Scavenger Species Research Articles

Depth distribution of the bigeye hound sharkIago omanensisand other deep-sea species observed by baited-camera in the Red Sea

AbstractThe Red Sea is a largely homogeneous water column beyond the top 300 m, unique in exhibiting warm bottom water (~21.5 °C) at depths down to ~2900 m. The unusual conditions coupled with barriers to colonization by primary deep-sea species has resulted in an impoverished but distinct deep fauna. This study presents a rare investigation of the deep Red Sea. The bigeye hound sharkIago omanensisis a known deep-sea shark in the Red Sea. However, its full depth distribution has never been conclusively studied. Here, we confirm with videographic evidence the presence ofI. omanensisat depths to 2522 m in the Red Sea, along with observations of other deep-sea species.Iago omanensiswas the only species of scavenging fish observed and only in moderate numbers. The additional six species were mostly crustacea in low abundance. The lack of scavenging species present in the deep Red Sea is likely explained by the low productivity of the overlying surface waters and unusually warm water temperature resulting in low energetic input but high metabolic demands in deep communities.

Carcass appearance does not influence scavenger avoidance of carnivore carrion

The selection or avoidance of certain carrion resources by vertebrate scavengers can alter the flow of nutrients in ecosystems. Evidence suggests higher trophic level carrion is scavenged by fewer vertebrate species and persists longer when compared to lower trophic level carrion, although it is unclear how scavengers distinguish between carcasses of varying species. To investigate carnivore carrion avoidance and explore sensory recognition mechanisms in scavenging species, we investigated scavenger use of intact and altered (i.e., skin, head, and feet removed) coyote—Canis latrans (carnivore) and wild pig—Sus scrofa (omnivore) carcasses experimentally placed at the Savannah River Site, SC, USA. We predicted carnivore carcasses would persist longer due to conspecific and intraguild scavenger avoidance. Further, we hypothesized visually modifying carcasses would not reduce avoidance of carnivore carrion, given scavengers likely depend largely on chemical cues when assessing carrion resources. As expected, mammalian carnivores largely avoided scavenging on coyote carcasses, resulting in carnivore carcasses having longer depletion times than wild pig carcasses at intact and altered trials. Therefore, nutrients derived from carnivore carcasses are not as readily incorporated into higher trophic levels and scavengers largely depend on olfactory cues when assessing benefits and risks associated with varying carrion resources.

Scavenging in the realm of senses: smell and vision drive recruitment at carcasses in Neotropical ecosystems.

Social information, acquired through the observation of other individuals, is especially relevant among species belonging to the same guild. The unpredictable and ephemeral nature of carrion implies that social mechanisms may be selected among scavenger species to facilitate carcass location and consumption. Here, we apply a survival-modelling strategy to data obtained through the placement and monitoring of carcasses in the field to analyse possible information transmission cascades within a Neotropical scavenger community. Our study highlights how the use of different senses (smell and sight) within this guild facilitates carcass location through the transmission of social information between species with different carrion foraging efficiencies. Vultures with a highly developed sense of smell play a key role in this process, as they are the first to arrive at the carcasses and their presence seems to serve as a visual cue for other species to locate the resource. Our study supports the local enhancement hypothesis within scavengers, whereby individuals locate carcasses by following foraging heterospecifics, also suggesting the importance of the sense of smell in the maintenance of the community structure.

Chlorophyll sensitized and salicylic acid functionalized TiO2 nanoparticles as a stable and efficient catalyst for the photocatalytic degradation of ciprofloxacin with visible light

Developing efficient and stable visible light active photocatalyst has significant environmental applications. Though dye sensitization of TiO2 nanoparticles with natural chlorophyll pigments can potentially impart visible light activity, their long-term stability is a major concern. We investigated the functionalization of TiO2 with salicylic acid, and subsequent sensitization with chlorophylls to improve the catalyst stability for the photocatalytic degradation of Ciprofloxacin (CPX) under visible light. A significant improvement in the degradation efficiency and catalyst stability was observed for five reuse cycles. Further, an optimum CPX degradation of ∼75% was achieved with 0.75 g L−1 catalyst dosage of 0.1 chl/0.1 SA-TiO2, initial pH of 6, and 10 ppm of initial CPX for a visible light exposure of 2 h. The degradation followed the pseudo-second-order kinetics. In addition, the ciprofloxacin degradation was reduced in the wastewater matrix system due to the presence of other scavenging species such as chlorides, sulphates, and alkalinity. Significant reduction in the toxicity of degradation compounds after the photocatalytic degradation was observed in comparison to parent CPX. Further, the degradation pathway and plausible mechanism of degradation of CPX were also proposed.

