scholarly journals Behavioural Indicators of Intra- and Inter-Specific Competition: Sheep Co-Grazing with Guanaco in the Patagonian Steppe

Animals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3333
Author(s):  
Tomás Fernández ◽  
Alex Lancaster ◽  
Claudio A. Moraga ◽  
Sergio Radic-Schilling ◽  
Achaz von Hardenberg ◽  
...  
Keyword(s):  
Food Availability ◽  
Intraspecific Competition ◽  
Management Strategies ◽  
Domestic Sheep ◽  
Movement Rates ◽  
Behavioural Changes ◽  
Bite Rate ◽  
Chilean Patagonia ◽  
Potential Competitor ◽  
Time Spent Feeding

In extensive livestock production, high densities may inhibit regulation processes, maintaining high levels of intraspecific competition over time. During competition, individuals typically modify their behaviours, particularly feeding and bite rates, which can therefore be used as indicators of competition. Over eight consecutive seasons, we investigated if variation in herd density, food availability, and the presence of a potential competitor, the guanaco (Lama guanicoe), was related with behavioural changes in domestic sheep in Chilean Patagonia. Focal sampling, instantaneous scan sampling, measures of bite and movement rates were used to quantify behavioural changes in domestic sheep. We found that food availability increased time spent feeding, while herd density was associated with an increase in vigilant behaviour and a decrease in bite rate, but only when food availability was low. Guanaco presence appeared to have no impact on sheep behaviour. Our results suggest that the observed behavioural changes in domestic sheep are more likely due to intraspecific competition rather than interspecific competition. Consideration of intraspecific competition where guanaco and sheep co-graze on pastures could allow management strategies to focus on herd density, according to rangeland carrying capacity.

scholarly journals Towards evenly distributed grazing patterns: including social context in sheep management strategies

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2152 ◽  
Author(s):  
Agustina di Virgilio ◽  
Juan Manuel Morales
Keyword(s):  
Social Context ◽  
Management Practices ◽  
Spatial Scales ◽  
Management Strategies ◽  
Domestic Sheep ◽  
Conservation Of Resources ◽  
Landscape Conservation ◽  
Sheep Grazing ◽  
Rangeland Degradation ◽  
Natural Grasslands

Background.A large proportion of natural grasslands around the world is exposed to overgrazing resulting in land degradation and biodiversity loss. Although there is an increasing effort in the promotion of sustainable livestock management, rangeland degradation still occurs because animals’ foraging behaviour is highly selective at different spatial scales. The assessment of the ecological mechanisms modulating the spatial distribution of grazing and how to control it has critical implications for long term conservation of resources and the sustainability of livestock production. Considering the relevance of social interactions on animals’ space use patterns, our aim was to explore the potential effects of including animals’ social context into management strategies using domestic sheep grazing in rangelands as case study.Methods.We used GPS data from 19 Merino sheep (approximately 10% of the flock) grazing on three different paddocks (with sizes from 80 to 1000 Ha) during a year, to estimate resource selection functions of sheep grazing in flocks of different levels of heterogeneity. We assessed the effects of sheep class (i.e., ewes, wethers, and hoggets), age, body condition and time since release on habitat selection patterns.Results.We found that social rank was reflected on sheep habitat use, where dominant individuals (i.e., reproductive females) used more intensively the most preferred areas and low-ranked (i.e., yearlings) used less preferred areas. Our results showed that when sheep grazed on more heterogeneous flocks, grazing patterns were more evenly distributed at all the paddocks considered in this study. On the other hand, when high-ranked individuals were removed from the flock, low-ranked sheep shifted their selection patterns by increasing the use of the most preferred areas and strongly avoided to use less preferred sites (i.e., a highly selective grazing behaviour).Discussion.Although homogenization and segregation of flocks by classes are common practices to increase flock productivity, we are proposing an alternative that employs behavioural interactions in heterogeneous flocks to generate more evenly distributed grazing patterns. This practice can be combined with other practices such as rotational grazing and guardian dogs (to decrease mortality levels that may be generated by sheep grazing on more risky habitats). This does not imply any modifications of livestock stocking rates and densities or any additional investments for labour and materials. Considering livestock behaviour is critical for the design of sustainable management practices that balance landscape conservation and livestock productivity.

