48 research outputs found

    Seasonal variation in the diet of common quail Coturnix coturnix in the Eastern Cape

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    Crops were analysed and dietary components identified from a total of 175 quails (Coturnix catumix) sampled on several farms in the Alexandria district (Eastern Cape) during Sept 1994-Sept 1995. Quail were found to feed primarily on forb seeds and insects. Diet did not vary between male and female quail, but varied seasonally, with a decrease in seed consumption during the period of peak quail abundance and breeding (October-November), when insect consumption increased. Overall, seed was the dominant food type (both in frequency and quantity). Quail have a seasonally varied diet, relying on seeds of forbs characteristic of cultivated and fallow fields

    Predators on private land: broad-scale socioeconomic interactions influence large predator management

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    The proliferation of private land conservation areas (PLCAs) is placing increasing pressure on conservation authorities to effectively regulate their ecological management. Many PLCAs depend on tourism for income, and charismatic large mammal species are considered important for attracting international visitors. Broad-scale socioeconomic factors therefore have the potential to drive fine-scale ecological management, creating a systemic scale mismatch that can reduce long-term sustainability in cases where economic and conservation objectives are not perfectly aligned. We assessed the socioeconomic drivers and outcomes of large predator management on 71 PLCAs in South Africa. Owners of PLCAs that are stocking free-roaming large predators identified revenue generation as influencing most or all of their management decisions, and rated profit generation as a more important objective than did the owners of PLCAs that did not stock large predators. Ecotourism revenue increased with increasing lion (Panthera leo) density, which created a potential economic incentive for stocking lion at high densities. Despite this potential mismatch between economic and ecological objectives, lion densities were sustainable relative to available prey. Regional-scale policy guidelines for free-roaming lion management were ecologically sound. By contrast, policy guidelines underestimated the area required to sustain cheetah (Acinonyx jubatus), which occurred at unsustainable densities relative to available prey. Evidence of predator overstocking included predator diet supplementation and frequent reintroduction of game. We conclude that effective facilitation of conservation on private land requires consideration of the strong and not necessarily beneficial multiscale socioeconomic factors that influence private land management

    Are we sinking African cheetahs in India?

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    SIGNIFICANCE : The current initiative to export African cheetahs to India has a limited scientific basis, placing the Asian subspecies and the translocated animals at risk. There is no evidence that this will benefit African cheetah conservation. We call for a globally coordinated approach to cheetah conservation, based on sound science.http://www.sajs.co.zahj2023Mammal Research InstituteZoology and Entomolog

    And then there was one: a camera trap survey of the declining population of African elephants in Knysna, South Africa

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    Conservation agencies rely on accurate wildlife population estimates to inform management practices. The importance of accuracy increases with smaller, threatened populations, but so too does the challenge in achieving it, especially for evasive species in low-visibility terrain. Non-invasive survey techniques have been successfully applied in such conditions; however, each technique bears a unique set of limitations and often deliver different results. The shy Knysna elephants (Loxodonta africana) occur at extremely low numbers in difficult terrain, and the past few decades have seen debates raging about their numbers, fuelled in part by differing survey outcomes, although a decline has been apparent over the last 150 years. We surveyed the known range of the Knysna elephant population for 15 months (July 2016 – October 2017), using camera traps, and identified one adult female elephant. The reliability of using camera trapping for surveying animal populations in conditions such as the Knysna elephant is compared with the previous faecal DNA genotyping survey. We conclude that this population has declined to a single individual and discuss the implications for local conservation authorities. Additionally, we highlight the importance of designing rigorous survey approaches where only a few individual animals are present.The South African National Parks’ (SANParks) Garden Route National Park management teamhttp://www.sawma.co.zahj2020Mammal Research Institut

    Top–down limits on prey populations may be more severe in larger prey species, despite having fewer predators

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    Variation in the vulnerability of herbivore prey to predation is linked to body size, yet whether this relationship is size‐nested or size‐partitioned remains debated. If size‐partitioned, predators would be focused on prey within their preferred prey size range. If size‐nested, smaller prey species should become increasingly more vulnerable because increasingly more predators are capable of catching them. Yet, whether either of these strategies manifests in top–down prey population limitation would depend both on the number of potential predator species as well as the total mortality imposed. Here we use a rare ecosystem scale ‘natural experiment’ comparing prey population dynamics between a period of intense predator persecution and hence low predator densities and a period of active predator protection and population recovery. We use three decades of data on herbivore abundance and distribution to test the role of predation as a mechanism of population limitation among prey species that vary widely in body size. Notably, we test this within one of the few remaining systems where a near‐full suite of megaherbivores occur in high density and are thus able to include a thirtyfold range in herbivore body size gradient. We test whether top–down limitation on prey species of particular body size leads to compositional shifts in the mammalian herbivore community. Our results support both size‐nested and size‐partitioning predation but suggest that the relative top–down limiting impact on prey populations may be more severe for intermediate sized species, despite having fewer predators than small species. In addition we show that the gradual recovery of predator populations shifted the herbivore community assemblage towards large‐bodied species and has led to a community that is strongly dominated by large herbivore biomass.The Earthwatch Institute, Ezemvelo KwaZulu-Natal Wildlife and a Marie Curie Grant held by JC (grant # PCIG10-GA-2011-304128). ElR was supported by the South African National Research Foundation, Nelson Mandela Univ. and the Claude Leon Foundation.http://www.ecography.org2020-06-01hj2019Centre for Wildlife Managemen

