Cannibalistic necrophagy in red foxes: do the nutritional benefits offset the potential costs of disease transmission?

Cannibalism, or intraspecific predation, occurs when an individual consumes another individual of its own species; c.f. ‘cannibalistic/conspecific/intraspecific necrophagy’ when the individual consumes all or part of a dead conspecific. These behaviors are widespread across animal taxa but are considered rare among mammalian carnivores. The consumption of conspecifics could involve ecological and nutritional benefits in providing high-quality resources. However, it can carry potential risks such as those related to pathogen transmission. Despite this, the overall role of conspecific consumption in disease transmission among animals has received little attention. Here, we report the first direct observations of cannibalistic necrophagy in red foxes Vulpes vulpes. Our photographs of this behavior prompt speculation on the role of cannibalism in fox population dynamics and intraspecific disease transmission. We placed six fox and seven lamb carcasses of similar size to determine possible differences in the scavenging behavior of red foxes between dead conspecifics and heterospecifics. Conspecific necrophagy was recorded at all fox carcasses, involving foxes scavenging fox carcasses at different stages of decay. Carcass detection time by foxes was similar at both fox and lamb carcasses, but lambs were completely consumed in a shorter period, evidencing a preference for heterospecific consumption. Our findings contrast with other studies which argue that cannibalism avoidance in mammalian carnivores is due to an evolutionary strategy to reduce the probability of disease transmission. In fact, our observations of conspecific necrophagy provide direct evidence against the parasite-avoidance hypothesis, suggesting that carnivore and conspecific carcasses can represent an alternative trophic resource for foxes in certain areas and circumstances.We are grateful to P. Ferreras, M. Moleón and an anonymous reviewer for their useful comments on the manuscript. The Generalitat de Catalunya, University of Lleida and the Ministry of Science, Innovation and Universities (Project RTI2018-099609-B-C22) provided financial support for this study

Scavenging in changing environments: woody encroachment shapes rural scavenger assemblages in Europe

Rural abandonment and subsequent vegetation regeneration (‘passive rewilding') are expected to increase worldwide, producing cascades of dynamic socioeconomic, landscape and biological changes. Although landscape characteristics strongly influence the structure and functioning of scavengers, little is known about the ecological consequences of passive rewilding due to woody encroachment (i.e.‘landscape closure') on scavenging assemblages. We investigated differences in ‘scavenger assemblage composition' (species richness and abundances) and ‘scavenging efficiency' (scavenging frequency, detection and consumption times and consumption rates) in a mountain agroecosystem (Pyrenees) undergoing passive rewilding. We monitored 178 carcasses in three landscapes: ‘open', ‘shrubland' and ‘forest', and evaluated the effects of landscape type on ‘scavenger assemblage composition' and ‘scavenging efficiency' at the community and species levels, while accounting for the influences of carcass size, type and placement time. We also examined whether the locally most abundant and efficient scavenger (i.e. the griffon vulture Gyps fulvus) affects scavenging patterns. We found that landscape type was the main factor governing scavenging dynamics. Overall and average scavenger richness were similar in open and shrubland landscapes, while forests contained the lowest number of scavengers, mainly comprising mammals. Unlike mammals, avian scavenging frequency decreased as vegetation cover increased, especially for obligate scavengers (i.e. vultures). Scavenger abundances were highest in open landscapes, and carcasses were detected and consumed more rapidly in these landscapes. Carcass size did not influence detection and consumption times, although it did affect average scavenger richness, abundances and consumption rates. Consumption rates were higher in open landscapes and were strongly associated with the presence of griffon vultures. Interestingly, we found that griffon vultures influenced scavenging dynamics via facilitation processes. However, woody encroachment could reduce the scavenging role of this species, while favoring mammalian facultative scavengers. Finally, our findings highlight the pivotal role of griffon vultures, mediated by landscape characteristics, in reducing carcass persistence.POV and AM were funded within the framework of the project RTI2018-099609-B-C22, from the I + D + I National Plan funded by the Ministry of Science, Innovation and Universities. ESG was funded by a Ramón y Cajal fellow (RYC-2019-027216-I)

