM AUTHOR]

Simple Summary: Animal welfare measures have been designed to improve the health and environmental conditions of animals living under human control, for whatever reason. Welfare regulations have evolved also in line with new research insights into the cognitive, affective, and physiological domain of birds, as this paper discusses. This paper casts a critical eye on areas that Animal Welfare regulations have not reached at all, have not gone far enough, or are not regulated or supervised. It identifies the plight of birds living in captivity or being studied in the field, which either by neglect, ignorance, or design are subject to practices and procedures that may not meet basic welfare standards. The paper discusses some profound contradictions in the way we think about birds and their plight in today's world: marked for extinction on one hand and highly admired as pets on the other; damaging fieldwork on one hand and the aims of conservation on the other. It highlights some common and distressing examples of poor welfare in birds. It also offers some solutions involving simple legislative changes and ways to eliminate some unacceptably low ethical standards in the handling and management of birds. This paper discusses paradoxes in our relationship to and treatment of birds in captive and conservation contexts. The paper identifies modern and new challenges that arise from declining bird numbers worldwide. Such challenges have partly changed zoos into providers of insurance populations specifically for species at risk of extinction. They have also accelerated fieldwork projects, but by using advanced technological tools and in increasing numbers, contradictorily, they may cause serious harm to the very birds studied for conservation purposes. In practice, very few avian species have any notable protection or guarantee of good treatment. The paper first deals with shortcomings of identifying problematic avian behavior in captive birds. It then brings together specific cases of field studies and captive breeding for conservation in which major welfare deficits are identified. Indeed, the paper argues that avian welfare is now an urgent task. This is not just because of declining bird numbers but because of investment in new technologies in field studies that may have introduced additional stressors and put at risk bird survival. While the paper documents a substantial number of peer-reviewed papers criticizing practices counter to modern welfare standards, they have by and large not led to changes in some practices. Some solutions are suggested that could be readily implemented and, to my knowledge, have never been considered under a welfare model before. [ABSTRACT FROM AUTHOR]

This paper presents results on three medieval avian bone assemblages found at Debrecen-Monostor-erdő and Debrecen-Tócó-part. respectively. Domestic chicken yielded most of the bird remains to evidence the exploitation of adult birds for egg production and flock maintenance in particular. In addition. feather harvesting and fat production could have been the target of goose (and possibly duck) husbandry. Although the goose bone sizes resemble the greylag goose. the keeping of an unimproved form of domestic goose rather than the hunting of the wild ancestor is suggested by the structure of the assemblage and the presence of healed bones. Wild birds seem to have been rarely consumed by the settlers of the two villages. but the feathers or wings or carcasses of diurnal birds of prey and crows may have been used for special purposes. Either killed for their symbolic meaning or only persecuted for protecting the backyard animals. the red kite (Milvus milvus) and the hen harrier (Circus cyaneus) represent new species for the medieval avifauna of Hungary. similarly to the Northern shoveler (Anas clypeata) and the Northern lapwing (Vanellus vanellus) that could have been hunted in the marshy environment provided by the Tócó creek. Moreover. the use of trained saker falcon (Falco cherrug) for hawking cannot be excluded either. In addition to the exploitation of birds for the abovementioned goods and values. two needle cases made from goose bones evidence the utilization of their skeletal parts as raw material for producing artefacts as well. [ABSTRACT FROM AUTHOR]

Although Korean and late Sasanian texts are silent about mutual relations, archaeological evidences provide a different perspective. This paper deals with an object known at Gyeongju National Museum of the Republic of Korea. The loop was discovered in Bunhwangsa Buddhist Temple in Geun-jik (Gyeongju) region in 2001. Gyeongju's loop includes a round form made of clay, with a pearly chain (running) in the border and two birds (ducks most probably) appearing in the center of the motif while they are trying to hold a stalk of a herb. Many scholarly works have been published about it and interpreted it as the 'tree of life.' The author believes that this herb (as distinct from a plant) is a sacred lotus. In fact, the birds try to hold it in their beaks. So, an expert creator of the object used known Sasanian artistic elements on the one hand and combined them with a famous Buddhist element on the other hand. It is possible the creator attempted to immortalize his work with this sacred lotus: in a Buddhist temple, only such an element was allowed to be introduced. [ABSTRACT FROM AUTHOR]

