Scavenger Species Research Articles

Linear infrastructure and associated wildlife accidents create an ecological trap for an apex predator and scavenger

Animals may fall into an ‘ecological trap’ when they select seemingly attractive habitats at the expense of their fitness. This maladaptive behavior is often the result of rapid, human-induced changes in their natal environment, such as the construction of energy and transportation infrastructure. We tested the ecological trap hypothesis regarding human-created linear infrastructure on a widely distributed apex predator and scavenger—the Golden Eagle (Aquila chrysaetos), whose range spans the entire Northern Hemisphere. Roads and railways offer novel and attractive feeding opportunities through traffic-induced mortality of other species, while powerline areas provide perching or nesting sites and scavenging opportunities from electrocuted or collision-killed birds. These conditions may have negative demographic consequences for eagles if these apparent opportunities turn into traps. Using step selection functions, we analyzed habitat selection of 74 GPS-tracked Golden Eagles (37 adults and 37 immatures) during eleven years in Fennoscandia. To assess habitat attractiveness, we used wildlife traffic accident statistics for dominant wild species, and to evaluate demographic consequences, we used mortality data from the GPS-tagged eagles. Our analysis revealed that eagles selected linear features such as roads, railways and powerlines at both the population and individual levels. Both adult and immature eagles consistently selected these features, and the strength of selection for linear features increased with age in immature eagles. The linear features however had 5.5 times higher mortality risk for eagles than other selected habitats indicating the presence of an ecological trap. We discuss the implications of these findings for the conservation and population ecology of apex predators and scavengers, as well as their potential demographic consequences. To mitigate this issue, we urgently recommend the removal of carcasses from roads and tracks to prevent ecological traps for raptors and scavenger species worldwide. Additionally, we advocate for the development of methods and strategies to reduce wildlife traffic accidents.

Feathers, folklore, and eco-literacy: Stories ascribe cultural keystone status to avian scavengers in South Asian cities

Abstract We examined the cultural significance of commensal avian scavenger species—vultures, kites, and crows—and their exploitation of anthropogenic resources and sentiments within Delhi’s urban landscapes. For this, we investigated the intrinsic values attributed to these birds by people, which are indicative of complex, rapidly urbanizing social-ecological systems. Semi-structured interviews revealed folk perceptions intertwined with socio-cultural narratives and traditions, shaped by observations of avian morphology, ecology, and behavior. Birds’ nesting habits, habitats, home ranges, and foraging behaviors affected people’s perceptions, while ecosystem services inspired zoomorphism and anthropomorphism via vernacular-nomenclature (e.g., chidiya collectively for songbirds, giddha for scavenging raptors). Culturally rooted perceptions, which informed ritual feeding practices and shaped prevalent attitudes towards commensal species, fostered mutual tolerance, and brought people into closer contact with urban biodiversity. Such physical and cultural proximity is a defining characteristic distinguishing tropical urban ecosystems from their Western counterparts. We also uncovered the web of social-technological influences on animal-related folk stories. The urbanization of perceptions in vulture extinction zones revealed shifts in social-ecological relationships with wildlife. It adds cultural dimensions to the currently appreciated keystone status of vultures, vital for their erstwhile coexistence at extremely high densities in South Asia. Urban transformations, technological advancements, and media exposure potentially reshaped human–animal interface, with media misinformation affecting personalized ecologies. Conflicts and health concerns arose from media narratives on garbage-consuming animals. Our findings offer insights to prevent severing of people and nature connections due to urbanization (e.g., technological applications can integrate scientific knowledge with biocultural narratives and folklore), promoting a new-age eco-literacy.

