Scavenging Behavior Research Articles

Soft tissue scavenging patterns of mice on human remains.

Rodent scavenging of human remains is repeatedly documented in literature. However, most of this documentation is based on single-case examples. While this information is valuable, it does not provide an in-depth understanding of scavenger behavior in a single environment. Mouse scavenging data, in particular, lack larger sample sizes and data representing the full duration of scavenging activity. In documented cases, mice scavenge primarily the hands, the feet, and the head without significant progression into the rest of the body. At the Forensic Investigation Research Station in Whitewater, Colorado, deer mice (Peromyscus maniculatus group) scavenged tissue from 11 human donors. Motion activated game cameras and regular field photography documented scavenging progression and deer mouse behavior. Deer mice generally showed a preference for skin and fat, rarely consuming enough muscle to expose bone. The most scavenged sections of the body were the limbs and deer mice generally ignored the hands, the feet, and the head, unlike previous documentation. In a few cases, deer mice consumed tissue on the limbs in a distinct trail pattern. Most of the scavenging began in spring. This sample greatly expands on the existing documentation of mice overall and contributes much needed data on the progression of scavenging. Scavengers can have a significant impact on a death scene, so detailed documentation of different scavengers in a variety of environments can prove useful in the investigation process.

Global and regional prediction of heterakidosis population prevalence in extensive backyard chickens in low-income and middle-income countries

Extensive backyard chickens are one of the most common production systems in low-income and middle-income countries (LMICs). In this production system, chickens are exposed to infectious forms of parasites as a result of the outdoor access and scavenging behaviour. Heterakis gallinarum is one of the most common nematode parasites present in the environment, and estimating its global and regional prevalence is essential for attributing the economic losses in extensive backyard chickens. The objective of this study is to predict the prevalence of heterakidosis in extensive backyard chickens at global and regional levels in LMICs using regression imputation methods. A binomial random effect model was developed using empirical data on heterakidosis prevalence and climatic factors as main predictors. Prevalence data were then imputed in all regions based on the regression model. Global and country prevalence were estimated based on regional predictions and their beta distributions. Minimum precipitation, minimum temperature and maximum temperature were selected as significant predictors. The population prevalence of heterakidosis was 0.24 (0.19–0.29). Countries with continental and dry climates had a higher mean prevalence, whereas countries with tropical climates had a lower mean prevalence of heterakidosis. As more empirical data on heterakidosis prevalence become available, this model and predictions should be redefined and updated to capture a more representative association and increase the accuracy of the predictions. The results of this study can be used to attribute the economic losses of extensive backyard chickens, taking into account a holistic approach as promoted by the GBADs programme and therefore, to identify which diseases are more costly to backyard farmers. Furthermore, results can be also served as a proxy for the risk of histomoniasis in extensive backyard chickens.

Do marine food subsidies predict large scale distribution of scavenging seabirds within the Bay of Biscay?

Omnivorous and opportunistic species have the potential to exploit human food subsidies. In marine ecosystem, understanding interaction between seabirds and fishery activities, particularly their scavenging behaviour on discards is crucial nowadays, in the context of EU landing obligation. The Bay of Biscay is one of the major fishing zones in Europe and a central area for the wintering of a high number of seabird species. During spring and autumn, oceanographic surveys were conducted by the R/V Thalassa with the aim to evaluate fishing resources along transects over the continental shelf, thereby providing an opportunity to study the distribution and scavenging behaviour of seabirds in this area. We investigated the influence of fishery activities (i.e. distribution of professional fishing vessels, quantity of discards) at large scale, and oceanographic conditions on the distribution of scavenging seabirds along the continental shelf. On average, large gulls (Larus spp) and northern gannets accounted for 70 % of the seabirds scavenging on discards. We compared model predictions using oceanographic variables with those using both oceanographic variables and fishery activities, in separate for spring and autumn and group of seabirds (i.e. large gulls and northern gannets). Results suggested that the distribution of scavenging seabirds was better predicted by oceanographic variables than by fishery activities. The predicted numbers of scavenging seabirds were higher in autumn than in spring, probably due to the annual cycle of seabirds (i.e. breeding versus wintering). At large scale, oceanographic variables were better predictors of suitable habitat. However, a closer evaluation of prediction differences between the two models highlighted high anomaly values for large gulls in autumn along the coast, that may indicate over predictions. These results have provided new knowledge on the ecology of scavenging seabirds, in an area with high fishery activity, especially in the context of landing obligation.

