123 research outputs found
Hen Harrier Circus cyaneus population trends in relation to wind farms
Capsule: The data presented here demonstrate a considerable spatial overlap between wind farms and the breeding distribution of Hen Harriers in Ireland, but evidence for a negative impact of wind farms on their population is weak. Aims: To assess the extent of the overlap between wind farms and breeding Hen Harriers and to investigate their potential impact on Hen Harrier population trends. Methods: Data on Hen Harrier breeding distribution in 10 km × 10 km survey squares from national surveys were used in conjunction with information on the location of wind farms to examine whether, and to what extent, changes in Hen Harrier distribution and abundance between 2000 and 2010 were related to wind energy development. Results: Of the 69 survey squares holding Hen Harriers during the 2010 breeding season, 28% also overlapped with one or more wind farms. Data from 36 of the squares with breeding Hen Harriers during the 2000 survey revealed a marginally non-significant negative relationship between wind farm presence and change in the number of breeding pairs between 2000 and 2010. Conclusions: A considerable overlap exists between Hen Harrier breeding distribution and the location of wind farms in Ireland, particularly in areas between 200 and 400 m above sea level. The presence of wind farms is negatively related to Hen Harrier population trends in squares surveyed in 2000 and 2010, but this relationship is not statistically significant, and may not be causal. This is the first study to assess the influence of wind energy development on Hen Harriers at such a large geographic and population scale
Density-dependent productivity in a colonial vulture at two spatial scales
. Understanding how density dependence modifies demographic parameters
in long-lived
vertebrates is a challenge for ecologists. Two alternative hypotheses have
been used to explain the mechanisms behind density-dependent
effects on breeding output:
habitat heterogeneity and individual adjustment (also known as interference competition).
A number of studies have highlighted the importance of habitat heterogeneity in density
dependence in territorial species, but less information exists on demographic processes in
colonial species. For these, we expect density-dependent
mechanisms to operate at two
spatial scales: colony and breeding unit. In this study, we used long-term
data from a
recovering population of Cinereous Vultures (Aegypius monachus) in southern Spain. We
analyzed a long-term
data set with information on 2162 breeding attempts at four colonies
over a nine-year
period (2002–2010) to evaluate environmental and population parameters
influencing breeding output. Our results suggest that breeding productivity is subject to
density-dependent
processes at the colony and the nest site scale and is best explained by
interference competition. Factors intrinsic to each colony, as well as environmental constraints
linked to physiography and human presence, also play a role in regulatory processes.
We detected the existence of a trade-off
between the disadvantages of nesting too
close to conspecifics and the benefits of coloniality. These could be mediated by the agonistic
interactions between breeding pairs and the benefits derived from social sharing of information
by breeding individuals. We propose that this trade-off
may play a role in defining
colony structure and may hold true for other colonial breeding bird species. Our findings
also have important management implications for the conservation of this threatened
species.Peer reviewe
Evidencia en video de fratricidio y canibalismo, movimiento de polluelos e interacciones con depredadores en nidos de Circus cyaneus
During a nest-camera study of Hen Harriers (Circus cyaneus), we recorded siblicide, cannibalism, movement of nestlings by adult birds, and interactions with predators. We deployed cameras at 13 nests across three study areas in Ireland between 2008 and 2010. At a nest with two well-developed nestlings (approximately 25–30 d old), the older nestling killed its sibling and fed on it. This was the first documented case of siblicide in this species, to our knowledge. Recordings also revealed three other events of cannibalism in which one of the nestlings in a brood died from unknown causes and was then eaten by its siblings (n = 1), by the adult male (n = 1), or was used by the adult female to feed the