Elucidating the Limit of Lithium Difluorophosphate Electrolyte Additive for High‐Voltage Li/Mn‐Rich Layered Oxide || Graphite Li Ion Batteries

Li/Mn‐rich layered oxide (LMR) cathode active materials offer remarkably high specific discharge capacity (>250 mAh g−1) from both cationic and anionic redox. The latter necessitates harsh charging conditions to high cathode potentials (>4.5 V vs Li|Li+), which is accompanied by lattice oxygen release, phase transformation, voltage fade, and transition metal (TM) dissolution. In cells with graphite anode, TM dissolution is particularly detrimental as it initiates electrode crosstalk. Lithium difluorophosphate (LiDFP) is known for its pivotal role in suppressing electrode crosstalk through TM scavenging. In LMR || graphite cells charged to an upper cutoff voltage (UCV) of 4.5 V, effective TM scavenging effects of LiDFP are observed. In contrast, for an UCV of 4.7 V, the scavenging effects are limited due to more severe TM dissolution compared an UCV of 4.5 V. Given the saturation in solubility of the TM scavenging agents, which are LiDFP decomposition products, e.g., PO43− and PO3F2−, higher concentrations of the LiDFP as “precursor” cannot enhance the amount of scavenging species, they rather start to precipitate and damage the anode.

A call to further understand the role of carrion in food webs: a case study of the Australian Alps

ABSTRACT Carcasses are integral to the structure and function of ecosystems, providing a food source for a variety of scavenger species that recycle nutrients back into the biosphere. However, in many systems globally there is limited information on the extent of carcass use by scavengers and the length of carcass persistence. This prevents land managers from making well-informed decisions on whether carcasses should be removed if produced in excessive numbers following activities such as culling, or extreme weather and disease outbreaks, or when to undertake management operations that add to the overall carcass biomass in ecosystems. In this paper, we focus on the Australian Alps and highlight results from recent studies to show that carcasses persist in this bioregion for long periods in winter when insects are less active. We show that vertebrate scavenging rates are relatively low in the Australian Alps compared to other bioregions in Australia, and that carcasses in this system can become hotspots for introduced species like European wasps (Vespula germanica), red foxes (Vulpes vulpes), and feral pigs (Sus scrofa). We advocate that further carcass monitoring in the Australian Alps should focus on scavenger use and persistence rates for different carcasses species, including across different elevations, seasons, and following culling operations. This will ultimately help to guide understanding around when native scavenger guilds can effectively accelerate carcass biomass loss, which is a key indicator of a healthy, functioning ecosystem.

Contrasting metal bioaccumulation in marine benthic invertebrate groups in polluted harbor sediments

This study examined the sediment metal fractions and availability to infer bioaccumulation in marine harbor benthic organisms. Total metals were analyzed using atomic absorption spectrometry and inductively coupled plasma-optical emission spectrometry for chemical fractions and organisms. The results showed similar metal concentrations and distribution driven by rivers and harbor pollution. We found significant differences in metal accumulation in marine benthic groups, highest in scavenger species. Their metal concentrations in decreasing order were 1.97–4568, 0.10–1260, 1.64–159, and 0.105–112 μg g−1 dw for hermit crabs, forams, bivalves, and polychaetes. Moreover, certain organisms, such as tusk shells, sea pens, bivalves, forams, and isopods, may exhibit selective metal accumulation. Biota-sediment accumulation factors (>1) were highest for essential metals like Cu, Zn, and Mn, while toxic metals like As, Cr, Co, and Ni increased. This concurrent assessment provides more comprehensive data for metal bioaccumulation in marine benthic ecosystems.

Widespread use of anticoagulant rodenticides in agricultural and urban environments. A menace to the viability of the endangered Bonelli's eagle (Aquila fasciata) populations

Anticoagulant rodenticides (ARs) are one of the most toxic groups of compounds currently used worldwide for rodent pest control. Toxic baits are often, directly or indirectly, ingested by non-target animals, resulting in secondary poisoning and frequently affecting apex predators. Their presence in many species of raptors is quite common, particularly scavenger species, with some of these acting as sentinels for the presence of these substances in the environment. However, there is less data on the presence of ARs in Bonelli's eagle, one of the most endangered eagle species in Spain and which is experiencing a negative population trend in Europe. This medium-sized eagle feeds predominantly on live species, and rarely consumes carrion.In this study, 17 carcasses of Bonelli's eagles from the Eastern Spain were necropsied. Both first and second generation ARs in their livers were analyzed by HPLC-MS-TOF revealing that all the eagles studied had been exposed to at least 5 ARs, out of a total of 10 ARs analyzed, with 7 being the highest number of ARs detected in a sample. Second generation ARs were the most prevalent, particularly bromadiolone and brodifacoum, with the highest concentrations in 94% of the cases. More than a third of the eagles presented a liver concentration of greater than 200 ng/g ARs, suggesting AR poisoning.The elevated presence of these compounds in Bonelli's eagles could be a new cause of mortality for this species or could explain other causes of death, such as the increased mortality in power lines, and should be taken into account for their conservation. At the same time, the presence of these compounds in the environment also represents a risk to public health, as the most frequent species in the diet of Bonelli's eagle (rabbits and partridges) are also hunted and consumed by hunters and their families.

