278 research outputs found
Diet composition of the golden jackal (Canis aureus) in the Ngorongoro Crater, Tanzania
The Ngorongoro crater is known for having the highest density of carnivores in the world. In the past, most of the research focused on large carnivores such as lions and spotted hyenas. Medium sized carnivores such as jackals have received very little attention and the information on these carnivores including their diet composition is limited. Diet composition of golden jackal(Canis aureus) was studied in the Ngorongoro crater from July 2014 to May 2015 covering both dry and wet seasons using focal animal observation (direct method) and collection (and analysis) of faecal/scat samples from known individuals in the field (indirect method). In both seasons, insects (mostly dung beetles, Family Scarabaeidae) were the most common food item consumed. Quantitatively, carrion (carcasses of large herbivores mainly wildebeest and buffalo) and Abdim's storks (Ciconia abdimii) contributed the most to the diet of golden jackal in the dry and wet season respectively. Jackals also consumed plant materials of the family Cucurbitaceae in both dry and wet seasons. Seasonal variation in types of food was noted; in wet season when the jackals consumed birds (Abdim's storks), Thomson's gazelle fawns and wildebeest placenta. The results suggest that the golden jackals are omnivorous and opportunistic foragers.Key words: diet, season, golden jackal, Ngorongor
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A Comparative Analysis of the Orgelbüchlein by J.S. Bach and Choral-Vorspiele für Orgel by Max Reger
One of the outstanding aspects of nineteenth-century romanticism was its preoccupation with the past. This interest in the music or the old masters has lasted well into the twentieth century, and one whose lifetime bridged the two centuries was the composer Max Reger (1873-1916). Reger's admiration for the music of the past pervaded his own works. His preference for contrapuntal textures and devices, his use of baroque forms, his distaste for program music--all bespeak Reger's especial interest in the old masters, particularly in 5. S. Bach. These qualities led some to regard him as the successor of Johannes Brahms, who held similar tenets. Because of his particular interest in composing for the organ, Reger was viewed as a "nineteenth-century Bach.
Food availability and population structure: How do clumped and abundant sources of carrion affect the genetic diversity of the black-backed jackal?
Carnivores frequently come into conflict with humans in agricultural and livestock- producing areas around the world. Understanding their fidelity and dispersal patterns in response to food availability is therefore important given the effort invested in conflict mitigation strategies. In this study, we investigated the influence of clumped and abundant sources of carrion on the genetic diversity of the black-backed jackal Canis mesomelas within six private game farms in the North-West and Gauteng provinces of South Africa. It is predicted that clumped and abundant sources of carrion will increase immigration and thus genetic diversity in the local subpopulation. By quantifying the variability in microsatellite loci in black-backed jackals subjected to artificially increased carrion availability, and comparing them with individuals from control sites, we were able to describe patterns of historic gene flow within the total sampled population. The results of this investigation indicate that clumped and abundant sources of carrion promote genetic structuring (FST = 0.0302) which implies a lack of gene flow and a degree of isolation. Genetic artefacts of three populations could be identified through Bayesian clustering analysis of individuals based on their genetic identity. Individuals sampled from the two supplementary feeding sites could be assigned to one of two ancestral populations with an average population assignment of 69 and 82%, while individuals from the remaining four control sites, originate from a third population with percentage assignments of 63%, 46%, 53% and 42%. It is therefore likely that clumped and abundant sources of carrion in the agricultural landscape of South Africa can affect the population dynamics of the black-backed jackal and result in subpopulations with limited migration and dispersal when compared with the total population
Diet of the Golden Jackal (Canis aureus) and Silver-Backed Jackal (Canis mesomelas) in the Southern Part of the Serengeti Ecosystem, Tanzania: A Comparative Study
Habitat and food resource partitioning are predicted to facilitate the coexistence of similar-sized carnivores. The golden jackal (Canis aureus) and silver-backed jackal (Canis mesomelas) are similar-sized canids that respectively inhabit grassland and woodland in the Serengeti ecosystem, Tanzania. As information on the diet and food-intake of these two species in this ecosystem is limited, we aimed to compare the diet and food-intake of these canids in the wet and dry seasons, using data from focal samples of foraging behaviour and scat analysis. We predicted dietary differences between these species, seasonal differences within species and peak food intake when breeding. Result of a logistic regression considering insect and small mammal remains in scats revealed dietary differences both between species and within-species seasonal differences. Results of a censored regression model on the estimated weigh of food intake by foraging individuals indicated that intake was highest during the breeding season of each species, which occurs in the wet season in golden jackals and the dry-season in silver-backed jackals. Our study provides new insights on differences in the foraging ecology of these two jackal species in the Serengeti ecosystem.