Brushing up on carcass consumption: Investigating spatiotemporal scavenging dynamics of brushtail possums in Australian ecosystems

AbstractBrushtail possums (Trichosurus vulpecula) are becoming increasingly recognized as key members of local scavenger guilds in Australia. Yet, our understanding of the spatiotemporal scavenging dynamics of this mainly herbivorous marsupial species remains limited. We investigated abiotic and biotic factors influencing possum carcass use across an alpine and temperate bioregion in Australia. Using camera traps set on experimentally placed kangaroo carcasses, we first examined the influence of both open and closed canopy habitats and warm and cool seasons on possum scavenging behaviour across both bioregions. While scavenging was minimal in open habitats across both bioregions—likely a reflection of possums being an arboreal species—seasonality did significantly influence possum activity. Possums scavenged on carcasses in temperate regions entirely during cooler months. Scavenging was recorded year‐round in the alpine region, but with total possum feeding time on carcasses 5.9 times higher in cooler months. A more detailed 12‐month study in the alpine region confirmed this strong seasonal influence on possum scavenging, with possums up to 5.4 times more likely to discover carcasses in winter and spend up to 6.7 times longer feeding on carcasses during this season. The variability in possum scavenging behaviour between bioregions and seasons highlights the spatiotemporal complexity of possum scavenging behaviour and the importance of considering abiotic and biotic factors to understand the behaviours of scavengers more broadly. Recognizing primarily herbivorous animals as important yet often overlooked members of local scavenger guilds can help advance our understanding of complex scavenging networks and the intricate pathways through which energy flows in ecosystems, both in Australia and in other systems. Improving our understanding of the spatiotemporal scavenging dynamics of typically herbivorous species may also help to inform more nuanced and effective wildlife management strategies, where supplementary foraging on atypical food resources poses conservation concerns.

Taphonomic impact of vertebrate scavengers on degradation and dispersal of remains, southeastern British Columbia.

Vertebrate scavengers represent important taphonomic agents that can act on a body, particularly when in an outdoor environment. Understanding the effects of these agents will direct how and where to search for human remains and influence the likelihood of discovery in a particular region. The current study aimed to identify the taphonomic impact of scavenger guilds in the peri-urban and rural regions of southeastern British Columbia. Vertebrate scavenger activity on pig carcasses was recorded remotely using trail cameras and analyzed to determine temporal scavenging profiles. Both the peri-urban and rural environments produced comparable scavenger guilds, namely: turkey vultures, American crows/northern ravens (classified as "corvids"), American black bears, and coyotes. Although the two locations had different study lengths due to variable degrees of scavenging, for the period that was common to both locations (summer to early fall), the black bear was the most frequent scavenger followed by coyote. However, the dispersal of remains by the mammalian scavengers was distinctly different between sites. Only 12%-33% of skeletal elements were recovered at the rural sites compared to 80%-90% recovered at the peri-urban sites, even though the latter sites had a longer study timeframe. The extended timeframe of the peri-urban sites confirmed that certain scavengers (e.g., turkey vultures and black bears) are only seasonally active in this region. These findings demonstrate the variability of scavenger behavior and the need to assign caution and local ecological knowledge when predicting scavenger trends. Such taphonomic information is relevant for human remains searches in regions with comparable scavenger guilds.

Taphonomic signatures of early scavenging by black and turkey vultures.

