Prevalence of beak and feather disease virus in wild Platycercus elegans: comparison of three tissue types using a probe-based real-time qPCR test

The detection of avian viruses in wild populations has considerable conservation implications. For DNA-based studies, feathers may be a convenient sample type for virus screening and are, therefore, an increasingly common technique. This is despite recent concerns about DNA quality, ethics, and a paucity of data comparing the reliability and sensitivity of feather sampling to other common sample types such as blood. Alternatively, skeletal muscle tissue may offer a convenient sample to collect from dead birds, which may reveal viraemia. Here, we describe a probe-based quantitative real-time PCR for the relative quantification of beak and feather disease virus (BFDV), a pathogen of serious conservation concern for parrots globally. We used this method to test for BFDV in wild crimson rosellas (Platycercus elegans), and compared three different sample types. We detected BFDV in samples from 29 out of 84 individuals (34.5%). However, feather samples provided discordant results concerning virus presence when compared with muscle tissue and blood, and estimates of viral load varied somewhat between different sample types. This study provides evidence for widespread infection of BFDV in wild crimson rosellas, but highlights the importance of sample type when generating and interpreting qualitative and quantitative avian virus data.

Feeding wild birds in gardens: a test of water versus food

Bird feeding in residential gardens is an increasingly popular human-wildlife interaction. In Australia, the practice is discouraged by most government and nongovernment wildlife conservation agencies, although advice varies and the most common recommendation is to provide water and habitat for birds rather than supplementary food. This study compares bird abundance and diversity when residents in a Melbourne municipality provide water for birds versus food. Bird abundance was greater when food was provided compared with water, but avian assemblages did not differ.

Movement ecology of nomadic arid zone waterfowl

This thesis provides insights into the spatial and temporal patterns of movement in nomadic waterfowl, the response of birds to rapid environmental change, behavioural flexibility of avian movements and the ability of birds to locate seemingly unpredictable water bodies in vast arid landscapes.

Flying, fasting, and feeding in birds during migration: a nutritional and physiological ecology perspective

Unlike exercising mammals, migratory birds fuel very high intensity exercise (e.g., flight) with fatty acids delivered from the adipose tissue to the working muscles by the circulatory system. Given the primary importance of fatty acids for fueling intense exercise, we discuss the likely limiting steps in lipid transport and oxidation for exercising birds and the ecological factors that affect the quality and quantity of fat stored in wild birds. Most stored lipids in migratory birds are comprised of three fatty acids (16:0, 18:1 and 18:2) even though migratory birds have diverse food habits. Diet selection and selective metabolism of lipids play important roles in determining the fatty acid composition of birds which, in turn, affects energetic performance during intense exercise. As such, migratory birds offer an intriguing model for studying the implications of lipid metabolism and obesity on exercise performance. We conclude with a discussion of the energetic costs of migratory flight and stopover in birds, and its implications for bird migration strategies.

Flocking and feeding in the fiddler crab (UCA tangeri): prey availability as risk-taking behaviour

For a full understanding of prey availability, it is necessary to study risk-taking behaviour of the prey. Fiddler crabs are ideally suited for such a study, as they have to leave their safe burrow to feed on the surface of the intertidal flats during low tide, thereby exposing themselves to avian predators. A study in an intertidal area along the coast of Mauritania showed that small crabs always stayed in the vicinity of their burrow, but large crabs wandered in large flocks (also referred to as droves) to feed on sea-grass beds downshore. Transplanting downshore feeding substrate to the burrowing zone of the small crabs proved that they too preferred to feed on it. Since small crabs can be preyed upon by more species of birds, this suggests that the decision not to leave the burrowing zone might be related to the risk of being fed upon by birds. We calculated predation risk from measurements on the density and feeding activity of the crabs, as well as the feeding density, the intake rate and the size selection of the avian predators. Per hour on the surface, crabs in a flock were more at risk than crabs feeding near their burrow. Thus, though flocking crabs may have benefited from ‘swamping the predator’ by emerging in maximum numbers during some tides only, this did not reduce their risk of predation below that of non-flocking crabs. Furthermore we found that irrespective of activity, large crabs suffered a higher mortality per tide from avian predators than small crabs. This suggests that large crabs could not sufficiently reduce their foraging time to compensate for the increased risk while foraging in a flock, even though they probably experienced better feeding conditions than small crabs staying near their burrow. The greater energy demands of large crabs were reflected in a greater surface area grazed. Thus, with increasing size a fiddler crab has to feed further away from its burrow and so may derive less protection from staying near to it. It seems that growing big does not reduce the risk of predation for fiddler crabs, as it does in many other species with indeterminate growth. As in such species, the most probable advantage of growing big is increased mating success. Ultimately, therefore, prey availability must be understood from the life-history decisions of the prey species.