Problem behaviour of black bears (Ursus americanus) in central Ontario: the effects of hunting and natural food availability

2015 ◽  
Vol 65 (2) ◽  
pp. 151-161 ◽  
Author(s):  
Josef Hamr ◽  
Jesse N. Popp ◽  
Dorthy L. Brown ◽  
Frank F. Mallory
Keyword(s):  
Food Availability ◽  
Management Strategies ◽  
Black Bears ◽  
Management Policy ◽  
Natural Food ◽  
Behaviour Problem ◽  
Residential Areas ◽  
Problem Behaviour ◽  
Highly Correlated ◽  
Activity Indices

Problem bear behaviour in residential areas often results in human anxiety and potential injury, bear mortality and demographic instability. Identifying and understanding factors related to problem bear activity and encounters is important for developing successful management strategies. Indices of natural bear forage availability and hunting pressure were related to problem bear activity in central Ontario. Data were collected 5 years before and 5 years after the cancellation of a spring bear hunt, providing a unique opportunity to study the effect of management policy on problem behaviour. Problem bear activity indices increased significantly following the closure of the spring hunt. Natural food availability from the previous year was found to be highly correlated with early season problem bear activity indices; however, natural food availability during the same year was not significantly related to early or late season problem activity rates. This demonstrates that multiple potential causal agents of problem bear behaviour need to be considered when developing management strategies.

Experimental analysis of intraspecific composition in an intertidal gastropod, Littorina unifasciata

1981 ◽  
Vol 32 (4) ◽  
pp. 573 ◽  
Author(s):  
GM Branch ◽  
ML Branch
Keyword(s):  
Food Availability ◽  
Intraspecific Competition ◽  
Field Experiments ◽  
Small Body ◽  
Standing Stock ◽  
Rocky Shores ◽  
Physiological Tolerance ◽  
South Wales ◽  
Body Sizes ◽  
Population Mortality

L. unifasciata dominates the upper levels of rocky shores at Cape Banks, New South Wales. Peak densities of up to 9600 m-2 occur near the centre of the littorine's vertical zonation and are associated with small body sizes. Density declines, and mean size rises, further down and more particularly further up the shore. Largest animals occur at the top of the shore and in areas experiencing strong wave action, where densities are low. Field experiments showed that increase in density results in a decrease in body weight and an increase in mortality. However, even at a density four times that of the natural population, mortality remained remarkably low, and this is probably a key feature allowing L. unifasciata to penetrate high up the shore. L. unifasciata feeds mainly on lichens and food levels are low over most of the zone occupied by this littorine, rising above and below this zone and being particularly high in the supralittoral immediately above the range of L. unifasciata. Thus, food cannot be a factor limiting the height that L. unifasciata extends up the shore. Experimental caging shows that the standing stock of lichen is inversely related to the density of L. unifasciata. The zonation pattern and size gradient of L. unifasciata may be due to a combination of two factors: a decline of body size due to increasing intraspecific competition at higher densities, and the tendency of L. unifasciata to migrate (probably upwards) away from areas of low food availability. The latter was experimentally demonstrated. L. unifasciata suffers from intense intraspecific competition and is responsible for limiting the availability of its food. Its populations are seemingly not regulated by predators. It borders on a zone of high food availability in which there are no important competitors. These are all circumstances favouring range expansion of the species, to the limits of physiological tolerance, to allow the species to capitalize on the adjacent rich food source.

Habitat selection by roe deer and sheep: does habitat ranking reflect resource availability?

1999 ◽  
Vol 77 (5) ◽  
pp. 776-783 ◽  
Author(s):  
Atle Mysterud ◽  
Per Kristian Larsen ◽  
Rolf Anker Ims ◽  
Eivind Østbye
Keyword(s):  
Habitat Selection ◽  
Food Availability ◽  
Resource Availability ◽  
Roe Deer ◽  
Antipredator Behavior ◽  
Spatial Scales ◽  
Ovis Aries ◽  
Domestic Sheep ◽  
Trade Offs ◽  
Temporal And Spatial