Scavenger assemblages are structured by complex competition and facilitation processes among vultures

AbstractUnderstanding the factors that allow multiple species to coexist and share resources is an outstanding question in community ecology. Animals that share resources tend to use different strategies to decrease potential competition, through morphological adaptations, establishment of hierarchies, behavioral adaptations or spatial or temporal segregation. The main objective of this study was to infer interspecific processes of competition and facilitation through the study of species co‐occurrence patterns in a vertebrate scavenger guild in de Brazilian cerrado. We analyzed patterns of spatial and temporal co‐occurrence between species pairs, both qualitatively and quantitatively, and determined the activity patterns of the different scavenger species. For this purpose, we placed and monitored 11 large (i.e. goat) and 45 small (i.e. chicken) carcasses by camera‐trapping, obtaining a total of 27 448 images. Our results show complex competitive and facilitative relationships among scavenging species in the Brazilian cerrado that are influenced by carcass size and change depending on the spatial and temporal scale at which they are analyzed. The scavenger assemblages that consumed large and small carcasses were different, evidencing resource partitioning between obligate and facultative scavengers. Furthermore, as an alternative to reduce competition levels, most species showed differences in their scavenging patterns, in addition to a strong temporal segregation during carcass consumption. Regarding New World vultures, our results suggest a strong interference competition between species with clear differences in their ecological traits (e.g. size, social behavior). However, we also found evidence of facilitation processes between vulture species in the location and access to the interior of the carcasses. Our findings highlight the role of obligate scavengers both in competition and facilitation processes in this vertebrate scavenger community. Future research should focus on investigating which species play the most important role in the structure and dynamics of this community, also considering intraspecific and behavioral patterns.

Removal of bottom-towed fishing from whole-site Marine Protected Areas promotes mobile species biodiversity

Marine habitats are being altered by anthropogenic pressures, influencing the diversity and distribution of species. Marine Protected Areas (MPAs) are increasingly used as spatial management tools to mitigate these human impacts on marine systems, but levels of protection vary. MPAs that exclude bottom-towed fishing activities from all habitats within their boundaries while still allowing static gear fishing, taking a “whole-site approach”, have shown benefits in terms of increasing biodiversity and biomass on reef habitat. In this study we use Baited Remote Underwater Videos (BRUVs) to quantify differences in mobile species assemblage composition, diversity and abundance on mixed sediment habitats inside and outside three MPAs adopting this whole-site approach within Jersey's territorial waters. Greater numbers of taxa were recorded within all three MPAs compared to nearby unprotected areas, with an average of 4.9 ± 1.8 taxa observed per deployment inside the MPAs compared to 3.9 ± 1.7 taxa outside the MPAs. No significant difference was observed in the overall abundance. The proportion of presence of two indicator species (Labridae Spp. and juvenile bream Spondyliosoma cantharus) was greater within the MPAs than the nearby unprotected areas. IUCN threatened and vulnerable shark species were observed on more BRUVs inside the MPAs, while IUCN threatened and vulnerable ray species were present on fewer BRUVs in the MPAs, but both occurred in too few numbers to statistically assess. Not all species responded positively to the MPAs, with scavenging species such as spider crab (Maja brachydactyla) recorded in lower numbers in two out of the three MPAs compared to the nearby unprotected areas. BRUV surveys that have been used to survey MPAs that exclude bottom-towed fishing in Europe are sparse and have primarily focussed on reef habitat. This study provides the first account of how this whole-site approach for mixed sediment habitats in three MPAs affects mobile species. These results evidence the merit of an ecosystem-based approach to MPA management for species of both conservation and commercial importance.

