Phylogenetic and functional diversity in large carnivore assemblages

Large terrestrial carnivores are important ecological components and prominent flagship species, but are often extinction prone owing to a combination of biological traits and high levels of human persecution. This study combines phylogenetic and functional diversity evaluations of global and continental large carnivore assemblages to provide a framework for conservation prioritization both between and within assemblages. Species-rich assemblages of large carnivores simultaneously had high phylogenetic and functional diversity, but species contributions to phylogenetic and functional diversity components were not positively correlated. The results further provide ecological justification for the largest carnivore species as a focus for conservation action, and suggests that range contraction is a likely cause of diminishing carnivore ecosystem function. This study highlights that preserving species-rich carnivore assemblages will capture both high phylogenetic and functional diversity, but that prioritizing species within assemblages will involve trade-offs between optimizing contemporary ecosystem function versus the evolutionary potential for future ecosystem performance.Research fellowship from University of Pretoria and by incentive funding from the National Research Foundation of South Africahttp://rspb.royalsocietypublishing.org/hb2013ab201

Identifying the role of conservation biology for solving the environmental crisis

Humans are altering their living environment to an extent that could cause environmental collapse. Promoting change into environmentally sustainability is therefore urgent. Despite a rapid expansion in conservation biology, appreciation of underlying causes and identification of long-term solutions have largely been lacking. I summarized knowledge regarding the environmental crisis, and argue that the most important contributions towards solutions come from economy, political sciences, and psychology. Roles of conservation biology include providing environmental protection until sustainable solutions have been found, evaluating the effectiveness of implemented solutions, and providing societies with information necessary to align effectively with environmental values. Because of the potential disciplinary discrepancy between finding long-term solutions versus short term protection, we may face critical trade-offs between allocations of resources towards achieving sustainability. Since biological knowledge is required for such trade-offs, an additional role for conservation biologists may be to provide guidance towards finding optimal strategies in such trade-offs.University of Pretoria, South Africa and the National Research Foundation.http://link.springer.com/journal/13280hb201

Descriptive versus explanatory hypotheses in evolutionary research : a potentially concerning bias exemplified by research into the evolution of social organisations in carnivores

In this note I want to point out a potentially concerning bias in evolutionary hypothesis testing. In evolutionary research, deductive hypothesis testing is the most common way of achieving information on causal relationships (QUINN & DUNHAM 1983; LOEHLE 1987). Two general classes of hypotheses can be identified in research on trait evolution, although these may not always be explicitly stated. Hypotheses of the first class are descriptive in that they specifically relate to how traits have evolved. These hypotheses typically focus on evolutionary trajectories, but may also include rates of evolutionary change or the nature of the evolutionary process itself (PAGEL 1997). Hypotheses of this class are often tested using phylogenetic methods (e.g., SWOFFORD & MADDISON 1987; MADDISON 1994; SCHLUTER 1995; SCHLUTER et al. 1997; PAGEL 1999), and generally make no assumptions regarding the causes for evolutionary events. Hypotheses belonging to the second class, on the other hand, are explanatory in that they focus on explaining why a particular evolutionary process has occurred. These hypotheses therefore rest on an assumption that a specific course of evolution has taken place. They are generally analysed using a fitness maximization framework, and in contrast to descriptive hypotheses are not frequently tested using phylogenetic approaches (WADE & KALISZ 1990).A fellowship from the University of Pretoria Research Fellowship Programme and by a fellowship from the National Research Foundation of South Africa.http://www.tandfonline.com/loi/teee20nf201

Arctic Fox (Alopex lagopus) Diet in Karupelv Valley, East Greenland, during a Summer with Low Lemming Density