In this data paper, Bird tracking - GPS tracking of Lesser Black-backed Gulls and Herring Gulls breeding at the southern North Sea coast is described, a species occurrence dataset published by the Research Institute for Nature and Forest (INBO). The dataset (version 5.5) contains close to 2.5 million occurrences, recorded by 101 GPS trackers mounted on 75 Lesser Black-backed Gulls and 26 Herring Gulls breeding at the Belgian and Dutch coast. The trackers were developed by the University of Amsterdam Bird Tracking System (UvA-BiTS, http://www.uva-bits.nl). These automatically record and transmit bird movements, which allows us and others to study their habitat use and migration behaviour in great detail. Our bird tracking network is operational since 2013. It is funded for LifeWatch by the Hercules Foundation and maintained in collaboration with UvA-BiTS and the Flanders Marine Institute (VLIZ). The recorded data are periodically released in bulk as open data (http://dataset.inbo.be/bird-tracking-gull-occurrences), and are also accessible through CartoDB and the Global Biodiversity Information Facility (GBIF). [ABSTRACT FROM AUTHOR]

Summary. Homing pigeons were displaced and kept until they were released in airtight containers ventilated with environmental air that could be passed through: (a) a filter made of fiberglass paper retaining large portions of the solid and liquid aerosol particles, (b) an additional filter consisting of activated charcoal, or (c) no filter (controls). Before its release, each bird was taken out of the container, and its olfactory epithelium was immediately anesthetized by lidocaine (Xylocaine). Thus, neither experimentals nor controls were able to smell while their initial orientation behavior was being observed. The controls' initial bearings were better homeward-oriented than those of pigeons ventilated with charcoal-filtered air in 14 of 17 releases conducted in Italy and Germany, at distances of 24-155 km. In the final analysis, the bearings of the charcoal-filter birds did not show any relation to the direction toward home, whereas those of the controls did. Pigeons ventilated with air that had passed through only the paper filter did not behave noticeably differently from control pigeons. It is concluded that the material bases of olfactory navigation in pigeons are substances dispersed in the atmosphere, most probably in a molecular state. [ABSTRACT FROM AUTHOR]

It is generally the case that a significant degree of uncertainty exists concerning the behavior of ecological systems. Adaptive management has been developed to address such structural uncertainty, while recognizing that decisions must be made without full knowledge of how a system behaves. This paradigm attempts to use new information that develops during the course of management to learn how the system works. To date, however, adaptive management has used a very limited information set to characterize the learning that is possible. This paper uses an extension of the Partial Observable Markov Decision Process (POMDP) framework to expand the information set used to update belief in competing models. This feature can potentially increase the speed of learning through adaptive management, and lead to better management in the future. We apply this framework to a case study wherein interest lies in managing recreational restrictions around golden eagle (Aquila chrysaetos) nesting sites. The ultimate management objective is to maintain an abundant eagle population in Denali National Park while minimizing the regulatory burden on park visitors. In order to capture this objective, we developed a utility function that trades off expected breeding success with hiker access. Our work is relevant to the management of human activities in protected areas, but more generally demonstrates some of the benefits of POMDP in the context of adaptive management. [ABSTRACT FROM AUTHOR]

This paper introduces a novel surrogate-assisted multi-objective nutcracker optimization algorithm. This algorithm is built upon the recently proposed nutcracker optimization algorithm, drawing inspiration from the behaviours observed in Clark's nutcrackers. The algorithm is developed based on two distinct behaviours exhibited by these birds. To comprehensively evaluate the performance of the proposed algorithm, a dual-pronged approach is adopted. On the one hand, a set of artificial test problems is employed to scrutinize the algorithm's capabilities, while on the other hand, a set of real-world problems is considered to assess its practical efficacy. The results of the proposed algorithm are evaluated in comparison to existing baseline algorithms and state-of-the-art algorithms, using well-recognized performance metrics, both qualitatively and quantitatively. The obtained results provide convincing evidence of the performance of the proposed algorithm. [ABSTRACT FROM AUTHOR]

Pitch or fundamental frequency is an important feature of bird song, from which scientists can learn much about a population. To use pitch as a feature, researchers need confidence in their pitch extraction system. Pitch detection algorithms (PDAs) proven to work on human speech may not be suitable for all types of bird vocalizations. This paper discusses pitch estimation performance on a variety of common bird vocalizations. The presence of multiple partials or tones simultaneously, extended frequency sweeps through multiple octaves and rapid pitch modulations are just some of the difficulties encountered when estimating the pitch of bird song. Carefully tuned parameters improve pitch tracking with YIN, but optimal parameters can change quickly even within one song. YIN is a PDA which estimates pitch of human speech very well. This paper presents YIN-bird, a modified version of YIN which exploits spectrogram properties to automatically set a minimum fundamental frequency parameter for YIN. Gross pitch errors on whistles and trills were reduced by up to 4% on a ground truth data-set of synthetic bird song with known pitch. This data-set was evaluated by expert listeners and described as "sounding like original & can hardly tell it is synthetic". A qualitative analysis showing YIN-bird not to be suitable for more complex bird vocalizations, such as nasals, is also presented. [ABSTRACT FROM AUTHOR]