Habitat selection and energetics of the fiddler crab (Uca tangeri)

We tried to unravel the possible links between the skewed predation risk in Uca tangeri (where large individuals are more at risk from avian predators) and size-dependent changes in the physiology and habitat choice of this fiddler crab species. Over a transect running from low to high in the tidal zone of a beach in Mauritania, the temperature profile at various depths in the substrate, the water-table level of seep water, salt concentration of seep water, depth of the aerobic level, operative temperatures on the surface, and size distribution of crabs were assessed. In addition, resting metabolic rates, Q10 and thermal and starvation tolerances were estimated. Going from low to high in the tidal zone, crab size and burrow depth increased. At the preferred burrowing depth, microclimatological conditions appeared to be equally favourable at all sites. At the surface, conditions were more favourable low in the tidal zone, where also food availability is sufficient to enable small crabs to forage in the vicinity of their burrows. Large crabs have higher energy requirements and are thereby forced to forage in flocks low in the tidal zone where food is probably more abundant. Low in the tidal zone, digging deeply is impossible as the aerobic layer is rather thin. Large crabs prefer living high in the tidal zone as (1) deep burrows ensure better protection against predators, (2) more time is available for digging holes and (3) the substrate is better suited for reproduction. Energy reserves in late summer ensured an average of 34 days of survival. It is argued that the allotment of energy to growth must be considerable even in reproducing animals; the rewards of growth being the disproportional increase in reproductive output with size.

High basal metabolic rates of shorebirds while in the Arctic: a circumpolar view

The basal metabolic rate (BMR) of Old World long-distance-migrant shorebirds has been found to vary along their migration route. On average, BMR is highest in the Arctic at the start of fall migration, intermediate at temperate latitudes, and lowest on the tropical wintering grounds. As a test of the generality of this pattern, we measured the BMR of one adult and 44 juvenile shorebirds of 10 species (1-18 individuals of each species, body-mass range 19-94 g) during the first part of their southward migration in the Canadian Arctic (68-76°N). The interspecific relationship between BMR and body mass was almost identical to that found for juvenile shorebirds in the Eurasian Arctic (5 species), although only one species appeared in both data sets. We conclude that high BMR of shorebirds in the Arctic is a circumpolar phenomenon. The most likely explanation is that the high BMR reflects physiological adaptations to low ambient temperatures. Whether the BMR of New World shorebirds drops during southward migration remains to be investigated.

Synchronization by low-amplitude light-dark cycles of 24-hour pineal and plasma melatonin rhythms of hatchling European starlings (Sturnus vulgaris)

In young European starlings, as in other avian species, high-amplitude 24-hr rhythms in plasma and pineal melatonin are already present around the time of hatching. In chickens this rhythmicity results at least partly from the light sensitivity of the melatonin-producing and -secreting system. In contrast to the chicken, the starling is a hole-nesting bird, and it seemed questionable whether the low light intensities in the nest are sufficient to synchronize perinatal melatonin rhythms. We therefore exposed starling eggs to light cycles roughly simulating those measured in nest-boxes, i.e., an 11-hr phase of complete darkness and a 13-hr phase consisting of 15 min of dim light (10 lux) alternating with 30 min of darkness. For one group the photophase lasted from 0600 to 1900 hr; for the other group the photophase lasted from 1800 to 0700 hr. In approximately 10-hr-old hatchlings of both groups, plasma and pineal melatonin concentrations were high during the dark phase and low during the light phase. We conclude that perinatal low-amplitude light intensity changes of the kind experienced by hatching starlings in the field are sufficient for synchronizing the melatonin-producing and -secreting system in the pineal and possibly other organs.

