Plumage colour and feather pecking in laying hens, a chicken perspective?

International audience1. This study investigated whether feather damage due to feather pecking and bird behaviour were influenced by plumage colour in Oakham Blue laying hens (black, white, grey colour variants). The reflectance properties of feathers and spectral composition of light environments experienced by the hens were also examined. 2. 979 birds were inspected and scored for feather damage. 10.5 hours of video recordings were examined to record feather pecking and bird behaviour. Feathers and light environments were measured using a USB-2000 spectrometer and DH-2000-CAL-DTH lamp. 3. Oakham Blue birds with white plumage had less feather damage due to feather pecking than black or grey birds. There was more severe feather pecking in the mornings than in the afternoon and white birds severe feather pecked more than black or grey birds, although there were no other behavioural differences between plumage colours. White feathers reflected at a higher intensity than black or grey feathers. However, black and grey feather spectra were relatively flat and the contribution of UV wavelengths to plumage reflection was proportionally greater than that for white feathers. Light intensity inside a poultry house was 100 x (UW/cm2/nm) less than on the range and there was low or no UV reflectance. 4. Under the dim, artificial lights inside a poultry house, Oakham Blue hens with black and grey feathers may be less visible to conspecifics than white birds because their plumage reflects at a lower intensity. Furthermore, the lack of available UV light inside versus outside and the higher contribution of UV reflectance to black and grey plumage, may make black and grey birds appear more different inside the house than white birds. It is possible that this novel/unusual appearance may make black or grey Oakham Blue hens more susceptible to feather pecking

Unmanned aircraft systems as a new source of disturbance for wildlife: A systematic review.

The use of small Unmanned Aircraft Systems (UAS; also known as "drones") for professional and personal-leisure use is increasing enormously. UAS operate at low altitudes (<500 m) and in any terrain, thus they are susceptible to interact with local fauna, generating a new type of anthropogenic disturbance that has not been systematically evaluated. To address this gap, we performed a review of the existent literature about animals' responses to UAS flights and conducted a pooled analysis of the data to determine the probability and intensity of the disturbance, and to identify the factors influencing animals' reactions towards the small aircraft. We found that wildlife reactions depended on both the UAS attributes (flight pattern, engine type and size of aircraft) and the characteristics of animals themselves (type of animal, life-history stage and level of aggregation). Target-oriented flight patterns, larger UAS sizes, and fuel-powered (noisier) engines evoked the strongest reactions in wildlife. Animals during the non-breeding period and in large groups were more likely to show behavioral reactions to UAS, and birds are more prone to react than other taxa. We discuss the implications of these results in the context of wildlife disturbance and suggest guidelines for conservationists, users and manufacturers to minimize the impact of UAS. In addition, we propose that the legal framework needs to be adapted so that appropriate actions can be undertaken when wildlife is negatively affected by these emergent practices

Evolution of Anolis Lizard Dewlap Diversity

BACKGROUND: The dewlaps of Anolis lizards provide a classic example of a complex signaling system whose function and evolution is poorly understood. Dewlaps are flaps of skin beneath the chin that are extended and combined with head and body movements for visual signals and displays. They exhibit extensive morphological variation and are one of two cladistic features uniting anoles, yet little is known regarding their function and evolution. We quantified the diversity of anole dewlaps, investigated whether dewlap morphology was informative regarding phylogenetic relationships, and tested two separate hypotheses: (A) similar Anolis habitat specialists possess similar dewlap configurations (Ecomorph Convergence hypothesis), and (B) sympatric species differ in their dewlap morphologies to a greater extent than expected by chance (Species Recognition hypothesis). METHODOLOGY/PRINCIPAL FINDINGS: We found that dewlap configurations (sizes, patterns and colors) exhibit substantial diversity, but that most are easily categorized into six patterns that incorporate one to three of 13 recognizable colors. Dewlap morphology is not phylogenetically informative and, like other features of anoles, exhibits convergence in configurations. We found no support for the Ecomorph Convergence hypothesis; species using the same structural habitat were no more similar in dewlap configuration than expected by chance. With one exception, all sympatric species in four communities differ in dewlap configuration. However, this provides only weak support for the Species Recognition hypothesis because, due to the great diversity in dewlap configurations observed across each island, few cases of sympatric species with identical dewlaps would be expected to co-occur by chance alone. CONCLUSIONS/SIGNIFICANCE: Despite previous thought, most dewlaps exhibit easily characterizable patterns and colorations. Nevertheless, dewlap variation is extensive and explanations for the origin and evolution of this diversity are lacking. Our data do not support two hypothesized explanations for this diversity, but others such as sexual selection remain to be tested

Improved Innate and Adaptive Immunostimulation by Genetically Modified HIV-1 Protein Expressing NYVAC Vectors.