Scavenger-induced scattering of wild boar carcasses over large distances and its implications for disease management

Vertebrate scavengers provide essential ecosystem services such as accelerating carrion decomposition by consuming carcasses, exposing tissues to microbial and invertebrate decomposers, and recycling nutrients back into the ecosystem. Some scavengers do not consume carcasses on site but rather scatter their remains in the surroundings, which might have important implications for nutrient transport, forensic investigations and the spread of diseases such as African Swine Fever. However, only a few studies have investigated and measured the scatter distances. Using wild boar (Sus scrofa) carcasses and limbs, we monitored scavenging behavior and measured scatter distances of mammals. We placed 20 carcasses (up to 25 kg) and 21 separate limbs equipped with very high frequency (VHF) transmitters and monitored scavenger activity using camera traps in a mountainous region in southeast Germany. Except for one carcass, all other carcasses and limbs were scattered. We measured 72 scatter distances (of 89 scattering events; mean = 232 m, maximum = 1250 m), of which 75% were dispersed up to 407 m. Scavengers moved scattered pieces into denser vegetation compared to the half-open vegetation at provisioning sites. Red foxes (Vulpes vulpes) were the most common scavenger species, contributing to 72 scattering events (58 measured scatter distances). Our results provide evidence of scatter distances farther than previously assumed and have far-reaching implications for disease management or forensic investigations, as the broader surroundings of carcasses must be included in search efforts to remove infectious material or relevant body parts for forensic analysis.

Squamate scavenging services: Heath goannas (Varanus rosenbergi) support carcass removal and may suppress agriculturally damaging blowflies.

Human-induced environmental change has caused widespread loss of species that support important functions for ecosystems and society. For example, vertebrate scavengers contribute to the functional health of ecosystems and provide services to agricultural landscapes by removing carcasses and associated pests. Widespread extirpation of native Australian mammals since the arrival of Europeans in Australia has removed many scavenging species from landscapes, while scavenging mammals such as European red foxes (Vulpes vulpes) have been introduced. In much of Australia, squamate reptiles are the largest native terrestrial scavengers remaining, where large native mammals are extinct and conservation management is being undertaken to remove invasive mammals. The contribution of reptiles to scavenging functions is not well understood. In this study, we investigated the ecosystem functions provided by large reptiles as scavengers to better understand how populations can be managed to support ecosystem services. We investigated the ecosystem services provided by vertebrate scavengers in Australian coastal mallee ecosystems, focusing on the heath goanna (Varanus rosenbergi), the only extant native terrestrial scavenger in the region. We carried out exclosure experiments, isolating the scavenging activity of different taxonomic groups to quantify the contribution of different taxa to scavenging services, specifically the removal of rat carcasses, and its impact on the occurrence of agriculturally damaging blowflies. We compared areas with different native and invasive scavenger communities to investigate the impact of invasive species removal and native species abundance on scavenging services. Our results indicated that vertebrate scavenging significantly contributes to carcass removal and limitation of necrophagous fly breeding in carcasses and that levels of removal are higher in areas associated with high densities of heath goannas and low densities of invasive mammals. Therefore, augmentation of heath goanna populations represents a promising management strategy to restore and maximize scavenging ecosystem services.