Assessment of the potential effects of diclofenac on spanish avian scavengers guild

Póste

Griffon vultures, livestock and farmers: Unraveling a complex socio-economic ecological conflict from a conservation perspective

An unexpected human-wildlife conflict between vultures and livestock has emerged in Europe during the last two decades. Farmers attributed changes in vulture behavior, due to food shortages caused by sanitary regulations, to increasing livestock interactions (‘vulture attacks’). To disentangle this conflict, we analyzed 683 farmer complaints between 1996 and 2020 in Catalonia (northeastern Spain) and investigated the eco-anthropological factors driving their frequency. We also assessed farmers' perception through 127 interviews. Most complaints (80 %) occurred during the birthing season, mainly involving cattle (76.5 %), followed by horses (14.9 %) and sheep/goats (8.6 %). From 2008 to 2020, vulture-livestock conflicts cost the government €192,000 (~22 % of claims compensated). The frequency of complaints was positively associated with extensive livestock density, griffon vulture Gyps fulvus abundance (breeding and non-breeding), shorter distances to landfill sites and, to a lesser extent, to supplementary feeding stations. In contrast, there was a negative relationship between complaints and the number of griffon vulture breeding pairs, suggesting that long-distance foraging movements by both breeding and non-breeding individuals may play a major role in determining the occurrence of conflicts. Farmers (88 %) said that vultures attack livestock and that attacks had increased in recent years because of significant vulture population increases and food shortages due to sanitary regulations. They considered government policies and compensation ineffective. We highlight the critical need for mitigation in areas with high extensive livestock numbers, particularly during birthing times. Scientific assessments and interdisciplinary awareness campaigns on the coexistence of vultures and livestock are necessary to harmonize biodiversity conservation and agro-pastoral practices in rural economies.We thank Ferran Miralles, Ricard Casanovas and Olga Lao (Generalitat de Catalunya), Gabriel Lampreave (Cos d'Agents Rurals), Roser Costa (Unió de Pagesos) for logistical support and all farmers interviewed for accepted to be interviewed and generously sharing their knowledge. R. Baraut, M. Comas, L. Pelayo and J. Subiron helped with the survey.The comments of B. Fisher, I. Zuberogoitia and an anonymous reviewer improved an earlier draft of the manuscript. This study was partially funded by the Generalitat de Catalunya and by the projects RTI2018-099609-B-C22 and PID2020-117909RB-I00 from the I+D+I National Plan funded by the Ministry of Science, Innovation and Universities . POV and AM were funded within the framework of the project RTI2018-099609-B-C22

Griffon vultures, livestock and farmers: Unraveling a complex socio-economic ecological conflict from a conservation perspective.

An unexpected human-wildlife conflict between vultures and livestock has emerged in Europe during the last two decades. Farmers attributed changes in vulture behavior, due to food shortages caused by sanitary regulations, to increasing livestock interactions ('vulture attacks'). To disentangle this conflict, we analyzed 683 farmer complaints between 1996 and 2020 in Catalonia (northeastern Spain) and investigated the eco-anthropological factors driving their frequency. We also assessed farmers' perception through 127 interviews. Most complaints (80 %) occurred during the birthing season, mainly involving cattle (76.5 %), followed by horses (14.9 %) and sheep/goats (8.6 %). From 2008 to 2020, vulture-livestock conflicts cost the government 192,000 (~22 % of claims compensated). The frequency of complaints was positively associated with extensive livestock density, griffon vulture Gyps fulvus abundance (breeding and non-breeding), shorter distances to landfill sites and, to a lesser extent, to supplementary feeding stations. In contrast, there was a negative relationship between complaints and the number of griffon vulture breeding pairs, suggesting that long-distance foraging movements by both breeding and non-breeding individuals may play a major role in determining the occurrence of conflicts. Farmers (88 %) said that vultures attack livestock and that attacks had increased in recent years because of significant vulture population increases and food shortages due to sanitary regulations. They considered government policies and compensation ineffective. We highlight the critical need for mitigation in areas with high extensive livestock numbers, particularly during birthing times. Scientific assessments and interdisciplinary awareness campaigns on the coexistence of vultures and livestock are necessary to harmonize biodiversity conservation and agro-pastoral practices in rural economies