Keywords: Canis aureus; Canis mesomelas, diet, Serengeti ecosystem, season
Comparative Foraging Efficiency of Two Sympatric Jackals, Silver-Backed Jackals ( Canis mesomelas
The foraging efficiency of two sympatric species of jackals, silver-backed jackals (Canis mesomelas) and golden jackals (Canis aureus), was studied in the Ngorongoro crater from July 2014 through May 2015. The focal animal observation method was used and individuals of both species were followed as they foraged from morning to evening. Observations of individuals of both jackal species were made from a vehicle using binoculars and a spotting scope. Three major parameters were used for determination of foraging efficiency: distance travelled while foraging, time spent foraging, and amount of food secured in foraging period. The Mann–Whitney U test showed no significant difference (P>0.05) in distance travelled per unit time of foraging between the two species in the dry and wet seasons, respectively. Golden jackals secured a significantly higher amount of food than the silver-backed jackals in the wet season (Mann–Whitney U test, P<0.05, U=1035.4). Hunting of prey larger than Thomson’s gazelle (Eudorcas thomsonii) fawns was not common. Both species mainly fed on smaller prey such as invertebrates and rodents and scavenged opportunistically. Efficient foraging is crucial for both jackal species especially during their breeding season when they are provisioning dependent pups
An online mechanism for multi-unit demand and its application to plug-in hybrid electric vehicle charging
Towards resolving taxonomic uncertainties in wolf, dog and jackal lineages of Africa, Eurasia and Australasia
Successful conservation depends on accurate taxonomy. Currently, the taxonomy of canids in Africa, Eurasia and Australasia is unstable as recent molecular and morphological studies have questioned earlier phenetic classifications. We review available information on several taxa of Old World and Australasian Canis with phylogenetic uncertainties (namely, African jackals, Asian wolves and Australasian dogs), in order to assess the validity of suggested scientific names and provide a scientific basis for reaching a taxonomic consensus primarily based on molecular data, but also including morphology, biogeography and behavioural ecology. We identify major knowledge gaps, provide recommendations for future research and discuss conservation implications of an updated taxonomic framework. Recent molecular studies indicate that the former Afro-Eurasian 'golden jackal' represents two distinct lineages, the golden jackal (Canis aureus) from Eurasia and the African wolf (C. lupaster) from Africa. Phylogenetic research also indicates that the side-striped and black-backed jackals form a monophyletic group that branched earlier than Canis, Cuon and Lycaon, which should be reassigned to the genus Lupulella as L. adusta and L. mesomelas, respectively. The Himalayan/Tibetan and Indian wolf lineages appear to have diverged earlier and are distinct from all other grey wolves (C. lupus) based on mitochondrial and nuclear genome data. However, until genome-wide data from multiple individuals across the range clarify relationships with other taxa, we suggest referring to the Himalayan/Tibetan wolf lineage as Canis lupus chanco. We support the currently accepted nomenclature for the Indian wolf Canis lupus pallipes for the wolf populations found on the Indian subcontinent and possibly also in south-western Asia (exact geographical boundary pending). The information presented here provides a current and consistent taxonomic framework for use by conservationists and other practitioners, but it is also intended to stimulate further research to resolve current uncertainties affecting the taxonomy of Old World canids.Peer reviewe
Auditory communication in domestic dogs: vocal signalling in the extended social environment of a companion animal
Domestic dogs produce a range of vocalisations, including barks, growls, and whimpers, which are shared with other canid species. The source–filter model of vocal production can be used as a theoretical and applied framework to explain how and why the acoustic properties of some vocalisations are constrained by physical characteristics of the caller, whereas others are more dynamic, influenced by transient states such as arousal or motivation. This chapter thus reviews how and why particular call types are produced to transmit specific types of information, and how such information may be perceived by receivers. As domestication is thought to have caused a divergence in the vocal behaviour of dogs as compared to the ancestral wolf, evidence of both dog–human and human–dog communication is considered. Overall, it is clear that domestic dogs have the potential to acoustically broadcast a range of information, which is available to conspecific and human receivers. Moreover, dogs are highly attentive to human speech and are able to extract speaker identity, emotional state, and even some types of semantic information
Foraging ecology of Eurasian lynx populations in southwest Asia: Conservation implications for a diet specialist
Intraspecific variation in key traits of widespread species can be hard to predict, if populations have been very little studied in most of the distribution range. Asian populations of the Eurasian lynx (Lynx lynx), one of the most widespread felids worldwide, are such a case in point. We investigated the diet of Eurasian lynx from feces collected Mediterranean, mixed forest‐steppe, and subalpine ecosystems of Turkey. We studied prey preferences and functional responses using prey densities obtained from Random Encounter Modelling. Our analysis revealed that the main prey was brown hare (Lepus europaeus) in all three areas (78%–99% of biomass consumed) and lynx showed a strong preference for brown hare (Chesson's selectivity index, α = 0.90–0.99). Cannibalism contributed at least 5% in two study areas. The type II functional response of lynx populations in Turkey was similar to the Canada lynx (Lynx canadensis) and daily food intake in grams per lynx matched that of Canada lynx and Iberian lynx (Lynx pardinus), both lagomorph specialists, rather than those of Eurasian lynx from Europe. Therefore, lynx in Turkey may be better described as a lagomorph specialist even though it coexists with ungulate prey. We suggest that ungulate‐based foraging ecology of Eurasian lynx in Europe may be a recent adjustment to the availability of high densities of ungulates and cannot be representative for other regions like Turkey. The status of lagomorphs should become an essential component of conservation activities targeted at Eurasian lynx or when using this species as a flagship species for landscape preservation
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