Prey selection and the impact of cheetah predation on prey populations

2017 ◽  
Author(s):  
M.G.L. Mills ◽  
M.E.J. Mills
Keyword(s):  
Prey Selection ◽  
Selection Process ◽  
Late Pregnancy ◽  
Prey Preference ◽  
Regulatory Role ◽  
Density Dependent ◽  
Selection For ◽  
Preferred Species ◽  
The Impact ◽  
Prey Populations

Small springbok lambs were killed more frequently than expected and large lambs and subadults in more or less expected proportions. Adults were killed less frequently than expected, although old animals, females in late pregnancy, and males were vulnerable. A similar selection process was observed in steenbok, except medium-sized lambs, not small lambs, were usually killed, and there was no selection for sex. Cheetah predation was found to have an important density-dependent regulatory role on these two species. Analyses of prey preference using Jacob’s index showed that springbok were the most preferred species, although their distribution was limited, and springhares the most important avoided species, despite their prevalence in solitary cheetahs’ kills. Examples of diet flexibility in the cheetah occurred during an eland influx into the study area, when coalition males killed a number of calves, and when an emaciated female took to preying on unpalatable bat-eared foxes.

Interpreting Selectivity Indices Calculated from Field Data or Conditions of Prey Replacement

1987 ◽  
Vol 44 (9) ◽  
pp. 1529-1533 ◽  
Author(s):  
John L. Confer ◽  
Marianne V. Moore
Keyword(s):  
Relative Abundance ◽  
Prey Item ◽  
Field Data ◽  
Prey Selection ◽  
Prey Type ◽  
Neutral Selection ◽  
Field Samples ◽  
Linear Index ◽  
Selection For ◽  
The Impact

Indices of prey selection are compared empirically to clarify the kind of information each can provide and when the indices can be used appropriately. Emphasis is given to Chesson's alpha (α) and Strauss' Linear index (Li) because they are commonly used and represent two mathematically dissimilar approaches to measuring selection. Neutral selection for α and Li is not equivalent. For Li, neutral selection for a prey type occurs when selectivity equals the weighted (by relative abundance) average selectivity for all other prey types. For α, neutral selection equals the unweighted average for all prey types, which is equivalent to 1 divided by the number of prey types. Li and α respond differently to rare prey types. This is especially evident in field samples having large differences in relative prey abundances. Li values decrease as abundance of a prey type decreases in the environment, in contrast, α values often increase greatly as the proportional abundance of a prey type in the environment decreases. Consequently, α values, but not Li values, are often strongly influenced by the values for very rare prey, α values are sensitive to changes in the number of prey types, but not to changes in prey proportion. When the number of prey types is constant, α may be the most meaningful indicator of prey type preference. In contrast, Li values are sensitive to changes in prey proportions in the environment. When prey proportions are constant among experiments, Li is appropriate for measuring changes in the impact of a predator on a prey type and changes in selectivity relative to the average prey item. If number of prey types and prey proportions vary among experiments, Vanderploeg and Scavia's W or E* may be most appropriate.

Students’ Management to Increase the Character and Achievement in MAN 2 Banjarnegara

2018 ◽  
Vol 2 ◽  
Author(s):  
Sidik Wibowo Akhmad
Keyword(s):  
Academic Achievement ◽  
Extracurricular Activities ◽  
Selection Process ◽  
Skill Test ◽  
Spare Time ◽  
New Students ◽  
Strong Motivation ◽  
Character Building ◽  
The Impact ◽  
Enrollment Process

The purpose of this study was to describe the students’ management in increasing the character and achievement in MAN 2 Banjarnegara including: (1) the enrollment process of new students, (2) guiding students through discipline, noble character building, academic and non-academic achievement, and (3) the impact of character building and the achievement for students MAN 2 Banjarnegara. This research implemented descriptive qualitative approach. The data collection techniques were in-depth interview, observation, and documentation study. The validity of the data used three criteria; namely credibility, dependability, and conformability. The findings of this study were: The first, the enrollment process of the new students was made a breakthrough during the registration of academic and non-academic achievement of scholarships, the selection process was conducted through the value of official learning reports, certificate of championship/achievement, academic potential test and non-academic, and also the skill test. For the students who passed the selection process were supposed to sign the achievement contract during the learning process at MAN 2 Banjarnegara. The second, the character building was done by the concept of habituation and activities program that were integrated in curricular and extracurricular activities. The third, students who joined the academic and non-academic achievement programs at MAN 2 Banjarnegara had strong motivation, spirit of competition to achieve higher achievement and more focus on self-development and they could anticipate the usage of spare time for positive things/activities.