Reduction of organic waste in a landfill lowers the visitation probability but not the local abundance of a long-lived scavenger species

Summary Globally, vultures are one of the most threatened of all groups of birds. European vulture populations are benefited by several anthropogenic food sources such as landfills. Current European Union directives aim to decrease the amount of organic matter dumped in landfills, reducing this important food source for some vulture species. In this context, we assessed the effect of the reduction of organic waste available and accessible for scavengers in a landfill on the visitation probability and abundance of a local Eurasian Griffon Vulture Gyps fulvus population in Central Catalonia (NE Iberian Peninsula), using a long-term dataset of captured-marked-recaptured individuals in the period 2012–2018. Our results indicated a decrease in the visitation probability due to a significant reduction of organic matter dumped into the landfill after a waste treatment centre was built (0.82 to 0.76) that may cause a permanent emigration of vultures in response to food reduction. However, the estimated annual abundance of vultures tended to grow over time due to the positive trend that regional vulture populations have experienced in recent decades. These results suggest that population processes occurring at regional scales are more relevant to vulture populations than local waste management measures. A reduction in locally available food can make a site less attractive, but species with high dispersal capacity such as vultures may overcome this issue by moving to other suitable sites. Although Griffon Vultures obtain most of the food from domestic and wild ungulates, a regional application of European directives could threaten an important alternative feeding source, especially in food shortage seasons where landfills could be supporting the energetic requirements of the species. Conservation strategies should be planned to counteract the possible negative effects of new European directives on scavenger populations.

Tissue regeneration effect of betulin via inhibition of ROS/MAPKs/NF-ĸB axis using zebrafish model

Betulin is the primary anti-inflammatory component of Betula platyphylla suk. cortex (birch bark), a time-honored Traditional Chinese Medicine (TCM) for healing trauma and tissue regeneration. However, the tissue regeneration effects and underlying molecular mechanism of betulin remain unknown. Therefore, it is necessary to investigate the wound repair effects and validate the mechanism of betulin in an appropriate model. In the present study, we evaluated the effects of tissue regeneration, melanin scavenging, and reactive oxygen species (ROS) inhibition of betulin using a zebrafish model. The mechanism of target genes and pathways were confirmed using quantitative polymerase chain reaction and western blotting in vivo, while molecular docking, absorption, distribution, metabolism, excretion, and toxicity investigations in-silico were conducted. Betulin significantly promoted the regeneration of zebrafish caudal fin length and area and alleviated melanin aggregation, as well as ROS generation. The relative mRNA expression of IL-1β, TNF-α, p38α, ERK1/2, and Caspase3, and the relative protein expression of p38α, ERK1/2, Caspase3, phosphorylated proteins of p-p38α, p-ERK1/2, and p-p65 were down-regulated following betulin administration. Meanwhile, the protein ratios of p-p38α/p38α, p-ERK/ERK, and p-p65/p65 were significantly decreased. In an in-silico study, binding affinities between betulin and P38α, ERK1, ERK2, and Caspase3, and the pharmacokinetic profile of betulin were predicted. The findings suggest that the tissue regeneration mechanism of betulin is based on the inhibition of excessive inflammatory responses, melanin aggregation, and the pro-apoptotic factor, Caspase3, during the proliferation phase via the ROS/MAPKs/NF-ĸB signaling axis. Our results suggest betulin as a potential candidate for tissue regeneration.

Cheetah marking sites are also used by other species for communication: evidence from photographic data in a comparative setup

Many mammalian species communicate via olfactory communication placed at particular locations. The majority of these studies focused on intraspecific communication. More recently, studies have also investigated interspecific communication and recorded prey animals sniffing olfactory cues left by predators and predators investigating or counter-marking cues left by other predator species. The purpose of exchanging olfactory cues within a species community is little understood. Using a comparative study design, we investigated the behaviour of a mammalian community at cheetah marking trees and paired control trees using camera traps on Namibian farmland. We tested the predictions derived from hypotheses regarding the reasons for visits to the marking trees. Cheetah marking trees and control trees were visited 1101 times by 29 mammalian species (excluding cheetahs), with more species recorded at the marking trees than control trees. Two competitively subordinate carnivore species made more visiting and sniffing events, respectively, at cheetah marking trees than control trees, possibly to assess the time since cheetahs were in the area. Two opportunistic scavenger species sniffed more frequently at the marking trees than control trees, perhaps to feed on undigested prey remains in scats. One common prey species of cheetahs had fewer visiting events at the marking trees than control trees, likely to reduce encounters with cheetahs. Further, one species that is rarely preyed by cheetahs marked cheetah marking trees at the same frequency as control trees, suggesting it uses conspicuous sites rather for intraspecific than interspecific communication. Thus, trees used by cheetahs for marking also play an important role in olfactory communication for a variety of mammalian species.