Seasonal variability of scavenger visitations is independent of carrion predictability

In temperate regions, larger mammalian carrion naturally occurs in terrestrial landscapes as a pulsed resource towards the end of the winter through enhanced ungulate mortality due to starvation or exhaustion. The return of large carnivores in Central Europe provides carrion more equally throughout the year and the active enhancement of carrion for biodiversity by game managers has increased, raising the question of how different scavengers respond to the temporal variation in carrion supply. To address this question, we experimentally deployed 106 cervid carcasses throughout the year in a temperate forest of south-eastern Germany on two types of plots: permanent (i.e., site with multiple subsequent deployments) or random (i.e., site with unique deployment), and reported vertebrate scavenger visitations by camera trapping. Deployment on random or permanent sites did not affect carrion use by any single species. Generalized additive modelling revealed that vertebrate scavenging peaked in the winter season and summer independent of carrion supply. Still, different scavenger species showed different temporal patterns. While wild boar as ungulate omnivores did not display any seasonal patterns, avian scavengers showed significant variation in visitation rates. The mesopredator red fox consumed carrion significantly more often from late winter to summer, while pine marten was present at carrion only during winter. Finally, the specialist large carnivore Eurasian lynx, visited carrion sites most frequently in late winter and early spring. Our results suggest that global warming might impact some groups of vertebrate scavengers more strongly than others by reducing carrion availability in late winter, while returning carnivores could mitigate these impacts.

A multi-species, multi-pathogen avian viral disease outbreak event: Investigating potential for virus transmission at the wild bird – poultry interface

ABSTRACT A free-range organic broiler (Gallus gallus domesticus) premises in Staffordshire was infected by high pathogenicity avian influenza virus (HPAIV) H5N8 during the 2020–2021 epizootic in the United Kingdom (UK). Following initial confirmation of the infection in poultry, multiple wild bird species were seen scavenging on chicken carcasses. Detected dead wild birds were subsequently demonstrated to have been infected and succumbed to HPAIV H5N8. Initially, scavenging species, magpie (Pica pica) and raven (Corvus corax) were found dead on the premises but over the following days, buzzards (Buteo buteo) were also found dead within the local area with positive detection of HPAIV in submitted carcasses. The subacute nature of microscopic lesions within a buzzard was consistent with the timeframe of infection. Finally, a considerable number of free-living pheasants (Phasianus colchicus) were also found dead in the surrounding area, with carcasses having higher viral antigen loads compared to infected chickens. Limited virus dissemination was observed in the carcasses of the magpie, raven, and buzzard. Further, an avirulent avian paramyxovirus type 1 (APMV-1) was detected within poultry samples as well as in the viscera of a magpie infected with HPAIV. Immunohistochemistry did not reveal colocalization of avian paramyxovirus antigens with lesions, supporting an avirulent APMV-1 infection. Overall, this case highlights scenarios in which bi-directional transmission of avian viral diseases between commercial and wild bird species may occur. It also underlines the importance of bio separation and reduced access when infection pressure from HPAIV is high.

Deep mitochondrial phylogeographical pattern: cryptic population structure within an ecological niche in the near-threatened Himalayan vulture (Gyps himalayensis)

Abstract The Himalayan vulture (Gyps himalayensis) has higher environmental specificity than other species in the same genus, and its population has declined due to diclofenac exposure and shortage of carcasses as a food source. Previous analysis of mitochondrial (mt) DNA cytochrome b (Cyt b) sequences reported no distinct geographical population structure in the Himalayan vulture. Contradictory results were obtained in the present study, which investigated the population structure of 14 Himalayan vultures that migrated to Thailand during winter. Using samples obtained between 2010 and 2021, as well as limited GenBank samples, the study found that the Cyt b locus was incapable of distinguishing population structure. This dataset contrasted with the mtDNA control region (CR) and Cyt b + CR dataset, which divided them into two groups, as explained by the Middle–Late Pleistocene climate change scenario. The species split into populations from the central, western, and northern regions of its distribution range within the highland vulture ecological niche. This study reviews the different methods used as compared with previous proposals for defining guidelines for the conservation of this near-threatened scavenging species.