Desarrollo y elaboración de recursos didácticos on line para fomentar el autoaprendizaje interactivo y la autoevaluación en Química Farmacéutica con el apoyo del Campus Virtual

En este Proyecto de Innovación Docente se ha pretendido de manera general optimizar las alternativas ofrecidas en el Campus Virtual, mediante el diseño, elaboración y evaluación de actividades didáticas on-line que permitan que el Aula Virtual se convierta en un apoyo activo en el proceso enseñanza-aprendizaje en la asignatura de Química Farmacéutica II. Se ha llevado a cabo la elaboración de cuestionarios interactivos de autoevaluación que permitan al alumno conocer la adecuación de los conocimientos adquiridos, y al docente poder realizar un seguimiento rápido de cada alumno

Modelling the SARS-COV-2 outbreak: assessing the usefulness of protective measures to reduce the pandemic at population level

A new bioinspired computational model was developed for the SARS-CoV-2 pandemic using the available epidemiological information, high-resolution population density data, travel patterns, and the average number of contacts between people. The effectiveness of control measures such as contact reduction measures, closure of communities (lockdown), protective measures (social distancing, face mask wearing, and hand hygiene), and vaccination were modelled to examine possibilities for control of the disease under several protective vaccination levels in the population. Lockdown and contact reduction measures only delay the spread of the virus in the population because it resumes its previous dynamics as soon as the restrictions are lifted. Nevertheless, these measures are probably useful to avoid hospitals being overwhelmed in the short term. Our model predicted that 56% of the Spanish population would have been infected and subsequently recovered over a 130 day period if no protective measures were taken but this percentage would have been only 34% if protective measures had been put in place. Moreover, this percentage would have been further reduced to 41.7, 27.7, and 13.3% if 25, 50 and 75% of the population had been vaccinated, respectively. Finally, this percentage would have been even lower at 25.5, 12.1 and 7.9% if 25, 50 and 75% of the population had been vaccinated in combination with the application of protective measures, respectively. Therefore, a combination of protective measures and vaccination would be highly efficacious in decreasing not only the number of those who become infected and subsequently recover, but also the number of people who die from infection, which falls from 0.41% of the population over a 130 day period without protective measures to 0.15, 0.08 and 0.06% if 25, 50 and 75% of the population had been vaccinated in combination with protective measures at the same time, respectively.This study was partially funded by the University of Lleida (UdL). The comments of four anonymous reviewers improved a previous version of this article

Scavenging patterns of generalist predators in forested areas: the potential implications of increase in carrion availability on a threatened capercaillie population

The increases in ungulate populations and hunting bags throughout Europe and North America have resulted in higher carcass numbers available for mesocarnivore species in temperate and boreal forests. The increase in food resources can sustain denser predator populations, potentially affecting prey species such as the threatened western capercaillie Tetrao urogallus. We investigated the ungulate population trends in recent decades and the carrion use by facultative scavengers in areas of the Pyrenees occupied by capercaillie to assess the potential effects on predation of nests and adult birds, and on its population trend. We found a significant increase in the number of ungulates harvested during the period of sharp capercaillie population decline. Carrion was provided experimentally in forested areas occupied by capercaillie showing that remains were mainly consumed by red fox Vulpes vulpes, followed by wild boar Sus scrofa and marten species (Martes sp.). Season (cold or warm) was the most important factor determining scavenging activity in most species. Main predators of capercaillie nests and adults were martens and red fox, with no predation by wild boar. Our data show that main predators of capercaillie are the same species that mainly consume carrion, especially in winter, and that plentiful carrion resources could maintain higher populations of these species, potentially increasing predation pressure on the capercaillie population. This study shows that managing carrion arising from hunting activity in areas of capercaillie distribution is a necessary management action to reduce the available carrion biomass and so reduce the impact of mesocarnivores on capercaillie conservation.We acknowledge the forestry rangers of Generalitat de Catalunya for field work. The comments of two anonymous reviewers improved the previous version. This work was funded by the Spanish Ministry of Science, Innovation and Universities (RTI2018-099609-B-C22) and the Spanish Ministry for the Ecological Transition and the Demographic Challenge