    Why humans kill animals and why we cannot avoid it

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    Killing animals has been a ubiquitous human behaviour throughout history, yet it is becoming increasingly controversial and criticised in some parts of contemporary human society. Here we review 10 primary reasons why humans kill animals, discuss the necessity (or not) of these forms of killing, and describe the global ecological context for human killing of animals. Humans historically and currently kill animals either directly or indirectly for the following reasons: (1) wild harvest or food acquisition, (2) human health and safety, (3) agriculture and aquaculture, (4) urbanisation and industrialisation, (5) invasive, overabundant or nuisance wildlife control, (6) threatened species conservation, (7) recreation, sport or entertainment, (8) mercy or compassion, (9) cultural and religious practice, and (10) research,education and testing. While the necessity of some forms of animal killing is debatable and further depends on individual values, we emphasise that several of these forms of animal killing are a necessary component of our inescapable involvement in a single, functioning, finite, global food web. We conclude that humans (and all other animals) cannot live in a way that does not require animal killing either directly or indirectly, but humans can modify some of these killing behaviours in ways that improve the welfare of animals while they are alive, or to reduce animal suffering whenever they must be killed. We encourage a constructive dialogue that (1) accepts and permits human participation in one enormous global food web dependent on animal killing and (2) focuses on animal welfare and environmental sustainability. Doing so will improve the lives of both wild and domestic animals to a greater extent than efforts to avoid, prohibit or vilify human animal-killing behaviour. Animal ethics Conservation biology Culling Factory farmingpublishedVersio

    Why humans kill animals and why we cannot avoid it

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    Killing animals has been a ubiquitous human behaviour throughout history, yet it is becoming increasingly controversial and criticised in some parts of contemporary human society. Here we review 10 primary reasons why humans kill animals, discuss the necessity (or not) of these forms of killing, and describe the global ecological context for human killing of animals. Humans historically and currently kill animals either directly or indirectly for the following reasons: (1) wild harvest or food acquisition, (2) human health and safety, (3) agriculture and aquaculture, (4) urbanisation and industrialisation, (5) invasive, overabundant or nuisance wildlife control, (6) threatened species conservation, (7) recreation, sport or entertainment, (8) mercy or compassion, (9) cultural and religious practice, and (10) research,education and testing. While the necessity of some forms of animal killing is debatable and further depends on individual values, we emphasise that several of these forms of animal killing are a necessary component of our inescapable involvement in a single, functioning, finite, global food web. We conclude that humans (and all other animals) cannot live in a way that does not require animal killing either directly or indirectly, but humans can modify some of these killing behaviours in ways that improve the welfare of animals while they are alive, or to reduce animal suffering whenever they must be killed. We encourage a constructive dialogue that (1) accepts and permits human participation in one enormous global food web dependent on animal killing and (2) focuses on animal welfare and environmental sustainability. Doing so will improve the lives of both wild and domestic animals to a greater extent than efforts to avoid, prohibit or vilify human animal-killing behaviour. Animal ethics Conservation biology Culling Factory farmingpublishedVersio

    Factors affecting the prey preferences of jackals (Canidae)

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    Prey selection by carnivores can be affected by top-down and bottom-up factors. For example, large carnivores may facilitate food resources for mesocarnivores by providing carcasses to scavenge, however mesocarnivores may hunt large prey themselves, and their diets might be affected by prey size and behaviour. We reviewed jackal diet studies and determined how the presence of large carnivores and various bottom-up factors affected jackal prey selection. We found 20 studies of black-backed jackals (Canis mesomelas) from 43 different times or places, and 13 studies of Eurasian golden jackals (Canis aureus) from 23 different times or places reporting on 3900 and 2440 dietary records (i.e. scats or stomach contents), respectively. Black-backed jackals significantly preferred small (< 30 kg) ungulate 3 species that hide their young (duiker Sylvicapra grimmia, bushbuck Tragelaphus scriptus and springbok Antidorcas marsupialis), and avoided large (> 120 kg) hider species and follower species of any body size. They had a preferred and accessible prey weight range of 14-26 kg, and a predator to ideal prey mass ratio of 1:3.1. Eurasian golden jackal significantly prefer to prey on brown hare (Lepus europaeus; 4 kg), yielding a predator to preferred prey mass ratio of 1:0.6, and a preferred and accessible prey weight range of 0 – 4 kg and 0 – 15 kg, respectively. Prey preferences of jackals differed significantly in the presence of apex predators, but it was not entirely due to carrion availability of larger prey species. Our results show that jackal diets are affected by both top-down and bottom-up factors, because apex predators as well as prey size and birthing behaviour affected prey preferences of jackals. A better understanding of the factors affecting jackal prey preferences, as presented here, could lead to greater acceptance of mesocarnivores and reduced human-wildlife conflict
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