Evidence that vulture restaurants increase the local abundance of mammalian carnivores in South Africa

Vulture restaurants are used worldwide as a conservation tool to provide threatened vultures with a source of supplementary carrion free from anthropogenic contaminants such as poisons and veterinary drugs. While the impacts of supplementary feeding sites on ecosystem and scavenging community dynamics have been investigated in Europe, no information is currently available for southern Africa. This study presents evidence that providing supplementary carrion for vultures stimulated an increase in local abundance of two species of mammalian carnivores, the brown hyaena (Hyaena brunnea) and the black-backed jackal (Canis mesomelas). These findings require that the wider impacts of providing supplementary carrion for conserving threatened species are fully investigated

White-headed Vultures Trigonoceps occipitalis show visual field characteristics of hunting raptors

The visual fields of Aegypiinae vultures have been shown to be adapted primarily to meet two key perceptual challenges of their obligate carrion-feeding behaviour: scanning the ground and preventing the sun’s image falling upon the retina. However, field observations have shown that foraging White-headed Vultures (Trigonoceps occipitalis) are not exclusively carrion-feeders; they are also facultative predators of live prey. Such feeding is likely to present perceptual challenges that are additional to those posed by carrion-feeding. Binocularity is the key component of all visual fields and in birds it is thought to function primarily in the accurate placement and time of contact of the talons and bill, especially in the location and seizure of food items. We determined visual fields in White-headed Vultures and two species of carrion-eating Gyps vultures, and show that the visual field of White-headed Vultures have more similarities with those of predatory raptors (e.g. Accipitrid hawks), compared with the taxonomically more closely related Gyps vultures. We found that maximum binocular field width in White-headed vultures (30°) is significantly wider than Gyps vultures (20°). The broader binocular fields in White-headed Vultures probably facilitate accurate placement and timing of the talons when capturing evasive live prey

Carrion Availability in Space and Time

Introduction Availability of carrion to scavengers is a central issue in carrion ecology and management, and is crucial for understanding the evolution of scavenging behaviour. Compared to live animals, their carcasses are relatively unpredictable in space and time in natural conditions, with a few exceptions (see below, especially Sect. “Carrion Exchange at the Terrestrial-Aquatic Interface”). Carrion is also an ephemeral food resource due to the action of a plethora of consumers, from microorganisms to large vertebrates, as well as to desiccation (i.e., loss of water content; DeVault et al. 2003; Beasley et al. 2012; Barton et al. 2013; Moleón et al. 2014). With a focus on vertebrate carcasses, here we give an overview of (a) the causes that produce carrion, (b) the rate of carrion production, (c) the factors affecting carrion quality, and (d) the distribution of carrion in space and time, both in terrestrial and aquatic environments (including their interface). In this chapter, we will focus on naturally produced carrion, whereas non-natural causes of animal mortality are described in chapter “Human-Mediated Carrion: Effects on Ecological Processes”. However, throughout this chapter we also refer to extensive livestock carrion, because in the absence of strong restrictions such as those imposed in the European Community after the bovine spongiform encephalopathy crisis (Donázar et al. 2009; Margalida et al. 2010), the spatiotemporal availability of carrion of extensive livestock and wild ungulates is similar

Estimating ungulate carrion biomass and possible ecological effects on red fox (Vulpes vulpes) in central Norway

Ungulates constitute the bulk of carrion in many terrestrial ecosystems. Knowledge of carrion availability is paramount to understand its ecological effects and I aimed to estimate carrion availability in Nord-Trøndelag county in central Norway. I also discuss possible ecological effects of carrion availability on a key stone predator in Scandinavia, the red fox (Vulpes vulpes). I used literature to estimate average monthly carrion availability from wild ungulates (moose Alces alces and roe deer Capreolus capreolus) and livestock (domestic sheep Ovis aries and semi-domestic reindeer Rangifer tarandus tarandus). I estimated monthly carrion supply from four carrion sources; i) predation remains, ii) harvest remains, iii) traffic collisions and iv) other causes of death (OCD). Spatio-temporal carrion availability was divided in forest/agricultural areas and mountain areas during the cold and the warm season, respectively. I found that domestic sheep contributed to maintain the annual stability of carrion supply in both areas by providing carrion only in the warm season. Estimated average annual carrion supply was by far most prominent in forest/agricultural areas (70 kg/km2). The supply peaked in the end of the warm season due to remains from the autumn harvest (25 kg/km2) from which discarded internal organs from moose constituted 20 kg/km2. Estimated carrion supply from harvest and OCD was of same magnitude and both resources are available over large areas. I suggest that harvest remains appear as more clumped distribution in lower altitudes near farmland due to moose and roe deer habitat preferences. I also suggest a similar distribution of OCD carcasses during the cold season due to migratory effects. Furthermore, winter severity most likely skews this availability towards late winter and spring. Based on the findings, I expect increased red fox survival when the availability of voles is low. This is mainly due to the combined effect of estimated amounts of harvest remains in the face of winter and the amount of carrion supply during the cold season. Future research should focus on the importance of carrion availability on red fox distribution, density and reproduction

Effect of Habitat on Blow Fly (Diptera: Calliphoridae) Oviposition in Michigan

Forensic entomology applies data gained from insects to aid the criminal justice system. Blow flies (Diptera: Calliphoridae) are usually the first insects to arrive and oviposit (lay eggs) on carrion. Their quick appearance is the foundation for post mortem interval estimations, making any factors that influence their oviposition crucial. This study examined the effects of habitat (forest vs. prairie) on blow fly oviposition timing. Research was conducted in 2015 at Pierce Cedar Creek Institute in Barry County, Michigan. No significant differences were found in oviposition timing or frequency between prairie and forest habitats. Temperature and humidity were not correlated with oviposition timing, which contradicted previous studies. Lucilia coeruleiviridis (Macquart) was the dominant species found, comprising about 90% of collected specimens. The data confirm previous reports that Lucilia species are the first to arrive on carrion

Spring Season Survey of the Urban Blowflies (Diptera: Calliphoridae) of Chicago, Illinois

During May 1980, 1165 blowflies of 12 species were trapped on chemically enhanced rat carrion baits in a dense urban setting in Chicago. In descending order, Cynomyopsis cadaverina, Lucilia sericata, and Phormia regina were the most abundant species recovered (92% of total). These results are contrasted with other nearby blowfly surveys