We investigated the diet of arctic foxes (Alopex lagopus) in the Karupelv valley, East Greenland, during the summer of 1997. Despite a low density, lemmings were the most utilized prey, comprising 65.3% of dry fecal weight in fresh feces. This demonstrates the importance of lemming species as prey for arctic foxes all through a lemming cycle. Birds, arctic hare (Lepus arcticus), and insects also contributed to the diet. Arctic fox remains suggested that the foxes had scavenged their own species. Vegetation, muskoxen (Ovibos moschatus), and seal (Phocidae) were found in small amounts. We compared estimates of prey availability and diets of arctic foxes for a coastal area (<10 km from the shore) and an inland area (>10 km from the shore). Abundance of avian prey tended to be higher in the coastal area. Fresh feces indicated a significant overall difference in arctic fox diets between the coastal and inland areas. Within prey categories, lemmings were significantly more represented in the inland area, while the coastal area had a more diverse diet overall. We also suggest that the existence of arctic foxes in East Greenland is dependent on regular peak years in lemming density.Au cours de l'été de 1997, on a étudié le régime alimentaire du renard arctique (Alopex lagopus) dans la vallée de la Karupelv (Groenland oriental). Malgré sa faible densité, le lemming était la proie la plus courante, constituant 65,3 p. cent de poids fécal sec dans les excréments frais. Ce fait illustre l'importance de l'espèce du lemming comme proie pour le renard arctique durant un cycle complet de lemmings. Les oiseaux, le lièvre arctique (Lepus arcticus) et les insectes entraient aussi dans le régime alimentaire. Des restes de renard arctique donnent à penser que les renards se nourrissaient des charognes de leurs congénères. On a trouvé de petites quantités de plantes, de boeuf musqué (Ovibos moschatus) et de phoque (Phocidae). On a comparé les estimations de la disponibilité des proies et le régime des renards arctiques pour une région côtière (< 10 km du rivage) et pour une région à l'intérieur des terres (> 10 km du rivage). L'abondance des proies aviaires tendait à être plus grande dans la région côtière. Les excréments frais révélaient une différence globale importante dans le régime du renard arctique entre la région côtière et l'intérieur des terres. Si l'on considère les catégories de proies, le lemming se retrouvait en quantité relativement plus élevée dans la région située à l'intérieur des terres, alors que la région côtière avait dans l'ensemble un régime plus diversifié. On suggère également que l'existence du renard arctique dans l'est du Groenland est liée à la régularité des années d'abondance dans la densité de lemmings

Landscape Level Effects of Lion Presence (Panthera leo) on Two Contrasting Prey Species

Due to the strong individual cost of being predated, potential prey species alter their behavior and physiology in response to predation risk. Such alterations may cause major indirect consequences on prey populations that are additive to the direct demographic effects caused by prey being killed. However, although earlier studies showed strong general effects of the presence of apex predators, recent data suggest that indirect effects may be highly context dependent and not consistently present. We combined behavioral data with data on endocrine stress and stable isotopes to assess landscape level effects of lion (Panthera leo) presence on two prey species in South Africa, impala (Aepyceros melampus) and blue wildebeest (Connochaetes taurinus). We also evaluated if there was any seasonal variation in such effects. In addition, we provide results from a physiological validation for an enzyme-linked immunoassay (EIA) that can be used for non-invasive monitoring of glucocorticoid stress metabolite concentrations in impala from fecal pellets. We did not find any significant differences in vigilance behavior, fecal glucocorticoid metabolite concentrations, δ13C values or isotope niche breadth between animals living with and without lions for either species. However, wildebeest living in a reserve with lions spent more time foraging compared to wildebeest in a lion-free environment, but only during the wet season. Values of fecal δ15N suggest a shift in habitat use, with impala and wildebeest living with lions potentially feeding in less productive areas compared to animals living without lions. For both species, characteristics of the social groups appeared to be more important than individual characteristics for both foraging and vigilance behavior. Our results highlight that antipredator responses may be highly dynamic and scale-dependent. We urge for further studies that quantify at what temporal and spatial scales predation risk is causing indirect effects on prey populations

Game auction prices are not related to biodiversity contributions of southern African ungulates and large carnivores