The goal of this paper is to propose a bio-inspired radio access mechanism for cognitive networks mimicking the behavior of a flock of birds swarming in search for food in a cohesive fashion without colliding with each other. The equivalence between swarming and radio resource allocation is established by modeling the interference distribution in the resource domain, e.g., frequency and time, as the spatial distribution of food, while the position of the single bird represents the radio resource chosen by each radio node. The swarming mechanism is enforced by letting every node allocate its resources (power/bits) in the time-frequency regions where the interference is minimum (the food density is maximum), avoiding collisions with other nodes (birds), yet limiting the spread in the time-frequency domain (i.e., maintaining the swarm cohesion). The solution is given as the distributed minimization of a functional, borrowed from social foraging swarming models, containing the average interference plus repulsion and attraction terms that help to avoid conflicts and maintain cohesiveness, respectively. [ABSTRACT FROM AUTHOR]

The article reviews the 1970 article by Peter Lissaman and Carl Shollenberger about the formation flight in birds. It explains the aerodynamic model of birds and their ability and power to position side-by-side or wingtip spacing in a V formation. The author agrees with Lissaman and Shollenberger that the optimal positioning of birds could reduce the induced power to maintain enough lift to overcome the force of gravity required by each bird in the flock.

Scheduling is a key problem in distributed heterogeneous computing systems in order to benefit from the large computing capacity of such systems and is an NP-complete problem. In this paper, we present a metaheuristic technique, namely the Particle Swarm Optimization (PSO) algorithm, for this problem. PSO is a population-based search algorithm based on the simulation of the social behavior of bird flocking and fish schooling. Particles fly in problem search space to find optimal or near-optimal solutions. The scheduler aims at minimizing makespan, which is the time when finishes the latest task. Experimental studies show that the proposed method is more efficient and surpasses those of reported PSO and GA approaches for this problem. [ABSTRACT FROM AUTHOR]

Background: Amos [1] suggested recently that a previously reported positive relationship between minisatellite mutation rates and extra-pair paternity among species of birds [2] was confounded by transcription errors and selective inclusion of studies. Here we attempted to replicate the results reported by Amos [1], but also tested for the relationship by expanding the data base by including studies published after our original paper. Results: We were able to replicate the positive association between mutation rate and extra-pair paternity in birds, even after controlling statistically for the confounding effecs of mean number of bands scored, using 133 species, compared to 81 species in our first report [2]. We suggest that Amos [1] failed to reach a similar conclusion due to four different potential causes of bias. First, Amos [1] missed 15 studies from the literature that we were able to include. Second, he used estimates of mutation rates that were based on both within- and extra-pair offspring, although the latter will cause bias in estimates. Third, he made a number of transcription errors from the original publications for extra-pair paternity, mutation rates, number of novel bands, and mean number of bands scored per individual. Fourth, he included Vireo olivaceus although the mutation rate estimate was based on one single offspring! Conclusion: There was a positive association between mutation rates and extra-pair paternity in birds, accounting for an intermediate effect size that explained 5-11% of the variance; estimates that are bound to be conservative due to many different causes of noise in the data. This result was robust to statistical control for potentially confounding variables, highlighting that it is important to base comparative studies on all available evidence, and that it is crucial to critically transcribe data while simultaneously checking published estimates for their correctness. [ABSTRACT FROM AUTHOR]