Attenuated poxviruses are safe and capable of expressing foreign antigens. Poxviruses are applied in veterinary vaccination and explored as candidate vaccines for humans. However, poxviruses express multiple genes encoding proteins that interfere with components of the innate and adaptive immune response. This manuscript describes two strategies aimed to improve the immunogenicity of the highly attenuated, host-range restricted poxvirus NYVAC: deletion of the viral gene encoding type-I interferon-binding protein and development of attenuated replication-competent NYVAC. We evaluated these newly generated NYVAC mutants, encoding HIV-1 env, gag, pol and nef, for their ability to stimulate HIV-specific CD8 T-cell responses in vitro from blood mononuclear cells of HIV-infected subjects. The new vectors were evaluated and compared to the parental NYVAC vector in dendritic cells (DCs), RNA expression arrays, HIV gag expression and cross-presentation assays in vitro. Deletion of type-I interferon-binding protein enhanced expression of interferon and interferon-induced genes in DCs, and increased maturation of infected DCs. Restoration of replication competence induced activation of pathways involving antigen processing and presentation. Also, replication-competent NYVAC showed increased Gag expression in infected cells, permitting enhanced cross-presentation to HIV-specific CD8 T cells and proliferation of HIV-specific memory CD8 T-cells in vitro. The recombinant NYVAC combining both modifications induced interferon-induced genes and genes involved in antigen processing and presentation, as well as increased Gag expression. This combined replication-competent NYVAC is a promising candidate for the next generation of HIV vaccines

Carrier cultures of human fetal diploid cells infected with coxsackievirus type B2

Carrier cultures of coxsackievirus type B2, strain V1-013 were established without the use of “normal” human serum or serum containing viral antibodies, and without frequent changes of medium. Blind passage of virus strain V1-013 in human fetal diploid (HFD) cell cultures on maintenance medium resulted in viral multiplication without apparent CPE. In addition, human fetal diploid cultures infected with the V1-013 virus strain could be subcultivated for over 20 transfers, and infectious virus and antigen demonstrable by immunofluorescent staining were present at each passage level; again, viral multiplication occurred without apparent CPE. Sustained infections were not observed when HFD cells were inoculated with two other (Ohio and Lincoln) B2 coxsackievirus strains; however, the life-span of inoculated cultures was reduced in comparison to that of control cultures.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41684/1/705_2005_Article_BF01556144.pd

Behavioural indicators of welfare in farmed fish

Behaviour represents a reaction to the environment as fish perceive it and is therefore a key element of fish welfare. This review summarises the main findings on how behavioural changes have been used to assess welfare in farmed fish, using both functional and feeling-based approaches. Changes in foraging behaviour, ventilatory activity, aggression, individual and group swimming behaviour, stereotypic and abnormal behaviour have been linked with acute and chronic stressors in aquaculture and can therefore be regarded as likely indicators of poor welfare. On the contrary, measurements of exploratory behaviour, feed anticipatory activity and reward-related operant behaviour are beginning to be considered as indicators of positive emotions and welfare in fish. Despite the lack of scientific agreement about the existence of sentience in fish, the possibility that they are capable of both positive and negative emotions may contribute to the development of new strategies (e. g. environmental enrichment) to promote good welfare. Numerous studies that use behavioural indicators of welfare show that behavioural changes can be interpreted as either good or poor welfare depending on the fish species. It is therefore essential to understand the species-specific biology before drawing any conclusions in relation to welfare. In addition, different individuals within the same species may exhibit divergent coping strategies towards stressors, and what is tolerated by some individuals may be detrimental to others. Therefore, the assessment of welfare in a few individuals may not represent the average welfare of a group and vice versa. This underlines the need to develop on-farm, operational behavioural welfare indicators that can be easily used to assess not only the individual welfare but also the welfare of the whole group (e. g. spatial distribution). With the ongoing development of video technology and image processing, the on-farm surveillance of behaviour may in the near future represent a low-cost, noninvasive tool to assess the welfare of farmed fish.Fundação para a Ciência e Tecnologia, Portugal [SFRH/BPD/42015/2007]info:eu-repo/semantics/publishedVersio

