Sheep avoidance of faeces creates a foraging trade-off between nutrient and parasite intake

2001 ◽  
Vol 2001 ◽  
pp. 94-94
Author(s):  
M. R. Hutchings ◽  
I. J. Gordon ◽  
I. Kyriazakis ◽  
F. Jackson
Keyword(s):  
Parasite Species ◽  
Avoidance Behaviour ◽  
Infective Stage ◽  
Costs And Benefits ◽  
Trade Off ◽  
Survival And Reproduction ◽  
Parasite Avoidance ◽  
Grazing Behaviour

Gastrointestinal (GI) parasites, acquired by sheep through the action of foraging, are the most pervasive challenge to their survival and reproduction. The eggs of many GI parasite species are deposited on pasture in faeces where they develop into infective stage larvae that contaminate surrounding swards. We test the hypotheses that (1) faeces and hence parasite avoidance behaviour of sheep creates a grazing trade-off between nutrition and parasitism and (2) the relative costs and benefits of the trade-off in relation to animal state of infection (parasitized, non-parasitized, immune) determines their subsequent grazing behaviour.

scholarly journals Fatal attraction: vegetation responses to nutrient inputs attract herbivores to infectious anthrax carcass sites

2014 ◽  
Vol 281 (1795) ◽  
pp. 20141785 ◽  
Author(s):  
Wendy C. Turner ◽  
Kyrre L. Kausrud ◽  
Yathin S. Krishnappa ◽  
Joris P. G. M. Cromsigt ◽  
Holly H. Ganz ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Camera Traps ◽  
Nutrient Inputs ◽  
Trade Off ◽  
Nutrient Effects ◽  
Fatal Attraction ◽  
Herbivore Species ◽  
Indirect Cues ◽  
Parasite Avoidance ◽  
Grazing Behaviour

Parasites can shape the foraging behaviour of their hosts through cues indicating risk of infection. When cues for risk co-occur with desired traits such as forage quality, individuals face a trade-off between nutrient acquisition and parasite exposure. We evaluated how this trade-off may influence disease transmission in a 3-year experimental study of anthrax in a guild of mammalian herbivores in Etosha National Park, Namibia. At plains zebra ( Equus quagga ) carcass sites we assessed (i) carcass nutrient effects on soils and grasses, (ii) concentrations of Bacillus anthracis (BA) on grasses and in soils, and (iii) herbivore grazing behaviour, compared with control sites, using motion-sensing camera traps. We found that carcass-mediated nutrient pulses improved soil and vegetation, and that BA is found on grasses up to 2 years after death. Host foraging responses to carcass sites shifted from avoidance to attraction, and ultimately to no preference, with the strength and duration of these behavioural responses varying among herbivore species. Our results demonstrate that animal carcasses alter the environment and attract grazing hosts to parasite aggregations. This attraction may enhance transmission rates, suggesting that hosts are limited in their ability to trade off nutrient intake with parasite avoidance when relying on indirect cues.

scholarly journals Evolution of pathogen and parasite avoidance behaviours

2018 ◽  
Vol 373 (1751) ◽  
pp. 20170256 ◽  
Author(s):  
Cecile Sarabian ◽  
Val Curtis ◽  
Rachel McMullan
Keyword(s):  
Avoidance Behaviour ◽  
Disease Avoidance ◽  
Behavioural Science ◽  
Free Living ◽  
Society Meeting ◽  
Neural Architecture ◽  
Trade Offs ◽  
Wide Range ◽  
Parasite Avoidance ◽  
Behavioural Adaptations

All free-living animals are subject to intense selection pressure from parasites and pathogens resulting in behavioural adaptations that can help potential hosts to avoid falling prey to parasites. This special issue on the evolution of parasite avoidance behaviour was compiled following a Royal Society meeting in 2017. Here we have assembled contributions from a wide range of disciplines including genetics, ecology, parasitology, behavioural science, ecology, psychology and epidemiology on the disease avoidance behaviour of a wide range of species. Taking an interdisciplinary and cross-species perspective allows us to sketch out the strategies, mechanisms and consequences of parasite avoidance and to identify gaps and further questions. Parasite avoidance strategies must include avoiding parasites themselves and cues to their presence in conspecifics, heterospecifics, foods and habitat. Further, parasite avoidance behaviour can be directed at constructing parasite-retardant niches. Mechanisms of parasite avoidance behaviour are generally less well characterized, though nematodes, rodents and human studies are beginning to elucidate the genetic, hormonal and neural architecture that allows animals to recognize and respond to cues of parasite threat. While the consequences of infection are well characterized in humans, we still have much to learn about the epidemiology of parasites of other species, as well as the trade-offs that hosts make in parasite defence versus other beneficial investments like mating and foraging. Finally, in this overview we conclude that it is legitimate to use the word ‘ disgust' to describe parasite avoidance systems, in the same way that ‘fear' is used to describe animal predator avoidance systems. Understanding disgust across species offers an excellent system for investigating the strategies, mechanisms and consequences of behaviour and could be a vital contribution towards the understanding and conservation of our planet's ecosystems. This article is part of the Theo Murphy meeting issue ‘Evolution of pathogen and parasite avoidance behaviours'.