Food supplementation experiments have provided considerable information about the importance of resource availability in timing reproduction. Supplemented birds usually advance breeding over non-supplemented controls. Initial observations suggested that degree of advancement in studies conducted at higher latitudes was less than in those at lower latitudes. We hypothesized that birds at high latitudes are less responsive to the “supplementary” cue of food. We tested this hypothesis using a literature-based meta-analysis of 36 papers which, because several papers presented separate data sets from different years, yielded 56 “studies.” We used step-wise regression to determine whether latitude, elevation, the duration of supplementation, and the migratory status of the species predicted the degree to which mean clutch initiation dates of food supplemented birds differed from non-supplemented controls (i.e., effect size = $$\overline {\text{X}} _{{{\text{cnt}}}} - \overline {\text{X}} _{{{\text{suppl}}}}$$ ). Consistent with our predictions, there was a significant inverse relationship between effect size and latitude: elevation, migratory status, and duration of treatment contributed little to the model. Because the response of animals’ reproductive systems to environmental information is mediated by the neuroendocrine system, we discuss two models: (1) the adaptive specialization hypothesis in which higher latitude species that experience a relatively short breeding season have evolved a reliance on photic cues while exhibiting reduced sensitivity to non-photic cues; and (2) the conditional plasticity hypothesis in which an individual might show a marked response to non-photic information if it lived at low latitudes, but be largely driven by photic cues, endogenous rhythms, or both to the relative exclusion of non-photic information if it lived at higher latitudes. [ABSTRACT FROM AUTHOR]

The main goal of this paper is to improve the performance of the Fireworks Algorithm (FWA). To improve the performance of the FWA we propose three modifications: the first modification is to change the stopping criteria, this is to say, previously, the number of function evaluations was utilized as a stopping criteria, and we decided to change this to specify a particular number of iterations; the second and third modifications consist on introducing a dispersion metric (dispersion percent), and both modifications were made with the goal of achieving dynamic adaptation of the two parameters in the algorithm. The parameters that were controlled are the explosion amplitude and the number of sparks, and it is worth mentioning that the control of these parameters is based on a fuzzy logic approach. To measure the impact of these modifications, we perform experiments with 14 benchmark functions and a comparative study shows the advantage of the proposed approach. We decided to call the proposed algorithms Iterative Fireworks Algorithm (IFWA) and two variants of the Dispersion Percent Iterative Fuzzy Fireworks Algorithm (DPIFWA-I and DPIFWA-II, respectively). [ABSTRACT FROM AUTHOR]

The neural processes of bird song and song development have become a model for research relevant to human acquisition of language, but in fact, very few avian species have been tested for lateralization of the way in which their audio-vocal system is engaged in perception, motor output and cognition. Moreover, the models that have been developed have been premised on birds with strong vocal dimorphism, with a tendency to species with complex social and/or monomorphic song systems. The Australian magpie (Gymnorhina tibicen) is an excellent model for the study of communication and vocal plasticity with a sophisticated behavioural repertoire, and some of its expression depends on functional asymmetry. This paper summarizes research on vocal mechanisms and presents field-work results of behavior in the Australian magpie. For the first time, evidence is presented and discussed about lateralized behaviour in one of the foremost songbirds in response to specific and specialized auditory and visual experiences under natural conditions. It presents the first example of auditory lateralization evident in the birds' natural environment by describing an extractive foraging event that has not been described previously in any avian species. It also discusses the first example of auditory behavioral asymmetry in a songbird tested under natural conditions. [ABSTRACT FROM AUTHOR]

Excluding age and experience effects, individual quality is frequently assumed to be a fixed trait. This paper tests whether an individual's apparent quality, as indicated by its timing of breeding, is indeed permanent. This is assessed by studying the repeatability of laying dates of a long-lived seabird, the great skua Catharacta skua. Laying date is known to be an important component of fitness in many seabirds, including great skuas. Mathematical models were constructed to evaluate the effect of age-specific timing of breeding on repeatability estimates. Simulations show that, in short-term studies (lasting 2or 3 years), age-specific laying dates can produce spurious repeatabilities with values ranging between 0.1 and 0.2, when the value should be zero. Field observations showed that individual consistency of timing of breeding was high over short time intervals, but disappearedover longer periods (4 or 5 years). A comparison between field data and the simulations demonstrated that the observed high repeatabilities in consecutive years, and the fast subsequent declines, cannot be fully accounted for by age effects. The mechanisms underlying this surprising pattern are completely unknown, but results clearly suggest that apparent individual quality is a transient attribute in these birds. [ABSTRACT FROM AUTHOR]