Scavenging is critical for nutrient cycling and maintenance of healthy ecosystems. While there is substantial research into the identification of taphonomic signatures from facultative mammalian scavengers, early stage scavenging signatures by vultures remain unknown. Further, some vulture species are opportunistic predators, highlighting the need to define signatures observed in the course of normal scavenging behavior. We placed stillborn neonatal calves in an unoccupied pasture and used motion-trigger camera traps to quantify scavenging effort, then conducted necropsies to evaluate the effect of black vulture (Coragyps atratus) and turkey vulture (Cathartes aura) scavenging effort on carcass consumption. We measured the order of consumption of different tissue types to delineate which anatomic structures vultures consume first. Scavenging trials with higher numbers of vultures feeding on the carcass for longer were associated with decreased remaining tongue and abdominal viscera, and a larger umbilical wound. Greater maximum flock sizes were associated with decreased remaining tongue and abdominal viscera, a larger umbilical wound, and greater biomass consumption. Black vultures targeted the perineum and tongue earlier, while turkey vultures targeted the eyes, perineum, and tongue. These results are consistent with the idea that vultures prefer tissues that are easy to access and contain high nutrient content. These patterns form a distinctive taphonomic signature that can be used to identify early scavenging by black and turkey vultures. Our results demonstrate that criteria commonly used to identify livestock depredation by black vultures only document vulture presence and not predation. This distinction implies that new and more definitive criteria need to be developed and put into practice for more accurate decision criteria in livestock depredation compensation programs.

Elasmobranch Mark–Recapture Experiment off the Balearic Islands: Insight into Scyliorhinus canicula Growth, Mobility, and Population Size

Despite the high diversity of elasmobranch fishes in the Balearic Islands, knowledge of their biology and population dynamics is still scarce. A recent mark-and-recapture experiment off the Balearic Islands tagged 3738 individuals of 23 shark and batoid species during MEDITS and CANAL bottom trawl scientific surveys from June 2021 to August 2023. Retrieval was reported for the sharks Scyliorhinus canicula and Mustelus mustelus, revealing relatively small home ranges for these species (0.2–38.5 km and 7.8–15.3 km for S. canicula and M. mustelus, respectively). Recapture efficiency was higher from scientific surveys than from commercial catches, highlighting potential challenges in collaboration with fishermen and recapture reports. Density estimates obtained from the MEDITS bottom trawl survey suggest a much larger population for S. canicula than estimates from the mark–recapture data, indicating MEDITS density estimates for this species may be overestimated due to its scavenger behavior perhaps favoring individuals searching for discards aggregated in the fishing grounds. This study emphasizes the importance of monitoring, collaborative efforts, and improved reporting mechanisms to enhance our understanding of elasmobranch populations and provide support for sustainable management of these vulnerable marine species.

Scavengers in the human-dominated landscape: an experimental study.

Rapid urbanization is a major cause of habitat and biodiversity loss and human-animal conflict. While urbanization is inevitable, we need to develop a good understanding of the urban ecosystem and the urban-adapted species, in order to ensure sustainable cities for our future. Scavengers play a major role in urban ecosystems, and often, urban adaptation involves a shift towards scavenging behaviour in wild animals. We experimented at different sites in the state of West Bengal, India, to identify the scavenging guild within urban habitats, in response to human-provided food. Our study found a total of 17 different vertebrate species across 15 sites, over 498 sessions of observations. We carried out network analysis to understand the dynamics of the system and found that the free-ranging dog and common myna were key species within the scavenging networks. This study revealed the complexity of scavenging networks within human-dominated habitats. This article is part of the theme issue 'Connected interactions: enriching food web research by spatial and social interactions'.