Forensic taphonomic experimental design matters: a study assessing clothing and carrion biomass load on scavenging in Cape Town, South Africa

The identification of unknown human remains is a significant and ongoing challenge in South Africa, worsened by the country’s high murder rate. The rate of decomposition in South Africa is significantly influenced by vertebrate scavenging, which, if not considered, can impede the accurate estimation of the post-mortem interval. Scavenging patterns vary greatly depending on the environment and ecological region, and there is limited data for the Western Cape province. To address this gap, two clothed and uncaged pig carcasses weighing 60 kg each were placed in the field in July 2021 and January 2022, respectively. Motion-activated infrared-capable trail cameras were used to observe decomposition, scavenger species, and their activities. Additionally, a comparative sample of 16 unclothed carcasses deployed between 2014 and 2016 in the same habitat were analyzed to assess the impact of clothing and biomass load. The study found three main results: (1) Regardless of habitat or biomass load, it took significantly less time to reach decomposition milestones (25%, 50%, and 75%) during the summer season; (2) the presence of mongoose scavengers had a greater impact on the time required to reach milestones during winter compared to summer; and (3) single carcass deployments reached the milestones faster than multi-carcass deployments in both seasons. This research highlights the potential inaccuracy of current methods for estimating the post-mortem interval when scavenging activity is not considered or documented in the underlying experimental data, particularly for environments or ecological biomes where scavengers actively impact decomposition rates.

Restoration promotes ecological functioning through greater complementarity

Restoration projects are increasingly widespread and many promote habitat succession and the diversity and abundance of faunal communities. These positive effects on biodiversity and abundance may extend to enhancing the ecological functioning and resilience of previously degraded ecosystems, but this is rarely quantified. This study surveyed a 200‐ha restoring coastal wetland and three control wetlands in the Maroochy River, eastern Australia to compare the effects of wetland restoration on the consumption of carrion and the biodiversity, abundance, and functional diversity of functionally important fish and crustaceans. Carrion consumption by fish and crustaceans was measured every 6 months from spring 2017 until spring 2021 for nine events using a combination of baited cameras and scavenging assays. We found restoration improved rates of carrion consumption and the biodiversity, functional diversity, and abundance of scavenger species. Despite positive effects on the diversity of scavengers and carrion consumption, the abundance of two species, longfin eels (Anguilla reinhardtii) and mud crabs (Scylla serrata), was the most important predictors of carrion consumption rates. The spatial distribution of carrion consumption was concentrated in areas with high saltmarsh extent, moderate to high mangrove extent, and high salinity, which also resembled the distribution of both longfin eels and mud crabs. We show that restoration can promote the rates of key ecological functions but that increases to functions are likely to be characterized by low functional redundancy and greater complementarity. Therefore, maintaining or increasing the abundance of functionally important species should become a key objective in future restoration projects.

The taphonomic impact of scavenger guilds in peri-urban and rural regions of central and southern Alberta. Part I - Identification of forensically relevant vertebrate scavengers.

As a body decomposes in an outdoor environment, numerous taphonomic agents can act on the process of human decomposition. It is important to understand the impact of these agents as they can vary the rate of soft and hard tissue loss which may alter postmortem interval estimations. One taphonomic factor which has not been extensively investigated in many regions of the world, including Canada, are vertebrate scavengers. The current study aimed to identify scavenger guilds in the peri-urban and rural regions of two major cities in Alberta (Calgary and Edmonton) where human remains are frequently located. Vertebrate scavenger activity was recorded continuously using cellular and noncellular trail cameras. Images were analyzed to determine how the scavenging profiles (i.e., scavenger species, arrival time, and feeding behavior) impacted the loss of soft and hard tissue. We identified a range of mammalian and avian scavengers and found that coyote and black-billed magpie were the predominant scavengers recorded at the Edmonton peri-urban and rural sites, and the Calgary peri-urban sites. In contrast, when a site was within bear territory such as the Calgary rural sites, black and grizzly bears were the predominant scavengers. At all sites, the large mammalian scavengers were responsible for most soft tissue loss and subsequent hard tissue dispersal. None of the scavengers demonstrated a clear preference for open versus closed sites. This taphonomic information is important to consider when searching for human remains at these locations or in other North American regions with comparable scavenger guilds.

Age-Specific Demographic Response of a Long-Lived Scavenger Species to Reduction of Organic Matter in a Landfill.