Reassortant highly pathogenic influenza a H5N2 virus containing gene segments related to eurasian H5N8 in British Columbia, Canada, 2014

In late November 2014 higher than normal death losses in a meat turkey and chicken broiler breeder farm in the Fraser Valley of British Columbia initiated a diagnostic investigation that led to the discovery of a novel reassortant highly pathogenic avian influenza (HPAI) H5N2 virus. This virus, composed of 5 gene segments (PB2, PA, HA, M and NS) related to Eurasian HPAI H5N8 and the remaining gene segments (PB1, NP and NA) related to North American lineage waterfowl viruses, represents the first HPAI outbreak in North American poultry due to a virus with Eurasian lineage genes. Since its first appearance in Korea in January 2014, HPAI H5N8 spread to Western Europe in November 2014. These European outbreaks happened to temporally coincide with migratory waterfowl movements. The fact that the British Columbia outbreaks also occurred at a time associated with increased migratory waterfowl activity along with reports by the USA of a wholly Eurasian H5N8 virus detected in wild birds in Washington State, strongly suggest that migratory waterfowl were responsible for bringing Eurasian H5N8 to North America where it subsequently reassorted with indigenous viruses.

Deploying aptameric sensing technology for rapid pandemic monitoring

The genome of virulent strains may possess the ability to mutate by means of antigenic shift and/or antigenic drift as well as being resistant to antibiotics with time. The outbreak and spread of these virulent diseases including avian influenza (H1N1), severe acute respiratory syndrome (SARS-Corona virus), cholera (Vibrio cholera), tuberculosis (Mycobacterium tuberculosis), Ebola hemorrhagic fever (Ebola Virus) and AIDS (HIV-1) necessitate urgent attention to develop diagnostic protocols and assays for rapid detection and screening. Rapid and accurate detection of first cases with certainty will contribute significantly in preventing disease transmission and escalation to pandemic levels. As a result, there is a need to develop technologies that can meet the heavy demand of an all-embedded, inexpensive, specific and fast biosensing for the detection and screening of pathogens in active or latent forms to offer quick diagnosis and early treatments in order to avoid disease aggravation and unnecessary late treatment costs. Nucleic acid aptamers are short, single-stranded RNA or DNA sequences that can selectively bind to specific cellular and biomolecular targets. Aptamers, as new-age bioaffinity probes, have the necessary biophysical characteristics for improved pathogen detection. This article seeks to review global pandemic situations in relation to advances in pathogen detection systems. It particularly discusses aptameric biosensing and establishes application opportunities for effective pandemic monitoring. Insights into the application of continuous polymeric supports as the synthetic base for aptamer coupling to provide the needed convective mass transport for rapid screening is also presented.

An experimental examination of interindividual variation in feather corticosterone content in the House Sparrow, Passer domesticus in southeast Australia

Non-invasive techniques for measuring glucocorticoids (GCs) have become more prevalent, due to the advantage of eliminating the effects of animal disturbance on GC levels and their potential to provide an integrated, historic estimate of circulating GC levels. In the case of birds, corticosterone (CORT) is deposited in feathers, and may reflect a bird's GC status over the period of feather synthesis. This technique thus permits a retrospective view of the average circulating GC levels during the moult period. While it is generally assumed that differences in feather CORT content (CORTf) between individuals reflects their different stress histories during either natural or induced moult, it is not clear how much of this variation is due to extrinsic versus intrinsic factors. We examined this question by determining CORTf in free-living house sparrows (Passer domesticus) from two populations, one urban and the other rural, that were plucked before and after exposure to different plasma CORT levels while held captive. We experimentally manipulated plasma CORT by implanting birds with either a corticosterone-filled, metyrapone-filled, or empty ('sham') silastic capsule as replacement feathers first emerged. The pattern of post-treatment CORTf was consistent with our expectations, based on plasma CORT levels of an experimentally implanted reference group. However, there was no statistically significant difference in CORTf between these treatment groups unless sex, population origin, and CORTf of original feathers for each individual were included in a model. Thus, birds with higher CORTf in feathers removed for this experiment tended to have higher CORTf in post-treatment replacement feathers, irrespective of treatment. In addition, we found that feather fault bar scores were significantly higher in CORT-treated birds than in the other two treatment groups, but did not vary directly with CORTf level. Our study therefore broadly confirms the use of feathers as a non-invasive tool to estimate plasma CORT during moult in birds, but importantly demonstrates the potential for intrinsic differences in stress characteristics between populations and individuals to obscure the effects extrinsic stressors might have on CORTf .