Feeding habits of the deep-sea shrimp Plesionika quasigrandis Chace, 1985 (Decapoda: Caridea: Pandalidae) in the southeastern Arabian Sea

ABSTRACT Species of PlesionikaSpence Bate, 1888 holds significant importance in the commercial harvesting of deep-sea shrimps along the southern coasts of India. Despite Plesionika quasigrandisChace, 1985 being a crucial resource on the southwest coast of India, there is a need for comprehensive information on its food and feeding habits. We investigated the diet of P. quasigrandis in relation to sex, size, and season. The species exhibited a diet primarily consisting of crustaceans, foraminiferans, and detritus. Both males and females showed a noteworthy reliance on detritus, as indicated by an index of preponderance values exceeding 45.8. The species displayed active scavenging behaviour alongside predatory dietary habits. We observed a decrease in feeding intensity from pre-monsoon to post-monsoon in both males and females. Permutational multivariate analysis of variance (PERMANOVA) revealed significant differences in the diets of P. quasigrandis, considering the combined effects of size and sex (P < 0.01). No significant distinctions were noted in the diet composition between males and females in relation to season.

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.

In situ O2-releasing quantum dot composites with enhanced radical scavenging behaviour, biosafety, and broadband UV shielding applications

Understanding the defect-driven photophysics-surface chemistry interplay at the nanoscale further augments new design considerations for active ingredients used in sun-protection, emphasizing affordability, safety, and multi-functionality. Accelerating it, our study unravelled broad-spectrum UV attenuation (250 nm–400 nm) and long-lasting photostability (>5 h) exhibited by in-house fabricated β-cyclodextrin functionalized, oxygen vacancy (VO●) engineered-CeO2(x)/ZnO(1-x) quantum dot composites (Em-C(x)Z(1-x)). A conceptually different strategy was pursued, involving artificially engineering surface VO● defects to modulate the band structure and enhance the molar absorptivity through photogenerated electron-hole separation. Unlike conventional inorganic UV blockers, these QD composites harnessed surface VO● for a self-cascading antioxidant effect, scavenging 62.8 % ●OH radicals. Results indicated that autocatalytic endogenous O2 generation from H2O2 scavenging, accelerated by Ce3+/Ce4+ couple, begets anti-photoaging and sunburn alleviation. Em-C(x)Z(1-x) demonstrated synergistic suppression of oxidative stress development and remarkable cell viability (≥90 %) even under UV irradiation. These underlying principles can be extended to prevent and treat other ROS-induced skin ailments. Incorporating Em-C0.3Z0.7 in commercial sunscreens unveiled a substantial enhancement in overall sun protection and antioxidative efficacy. Thus, it is envisioned that Em-C(x)Z(1-x) holds promise for developing safe, efficacious, and economical sunscreens.

Digestive Enzyme Activities in Mussel Mytilus californianus Endure Acute Heat Exposure in Air.

The mussel Mytilus californianus is an ecosystem engineer forming beds along the coastlines of Northeastern Pacific shores. As sessile organisms, they modulate their energy balance through valve movements, feeding, and digestive functionality. A recent study observed that activity of the digestive enzyme cellulase was higher than predicted in mussels high on the shore, where temperatures are characteristically high and food availability is limited compared to low-shore habitats. In the current study, we predicted that this scavenging behavior is induced to mitigate energy losses related to heat-shock responses-that cellulase and amylase will display hyperactivity for limited recourses in the face of aerial heating. In the laboratory, we acclimated mussels to three complex diets that differed in starch and cellulose composition, followed by two acute heat shocks (+8°C) in the laboratory. Results showed no hyperactivity of amylase and cellulase in heated mussels. These results differ from previous studies that showed lowered amylase activity following heat acclimation. This difference in amylase activity across heat-stress exposure time is important when analyzing mussel bed disturbances following heat waves that compromise energy balance or cause death within adult populations.

Black soldier fly (Hermetia illucens L.): A potential small mighty giant in the field of cosmeceuticals.