Habitat ranking is often assumed to reflect food availability, but habitat selection may involve trade-offs, for example, between selecting for food or cover. We tested whether the habitat selection of 27 radio-collared European roe deer (Capreolus capreolus) and 10 free-ranging domestic sheep (Ovis aries) on a forest range in southern Norway reflected resource availability. We predicted that ruminants of different feeding types would use habitats according to the main forage class, but that antipredator behavior might remove the correlation between habitat selection and food availability, thus making temporal and spatial scaling crucial. As predicted, habitat selection by sheep was highly correlated with grass availability on both the home-range and study-area scales. The habitat ranking of roe deer habitat selection did not correlate with the availability of herbs on either scale, but rather was correlated with the availability of canopy cover. We found a clear effect of temporal scale on habitat selection by roe deer. During summer, roe deer used forest habitats with more forage to a greater extent when they were active than when they were inactive, and tended to use habitats with greater availability of herbs at night. We conclude that scale-dependent trade-offs in habitat selection may cause inconsistent habitat rankings when pooled across temporal and spatial scales.

scholarly journals Larval size in acanthocephalan parasites: Influence of intraspecific competition and effects on intermediate host behavioural changes

2012 ◽  
Vol 5 (1) ◽  
Author(s):  
Lucile Dianne ◽  
Loïc Bollache ◽  
Clément Lagrue ◽  
Nathalie Franceschi ◽  
Thierry Rigaud
Keyword(s):  
Intermediate Host ◽  
Intraspecific Competition ◽  
Larval Size ◽  
Behavioural Changes

Managing confined populations: the influence of density on the home range and habitat use of reintroduced burrowing bettongs (Bettongia lesueur)

2004 ◽  
Vol 31 (4) ◽  
pp. 457 ◽  
Author(s):  
Graeme R. Finlayson ◽  
Katherine E. Moseby
Keyword(s):  
Home Range ◽  
Habitat Use ◽  
Food Availability ◽  
Reproductive Output ◽  
Reproductive Effort ◽  
High Density ◽  
Home Ranges ◽  
Low Density ◽  
Reproductive Condition ◽  
Behavioural Changes

The home range, reproductive condition and warren and habitat use of reintroduced female burrowing bettongs was compared within two enclosures in the Arid Recovery Reserve at estimated densities of 2.75 and 7.5 bettongs km–2. Bettongs at both densities exhibited similar behaviour, with females using an average of 2.7 warrens over six months and home ranges averaging 29 and 35 ha in the low- and high-density enclosure respectively. All five female bettongs studied in the low-density enclosure were carrying pouch young at the beginning and end of the six-month study but only one of the five females in the high-density enclosure was carrying pouch young after six months. Higher food availability may have accounted for the higher reproductive effort and slightly smaller home ranges observed in the low-density enclosure. Female bettongs at both densities favoured dune habitat over chenopod swales and all burrows were in dune habitat. Although some differences in reproductive output were observed, it is likely that densities are not yet high enough to cause significant behavioural changes.

scholarly journals Understanding foraging flexibility in urban vervet monkeys, Chlorocebus pygerythrus, for the benefit of human-wildlife coexistence

2020 ◽  
Vol 23 (6) ◽  
pp. 1349-1357 ◽  
Author(s):  
Harriet R. Thatcher ◽  
Colleen T. Downs ◽  
Nicola F. Koyama
Keyword(s):  
Food Consumption ◽  
Food Availability ◽  
Urban Areas ◽  
Urban Landscape ◽  
Management Strategies ◽  
Urban Environments ◽  
Natural Food ◽  
Vervet Monkeys ◽  
Chlorocebus Pygerythrus ◽  
Anthropogenic Food

Abstract Generalist wildlife species often thrive in urban environments because of increased anthropogenic resources. However, human-wildlife interactions, especially if negative, raise concerns for urban wildlife management. An enhanced understanding of wildlife behavioural flexibility has been suggested to be a key tool to provide educated and effective management strategies. We therefore investigated how availability of semi-naturally occurring food affected behavioural foraging patterns of urban vervet monkeys (Chlorocebus pygerythrus), a generalist primate commonly found in urban areas of KwaZulu-Natal, South Africa. Over one year, we conducted 20 min. focal animal observations recording foraging behaviour and food consumption. We used a combination of a generalised linear model and descriptive statistics to examine the relationship between anthropogenic food consumption and semi-natural food availability. Our analyses showed that anthropogenic food consumption decreased as semi-natural food availability increased. We also showed that increased aggression from humans towards vervet monkeys decreased time spent foraging on anthropogenic food. Our study highlights how vervet monkeys have adapted to their urban landscape, showing foraging flexibility in response to available food resources and the frequency of human interactions. We suggest how our results can be applied for management recommendations, particularly controlling anthropogenic food availability and decreasing negative human-wildlife interactions.

scholarly journals The effects of heat stress on the behaviour of dairy cows – a review

