Host migration strategy is shaped by forms of parasite transmission and infection cost

Journal of Animal Ecology, Journal Year: 2019, Volume and Issue: 88(10), P. 1601 - 1612

Published: June 20, 2019

Most studies on the evolution of migration focus food, mates and/or climate as factors influencing these movements, whereas negative species interactions such predators, parasites and pathogens are often ignored. Although infection its associated costs clearly have potential to influence migration, thoroughly studying is challenging without a solid theoretical framework from which develop testable predictions in natural systems. Here, we aim understand when favour migration. We general model enables us explore broad range biological conditions capture population dynamics over both ecological evolutionary time-scales. show that evolves depends whether paid reduced fecundity or survival. Also important parasite transmission mode spatiotemporal recovery (if it occurs). Finally, find partial (where only fraction migrates) can evolve but density-dependent. Our results highlight critical, if overlooked, role shaping long-distance movement patterns, suggest should be considered alongside more traditional drivers empirical studies.

Language: Английский

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How to study parasites and host migration: a roadmap for empiricists

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Journal Year: 2022, Volume and Issue: 97(3), P. 1161 - 1178

Published: Jan. 30, 2022

ABSTRACT Animal migration (round‐trip, predictable movements) takes individuals across space and time, bringing them into contact with new communities of organisms. In particular, migratory movements shape (and are shaped by) the costs risk parasite transmission. Unfortunately, our understanding how infection interact has not proceeded evenly. Although numerous conceptual frameworks (e.g. mathematical models) have been developed, most empirical evidence migration–parasite interactions drawn from pre‐existing studies that were conducted using other frameworks, which limits understanding. Here, we synthesise analyse existing work, then provide a roadmap for future (especially empirical) studies. First, developed to understand between parasites exposure, escape, allopatry, recovery, culling, separation, stalling relapse). Second, highlight current challenges studying empirically, integrating theoretical perspectives, particularly emphasizing challenge feedback loops. Finally, guide overcoming these in studies, comparative, observational experimental approaches. Beyond guiding this review aims inspire stronger collaboration empiricists theorists intersection infection. Such will help overcome interact, allow us predict critical ecological processes change future.

Language: Английский

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Immune challenge reduces daily activity period in free-living birds for three weeks

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2023, Volume and Issue: 290(2005)

Published: Aug. 16, 2023

Non-lethal infections are common in free-living animals and the associated sickness behaviours can impact crucial life-history trade-offs. However, little is known about duration extent of such animals, consequently how they affect decisions. Here, Eurasian blackbirds, Turdus merula , were immune-challenged with lipopolysaccharide (LPS) to mimic a bacterial infection their behaviour was monitored for up 48 days using accelerometers. As expected, birds less active than controls within first 24 h. Unexpectedly, this reduced activity remained detectable 20 days, before both groups returned similar levels. Furthermore, positively correlated pre-experimental index complement activity, but only birds, suggesting that modulated by constitutive immune function. Differences daily levels stemmed from resting earlier at dusk control while between during core daytime hours. Overall, 19% on average almost 1 h per day days. This unexpected longevity may have severe implications energy-intense annual-cycle stages (e.g. breeding, migration, winter). Thus, our data help understand consequences non-lethal animals.

Language: Английский

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Defence versus defence: Are crucian carp trading off immune function against predator‐induced morphology?

Journal of Animal Ecology, Journal Year: 2019, Volume and Issue: 88(10), P. 1510 - 1521

Published: July 8, 2019

Abstract Numerous species adopt inducible defence strategies; that is, they have phenotypically plastic traits decrease the risk of capture and consumption by potential predators. The benefits expressing alternative phenotypes in high‐ vs. low‐risk environments are well documented. However, anti‐predator also expected to incur costs, as not expressed when predators absent, yet empirical evidence such costs remains scarce. Virtually, all animals nature simultaneously under strong selection evade both infection parasites or pathogens and, hence, display a diverse arsenal defences combat these threats, raising possibility trade‐offs between defences. A classic example predator‐induced morphological is deep‐bodied shape crucian carp reduces predation from gape‐size‐limited goal this study was examine whether predator exposure affects immune function carp, degree traded off against individuals. Following manipulations perceived (predator presence/absence) long‐term experiment (8 months), key aspects innate individual differences expression were quantified. Predator‐exposed individuals showed lower haptoglobin levels complement activity, but higher natural antibody titres than fish predator‐free conditions. When experimentally challenged with mimicked bacterial (LPS injection), reared presence weaker response. Moreover, among predator‐exposed individuals, magnitude correlated baseline ability mount an relationships consistently supportive general trade‐off Our results suggest exposed on average reduce investment function, further, observed can best be explained fitness pace‐of‐life perspectives.

Language: Английский

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The Value of Experimental Approaches in Migration Biology

Physiological and Biochemical Zoology, Journal Year: 2020, Volume and Issue: 93(3), P. 210 - 226

Published: Feb. 3, 2020

The past several decades have ushered in a golden age the study of migration biology, leading to wealth descriptive articles that characterize various aspects and its implications for individuals, populations, ecosystems. However, relatively few studies adopted an experimental approach migration, fewer still combined lab field experiments glean insights into mechanisms underlying variation behavior success. Understanding proximate ultimate causes timing, energy allocation optimization, success, fitness is important aid conservation management wildlife populations by establishing appropriate protections or managing environmental conditions influence migration. With recent technological advances miniaturization animal-borne electronic tracking devices, as well ground-, water-, space-based telemetry infrastructure, researchers tools necessary experimentally test hypotheses central mechanics migrations individual therein. By pairing physiological measurements, molecular analyses, other approaches within framework, there potential understand not only how animal function but also what differentiates successful from failed associated implications. Experimental biology are particularly important, they will help us better comprehend hopefully predict responses anthropogenic changes isolating confounding variables challenge inferences observations.