Scavenger guild and consumption patterns of an invasive alien fish species in a Mediterranean wetland.

Invasive Alien Species (IAS) alter ecosystems, disrupting ecological processes and driving the loss of ecosystem services. The common carp Cyprinus carpio is a hazardous and widespread IAS, becoming the most abundant species in many aquatic ecosystems. This species transforms ecosystems by accumulating biomass to the detriment of other species, thus altering food webs. However, some terrestrial species, such as vertebrate scavengers, may benefit from dead carps, by incorporating part of the carp biomass into the terrestrial environment. This study describes the terrestrial vertebrate scavenger assemblage that benefits from carp carcasses in a Mediterranean wetland. We also evaluate the seasonal differences in the scavenger assemblage composition and carrion consumption patterns. Eighty carp carcasses (20 per season) were placed in El Hondo Natural Park, a seminatural mesohaline wetland in south‐eastern Spain, and we monitored their consumption using camera traps. We recorded 14 scavenger species (10 birds and four mammals) consuming carp carcasses, including globally threatened species. Vertebrates consumed 73% of the carrion biomass and appeared consuming at 82% of the carcasses. Of these carcasses consumed, 75% were completely consumed and the mean consumption time of carcasses completely consumed by vertebrates was 44.4 h (SD = 42.1 h). We recorded differences in species richness, abundance, and assemblage composition among seasons, but we did not find seasonal differences in consumption patterns throughout the year. Our study recorded a rich and efficient terrestrial vertebrate scavenger assemblage benefitting from carp carcasses. We detected a seasonal replacement on the scavenger species, but a maintenance of the ecological function of carrion removal, as the most efficient carrion consumers were present throughout the year. The results highlight the importance of vertebrate scavengers in wetlands, removing possible infectious focus, and moving nutrients between aquatic and terrestrial environments.

Integrating terrestrial scavenging ecology into contemporary wildlife conservation and management.

Scavenging plays a vital role in maintaining ecosystem health and contributing to ecological functions; however, research in this sub‐discipline of ecology is underutilized in developing and implementing wildlife conservation and management strategies. We provide an examination of the literature and recommend priorities for research where improved understanding of scavenging dynamics can facilitate the development and refinement of applied wildlife conservation and management strategies. Due to the application of scavenging research broadly within ecology, scavenging studies should be implemented for informing management decisions. In particular, a more direct link should be established between scavenging dynamics and applied management programs related to informing pharmaceutical delivery and population control through bait uptake for scavenging species, prevention of unintentional poisoning of nontarget scavenging species, the epidemiological role that scavenging species play in disease dynamics, estimating wildlife mortalities, nutrient transfer facilitated by scavenging activity, and conservation of imperiled facultative scavenging species. This commentary is intended to provide information on the paucity of data in scavenging research and present recommendations for further studies that can inform decisions in wildlife conservation and management. Additionally, we provide a framework for decision‐making when determining how to apply scavenging ecology research for management practices and policies. Due to the implications that scavenging species have on ecosystem health, and their overall global decline as a result of anthropic activities, it is imperative to advance studies in the field of scavenging ecology that can inform applied conservation and management programs.

The impact of wildfire and mammal carcasses on beetle emergence from heathland soils