There is an urgent need for human societies to become environmentally sustainable. Because public policy is largely driven by economic processes, quantifications of the relationship between market prices and environmental values can provide important information for developing strategies towards sustainability. Wildlife in southern Africa is often privately owned and traded at game auctions to be utilized for commercial purposes mostly related to tourism. This market offers an interesting opportunity to evaluate how market prices relate to biologically meaningful species characteristics. In this market, prices were not correlated with species contributions to either phylogenetic or functional diversity, and species contributions to phylogenetic or functional diversity did not influence the trends in prices over time for the past 20 years. Since this economic market did not seem to appreciate evolutionary or ecologically relevant characteristics, we question if the game tourism market may contribute towards biodiversity conservation in southern Africa. We suggest that market prices in general may have limited values as guides for directing conservation and environmental management. We further suggest that there is a need to evaluate what humans value in biological organisms, and how potentially necessary shifts in such values can be instigated.FD received financial support from University of Pretoria, the National Research Foundation and a Ramón y Cajal fellowship from the Spanish Ministry of Economy and Competitiveness.http://www.nature.com/scientificreportsam2016Mammal Research InstituteZoology and Entomolog

African ungulates recognize a locally extinct native predator

Large carnivores are important ecosystem components but frequently suffer local extinctions. However, reintroductions and shifting conservation attitudes have lead to some population repatriations. Since the ecological consequences of predation may relate to indirect effects of predation risk, reconstruction of carnivore ecosystem function could depend on adequate predator recognition by prey. We evaluated behavioral responses in naive and lion exposed impala (Aepyceros melampus), blue wildebeest (Connochaetes taurinus), and warthogs (Phacochoerus africanus) to audio calls of a native (African lion Panthera leo) and an alien (grey wolf Canis lupus) predator as well as to unfamiliar (music) and familiar (running water) neutral controls. Our results demonstrated stronger behavioral responses to lions than to any of the other calls, even in naive populations, and suggest that retained predator recognition may enable rapid reconstruction of carnivore ecosystem function throughout Africa. However, since recognition may be lost in large increments, we urge that carnivore repatriations should be a prioritized component of African ecosystem conservation.National Geographic/Wait’s Foundation (grant number W32-08), the National Research Foundation (grant number NRF66135), and by the University of Pretoria.http://beheco.oxfordjournals.org2016-01-30hb201

Interaction patterns within a multi-herbivore assemblage derived from stable isotopes

The ecological effects of consumer guilds are strongly driven by the relative resource use of included species. Here we use stable isotopes in faecal samples from 6 co-occurring mammalian herbivores in an African savanna to identify species-specific trophic niches and detect patterns of interactions between herbivores and their feeding resources. Species-specific foraging strategies were reflected in the faecal δ13C values, with species aligning along both a browser-grazer gradient and a niche breadth gradient. Within the broad foraging strategies outlined by δ13C, δ15N indicated a seasonal shift in resource use for some herbivores. We expected that 13C isotope niches would overlap in a nested fashion, with the niches of grazers and browsers being included in those of mixed feeders, and that 15N niches would separate into discrete modules reflecting leguminous and protein content of respective diets. However, the observed structure was more complex, with combined modular and nested patterns of interactions between herbivores and 13C isotopes. We identified an isolated module comprising eland and its exclusive δ13C values, and a series of nested structures with a set of specialist herbivores (hartebeest and sable) which δ13C values were nested within those of more generalist herbivores (impala, waterbuck and zebra). Networks based on δ15N, however, reflected a higher level of overlap in resource use with random patterns in herbivore interactions with resources, and only a significant modular interaction pattern during the dry season. We suggest that the combined modular and nested pattern of δ13C interactions reflect the simultaneous mutualistic and antagonistic characteristics of plant–herbivore interactions. We argue that such interaction patterns could stabilize ecosystems by constraining effects of perturbations to specific modules and by increasing functional redundancy through nested interactions.MM was supported by a Free-standing Postdoctoral Fellowship co-funded by the National Research Foundation (grant number: 76444) and the University of the Witwatersrand, and a Claude Leon Postdoctoral Fellowship. FP received financial support from the University of the Witwatersrand; FD from University of Pretoria and the National Research Foundation. Project funding was provided by the University of the Witwatersrand.http://www.elsevier.com /locate/ecocomhj201