Background: Modern agriculture has undoubtedly led to increasing wildlife-human conflicts, notably concerning bird damage in productive and attractive crops during some parts of the annual cycle. This issue requires utmost attention for sedentary birds that may impact agricultural crops at any stage of their annual life cycle. Reducing bird-human conflicts requires a better understanding of the relationship between bird foraging activity and the characteristics of agricultural areas, notably with respect to changes in food-resource availability and crop sensitivity across the year. Methods: We explored how GPS-tagged adult male western jackdaws– sedentary corvids– utilize agricultural areas throughout their annual cycle, in a context of crop depredation. More precisely, we described their daily occurrence distribution and the extent of habitat use and selection consistency with respect to landscape composition across time. Results: Jackdaws moved in the close agricultural surroundings of their urban nesting place over the year (< 2.5 km from the nest, on average). Daily occurrence distributions were restricted (< 2.2 km2), relatively centered on the nesting locality (distance between the daily occurrence centroid and the nest < 0.9 km), and rather spatially stable during each annual life-cycle period (overlap range: 63.4–76.1%). Their foraging patterns highlighted that they fed mainly in grasslands all year round, and foraged complementarily and opportunistically in maize (during sowing– coinciding with the first stages of the birds' breeding period) and cereal crops (during harvesting– their post-fledging period). Conclusions: Our findings demonstrate the very limited space use by breeding male jackdaws which foraged preferentially in grasslands. We call for future investigations in other agricultural contexts and also considering non-breeders for extrapolation purposes. [ABSTRACT FROM AUTHOR]

Bird sex chromosomes play a unique role in sex-determination, and affect the sexual morphology and behavior of bird species. Core waterbirds, a major clade of birds, share the common characteristics of being sexually monomorphic and having lower levels of inter-sexual conflict, yet their sex chromosome evolution remains poorly understood. Here, by we analyse of a chromosome-level assembly of a female crested ibis (Nipponia nippon), a typical core waterbird. We identify neo-sex chromosomes resulting from fusion of microchromosomes with ancient sex chromosomes. These fusion events likely occurred following the divergence of Threskiornithidae and Ardeidae. The neo-W chromosome of the crested ibis exhibits the characteristics of slow degradation, which is reflected in its retention of abundant gametologous genes. Neo-W chromosome genes display an apparent ovary-biased gene expression, which is largely driven by genes that are retained on the crested ibis W chromosome but lost in other bird species. These results provide new insights into the evolutionary history and expression patterns for the sex chromosomes of bird species. The evolutionary trajectory of avian sex chromosomes may be more intricate than previously understood. In this study, sequencing and analysis of the neo-sex chromosomes and genome of the Crested Ibis suggests a multidirectional evolution of sex chromosomes in core waterbirds. [ABSTRACT FROM AUTHOR]

Shorebirds are iconic examples of food resource partitioning through use of contrasted morphological structures to acquire food. Differences in beak lengths and shapes allow species catching their food at various sediment depths. Contrasted leg lengths allow species foraging at distinct water depths. Despite these morphological differences, shorebirds use a small number of stereotyped behaviors for food acquisition. We classify these behaviors by analyzing video sequences of ca. two dozen species of Western Palearctic shorebirds, during migration or wintering. We suggest disassembling food acquisition in three successive stages: foraging, feeding, and swallowing. The foraging stage regroups the locomotion behaviors associated to food detection, and the behaviors used during food capture. The feeding stage encompasses the handling behaviors used to kill or stun the prey and to extract its edible parts, and the behaviors used to transport the prey from the distal part of the beak to the bird’s pharynx. In the swallowing stage, the edible parts of the prey enter the pharynx. We show that three of these behaviors (locomotion, capture and transport) are made up of stereotypical, mutually exclusive components, and can be considered as performances. Each of our study species use one or maximum two components of these three performances. Overall, our study provides insights on interspecific variation in shorebird food acquisition behaviors that we put in a phylogenetic perspective. We confirm the long-standing hypothesis that pecking is the plesiomorphic behavior of food capture, and we show that those locomotion and transport behaviors associated with pecking differ from those associated with derived capture behaviors, leading to a syndrome of food acquisition behaviors in shorebirds. [ABSTRACT FROM AUTHOR]