Food availability shapes demographic parameters and population dynamics. Certain species have adapted to predictable anthropogenic food resources like landfills. However, abrupt shifts in food availability can negatively impact such populations. While changes in survival are expected, the age-related effects remain poorly understood, particularly in long-lived scavenger species. We investigated the age-specific demographic response of a Griffon vulture (Gyps fulvus) population to a reduction in organic matter in a landfill and analyzed apparent survival and the probability of transience after initial capture using a Bayesian Cormack-Jolly-Seber model on data from 2012-2022. The proportion of transients among newly captured immatures and adults increased after the reduction in food. Juvenile apparent survival declined, increased in immature residents, and decreased in adult residents. These results suggest that there was a greater likelihood of permanent emigration due to intensified intraspecific competition following the reduction in food. Interestingly, resident immatures showed the opposite trend, suggesting the persistence of high-quality individuals despite the food scarcity. Although the reasons behind the reduced apparent survival of resident adults in the final four years of the study remain unclear, non-natural mortality potentially plays a part. In Europe landfill closure regulations are being implemented and pose a threat to avian scavenger populations, which underlines the need for research on food scarcity scenarios and proper conservation measures.

Effects of proximity to humans on neophilia, foraging ecology and population structure of kea

ABSTRACT Neophilic tendencies in scavenging species living near humans may have adverse consequences for these animals. New Zealand’s kea (Nestor notabilis), an endangered parrot, potentially faces exacerbated mortality risk associated with proximity to humans. Hazards include lead building materials, introduced mammalian predators, and poison baits used to control these predators. How kea respond to these hazards can affect life expectancy. We modelled the effects of (1) proximity to humans, (2) age, (3) presence of conspecifics, and (4) blood lead levels, on the time taken to approach and contact a novel object. We also compared dietary trophic level between populations adjacent to and remote from humans using stable isotopes, and compared the age structure of these populations. Adjacent kea contacted the object faster than remote kea, as did younger individuals and those with elevated blood lead concentration, but conspecific presence did not affect approach latency. We conclude that adjacent kea exhibit enhanced neophilia, which may translate to reduced life expectancy due to interacting with anthropogenic hazards. Kea adjacent to humans were younger and foraged at a lower trophic level than remote kea, with a possible consequence of reduced productivity. Our results should be considered when setting management policy for kea habitat.

Bridging Evolutionary History and Conservation of New World Vultures.

The New World Vultures (Cathartidae) include seven species of obligate scavengers that, despite their ecological relevance, present critical information gaps around their evolutionary history and conservation. Insights into their phylogenetic relationships in recent years has enabled the addressing of such information gaps through approaches based on phylogeny. We reconstructed the ancestral area in America of the current species using two regionalization schemes and methods: Biogeography with Bayesian Evolutionary Analysis (BioGeoBears) and Bayesian Binary Model-Monte Carlo Markov Chains (BBM-MCMC). Then, we identified the priority species and areas for conservation by means of the Evolutionary Distinctiveness index (ED), as a proxy of the uniqueness of species according to phylogeny, and the Global Endangerment index (GE), mapping phylogenetic diversity. We found that the ancestral area of New World Vultures in America corresponds to South America, with dispersal processes that led to a recolonization of North America by Coragyps atratus, Gymnogyps californianus and Cathartes aura. We identified the Black Vulture, G. californianus and Vultur gryphus as priority species based on ED and "Evolutionary Distinct Globally Endangered" (EDGE) indexes, and the lowlands of Amazon River basin and the Orinoco basin and some tributaries areas of the Guiana Shield were identified as the priority areas when mapping the phylogenetic diversity. This study highlights the importance of filling knowledge gaps of species of conservation concern through the integration of evolutionary and ecological information and tools and, thus, developing adequate strategies to enhance the preservation of these species in the face of the current loss of biodiversity.