Complete mitochondrial genome of a bat-eared fox (Otocyon megalotis), along with phylogenetic considerations

The bat-eared fox, Otocyon megalotis, is the only member of its genus and is thought to occupy a basal position within the dog family. These factors can lead to challenges in complete mitochondrial reconstructions and accurate phylogenetic positioning. Here, we present the first complete mitochondrial genome of the bat-eared fox recovered using shotgun sequencing and iterative mapping to three distantly related species. Phylogenetic analyses placed the bat-eared fox basal in the Canidae family within the clade including true foxes (Vulpes) and the raccoon dog (Nyctereutes) with high support values. This position is in good agreement with previously published results based on short fragments of mitochondrial and nuclear genes, therefore adding more support to the basal positioning of the bat-eared fox within Canidae.The European Research Council (consolidator grant GeneFlow # 310763 to M.H), National Research Foundation (NRF, South Africa), Ministry of Economy and Competitiveness (MINECO, Spain), and Swedish Research Council Formas (Sweden).http://www.tandfonline.com/loi/tmdn20am2017Mammal Research InstituteZoology and Entomolog

Spotted hyaena space use in relation to human infrastructure inside a protected area

Increasing human population growth has led to elevated levels of human-carnivore conflict. However, some carnivore populations have adapted to urban environments and the resources they supply. Such associations may influence carnivore ecology, behaviour and life-history. Pockets of urbanisation sometimes occur within protected areas, so that anthropogenic influences on carnivore biology are not necessarily confined to unprotected areas. In this study we evaluated associations between human infrastructure and related activity and space use of spotted hyaenas within one of the largest protected areas in South Africa, the Kruger National Park. Home range size was smaller for the dominant female of a clan living in close proximity to humans than that of the dominant female of a clan without direct access to human infrastructure. The home range including human infrastructure was also used less evenly during the night, presumably when the animals were active. Within this home range, a village area was preferred during the night, when the least modified areas within the village were preferred and administration and highly modified areas were avoided. During the day, however, there were no preference or avoidance of the village area, but all habitats except unmodified habitats within the village area were avoided.Wesuggest that human infrastructure and associated activity influenced hyaena space use, primarily through alterations in the spatial distribution of food. However, these effects may have been indirectly caused by habitat modification that generated favourable hunting habitat rather than a direct effect caused by access to human food such as garbage. Because of the often pivotal effects of apex predators in terrestrial ecosystems, we encourage further work aimed to quantify how human presence influences large carnivores and associated ecosystem processes within protected areas.Supplement 1. Estimation of convergence of home range size estimates. To evaluate whether or not we had sufficient sample sizes to estimate seasonal home ranges we created accumulation curves for each clan and season. We created randomized sets of coordinates with increasing sample sizes from 10 relocations up to the actual sample size used for each seasonal range. For each sample size, we randomly drew 100 data sets without replacements from the original sets of coordinates that was utilized to calculate each seasonal home range, and for each random data set we calculated the area covered by a 100% MCP. These areas were plotted against sample size. (10.7717/peerj.2596/supp-1)Supplement 2. Raw data on animal locations. (DOI: 10.7717/peerj.2596/supp-2)This study was funded through incentive funding for rated researchers by the National Research Foundation (E Cameron, F Dalerum), a research fellowship from University of Pretoria (F Dalerum) as well as a Ramón y Cajal fellowship by the Spanish Ministry of Comptitiveness and Economy (F Dalerum).https://peerj.comam2017Mammal Research InstituteZoology and Entomolog