Abstract Wildfires alter the composition of insect communities due to fire‐induced mortality, and the post‐fire vegetation and soil conditions also affect the initial re‐colonisation and subsequent local emergence of adults from burnt soils. However, the impact of wildfires on re‐colonisation and emergence of carrion‐associated scavenging species from soils has previously been neglected. We established an experiment in an unmanaged heathland area that was affected by a severe wildfire in 2017 by adding wild boar carcasses to burnt and unburnt areas 204 days after the wildfire. Adult beetles were then collected with emergence tents at paired sites with and without carcasses and in burnt and unburnt areas from 27 April to 10 August 2018. The wildfire did not significantly affect the diversity or abundance of soil‐emerging beetles. Community composition in the burnt area differed significantly from the unburnt area with higher numbers of Staphylinidae and lower numbers of phytophagous beetle families (Curculionidae and Elateridae) emerging from soils, probably reflecting the structurally simpler vegetation and reduced litter one year after the wildfire. Scavenging beetles generally colonise mammal carcasses in burnt areas to the same extent as in unburnt areas, but the post‐fire conditions favoured some species with very specialised habitat preferences. A few rare species of conservation concern almost exclusively occurred in the burnt area and in most cases in combination with the presence of a carcass. This result highlights the joint importance of heathland wildfires and carcass resources for species conservation in beetle communities.

Assessing the catch efficiency of predators in the presence of prey using experimental gillnets in a temperate estuary

Fishery-independent sampling is designed to representatively sample faunal communities based on the effort-standardized catch rates of individual gears. In estuaries, experimental gillnets are widely used due to their ability to passively sample mobile fish communities with multiple panels of decreasing mesh sizes. To test if concurrently collected prey in experimental gillnets create a trophic-related sampling bias for predatory or scavenging (hereafter, predators) species, we set large mesh gillnets comprising two treatments, baited (n = 80) and unbaited (n = 78), using a paired design in Back Sound, North Carolina. Furthermore, we analyzed data from the North Carolina Division of Marine Fisheries (NC DMF) estuarine gillnet monitoring program with boosted regression tree models to correlate estuarine predator occurrence with environmental factors (salinity, temperature), habitat presence, and families of common prey species as predictor variables. In our experimental manipulation, neither total catch nor community composition statistically varied between treatments, determined using permutational multivariate analysis of variance (PERMANOVA). However, species richness estimated using species accumulation curves was higher in baited gillnets, with one frequently caught species (Atlantic sharpnose sharks) collected exclusively in baited gillnets. In NC DMF surveys, prey group variables were more important (average model importance; 10% ± 8.8% SD) than habitat composition (2% ± 1.7%) to the presence of predators, but less than abiotic environmental variables (21.1% ± 13.1%). This combined manipulative and mensurative study revealed mixed evidence towards increased catch efficiency of predatory fish collected in widely used experimental gillnets. These results should be considered in refining abundance estimations for estuarine predators, as catch efficiency for some piscivorous predators may vary in relation to the abundance and catch efficiency of prey.

Increased abundance of a common scavenger affects allocation of carrion but not efficiency of carcass removal in the Fukushima Exclusion Zone

The 2011 nuclear accident in Fukushima, Japan caused the evacuation of > 100,000 people and prompted studies on environmental impacts of radiological contamination. However, few researchers have explored how the human evacuation has affected ecosystem processes. Despite contamination, one common scavenger (wild boar, Sus scrofa) is 2–3× more abundant inside the Fukushima Exclusion Zone (FEZ). Shifts in abundance of some scavenger species can have cascading effects on ecosystems, so our objective was to investigate impacts of the evacuation and the resulting increase in wild boar on vertebrate scavenger communities. We deployed cameras at 300 carcasses in the FEZ and a nearby inhabited area, and quantified carcass fate, scavenger species, and detection/persistence times. We also tested effects of carcass size and habitat on scavenger community composition and efficiency by balancing trials across two carcass sizes and habitats in each zone. Overall scavenger richness and carcass removal rates (73%) were similar in the FEZ and inhabited area, but species-specific carcass removal rates and occurrence differed between zones. Wild boar removed substantially more carcasses inside the FEZ, with implications for nutrient and contaminant distribution. Our results suggest carcass size affects scavenging dynamics more than human activity or habitat, and abundance changes of common scavengers can influence carrion resource allocation.