Parasite avoidance: the cause of post-calving migrations in Rangifer?

1991 ◽  
Vol 69 (9) ◽  
pp. 2423-2429 ◽  
Author(s):  
Ivar Folstad ◽  
Arne C. Nilssen ◽  
Odd Halvorsen ◽  
Johan Andersen
Keyword(s):  
Rangifer Tarandus ◽  
Total Sample ◽  
Parasitic Infections ◽  
Larval Abundance ◽  
Infective Stage ◽  
Migration Distance ◽  
Behavioural Adaptation ◽  
Summer Grazing ◽  
Parasite Avoidance ◽  
Hypoderma Tarandi

Intensities of warble fly larvae, Hypoderma tarandi (L.), were examined in slaughtered reindeer (Rangifer tarandus tarandus L.) from different summer grazing areas of Finnmark County, northern Norway. To test the hypothesis that larval abundance decreases with increase in post-calving migration distance (i.e., distance from calving grounds), herds with differing migration distances were sampled. The prevalence of infection in the total sample of 1168 animals was 99.9%. The study revealed significant differences in larval abundance among herds from different summer grazing areas. Herds with post-calving migrations have significantly lower larval abundances than herds remaining on or near the calving grounds for the whole summer. Between-herds variation in abundance of H. tarandi larvae is assumed to reflect differing densities of the infective stage (adult flies) on the herds' summer ranges. Larval abundance in a herd is in turn negatively correlated with the distance between the main larval shedding areas (i.e., calving grounds) and the areas of greatest transmission (i.e., summer pastures). These results are discussed in relation to transmission of other parasites common to Rangifer and suggest that this host's post-calving migration may be a behavioural adaptation that reduces levels of parasitic infections.

scholarly journals Prophylactic host behaviour discourages pathogen exploitation

2019 ◽  
Author(s):  
Evan Mitchell ◽  
Geoff Wild
Keyword(s):  
Population Dynamics ◽  
Disease Transmission ◽  
Costs And Benefits ◽  
Dual Nature ◽  
Trade Off ◽  
Pathogen Virulence ◽  
Prophylactic Measures ◽  
Host Behaviour

SummaryMuch work has considered the evolution of pathogens, but little is known about how they respond to changes in host behaviour. We build a model where hosts are able to choose to engage in prophylactic measures that reduce the likelihood of disease transmission. This choice is mediated by costs and benefits associated with prophylaxis, but the fraction of hosts engaged in prophylaxis is also affected by population dynamics. We identify a critical cost threshold above which hosts do not engage in prophylaxis. Below the threshold, prophylactic host behaviour does occur and pathogen virulence, measured by the extent to which it exploits its host, is reduced by the action of selection relative to the level that would otherwise be predicted in the absence of prophylaxis. Our work emphasizes the significance of the dual nature of the trade-off faced by the pathogen between balancing transmission and recovery, and creating new infections in hosts engaging or not engaging in prophylaxis.

scholarly journals Hitting the buffers: conspecific aggression undermines benefits of colonial breeding under adverse conditions

2008 ◽  
Vol 4 (6) ◽  
pp. 630-633 ◽  
Author(s):  
Kate Ashbrook ◽  
Sarah Wanless ◽  
Mike P Harris ◽  
Keith C. Hamer
Keyword(s):  
Social Dynamics ◽  
Alloparental Care ◽  
Costs And Benefits ◽  
Trade Off ◽  
Adverse Conditions ◽  
Avian Predators ◽  
Colonial Breeding ◽  
Conspecific Aggression ◽  
The Uk ◽  
Transfer Of Information