AvianBuffer: an interactive tool for characterising and managing wildlife fear responses

The characterisation and management of deleterious processes affecting wildlife are ideally based on sound scientific information. However, relevant information is often absent, or difficult to access or contextualise for specific management purposes. We describe 'AvianBuffer', an interactive online tool enabling the estimation of distances at which Australian birds respond fearfully to humans. Users can input species assemblages and determine a 'separation distance' above which the assemblage is predicted to not flee humans. They can also nominate the diversity they wish to minimise disturbance to, or a specific separation distance to obtain an estimate of the diversity that will remain undisturbed. The dataset is based upon flight-initiation distances (FIDs) from 251 Australian bird species (n = 9190 FIDs) and a range of human-associated stimuli. The tool will be of interest to a wide audience including conservation managers, pest managers, policy makers, land-use planners, education and public outreach officers, animal welfare proponents and wildlife ecologists. We discuss possible applications of the data, including the construction of buffers, development of codes of conduct, environmental impact assessments and public outreach. This tool will help balance the growing need for biodiversity conservation in areas where humans can experience nature. The online resource will be expanded in future iterations to include an international database of FIDs of both avian and non-avian species.

Infecção por C. psittaci: uma revisão com ênfase em psitacídeos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The effects of anesthesia with a combination of intramuscular xylazine-diazepam-ketamine on heart rate, respiratory rate and cloacal temperature in roosters

Objective To examine the anesthetic effects of a xylazine-diazepam-ketamine (XDK) combination in roosters.Study design Prospective experimental trial.Animals Six healthy white Leghorn roosters weighing 2.03 +/- 0.08 kg.Methods Each rooster was pre-medicated with xylazine (3 mg kg(-1), IM) and after 15 minutes anesthesia was induced with a diazepam (4 mg kg(-1)) and ketamine (25 mg kg(-1)) combination injected into the pectoral muscles. Heart and respiratory rates were recorded before anesthesia and every 15 minutes after induction for 165 minutes. Cloacal temperature was measured before and 15 minutes after pre-medication and every 75 minutes thereafter during anesthesia. Quality of induction and recovery were scored subjectively; duration of loss of righting reflex, abolition of response to a painful stimulus and palpebral reflex were also recorded.Results Intramuscular injection of xylazine smoothly induced loss of the righting reflex within 3-4 minutes. Loss of response to a painful stimulus occurred at 13.1 +/- 2.9 minutes (mean +/- SD) after the administration of the D-K combination, and lasted for 63.0 +/- 5.3 minutes. Roosters anesthetized with this combination had a significant decrease in heart and respiratory rates and cloacal temperature. The recovery period lasted for up to 4 hours (227.5 +/- 15.4 minutes). Quality of recovery was satisfactory for four roosters but excitation was noted in two birds.Conclusions and clinical relevance The XDK combination was a useful anesthetic technique for typhlectomy in roosters. Nevertheless this drug combination should be used with caution and cardiopulmonary parameters monitored carefully. Under the conditions of this experiment it was associated with a decreased cloacal temperature and prolonged recoveries.

Expression of MyoD, myogenin, myostatin and Hsp70 transcripts in chicken embryos submitted to mild cold or heat

The expression of the MyoD, myogenin, myostatin and Hsp70 genes was estimated in chicken embryos submitted to mild cold (36 +/- 0.5degreesC) or heat (44 +/- 0.5degreesC) for 1 h. 2. Marked decreases in MyoD, myogenin and myostatin transcript levels were observed in embryos exposed to high temperature, contrasting to the higher expression of the Hsp70 mRNA detected in heat-stressed embryos. 3. The exposure of chicken embryos to low temperature significantly affected only the abundance of myogenin mRNA. 4. These findings suggest that myogenic proliferation and differentiation events are compromised by variations in environmental temperature during avian embryogenesis. (C) 2003 Elsevier B.V. Ltd. All rights reserved.