The scavenger spyglass: how recruiting hunters to watch carrion boosts wildlife research

AbstractHunters support scavengers with seasonal pulses of carrion. If those hunters also deploy remote cameras at kill sites, they could simultaneously contribute data to wildlife research while gaining first‐hand knowledge of scavenger ecology. In 2018–2020, we recruited hunters to monitor carcasses and offal with remote cameras across western Montana, USA. We increased our sampling effort by also setting up cameras following successful elk (Cervus canadensis) hunts at a private ranch. Cameras recorded 19 scavenger species. Golden eagles (Aquila chrysaetos) appeared at 55% of sites, and 3 individuals wore auxiliary markers, demonstrating how hunters can augment efforts to detect tagged wildlife. Cameras also documented elusive predators (e.g., wolves [Canis lupus]) and a seasonality of scavenging among American black bears (Ursus americanus). At 42% of the sites, ≥1 cervid investigated the carrion within 1 m, a behavior that may transmit the prions associated with chronic wasting disease. Hunters are willing and competent citizen scientists that can help generate wildlife observations at a broad spatial scale.

A Novel Method for the Syntheses of Imidazo-Thiadiazoles as Potential Antioxidants and Anti-Inflammatory Agents.

A literature survey revealed that many imidazo-thiadiazole molecules were used as key intermediates for the development of novel drugs. The synthesized imidazo-thiadiazole derivatives were tested for their in vitro antioxidant and anti-inflammatory properties. The purpose of this research paper is to provide readers with information regarding diseases caused by free radicals. The objective of this study is to develop novel antioxidant and anti-inflammatory drugs. Imidazo-thiadiazole derivatives 5a-f were synthesized through cyclo-condensation reactions in two steps. First, the synthesis of 2-amino-thiadiazole derivatives from substituted aromatic carboxylic acids and thiosemicarbazide by using POCl3 as a solvent as well as a catalyst was performed. In the next step, imidazo-thiadiazoles were prepared from 2-amino-thiadiazole derivatives with appropriate α-haloketones in the presence of polyethylene glycol-300 (PEG-300) as a green solvent. These imidazo- thiadiazole derivatives were prepared by using a novel method. The synthesized compounds were in vitro tested for their antioxidant and anti-inflammatory activities. In vitro evaluation report showed that nearly all molecules possess potential antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO), superoxide radical (SOR), and hydrogen peroxide (H2O2) radical scavenging activity. Most of the imidazo-thiadiazole derivatives have shown significant anti-inflammatory activity as compared to diclofenac sodium as a reference standard. In the search for novel therapies to treat inflammation and oxidation, we have made efforts to develop anti-inflammatory and antioxidant agents with a preeminent activity. Imidazo-thiadiazoles 5a, 5e as well as 5f showed potential anti-inflammatory activity. All tested imidazo-thiadiazole deriv-atives (5a-f) showed potential antioxidant activity against one more radical scavenging species as com-pared to ascorbic acid as the reference standard. Thus, imidazo-thiadiazole derivatives constitute an interesting template for the design and development of new antioxidant as well as anti-inflammatory agents.

Effects of supplying additional food for a scavenger species in a prey-predator-scavenger model with quadratic harvesting

ABSTRACT In this investigation, we proposed and analyzed a mathematical model among the interaction of prey-predator-scavenger species. Here, the harvesting of predator and scavenger have been considered. It is assumed that prey is consumed by predator and scavenger species consumes both dead prey as well as dead predator. It is also assumed that the scavenger species is partially supported by supplying constant amount of additional food. The boundedness and persistence conditions of the solution of the proposed model are derived. It is found that the model undergoes a Hopf-bifurcation around the interior equilibrium point. It is reported that the harvesting of predator and scavenger species can control the chaotic dynamics and make the system stable in the presence of additional food to the scavenger species. It is also reported that the supplying of additional food may make the system more stable than the system without supplying of additional food.

Identifying forensically relevant urban scavengers in Johannesburg, South Africa

Unidentified human remains are frequently recovered in urban environments in South Africa, which undergo forensic (medico-legal) investigations. These remains often exhibit animal scavenging modifications and are frequently scattered by animals. This impacts the collection and forensic analysis of the remains. This study aimed to identify scavenging animals present in two urban environments in Johannesburg, South Africa, and describe their scavenging and scattering behaviours. Six pig carcasses (Sus scrofa domesticus) (30–80 kg) were placed in a veldt in Johannesburg and in an abandoned building complex. Motion-activated cameras recorded the scavenging activities. Scavenger species were identified and their behaviours, scattering pattern, and scavenging bone modifications were described. Slender mongooses (Galerella sanguinea) were the most prolific veldt scavengers. They scattered remains to a maximum distance of 10.5 m in two directions: north and southeast. These mongooses scavenged during the advanced and dry decomposition stages. Gnawing on the angle of the mandible - with multiple parallel scores on the flat surfaces and the angle margin having a stepped appearance - may be a distinguishing scavenging modification feature of the slender mongoose. Hadeda ibis (Bostrychia hagedash) were the only scavengers recorded scavenging on the intestines of a pig carcass in the abandoned building complex. They favoured colonizing insects and created multiple, large holes in the skin and removed the lips to access the insects. The described scavenging behaviours will assist in the reconstruction of postmortem events in forensic cases and the location and collection of scattered remains in Southern Africa.