Chemoreception – the ability to smell and taste – is an essential sensory modality of most animals. The number and type of chemical stimuli that animals can perceive depends primarily on the diversity of chemoreceptors they possess and express. In vertebrates, six families of G protein-coupled receptors form the core of their chemosensory system, the olfactory/pheromone receptor gene families OR, TAAR, V1R and V2R, and the taste receptors T1R and T2R. Here, we study the vertebrate chemoreceptor gene repertoire and its evolutionary history. Through the examination of 1,527 vertebrate genomes, we uncover substantial differences in the number and composition of chemoreceptors across vertebrates. We show that the chemoreceptor gene families are co-evolving, highly dynamic, and characterized by lineage-specific expansions (for example, OR in tetrapods; TAAR, T1R in teleosts; V1R in mammals; V2R, T2R in amphibians) and losses. Overall, amphibians, followed by mammals, are the vertebrate clades with the largest chemoreceptor repertoires. While marine tetrapods feature a convergent reduction of chemoreceptor numbers, the number of OR genes correlates with habitat in mammals and birds and with migratory behavior in birds, and the taste receptor repertoire correlates with diet in mammals and with aquatic environment in fish. Chemoreception - the ability to smell and taste - relies on diverse receptor genes. Examining 1,527 vertebrate genomes, this study explores the dynamic evolution, lineage-specific expansions and losses of chemoreceptor genes as well as ecological and morphological factors associated with these. [ABSTRACT FROM AUTHOR]

Bird strike prevention in civil aviation has traditionally focused on the airport perimeter. Since the risk of especially damaging bird strikes outside the airport boundaries is rising, this paper investigates the safety potential of operational bird strike prevention involving pilots and controllers. In such a concept, controllers would be equipped with a bird strike advisory system, allowing them to delay departures which are most vulnerable to the consequences of bird strikes in case of high bird strike risk. An initial study has shown the strong potential of the concept to prevent bird strikes in case of perfect bird movement prediction. This paper takes the research to the next level by taking into account the limited predictability of bird tracks. As such, the collision avoidance algorithm is extended to a bird strike risk algorithm. The risk of bird strikes is calculated for birds expected to cross the extended runway center line and to cause aircraft damage upon impact. By specifically targeting these birds and excluding birds lingering on the runway which are taken care of by the local wildlife control, capacity reductions should be limited, and the implementation remain feasible. The extrapolation of bird tracks is performed by simple linear regression based on the bird positions known at the intended take-off times. To calculate the probability of collision, uncertainties resulting from variability in bird velocity and track are included. The study demonstrates the necessity to limit alerts to potentially damaging strikes with birds crossing the extended runway center line to keep the imposed delays tolerable for airports operating at their capacity limits. It is shown that predicting bird movements based on simple linear regression without considering individual bird behavior is insufficient to achieve a safety-effect. Hence, in-depth studies of multi-year bird data to develop bird behavior models and reliable predictions are recommended for future research. This is expected to facilitate the implementation of a bird strike advisory system satisfying both safety and capacity aspects. [ABSTRACT FROM AUTHOR]

Urban development has a marked effect on the ecological and behavioural traits of many living organisms, including birds. In this paper, we analysed differences in the numbers of wintering birds between rural and urban areas in Poland. We also analysed species richness and abundance in relation to longitude, latitude, human population size, and landscape structure. All these parameters were analysed using modern statistical techniques incorporating species detectability. We counted birds in 156 squares (0.25 km2 each) in December 2012 and again in January 2013 in locations in and around 26 urban areas across Poland (in each urban area we surveyed 3 squares and 3 squares in nearby rural areas). The influence of twelve potential environmental variables on species abundance and richness was assessed with Generalized Linear Mixed Models, Principal Components and Detrended Correspondence Analyses. Totals of 72 bird species and 89,710 individual birds were recorded in this study. On average (±SE) 13.3 ± 0.3 species and 288 ± 14 individuals were recorded in each square in each survey. A formal comparison of rural and urban areas revealed that 27 species had a significant preference; 17 to rural areas and 10 to urban areas. Moreover, overall abundance in urban areas was more than double that of rural areas. There was almost a complete separation of rural and urban bird communities. Significantly more birds and more bird species were recorded in January compared to December. We conclude that differences between rural and urban areas in terms of winter conditions and the availability of resources are reflected in different bird communities in the two environments. [ABSTRACT FROM AUTHOR]

This paper discusses paradoxes in our relationship to and treatment of birds in captive and conservation contexts. The paper identifies modern and new challenges that arise from declining bird numbers worldwide. Such challenges have partly changed zoos into providers of insurance populations specifically for species at risk of extinction. They have also accelerated fieldwork projects, but by using advanced technological tools and in increasing numbers, contradictorily, they may cause serious harm to the very birds studied for conservation purposes. In practice, very few avian species have any notable protection or guarantee of good treatment. The paper first deals with shortcomings of identifying problematic avian behavior in captive birds. It then brings together specific cases of field studies and captive breeding for conservation in which major welfare deficits are identified. Indeed, the paper argues that avian welfare is now an urgent task. This is not just because of declining bird numbers but because of investment in new technologies in field studies that may have introduced additional stressors and put at risk bird survival. While the paper documents a substantial number of peer-reviewed papers criticizing practices counter to modern welfare standards, they have by and large not led to changes in some practices. Some solutions are suggested that could be readily implemented and, to my knowledge, have never been considered under a welfare model before.