Colonial breeding in birds is widely considered to benefit individuals through enhanced protection against predators or transfer of information about foraging sites. This view, however, is largely based on studies of seabirds carried out under favourable conditions. Recent breeding failures at many seabird colonies in the UK provide an opportunity to re-examine costs and benefits of coloniality under adverse conditions. Common guillemots Uria aalge are highly colonial cliff-nesting seabirds with very flexible parental care. Although the single chick is normally never left alone, more than 50 per cent of offspring were left unattended at a North Sea colony in 2007, apparently because poor conditions forced both parents to forage simultaneously. Contrary to expectation, unattended chicks were not killed by avian predators. Rather, although non-breeders and failed breeders sometimes provided alloparental care, unattended chicks were frequently attacked by breeding guillemots at neighbouring sites, often with fatal consequences. These results highlight a previously unsuspected trade-off between provisioning chicks and avoiding conspecific attacks, and indicate that understanding how environmental conditions affect social dynamics is crucial to interpreting costs and benefits of colonial breeding.

scholarly journals How Consumers Trade Off Behavioural Costs and Benefits

1986 ◽  
Vol 20 (3/4) ◽  
pp. 19-34 ◽  
Author(s):  
Theo M.M. Verhallen ◽  
W. Fred van Raaij
Keyword(s):  
Costs And Benefits ◽  
Trade Off

scholarly journals Sociality and health: impacts of sociality on disease susceptibility and transmission in animal and human societies

2015 ◽  
Vol 370 (1669) ◽  
pp. 20140116 ◽  
Author(s):  
Peter M. Kappeler ◽  
Sylvia Cremer ◽  
Charles L. Nunn
Keyword(s):  
Disease Ecology ◽  
Group Living ◽  
Costs And Benefits ◽  
Evolutionary Transitions ◽  
Social Buffering ◽  
Health And Fitness ◽  
Key Factor ◽  
Health Related Research ◽  
Health Related ◽  
Survival And Reproduction

This paper introduces a theme issue presenting the latest developments in research on the impacts of sociality on health and fitness. The articles that follow cover research on societies ranging from insects to humans. Variation in measures of fitness (i.e. survival and reproduction) has been linked to various aspects of sociality in humans and animals alike, and variability in individual health and condition has been recognized as a key mediator of these relationships. Viewed from a broad evolutionary perspective, the evolutionary transitions from a solitary lifestyle to group living have resulted in several new health-related costs and benefits of sociality. Social transmission of parasites within groups represents a major cost of group living, but some behavioural mechanisms, such as grooming, have evolved repeatedly to reduce this cost. Group living also has created novel costs in terms of altered susceptibility to infectious and non-infectious disease as a result of the unavoidable physiological consequences of social competition and integration, which are partly alleviated by social buffering in some vertebrates. Here, we define the relevant aspects of sociality, summarize their health-related costs and benefits, and discuss possible fitness measures in different study systems. Given the pervasive effects of social factors on health and fitness, we propose a synthesis of existing conceptual approaches in disease ecology, ecological immunology and behavioural neurosciences by adding sociality as a key factor, with the goal to generate a broader framework for organismal integration of health-related research.

scholarly journals To breed or not to breed: a seabird's response to extreme climatic events

2010 ◽  
Vol 7 (2) ◽  
pp. 303-306 ◽  
Author(s):  
Sarah Cubaynes ◽  
Paul F. Doherty ◽  
E. A. Schreiber ◽  
Olivier Gimenez
Keyword(s):  
El Niño ◽  
El Nino ◽  
Life History Strategy ◽  
Adaptive Strategy ◽  
Age Classes ◽  
Trade Off ◽  
Survival And Reproduction ◽  
In The Wild ◽  
Breeding Attempt ◽  
Intermittent Breeding

Intermittent breeding is an important life-history strategy that has rarely been quantified in the wild and for which drivers remain unclear. It may be the result of a trade-off between survival and reproduction, with individuals skipping breeding when breeding conditions are below a certain threshold. Heterogeneity in individual quality can also lead to heterogeneity in intermittent breeding. We modelled survival, recruitment and breeding probability of the red-footed booby ( Sula sula ), using a 19 year mark–recapture dataset involving more than 11 000 birds. We showed that skipping breeding was more likely in El-Niño years, correlated with an increase in the local sea surface temperature, supporting the hypothesis that it may be partly an adaptive strategy of birds to face the trade-off between survival and reproduction owing to environmental constraints. We also showed that the age-specific probability of first breeding attempt was synchronized among different age-classes and higher in El-Niño years. This result suggested that pre-breeders may benefit from lowered competition with experienced breeders in years of high skipping probabilities.

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