The effect of climate change on avian offspring production: A global meta-analysis

Climate change affects timing of reproduction in many bird species, but few studies have investigated its influence on annual reproductive output. Here, we assess changes in the annual production of young by female breeders in 201 populations of 104 bird species (N = 745,962 clutches) covering all continents between 1970 and 2019. Overall, average offspring production has declined in recent decades, but considerable differences were found among species and populations. A total of 56.7% of populations showed a declining trend in offspring production (significant in 17.4%), whereas 43.3% exhibited an increase (significant in 10.4%). The results show that climatic changes affect offspring production through compounded effects on ecological and life history traits of species. Migratory and larger-bodied species experienced reduced offspring production with increasing temperatures during the chick-rearing period, whereas smaller-bodied, sedentary species tended to produce more offspring. Likewise, multi-brooded species showed increased breeding success with increasing temperatures, whereas rising temperatures were unrelated to reproductive success in single-brooded species. Our study suggests that rapid declines in size of bird populations reported by many studies from different parts of the world are driven only to a small degree by changes in the production of young.This meta-analysis was financed by the grant of the Polish National Science Centre (Narodowe Centrum Nauki) (no. 2017/27/B/NZ8/00465) awarded to Lucyna Hałupka.Peer reviewe

Song plasticity over time and vocal learning in clay-colored thrushes

Songbirds have been traditionally classified into close-ended or open-ended learning species according to the length of the sensitive period during which birds are able to memorize new vocalizations. Closed-ended learners are generally not capable of changing their song after the first year of life, while open-ended learners show song plasticity as adults. A few Turdus species have been sug- gested to be open-ended learners, but no long-term study has been conducted to investigate their song plasticity over time. We analyzed the songs of clay-colored thrushes, T. grayi, over four successive breeding seasons to assess song plasticity in their syllable repertoires within and between breeding seasons. A total of 16,262 syllables were classi- fied through visual inspection of spectrograms and multi- dimensional scaling analysis based on spectrogram correlations. On average, 563 ± 153 (SD) syllables per male per breeding season were analyzed. Male repertoire size was 9–20 syllable types. Males were capable of modifying their syllable repertoire between the initial and final periods of the breeding season. Song plasticity within breeding seasons may be associated with imitation between neighboring males, suggesting song learning in males that were C2 years old. This short-term plasticity is not enough, however, to explain the high proportion of change (mean = 65 % syllable types) in repertoire composition between breeding seasons in adult males. Song plasticity resulting from annual changes in repertoire composition could be explained by open-ended learning, but another mechanism, extended memory and re-expression, could also explain long-term plasticity. Experimental studies controlling the acoustic environment are needed to determine which mechanism is responsible for such a high level of song plasticity.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

The effect of climate change on avian offspring production: A global meta-analysis

Climate change affects timing of reproduction in many bird species, but few studies have investigated its influence on annual reproductive output. Here, we assess changes in the annual production of young by female breeders in 201 populations of 104 bird species (N = 745,962 clutches) covering all continents between 1970 and 2019. Overall, average offspring production has declined in recent decades, but considerable differences were found among species and populations. A total of 56.7% of populations showed a declining trend in offspring production (significant in 17.4%), whereas 43.3% exhibited an increase (significant in 10.4%). The results show that climatic changes affect offspring production through compounded effects on ecological and life history traits of species. Migratory and larger-bodied species experienced reduced offspring production with increasing temperatures during the chick-rearing period, whereas smaller-bodied, sedentary species tended to produce more offspring. Likewise, multi-brooded species showed increased breeding success with increasing temperatures, whereas rising temperatures were unrelated to repro- ductive success in single-brooded species. Our study suggests that rapid declines in size of bird populations reported by many studies from different parts of the world are driven only to a small degree by changes in the production of young