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Piotr Herbut ◽  
Gundula Hoffmann ◽  
Sabina Angrecka ◽  
Dorota Godyń ◽  
Frederico Márcio Corrêa Vieira ◽  
...  
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Bos Taurus ◽  
Management Strategies ◽  
Family Farms ◽  
Behavioural Changes ◽  
Effective Strategies ◽  
Key Factor ◽  
Negative Environmental Impact ◽  
Informatic System

AbstractHeat stress in livestock is a function of macro- and microclimatic factors, their duration and intensity, the environments where they occur and the biological characteristics of the animal. Due to intense metabolic processes, high-producing dairy cows are highly vulnerable to the effects of heat stress. Disturbances in their thermoregulatory capability are reflected by behavioural, physiological and production changes. Expression of thermoregulatory behaviour such as reduction of activity and feed intake, searching for a cooler places or disturbances in reproductive behaviours may be very important indicators of animal welfare. Especially maintain of standing or lying position in dairy cattle may be a valuable marker of the negative environmental impact. Highly mechanized farms with large numbers of animals have the informatic system can detect alterations automatically, while small family farms cannot afford these type of equipments. Therefore, observing and analysing behavioural changes to achieve a greater understanding of heat stress issue may be a key factor for developing the effective strategies to minimize the effects of heat stress in cattle. The aim of this review is to present the state of knowledge, over the last years, regarding behavioural changes in dairy cows (Bos Taurus) exposed to heat stress conditions and discuss some herd management strategies provided mitigation of the overheat consequences.

scholarly journals Advances in Understanding Vector Behavioural Traits after Infection

Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1376
Author(s):  
Nouman Javed ◽  
Asim Bhatti ◽  
Prasad N. Paradkar
Keyword(s):  
Management Strategies ◽  
Blood Feeding ◽  
Pathogen Transmission ◽  
Bed Nets ◽  
Host Feeding ◽  
Transmission Potential ◽  
Disease Epidemiology ◽  
Behavioural Changes ◽  
Host Seeking ◽  
Vector Borne

Vector behavioural traits, such as fitness, host-seeking, and host-feeding, are key determinants of vectorial capacity, pathogen transmission, and epidemiology of the vector-borne disease. Several studies have shown that infection with pathogens can alter these behavioural traits of the arthropod vector. Here, we review relevant publications to assess how pathogens modulate the behaviour of mosquitoes and ticks, major vectors for human diseases. The research has shown that infection with pathogens alter the mosquito’s flight activity, mating, fecundity, host-seeking, blood-feeding, and adaptations to insecticide bed nets, and similarly modify the tick’s locomotion, questing heights, vertical and horizontal walks, tendency to overcome obstacles, and host-seeking ability. Although some of these behavioural changes may theoretically increase transmission potential of the pathogens, their effect on the disease epidemiology remains to be verified. This study will not only help in understanding virus–vector interactions but will also benefit in establishing role of these behavioural changes in improved epidemiological models and in devising new vector management strategies.

Recruitment Limitation as a Consequence of Natural Selection for Use of Restricted Feeding Habitats and Predation Risk Taking by Juvenile Fishes

1993 ◽  
Vol 50 (10) ◽  
pp. 2058-2070 ◽  
Author(s):  
Carl J. Walters ◽  
Francis Juanes
Keyword(s):  
Predation Risk ◽  
Food Availability ◽  
Spatial Scales ◽  
Food Density ◽  
Additional Time ◽  
Density Dependent ◽  
Competitive Effects ◽  
Survival And Reproduction ◽  
Time Spent Feeding ◽  
Foraging Time

Juvenile fishes generally have spatial refuges from predation, and forage in limited but risky areas near refuges. Models of food density dynamics within such limited foraging areas predict that food availability and consumption per time spent feeding should depend strongly on Juvenile density. Selection should act on the time that Juveniles spend foraging, so as to strike a balance between growth and predation risk; we predict that optimum balance will occur at foraging times proportional to the minimum needed to reach viable sizes for later survival and reproduction plus an additional time inversely proportional to the predation risk per time. Combining the food availability and optimal foraging time predictions leads to stock–recruitment patterns similar to classic Beverton–Holt and Ricker forms, depending on how food organisms respond over time. Very strong density-dependent mortality can occur even without noticeable changes in juvenile growth rates or average food densities over large spatial scales, but intraspecific competitive effects should always be evident through density-dependent changes in foraging time.

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