Natural products are widely used in the pharmaceutical and cosmetics industries due to their high-value bioactive compounds, which make for "greener" and more environmentally friendly ingredients. These natural compounds are also considered a safer alternative to antibiotics, which may result in antibiotic resistance as well as unfavorable side effects. The development of cosmeceuticals, which combine the cosmetic and pharmaceutical fields to create skincare products with therapeutic value, has increased the demand for unique natural resources. The objective of this review is to discuss the biological properties of extracts derived from larvae of the black soldier fly (BSF; Hermetia illucens), the appropriate extraction methods, and the potential of this insect as a novel active ingredient in the formulation of new cosmeceutical products. This review also addresses the biological actions of compounds originating from the BSF, and the possible association between the diets of BSF larvae and their subsequent bioactive composition. A literature search was conducted using PubMed and Google Scholar to identify and evaluate the various biological properties of the BSF. One such natural resource that may be useful in the cosmeceutical field is the BSF, a versatile insect with numerous potential applications due to its nutrient content and scavenging behavior. Previous research has also shown that the BSF has several biological properties, including antimicrobial, antioxidant, anti-inflammatory, and wound healing effects. Given the range of biological activities and metabolites possessed by the BSF, this insect may have the cosmeceutical potential to treat a number of skin pathologies.

Recovering predators link aquatic and terrestrial ecosystems: River otters subsidize coyotes with carrion.

Despite global declines in the abundance and distribution of predators, conservation and reintroduction efforts are increasingly leading to predator recoveries. Unexpected species interactions and ecological consequences often arise when these predator recoveries occur. Here, we describe a novel species interaction in which coyotes (Canis latrans) kleptoparasitize North American river otters (Lontra canadensis) in a region of river otter recovery along the north-central California coast, USA. We describe eight observations of coyotes scavenging otter-killed waterbird carrion, including one observation in which river otters aggressively defended their prey from a coyote kleptoparasite. These observations highlight the importance of carrion provisioning as an overlooked pathway through which river otters facilitate nutrient subsidies to terrestrial scavengers. This behavior may have ecological implications including effects on the abundance, behavior, and health of scavengers as well as their interspecific interactions. We propose hypotheses and questions regarding these ecological consequences to guide further investigations into the cross-ecosystem impacts of recovering river otter populations.

First evidence of scavenging behaviour in Ichthyosaura alpestris (Laurenti, 1768)

The alpine newt is an opportunistic predator whose diet consists predominantly of aquatic and terrestrial invertebrates with Crustacea, Plecoptera, Collembola, Diptera, Isopoda and Gastropoda being the predominant prey groups. Consumption of amphibian eggs and larvae are another common food source. Here, we report the first documented case of adult Ichthyosaura alpestris feeding on a rodent carcass, thus adding to its menu a prey item that belongs to the Class Mammalia, while showcasing the previously unknown scavenging behaviour. This finding suggests that rodent carcasses can serve as an important resource for nutrients in remote, high-altitude populations of the alpine newt.

Morphological disparity and structural performance of the dromaeosaurid skull informs ecology and evolutionary history