ABSTRACT Most of the challenges of poultry production can be addressed by using smart technology, electronic devices, and operations-controlling gadgets in an organized, efficient, and easy way. Considering the reality that the prospects of using smart technologies in the poultry industry far outweigh its problems or challenges, this study reviews an impact analysis for the adoption and implementation of these technologies in poultry management systems. Drawing from the results of research studies, observations, intuition, and secondary data, this review paper stresses that smart technology poultry management is viable with several comparative advantages over the traditional poultry management system. The use of artificial intelligence in poultry production had shown multiple benefits such as reducing cost per unit production, reducing labor involvement, stress-free environment for birds' betterment, decreasing multiple losses and damages, etc. resulting in increased productivity, profitability, and efficiency of poultry, decision-making and control and the welfare/behavior of birds on the farm. Effective use of smart technologies in the poultry industry would usher in lots of prospects, revolution, and innovation in the poultry sector and hence will help to fulfil animal protein demand in the current recent scarcity era. However, until now this technology is not been fully exploited in developing countries as there is limited applicability and automatic operations. Therefore, it is recommended that sensor technology, smart networks, the internet of things and analysis tools, and big data analysis leading to a culture of rapid response to information should be imbibed in most poultry operations. Moreover, data protection rules and regulations should be improved to make fully operational and continuously efficient poultry production operations. [ABSTRACT FROM AUTHOR]

Automated assessment of broiler chicken welfare poses particular problems due to the large numbers of birds involved and the variety of different welfare measures that have been proposed. Active (sustained, defect-free) walking is both a universally agreed measure of bird health and a behavior that can be recognized by existing technology. This makes active walking an ideal starting point for automated assessment of chicken welfare at both individual and flock level. [ABSTRACT FROM AUTHOR]

This article documents the discovery and observation of a Superb Lyrebird nest in Black Range, New South Wales, Australia. The author, Matthew Higgins, used a trail camera to capture the activities of the female Lyrebird as she built the nest, incubated the egg, and raised the chick. The article provides information about the nest construction, the presence of other animals in the area, and the unfortunate loss of the egg due to the disturbance caused by a Sugar Glider. The author acknowledges the natural behavior of the Sugar Glider and expresses uncertainty about the female Lyrebird's future breeding attempts. [Extracted from the article]

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An understanding of how hunting affects migratory birds is essential for reaching sustainable management of hunted populations. The purpose of our paper was to synthesise current knowledge of autumn and winter hunting disturbance on migratory birds and to describe a case study in Hellas (Greece). Hunting may influence migratory bird behaviour and movements, but studies have not found a corresponding increase in non-hunting mortality factors or any reduction in feeding, body condition, breeding success and any long-term population decrease. We developed a diagnostic procedure which provides a tool for assessing the potential susceptibility of a species or group of species to hunting disturbance. The application of this procedure showed that the influence of hunting disturbance on quarry species is inverse to hunting harvest. This new insight should be considered in a holistic hunting management approach. [ABSTRACT FROM AUTHOR]

This paper presents a bio-inspired algorithm called Sooty Tern Optimization Algorithm (STOA) for solving constrained industrial problems.The main inspiration of this algorithm is the migration and attacking behaviors of sea bird sooty tern in nature. These two steps are implemented and mathematically modeled to emphasize exploitation and exploration in a given search space. The proposed algorithm is compared with nine well-known bio-inspired algorithms over 44 benchmark test functions. The analysis of convergence behaviors and computational complexity of the proposed algorithm have been evaluated. Furthermore, to demonstrate its applicability it is then employed to solve six constrained industrial applications. The outcomes of experiment reveal that the proposed algorithm is able to solve challenging constrained problems and is very competitive compared with other optimization algorithms. • A novel metaheuristic named Sooty Tern Optimization Algorithm is proposed. • The proposed algorithm is tested on 44 benchmark test functions. • The proposed algorithm is capable for exploration, exploitation, and local optima avoidance. • The results of engineering problems prove the applicability in real-life applications. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mundo de Antes is the property of Revista Mundo de Antes and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Through combining theoretical models and empirical data, complexity science has increased our understanding of social behavior of animals, in particular of social insects, primates, and fish. What are missing are studies of collective behavior of huge swarms of birds. Recently detailed empirical data have been collected of the swarming maneuvers of large flocks of thousands of starlings (Sturnus vulgaris) at their communal sleeping site (roost). Their flocking maneuvers are of dazzling complexity in their changes in density and flock shape, but the processes underlying them are still a mystery. Recent models show that flocking may arise by self-organization from rules of co-ordination with nearby neighbors, but patterns in these models come nowhere near the complexity of those of the real starlings. The question of this paper, therefore, is whether such complex patterns can emerge by self-organization. In our computer model, called StarDisplay, we combine the usual rules of co-ordination based on separation, attraction, and alignment with specifics of starling behavior: 1) simplified aerodynamics of flight, especially rolling during turning, 2) movement above a “roosting area” (sleeping site), and 3) the low fixed number of interaction neighbors (i.e., the topological range). Our model generates patterns that resemble remarkably not only qualitative but also quantitative empirical data collected in Rome through video recordings and position measurements by stereo photography. Our results provide new insights into the mechanisms underlying complex flocking maneuvers of starlings and other birds. [ABSTRACT FROM PUBLISHER]