Monitoring the dynamics of consumption of ungulate game by-products in vulture feeding stations in Iberian Mediterranean ecosystems

Vulture feeding stations (VFS) are strategic sites for the management of ungulate game by-products, with major implications for the conservation of obligate avian scavengers. These feeding points are designed to prevent access by facultative mammalian scavengers and to reduce the risk of trophically transmitted pathogen infection through scavenging behaviour. The aim of this study, using camera trap video recordings, was to evaluate the feeding dynamics around 32 lots of ungulate game by-products deposited in VFS in southern Spain. During the study period (2017–2022), 11 different avian and mammal scavenger species was detected. Also, many feeding events involving all scavenger species (51.1%; 362/709) and mammal scavenger species (23.4%; 166/709) was recorded. A significantly earlier presence of major obligate scavengers (Gyps fulvus and Aegypius monachus) (P = 0.023) and a lower persistence of by-products deposited (P < 0.001) were detected during October–December compared to January–March. Our results confirm that VFS play an important role in vulture conservation in Iberian Mediterranean ecosystems. However, we also point out the potential risk of VFS as hotspots of foodborne pathogens for mammal scavengers, particularly when the hunting offal persists longer. Consequently, we urge the competent authorities to update the regulations affecting VFS management, and hunting estate managers to make every effort to correctly apply those preventing scavenging mammals from gaining access to VFS. Further studies tackling access of non-target species to VFS are also warranted to properly assess the sanitary implications and geographical extent of these problems for mammal species inhabiting areas where VFS are installed.

Multi-ocean distribution of a brooding predator in the abyssal benthos

How far are species distributed on the abyssal plains? Spanning from 3000 to 6000 m below sea level, abyssal plains cover three-quarters of the ocean floor and are the largest but also least explored habitat on Earth. The question of vertical and horizontal distribution is central to understanding biogeographic and population genetic processes within species inhabiting the deep-sea benthos. Amphipod crustaceans are an important and dominant taxon in this ecosystem. As they are brooders, their dispersal capacities are more limited compared to species with free-swimming larvae, and with the exception of a few scavenging species deep-sea amphipods are restricted to a single ocean. Based on an integrative taxonomic approach (morphology, COI, 16S and 18S) we demonstrate the occurrence of a predatory amphipod species, Rhachotropis abyssalis, in three oceans: the Antarctic Ross Sea, the Northwest Pacific and the North Atlantic; regions more than 20,000 km apart. Although such extensive geographic distributions may represent a rare exception for brooding predators, these findings might also be no exception at all, but a reflection of the rare sampling and rare taxonomic investigation of invertebrate predators in the deep-sea. Our findings highlight our abysmal state of knowledge regarding biodiversity and biogeography on abyssal plains.

Effects of urbanization on the efficiency and composition of vertebrate scavengers

As human populations continue to expand, urbanization will increase and impact ecosystem processes, contribute to habitat fragmentation, and alter community composition of species. While some species can adapt to the rapidly changing environment, urbanization can favor generalist species and reshape food webs, which may result in ecological instability. Determining how wildlife respond to urbanization is necessary for management and city planning purposes in order to create suburban areas where humans and wildlife can coexist. One area that needs more focus is the effects of suburbanization on scavenging species, and how land development can alter scavenging dynamics and the redistribution of carrion-derived nutrients within food webs. We used motion activated cameras to monitor experimentally placed fish carcasses in riparian zones of suburban and rural areas in northeast Georgia, USA. We conducted 300 trials across both landscapes that were scavenged by 7 mammalian, 2 avian, and 2 reptilian species. Our results revealed fish carrion within riparian areas was readily consumed by terrestrial scavengers. However, carcass fate (whether the carcass was scavenged or not) and carcass persistence differed between suburban and rural landscapes. Carcasses were scavenged by vertebrates less often and persisted longer in rural landscapes. Species richness was similar and mesocarnivores were the predominant scavengers in both landscapes. However, scavenging by the Virginia opossum (Didelphis virginiana) was more prevalent in the suburban landscape relative to the rural landscape (61% and 36% of scavenging events, respectively). While raccoons (Procyon lotor) scavenged carcasses fairly equally across both landscapes, the American black bear (Ursus americanus) and red-shouldered hawk (Buteo lineatus) scavenged more frequently in rural areas. Our data suggest that suburban species, especially opossums, may be highly adapted to foraging in an anthropogenic environment. Additionally, nutrients from aquatic carcasses near water sources can readily move into terrestrial environments through scavenging. These results contribute to the growing body of scavenging ecology and the effects of urbanization on wildlife.