Non-avialan theropod dinosaurs had diverse ecologies and varied skull morphologies. Previous studies of theropod cranial morphology mostly focused on higher-level taxa or characteristics associated with herbivory. To better understand morphological disparity and function within carnivorous theropod families, here we focus on the Dromaeosauridae, ‘raptors’ traditionally seen as agile carnivorous hunters.We applied 2D geometric morphometrics to quantify skull shape, performed mechanical advantage analysis to assess the efficiency of bite force transfer, and performed finite element analysis to examine strain distribution in the skull during biting. We find that dromaeosaurid skull morphology was less disparate than most non-avialan theropod groups. Their skulls show a continuum of form between those that are tall and short and those that are flat and long. We hypothesise that this narrower morphological disparity indicates developmental constraint on skull shape, as observed in some mammalian families. Mechanical advantage indicates that Dromaeosaurus albertensis and Deinonychus antirrhopus were adapted for relatively high bite forces, while Halszkaraptor escuilliei was adapted for high bite speed, and other dromaeosaurids for intermediate bite forces and speeds. Finite element analysis indicates regions of high strain are consistent within dromaeosaurid families but differ between them. Average strain levels do not follow any phylogenetic pattern, possibly due to ecological convergence between distantly-related taxa.Combining our new morphofunctional data with a re-evaluation of previous evidence, we find piscivorous reconstructions of Halszkaraptor escuilliei to be unlikely, and instead suggest an invertivorous diet and possible adaptations for feeding in murky water or other low-visibility conditions. We support Deinonychus antirrhopus as being adapted for taking large vertebrate prey, but we find that its skull is relatively less resistant to bite forces than other dromaeosaurids. Given the recovery of high bite force resistance for Velociraptor mongoliensis, which is believed to have regularly engaged in scavenging behaviour, we suggest that higher bite force resistance in a dromaeosaurid taxon may reflect a greater reliance on scavenging rather than fresh kills.Comparisons to the troodontid Gobivenator mongoliensis suggest that a gracile rostrum like that of Velociraptor mongoliensis is ancestral to their closest common ancestor (Deinonychosauria) and the robust rostra of Dromaeosaurus albertensis and Deinonychus antirrhopus are a derived condition. Gobivenator mongoliensis also displays a higher jaw mechanical advantage and lower resistance to bite force than the examined dromaeosaurids, but given the hypothesised ecological divergence of troodontids from dromaeosaurids it is unclear which group, if either, represents the ancestral condition. Future work extending sampling to troodontids would therefore be invaluable and provide much needed context to the origin of skull form and function in early birds. This study illustrates how skull shape and functional metrics can discern non-avialan theropod ecology at lower taxonomic levels and identify variants of carnivorous feeding.

Revealing the Prevalence of Toxoplasma in Sierra Morena's Wild Boar: An ELISA-Based Study Using Meat Juice.

This research work focused on the prevalence of Toxoplasma gondii in wild boar from the Sierra Morena region. We conducted an ELISA analysis using meat juice samples. A total of 892 samples from six hunting seasons (2013-2019) were collected from the provinces that constitute the Sierra Morena Mountain range. These samples were analyzed using the Pigtype® ELISA kit, specifically developed for detecting T. gondii in meat juice. The overall prevalence of T. gondii in Sierra Morena was 23.2%. The highest prevalences were observed in Córdoba (31.6%) and Jaén (25.9%). These provinces exhibit the highest density of wild boar as well as the greatest presence of the Iberian lynx (Lynx pardinus). Further in-depth studies are necessary, but it appears that the presence of wild felids and scavenger behavior may be associated with this observation.

Wild boar (Sus scrofa) carcasses as an attraction for scavengers and a potential source for soil contamination with the African swine fever virus.

The wild boar (Sus scrofa) is a social animal species native to Eurasia. During the last decade, the wild boar population in Estonia has been severely affected by the African swine fever virus (ASFV), which has also affected domestic pig farming. The potential transmission routes of ASFV remain unclear and are currently under intensive investigation. This pilot study aimed to clarify the frequency and characteristics of contacts between living wild boars and the carcasses of their conspecifics, which could play a role in the transmission of ASFV. Wild animals' contact and scavenging behavior on wild boar carcasses were studied using trail cameras in an experimental setting on Hiiumaa, Western Estonia. Four legally hunted carcasses were used in the present study. This study aimed to determine whether intraspecies scavenging occurs in wild boars. The persistence of ASFV DNA in soil contaminated with infected wild boar carcasses was investigated separately. Among the 17 identified wildlife species that visited wild boar carcasses, the common raven (Corvus corax) was the most frequent one (37.26%), followed by raccoon dogs (Nyctereutes procyonoides; 4.25%), carcass conspecific/wild boars (3.16%), and red foxes (Vulpes vulpes; 2.14%). Regarding the direct contact with the carcass, the same species ranking was detected: common raven (74.95%), raccoon dogs (9.94%), wild boars (4.21%), and red foxes (4.21%). No clear signs of cannibalism were noted among the wild boars, although brief physical contact with the carcasses was evident. The persistence of ASFV DNA in soil contaminated by infected wild boar carcasses was investigated separately. This study revealed that ASFV DNA from infected carcasses could be detected in forest soil for prolonged periods, even after removing the carcasses. Hence, the carcasses of infected wild boars may play an important role in spreading the African swine fever virus in wild boar populations; thus, prompt removal and disinfection of the soil could be considered necessary to limit the spread of the infection.