Young waterfowl can frequently join foster females shortly after hatch, resulting in post-hatch brood amalgamation. Much uncertainty remains about physiological or ecological factors that motivate adoption including potential costs and benefits to fostered offspring as well as to females that either lose or accept young. Several hypotheses have been put forth to explain adoption. In this paper, we examine the salvage strategy (SSH) and accidental-mixing (AMH) hypotheses. According to the SSH, females abandon or lose their young due to substantial energetic constraints from incubation and brood rearing. The AMH posits that adoption results from local ecological conditions on breeding areas (i.e., adverse weather conditions, high brood densities) which act to separate offspring and mothers. We used multistate modeling to estimate relationships between probabilities of adoption by white-winged scoter ( Melanitta fusca) ducklings from natal to foster females and a set of hypothesized ecological covariates. Results showed that most adoption occurred within 6 days of hatch; additionally, likelihood of adoption was positively related to inclement weather and negatively related to hatch date, size, and condition of natal females, and duckling condition. We conclude that adoption in this population is consistent with both the salvage strategy and accidental-mixing hypotheses. Ultimately, we suggest that adoption in our study population was foremost an outcome of intense gull predation but also of local environmental conditions. [ABSTRACT FROM AUTHOR]

Many vertebrates grow up in the company of same or different-age siblings, and relations among them can be expected to significantly influence individual life histories and the development of individual morphological, physiological, and behavioral phenotypes. Although studies in birds still dominate and have stimulated most theoretical considerations, the increasing number of mammalian studies promises to broaden our understanding of this complex field by enabling interesting comparisons with the rather different bird system. It therefore seems timely to bring together recent studies of sibling relations in mammals and to demonstrate what these can offer in the way of fresh insights. In this brief review, intended to accompany a series of papers on a diverse range of mammals, we outline the current state of sibling research in mammals, comparing it to the better studied birds. Most obviously, in mammals, mother and young are in much closer contact during early life than in birds, and siblings can influence each other’s development as well as the mother’s physiology while still in utero. During nursing, mammalian young also encounter a very different feeding situation to bird siblings. These contrasts should help stimulate further debate, as well as provide further opportunities to study the relative importance of maternal versus sibling effects on individual development. Finally, we discuss the need to balance studies of sibling competition and conflict with a consideration of the benefits accruing to individuals from sibling presence and the need for long-term studies of the influence of early sibling relations on individual development and life histories. [ABSTRACT FROM AUTHOR]

Optimality models are frequently used in studies of long distance bird migration to help understand and predict migration routes, stopover strategies and fuelling behaviour in a spatially varying environment. These models typically evaluate bird behaviour by focusing on a single optimization currency, such as total migration time or energy-use, without explicitly considering trade-offs between the involved objectives. In this paper, we demonstrate that this classic single-objective approach downplays the importance of variability in bird behaviour. In the light of these considerations, we therefore propose to use a full multi-criteria optimization method to isolate the set of non-dominated, efficient or Pareto optimal solutions. Unlike single-objective optimization where there is only one combination of bird behaviour maximizing fitness, the Pareto solution set represents a range of optimal solutions to conflicting objectives. Our results demonstrate that this multi-objective approach provides important new ways of analyzing how environmental factors and behavioural constraints have driven the evolution of migratory behaviour. [ABSTRACT FROM AUTHOR]