remaining nestlings (n = 1). At two nests, recordings showed the adult female picking up and moving nestlings that were outside the nest cup. In addition, cameras recorded two instances of full brood predation by red fox (Vulpes vulpes) and an attack on a nest by a female Eurasian Kestrel (Falco tinnunculus) that had no apparent consequences for the nestlings or the female Hen Harrier. The behaviors reported here, which are difficult to observe directly, may have important consequences for our understanding of productivity and population dynamics of Hen Harriers.Durante un estudio sobre patrones de actividad de individuos reproductores de Circus cyaneus realizado con cámaras para monitoreo de nidos, registramos comportamientos de fratricidio, canibalismo, movimientos de polluelos e interacciones con depredadores. Colocamos cámaras en 13 nidos distribuidos en tres áreas de estudio en Irlanda entre 2008 y 2010. En un nido con dos polluelos en un estado de desarrollo avanzado (c. 25-30 días), el polluelo de mayor edad mató al otro y se alimentó de él. Este es el primer caso documentado de fratricidio en esta especie. Obtuvimos imágenes de otros tres casos de canibalismo en que uno o más polluelos fallecieron por causas desconocidas y sus cadáveres fueron usados como alimento por los otros polluelos (n = 1), por el macho adulto (n = 1) o por la hembra adulta para alimentar a los otros polluelos (n = 1). En dos nidos, las imágenes muestran a la hembra adulta repetidamente recogiendo polluelos que se alejan del nido para intentar llevarlos al nido. Por último, las cámaras captaron dos eventos de depredación de polluelos por parte de Vulpes vulpes y un enfrentamiento entre la hembra adulta de C. cyaneus y una hembra de Falco tinnunculus sin consecuencias para los polluelos o la hembra adulta. Estos comportamientos, difíciles de detectar mediante metodologías de monitoreo tradicionales, pueden tener consecuencias para el éxito reproductivo y la dinámica poblacional de esta especie
Sensors for fruit firmness assessment: Comparision and fusion
Non-destructive measurement of fruit firmness is a difficult problem and many different sensors have been developed in order to achieve this task. Three different European laboratories were associated in collaborative experiments on peaches, to compare three different sensing techniques, namely, sound, impact and micro-deformation. A Bayesian classifier is associated with each individual sensor and provides a classification into three categories, namely “soft”, “half firm” and “firm”. The fusion of the different sensors is performed by using Bayesian classifiers associated with heuristic methods for identity fusion. The result of the identity fusion is compared with the classification provided by an unsupervised algorithm based on destructive measurements. The fusion process provides some improvement in the classification results. For the individual sensors, the error rate of the classification varied from 19 to 28%, but the fusion process reduced this to 14%. Moreover, all measures of agreement between sensors lead to the conclusion that fusing sensors is better than using individual sensor
Effects of development of wind energy and associated changes in land use on bird densities in upland areas
Wind energy development is the most recent of many pressures on upland bird communities and their habitats. Studies of birds in relation to wind energy development have focused on effects of direct mortality, but the importance of indirect effects (e.g., displacement, habitat loss) on avian community diversity and stability is increasingly being recognized. We used a control‐impact study in combination with a gradient design to assess the effects of wind farms on upland bird densities and on bird species grouped by habitat association (forest and open‐habitat species). We conducted 506 point count surveys at 12 wind‐farm and 12 control sites in Ireland during 2 breeding seasons (2012 and 2013). Total bird densities were lower at wind farms than at control sites, and the greatest differences occurred close to turbines. Densities of forest species were significantly lower within 100 m of turbines than at greater distances, and this difference was mediated by habitat modifications associated with wind‐farm development. In particular, reductions in forest cover adjacent to turbines was linked to the observed decrease in densities of forest species. Open‐habitat species’ densities were lower at wind farms but were not related to distance from turbines and were negatively related to size of the wind farm. This suggests that, for these species, wind‐farm effects may occur at a landscape scale. Our findings indicate that the scale and intensity of the displacement effects of wind farms on upland birds depends on bird species’ habitat associations and that the observed effects are mediated by changes in land use associated with wind‐farm construction. This highlights the importance of construction effects and siting of turbines, tracks, and other infrastructure in understanding the impacts of wind farms on biodiversity