Local ecological knowledge and education drive farmers' contrasting perceptions of scavengers and their function in Nepal

Abstract There is a long‐standing relationship between humans and vertebrate scavengers, as scavengers' contributions take on regulating (e.g. nutrient recycling and disease control), material (e.g. competition and livestock depredation) and non‐material (e.g. sky burials and ecotourism) roles in society. A social–ecological approach to studying biodiversity is increasingly needed, since the inclusion of local perceptions and knowledge has proven critical for effective conservation programs and ecosystem management. We examine livestock farmers' perceptions and knowledge related to vertebrate scavengers in the highly diverse Chitwan‐Annapurna Landscape (Nepal) and assess the socio‐demographic traits that influence their perceived value of scavengers' ecosystem service provisioning (ESP) index, and function via scavenging services (SS). Farmers' perceptions of functional importance (SS) showed species‐specific gradation, unlike ESP, where only avian scavengers were perceived as beneficial. Our results show that the perception of scavenging as a beneficial ecosystem service and its importance as a biological function are decoupled for facultative scavengers and coupled for obligate scavengers. Relatedly, we identify that affluence‐related traits drove positive perceptions of ESP, and local ecological knowledge‐based traits were linked to increased knowledge of function via SS. Thus, this increased awareness of functional importance based on close contact with nature does not guarantee positive valuations of scavengers' contributions, whereas formal education did influence positive perceptions despite reduced awareness of function. Additionally, our findings suggest that existing environmental education measures are targeting the right groups, as these respondents coincide with lower favourability of scavengers' ecosystem services, but may be unable to overcome existing human–wildlife conflict. For the first time in South Asia, we survey relevant community stakeholder's attitudes towards an entire scavenging guild and their associated benefits, detriments and functional importance. Our study illustrates the varied perceptions that exist for different scavenger species and closely examines a wide‐ranging set of socio‐demographic traits that show disparate influences on farmers' knowledge of ecological function and perceived ecosystem service benefits. Crucially, these findings can guide conservation and management priorities by considering the differences in public perception and awareness of scavenging, as well as the interpretation of nature's contribution to people. Read the free Plain Language Summary for this article on the Journal blog.

Mass mortality events and declining obligate scavengers in the Anthropocene: Social feeders may be critical

A pervasive but understudied global change is occurring in the Anthropocene. Wildlife mass mortality events (MMEs) are increasing in frequency causing the abrupt entry of unusually large amounts of carrion into ecosystems, while most vertebrate obligate scavenger species are declining. We hypothesized that behavioral plasticity could still allow obligate-vertebrate scavengers to maintain carrion recycling with increasing carrion biomass as a result of relaxed competition, and that consumption is likely to be driven by those species less behaviorally constrained. We designed an experiment by establishing plots with increasing carrion biomass. The lowest carrion biomass represented a normal level of carrion with a single carcass, with each subsequent level of carrion biomass roughly doubling until reaching a carrion density similar to a recent MME. We monitored behavior of two obligate scavenger species: a social feeder (i.e., black vulture, Coragyps atratus) and a relatively solitary feeder (i.e., turkey vulture, Cathartes aura). In support of our hypothesis, group size and number of individuals feeding increased at the highest carrion biomass level for the more social feeder, while the less social increased solely the number of individuals feeding. Likewise, activity pattern overlap between the species increased with carrion biomass likely because both spent more of the day consuming larger carrion inputs. The effects of these behavioral changes resulted in an increase in estimated consumption with carrion biomass, which was primarily driven by the more social species. Our results indicate that vulture behavioral plasticity may be critical to maintain carrion recycling services in the Anthropocene.