Language: Английский

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Innate immune function and antioxidant capacity of nestlings of an African raptor covary with the level of urbanisation around breeding territories

Journal of Animal Ecology, Journal Year: 2022, Volume and Issue: 92(1), P. 124 - 141

Published: Nov. 10, 2022

Urban areas provide breeding habitats for many species. However, animals raised in urban environments face challenges such as altered food availability and quality, pollution pathogen assemblages. These can affect physiological processes immune function antioxidant defences which are important fitness. Here, we explore how levels of urbanisation influence innate function, response to a mimicked bacterial infection capacity nestling Black Sparrowhawks Accipiter melanoleucus South Africa. We also the effect timing rainfall on physiology since both environmental condition under nestlings raised. Finally, because indirectly, use path analyses direct indirect associations between urbanisation, oxidative stress. obtained measures immunity (haptoglobin, lysis, agglutination, bactericidal capacity), indices (total non-enzymatic (tAOX) total glutathione from 2015 2019. In addition, 2018 2019, by injecting with lipopolysaccharide quantified their response. Increased cover was associated an increase lysis decrease tAOX, but not any other parameters. Furthermore, except no parameters were breeding. Lysis capacity, however, varied consistently annual pattern. Immune decreased nor rainfall. Our suggested some via tAOX results show that early-life development environment is variation functions. The association impact likely factor mediating urban-dwelling animals. Future studies should these linked fitness whether responses adaptive

Language: Английский

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Recovery from infection is more likely to favour the evolution of migration than social escape from infection

Journal of Animal Ecology, Journal Year: 2020, Volume and Issue: 89(6), P. 1448 - 1457

Published: March 2, 2020

Pathogen and parasite infections are increasingly recognized as powerful drivers of animal movement, including migration. Yet, infection-related migration benefits can result from a combination environmental and/or social conditions, which be difficult to disentangle. Here, we focus on two mechanisms that favour migration: moving escape versus recover infection. By directly comparing the evolution in response each mechanism, evaluate likely importance changing abiotic conditions (linked migratory recovery) with escape) terms infection-driven We built mathematical model analysed it using numerically simulated adaptive dynamics determine when should evolve for recovery escape. found higher fraction population migrated under than also distinct strategies (e.g. some individuals always migrate others only occasionally migrate) sometimes coexisted within populations escape, but never recovery. Our results suggest is more promote behaviour, rather infected conspecifics (social escape).

Language: Английский

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Bird Migration and Vector-Borne Parasite Transmission

Springer eBooks, Journal Year: 2020, Volume and Issue: unknown, P. 513 - 526

Published: Jan. 1, 2020

Language: Английский

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Leukocyte profiles vary with breeding latitude and infection status in a seasonally sympatric songbird

Animal Migration, Journal Year: 2019, Volume and Issue: 6(1), P. 28 - 40

Published: Jan. 1, 2019

Abstract Billions of animals migrate annually in pursuit food, safety, and reproduction. Long-distance migration can be energetically expensive, which force tradeoffs with investment other physiological systems (e.g., suppressing immunity). Understanding the impacts is important to predict when where such may vulnerable parasites how changes might affect infectious disease risks. To isolate relationships between physiology from energetic hormonal shifts associated spring reproduction, we assessed differences leukocyte profiles seasonally sympatric resident recently arrived fall migrant dark-eyed juncos ( Junco hyemalis ) Appalachian Mountains. When examining heterophil:lymphocyte (HL) ratios, elevate for long durations after even mild stressors, found weak associations migratory strategy (resident or subspecies). In contrast, feather δ 2 H values showed that HL ratios were highest breeding at more northern latitudes, this relationship was strongest birds overwintering site infected haemosporidian Plasmodium Haemoproteus spp.). These patterns pronounced better indicated hematological responses stressors using multivariate analyses. Our findings suggest short- long-distance costly presence infection highlight approximating latitude analyses help understand host physiology.

Language: Английский

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Malaria infection status of European Robins seems to associate with timing of autumn migration but not with actual condition

Parasitology, Journal Year: 2019, Volume and Issue: 146(6), P. 814 - 820

Published: Jan. 14, 2019

Avian malaria parasites can negatively affect many aspects of the life passerines. Though these may strongly health and thus migration patterns birds also during autumn, previous studies on avian focused mainly spring breeding periods birds. We investigated whether prevalence blood varies in relation to biometrical traits, body condition arrival time European Robin (Erithacus rubecula) autumn migration. found no sex or age related differences relationship between infection status size actual was either. However, timing differed marginally infected non-infected juveniles, so that parasitized individuals arrived later at Hungarian stopover site. This is either because infections adversely speed birds, arriving come from more distant populations with possibly higher parasite prevalence. The possible delay cause could whole migratory strategy success next season.

Language: Английский

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