Kalahari Cheetahs

2017 ◽  
Author(s):  
Gus Mills ◽  
Margaret Mills
Keyword(s):  
Reproductive Success ◽  
Spatial Ecology ◽  
Prey Selection ◽  
Arid Ecosystems ◽  
Foraging Success ◽  
Ecological Processes ◽  
Demographic Groups ◽  
Important Prey ◽  
Hunting Behaviour ◽  
The Impact

This book demonstrates how cheetahs are adapted to arid savannahs like the southern Kalahari, and makes comparisons with other areas, especially the Serengeti. Topics dealt with are: demography and genetic status; feeding ecology, i.e. methods used for studying diet, diets of different demographic groups, individual diet specializations of females, prey selection, the impact of cheetah predation on prey populations, activity regimes and distances travelled per day, hunting behaviour, foraging success and energetics; interspecific competition; spatial ecology; reproductive success and the mating system; and conservation. The major findings show that cheetahs are well adapted to arid ecosystems and are water independent. Cheetah density in the study area was stable at 0.7/100 km2 and the population was genetically diverse. Important prey were steenbok and springbok for females with cubs, gemsbok, and adult ostrich for coalition males, and steenbok, springhares, and hares for single animals. Cheetahs had a density-dependent regulatory effect on steenbok and springbok populations. Females with large cubs had the highest overall food intake. Cheetahs, especially males, were often active at night, and competition with other large carnivores, both by exploitation and interference, was slight. Although predation on small cubs was severe, cub survival to adolescence was six times higher than in the Serengeti. There was no difference in reproductive success between single and coalition males. The conservation priority for cheetahs should be to maintain protected areas over a spectrum of landscapes to allow ecological processes, of which the cheetah is an integral part, to proceed unhindered.

scholarly journals The Impact of Social Media Use on Consumers’ Restaurant Consumption Experiences: A Qualitative Study

2021 ◽  
Vol 13 (12) ◽  
pp. 6581
Author(s):  
Jooyoung Hwang ◽  
Anita Eves ◽  
Jason L. Stienmetz
Keyword(s):  
Decision Making ◽  
Social Media ◽  
Selection Process ◽  
Decision Making Process ◽  
Structured Interviews ◽  
High Standards ◽  
Tourism And Hospitality Industry ◽  
Tourism And Hospitality ◽  
Search For Information ◽  
The Impact

Travellers have high standards and regard restaurants as important travel attributes. In the tourism and hospitality industry, the use of developed tools (e.g., smartphones and location-based tablets) has been popularised as a way for travellers to easily search for information and to book venues. Qualitative research using semi-structured interviews based on the face-to-face approach was adopted for this study to examine how consumers’ restaurant selection processes are performed with the utilisation of social media on smartphones. Then, thematic analysis was adopted. The findings of this research show that the adoption of social media on smartphones is positively related with consumers’ gratification. More specifically, when consumers regard that process, content and social gratification are satisfied, their intention to adopt social media is fulfilled. It is suggested by this study that consumers’ restaurant decision-making process needs to be understood, as each stage of the decision-making process is not independent; all the stages of the restaurant selection process are organically connected and influence one another.

scholarly journals Breathing space: deoxygenation of aquatic environments can drive differential ecological impacts across biological invasion stages

2021 ◽  
Author(s):  
James W. E. Dickey ◽  
Neil E. Coughlan ◽  
Jaimie T. A. Dick ◽  
Vincent Médoc ◽  
Monica McCard ◽  
...  
Keyword(s):  
Climate Change ◽  
Oxygen Saturation ◽  
Ecological Impacts ◽  
Neogobius Melanostomus ◽  
Aquatic Environments ◽  
Relative Impact ◽  
Low Oxygen ◽  
Per Capita ◽  
The Impact ◽  
Prey Populations

AbstractThe influence of climate change on the ecological impacts of invasive alien species (IAS) remains understudied, with deoxygenation of aquatic environments often-overlooked as a consequence of climate change. Here, we therefore assessed how oxygen saturation affects the ecological impact of a predatory invasive fish, the Ponto-Caspian round goby (Neogobius melanostomus), relative to a co-occurring endangered European native analogue, the bullhead (Cottus gobio) experiencing decline in the presence of the IAS. In individual trials and mesocosms, we assessed the effect of high, medium and low (90%, 60% and 30%) oxygen saturation on: (1) functional responses (FRs) of the IAS and native, i.e. per capita feeding rates; (2) the impact on prey populations exerted; and (3) how combined impacts of both fishes change over invasion stages (Pre-invasion, Arrival, Replacement, Proliferation). Both species showed Type II potentially destabilising FRs, but at low oxygen saturation, the invader had a significantly higher feeding rate than the native. Relative Impact Potential, combining fish per capita effects and population abundances, revealed that low oxygen saturation exacerbates the high relative impact of the invader. The Relative Total Impact Potential (RTIP), modelling both consumer species’ impacts on prey populations in a system, was consistently higher at low oxygen saturation and especially high during invader Proliferation. In the mesocosm experiment, low oxygen lowered RTIP where both species were present, but again the IAS retained high relative impact during Replacement and Proliferation stages at low oxygen. We also found evidence of multiple predator effects, principally antagonism. We highlight the threat posed to native communities by IAS alongside climate-related stressors, but note that solutions may be available to remedy hypoxia and potentially mitigate impacts across invasion stages.