Uppermost-Tortonian to present depocentre migration related with segmentation of the Palomares Fault Zone (PFZ), SE Betics, Spain
The Palomares Fault Zone (PFZ) is one of the main strike-slip brittle shear zones found in the Betics. It is segmented in several
faults that have been active between the Upper Tortonian and present day. Data from drill cores in the The Palomares Fault Zone (PFZ) is one of the main strike-slip brittle shear zones found in the Betics. It is segmented in several faults that have been active between the Upper Tortonian and present day. Data from drill cores in the Palomares area have permitted us to define the geometry and location of sedimentary depocentres related with the PFZ. These data show an eastward displacement between the Upper Tortonian to Messinian and the Pliocene–Quaternary sedimentary depocentres, towards the presently active Arteal fault, which bounds the western mountain front of Sierra Almagrera, showing that deformation along this fault zone has migrated towards the east, from the Palomares segment, with its main activity during the Upper Tortonian and Messinian, towards the Arteal fault, active during the Pliocene and Quaternary
Intestinal Protists in Captive Non-human Primates and Their Handlers in Six European Zoological Gardens. Molecular Evidence of Zoonotic Transmission
We assessed the occurrence, genetic diversity, and zoonotic potential of four protozoan (Cryptosporidium spp., Entamoeba histolytica, Entamoeba dispar, Giardia duodenalis), one stramenopile (Blastocystis sp.), one microsporidia (Enterocytozoon bieneusi), and two ciliate (Balantioides coli, Troglodytella abrassarti) intestinal parasite or commensal protist species in captive non-human primates (NHP) and their zookeepers from six European zoological gardens in France (n = 1), Germany (n = 1), and Spain (n = 4). Faecal samples from NHP (n = 454) belonging to 63 species within 35 genera and humans (n = 70) were collected at two sampling periods in each participating institution between October 2018-August 2021. Detection and species identification was accomplished by PCR and Sanger sequencing of the ssu rRNA and/or ITS genes. Sub-genotyping analyses using specific markers were conducted on isolates positive for G. duodenalis (gdh, bg, tpi) and Cryptosporidium spp. (gp60). Overall, 41.0% (186/454) and 30.0% (21/70) of the faecal samples of NHP and human origin tested positive for at least one intestinal protist species, respectively. In NHP, Blastocystis sp. was the most prevalent protist species found (20.3%), followed by G. duodenalis (18.1%), E. dispar (7.9%), B. coli and T. abrassarti (1.5% each), and Cryptosporidium spp. and E. bieneusi (0.9% each). Occurrence rates varied largely among NHP host species, sampling periods, and zoological institutions. The predominant protist species found in humans was Blastocystis sp. (25.7%), followed by Cryptosporidium spp. (2.9%), E. dispar (1.4%), and G. duodenalis (1.4%). Sequencing of PCR-positive amplicons in human and/or NHP confirmed the presence of Cryptosporidium in six isolates (C. hominis: 66.7%, C. parvum: 33.3%), G. duodenalis in 18 isolates (assemblage A: 16.7%, assemblage B: 83.3%), Blastocystis in 110 isolates (ST1:38.2%, ST2:11.8%, ST3: 18.2%, ST4: 9.1%, ST5: 17.3%, ST8: 2.7%, ST13: 0.9%), and E. bieneusi in four isolates (CM18: 75.0%, Type IV: 25.0%). Zoonotic transmission events involving Blastocystis ST1-ST4 were identified in four zoological institutions. Zoonotic transmission of C. hominis was highly suspected, but not fully demonstrated, in one of them. Monitoring of intestinal protist species might be useful for assessing health status of captive NHP and their zookeepers, and to identify transmission pathways of faecal-orally transmitted pathogens.This study was funded by the Health Institute Carlos III (ISCIII), Spanish Ministry of Economy and Competitiveness under project PI16CIII/00024. DG-B was recipient of a Sara Borrell Postdoctoral Fellowship (CD19CIII/00011) funded by the Spanish Ministry of Science, Innovation and Universities. AD was recipient of a PFIS contract (FI20CIII/00002) funded by the Spanish Ministry of Science and Innovation and Universities.S