Broad-spectrum ROS autonomous scavenging polysaccharide-based vehicle to improve the bioactivity of blueberry anthocyanidins through intestinal synergistic mucoadhesion

The harsh physiological environment of the gastrointestinal tract can significantly affect the stability, antioxidant activity, and bioactivity of blueberry anthocyanidins (An), which is usually addressed by intestinal targeting co-delivery of An and other antioxidant substances. However, the modification, synthesis of vehicle and subsequent co-encapsulation procedure involved in this tactic are not conducive to practical application. Herein, we propose an easy method of constructing a biocompatible vehicle with broad-spectrum ROS scavenging performance to enhance the bioactivity of An through synergistic intestinal targeted mucoadhesion, that is, a nanogel (Mgel) was prepared by using thiol-contained sodium alginate, selenized konjac glucomannan and crosslinking with calcium lactate for the intestinal targeted delivery of An (Mgel@An). We evaluated the loading behavior of Mgel on An, as well as the enhancement of Mgel on the stability and bioactivity of An. Mgel@An maintained spherical structure in the stomach but disintegrated and exposed functional groups for synergistic mucoadhesion after treatment with simulated intestinal fluids. Mgel@An exhibited broad-spectrum free radical scavenging activity for •OH, •ABTS+ and •DPPH, and also showed a mucin absorbed amount of 162.03 ± 1.53 μg and 85.63 ± 1.40% bioaccessibility of An. Furthermore, the biosafe Mgel@An extended the maximum lifespan of Caenorhabditis elegans by enhancing the activity of antioxidases, inhibiting the expression of aging key genes (daf-2, age-1), and promoting the expression of anti-aging genes (daf-16, sod-3), as well as anti-oxidative stress genes (sod-5, skn-1). This work highlights the great potential of the vehicle with ROS autonomous scavenging behavior for improving the bioactivity of An.

Prediction of coccidiosis prevalence in extensive backyard chickens in countries and regions of the Horn of Africa

Coccidiosis is one of the leading morbidity causes in chickens, causing a reduction of body weight and egg production. Backyard chickens are at risk of developing clinical and subclinical coccidiosis due to outdoor housing and scavenging behaviour, jeopardizing food security in households. The objectives of this study were to estimate clinical prevalence of coccidiosis at country and regional levels in the Horn of Africa in extensive backyard chickens. A binomial random effects model was developed to impute prevalence of coccidiosis. Previously gathered prevalence data (n = 40) in backyard chickens was used to define the model. Precipitation (OR: 1.09 (95% CI: 1.05–1.13) and the presence of seasonal rainfall (OR: 1.85, 95% CI: 1.27–2.70) significantly increase prevalence. Results showed an overall prevalence of coccidiosis in the Horn of Africa of 0.21 (95% CI: 0.15–0.29). Ethiopia, the Republic of South Sudan and Kenya showed the highest prevalence and Djibouti the lowest. Significant differences between Djibouti and the countries with highest prevalence were found. However, no evidence of a significant difference between the rest of the countries. Kenya and Ethiopia showed larger prevalence differences between regions. Results could assist with the targeting of testing for coccidiosis, the observation for clinical disease of chickens living in specific regions and as a baseline for the evaluation of future control measures.