scholarly journals Identifying Critical Binder Attributes to Facilitate Binder Selection for Efficient Formulation Development in a Continuous Twin Screw Wet Granulation Process

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 210
Author(s):  
Lise Vandevivere ◽  
Maxine Vangampelaere ◽  
Christoph Portier ◽  
Cedrine de Backere ◽  
Olaf Häusler ◽  
...  
Keyword(s):  
Dissolution Kinetics ◽  
Wet Granulation ◽  
Continuous Manufacturing ◽  
Formulation Development ◽  
Granulation Process ◽  
Low Viscosity ◽  
Twin Screw ◽  
Poorly Soluble ◽  
Selection For ◽  
The Impact

The suitability of pharmaceutical binders for continuous twin-screw wet granulation was investigated as the pharmaceutical industry is undergoing a switch from batch to continuous manufacturing. Binder selection for twin-screw wet granulation should rely on a scientific approach to enable efficient formulation development. Therefore, the current study identified binder attributes affecting the binder effectiveness in a wet granulation process of a highly soluble model excipient (mannitol). For this formulation, higher binder effectiveness was linked to fast activation of the binder properties (i.e., fast binder dissolution kinetics combined with low viscosity attributes and good wetting properties by the binder). As the impact of binder attributes on the granulation process of a poorly soluble formulation (dicalcium phosphate) was previously investigated, this enabled a comprehensive comparison between both formulations in current research focusing on binder selection. This comparison revealed that binder attributes that are important to guide binder selection differ in function of the solubility of the formulation. The identification of critical binder attributes in the current study enables rational and efficient binder selection for twin-screw granulation of well soluble and poorly soluble formulations. Binder addition proved especially valuable for a poorly soluble formulation.

scholarly journals Section 4: Sensor, Signal and Imaging Informatics: Sensors, Medical Image and Signal Processing

2006 ◽  
Vol 15 (01) ◽  
pp. 70-73
Author(s):  
R.W Westphal ◽  
Keyword(s):  
Medical Image ◽  
Selection Process ◽  
Imaging Informatics ◽  
Sensor Signal ◽  
Tissue Modeling ◽  
Excellent Research ◽  
Body Sensors ◽  
Selection For ◽  
Soft Tissue Modeling ◽  
Future Patient

SummaryObjectives:To summarize current excellent research in the field of sensor, signal and imaging informatics.Method:Synopsis of the articles selected for the IMIA Yearbook 2007.Results:The selection process for this yearbook section “Sensor, signal and imaging informatics” results in five excellent articles, representing research in four different nations. Papers from the fields of brain machine interfaces, sound surveillance in telemonitoring, soft tissue modeling, and body sensors have been selected.Conclusion:The selection for this yearbook section can only reflect a small portion of the worldwide copious work in the field of sensors, signal and image processing with applications in medical informatics. However, the selected papers demonstrate, how advances in this field may positively affect future patient care.

scholarly journals Transgenerational effects modulate density-dependent prophylactic resistance to viral infection in a lepidopteran pest

2015 ◽  
Vol 11 (3) ◽  
pp. 20150012 ◽  
Author(s):  
Kenneth Wilson ◽  
Robert I. Graham
Keyword(s):  
Disease Resistance ◽  
Survival Rates ◽  
Post Challenge ◽  
Transgenerational Effects ◽  
Density Dependent ◽  
Offspring Fitness ◽  
Rearing Density ◽  
Lepidopteran Pest ◽  
The Impact ◽  
Resistance To Viral Infection

There is an increasing appreciation of the importance of transgenerational effects on offspring fitness, including in relation to immune function and disease resistance. Here, we assess the impact of parental rearing density on offspring resistance to viral challenge in an insect species expressing density-dependent prophylaxis (DDP); i.e. the adaptive increase in resistance or tolerance to pathogen infection in response to crowding. We quantified survival rates in larvae of the cotton leafworm ( Spodoptera littoralis ) from either gregarious- or solitary-reared parents following challenge with the baculovirus S. littoralis nucleopolyhedrovirus. Larvae from both the parental and offspring generations exhibited DDP, with gregarious-reared larvae having higher survival rates post-challenge than solitary-reared larvae. Within each of these categories, however, survival following infection was lower in those larvae from gregarious-reared parents than those from solitary-reared, consistent with a transgenerational cost of DDP immune upregulation. This observation demonstrates that crowding influences lepidopteran disease resistance over multiple generations, with potential implications for the dynamics of host–pathogen interactions.

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