Canine leishmaniasis: the key points for qPCR result interpretation
Background: Diagnosis and follow up of CanL is difficult since the range of clinical signs is varied and seroprevalence is high in endemic areas. The aims of this study were: i) demonstrate the advantages of Leishmania qPCR to diagnose and control CanL and highlight its prognostic value and ii) propose guidelines for tissue selection and infection monitoring. Findings: This study included 710 dogs living in an endemic area of leishmaniasis. Forty percent (285/710) exhibited clinical signs consistent with CanL. Infection was detected in 36.3% (258/710) of the dogs of which 4.5% (32/710) were detected by qPCR, 16.2% (115/710) detected by ELISA and 15.6% (111/710) tested positive for both tests. Only 17.9% (127/710) of the dogs were classified sick (affected) with CanL. All symptomatic dogs with medium or high ELISA titers were qPCR-positive in blood samples. All dogs with inconclusive or low ELISA results with high or medium qPCR parasitemia values developed the disease. Seventy one percent of asymptomatic ELISA-positive dogs confirmed by qPCR (medium to high parasitemia) developed the disease. Bone marrow or lymph node aspirate should be selected to ensure the absence of the parasite in asymptomatic dogs: 100-1,000 parasites/ml in bone marrow are detectable in blood, whereas lower parasite loads are usually negative. Almost 10% of negative samples in blood were positive in conjunctival swabs. Conclusions: Because qPCR allows parasite quantification, it is an effective tool to confirm a diagnosis of CanL in (i) cases of inconclusive ELISA results, (ii) when the dog has not yet seroconverted, or (iii) for treatment monitoring
Global retrospective review of severe acute respiratory syndrome SARS CO-2 infections in nondomestic felids : March 2020-February 2021
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in nondomestic felids
have been documented in North America, South America, Africa, Europe, and Asia. Between March 2020 and
February 2021, at nine institutions across three continents, infection was confirmed in 16 tigers (Panthera tigris),
14 lions (Panthera leo), three snow leopards (Panthera uncia), one cougar (Puma concolor), and one Amur leopard
cat (Prionailurus bengalensis euptilurus) ranging from 2 to 21 yr old (average, 10 yr). Infection was suspected in an
additional 12 tigers, 4 lions, and 9 cougars. Clinical signs (in order of most to least common) included coughing,
ocular and/or nasal discharge, wheezing, sneezing, decreased appetite, lethargy, diarrhea, and vomiting.
Most felids recovered uneventfully, but one geriatric tiger with comorbidities developed severe dyspnea and
neurologic signs necessitating euthanasia. Clinical signs lasted 1–19 d (average, 8 d); one tiger was asymptomatic.
Infection was confirmed by various methods, including antigen tests and/or polymerase chain reaction
(PCR) of nasal or oral swabs, tracheal wash, and feces, or virus isolation from feces or tracheal wash. Infection
status and resolution were determined by testing nasal swabs from awake animals, fecal PCR, and observation
of clinical signs. Shedding of fecal viral RNA was significantly longer than duration of clinical signs. Postinfection
seropositivity was confirmed by four institutions including 11 felids (5 lions, 6 tigers). In most instances,
asymptomatic or presymptomatic keepers were the presumed or confirmed source of infection, although in
some instances the infection source remains uncertain. Almost all infections occurred despite using cloth facemasks
and disposable gloves when in proximity to the felids and during food preparation. Although transmission
may have occurred during momentary lapses in personal protective equipment compliance, it seems
probable that cloth masks are insufficient at preventing transmission of SARS-CoV-2 from humans to nondomestic
felids. Surgical or higher grade masks may be warranted when working with nondomestic felids.https://www.aazv.org/page/A8am2024Centre for Veterinary Wildlife StudiesProduction Animal StudiesSDG-03:Good heatlh and well-bein
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