Modeling of Vaccination and Contact Tracing as Tools to Control the COVID-19 Outbreak in Spain

We developed an agent-based stochastic model, based on P Systems methodology, to decipher the effects of vaccination and contact tracing on the control of COVID-19 outbreak at population level under different control measures (social distancing, mask wearing and hand hygiene) and epidemiological scenarios. Our findings suggest that without the application of protection social measures, 56.1% of the Spanish population would contract the disease with a mortality of 0.4%. Assuming that 20% of the population was protected by vaccination by the end of the summer of 2021, it would be expected that 45% of the population would contract the disease and 0.3% of the population would die. However, both of these percentages are significantly lower when social measures were adopted, being the best results when social measures are in place and 40% of contacts traced. Our model shows that if 40% of the population can be vaccinated, even without social control measures, the percentage of people who die or recover from infection would fall from 0.41% and 56.1% to 0.16% and 33.5%, respectively compared with an unvaccinated population. When social control measures were applied in concert with vaccination the percentage of people who die or recover from infection diminishes until 0.10% and 14.5%, after vaccinating 40% of the population. Vaccination alone can be crucial in controlling this disease, but it is necessary to vaccinate a significant part of the population and to back this up with social control measures.This research was funded by University of Lleida

Second-generation anticoagulant rodenticides in the blood of obligate and facultative European avian scavengers

The widespread use of second-generation anticoagulant rodenticides (SGARs) and their high persistence in animal tissues has led to these compounds becoming ubiquitous in rodent-predator-scavenger food webs. Exposure to SGARs has usually been investigated in wildlife species found dead, and despite growing evidence of the potential risk of secondary poisoning of predators and scavengers, the current worldwide exposure of free-living scavenging birds to SGARs remains scarcely investigated. We present the first active monitoring of blood SGAR concentrations and prevalence in the four European obligate (i.e., vultures) and facultative (red and black kites) avian scavengers in NE Spain. We analysed 261 free-living birds and detected SGARs in 39.1% (n = 102) of individuals. Both SGAR prevalence and concentrations (ΣSGARs) were related to the age and foraging behaviour of the species studied. Black kites showed the highest prevalence (100%), followed by red kites (66.7%), Egyptian (64.2%), bearded (20.9%), griffon (16.9%) and cinereous (6.3%) vultures. Overall, both the prevalence and average ΣSGARs were higher in non-nestlings than nestlings, and in species such as kites and Egyptian vultures foraging in anthropic landscapes (e.g., landfill sites and livestock farms) and exploiting small/medium-sized carrions. Brodifacoum was most prevalent (28.8%), followed by difenacoum (16.1%), flocoumafen (12.3%) and bromadiolone (7.3%). In SGAR-positive birds, the ΣSGAR (mean ± SE) was 7.52 ± 0.95 ng mL−1; the highest level detected being 53.50 ng mL−1. The most abundant diastereomer forms were trans-bromadiolone and flocoumafen, and cis-brodifacoum and difenacoum, showing that lower impact formulations could reduce secondary exposures of non-target species. Our findings suggest that SGARs can bioaccumulate in scavenging birds, showing the potential risk to avian scavenging guilds in Europe and elsewhere. We highlight the need for further studies on the potential adverse effects associated with concentrations of SGARSs in the blood to better interpret active monitoring studies of free-living birds.POV and AM were funded within the framework of the project RTI2018- 099609-B-C22, from the I + D + I National Plan funded by the Ministry of Science, Innovation and Universities. SGAR analyses have been performed with the own resources obtained from the Service of Toxicological Analysis at IREC (CGP170122, University of Castilla-La Mancha). PRC benefited from a contract of the Research Plan of the University of Castilla-La Mancha funded by European Fund for the Regional Development