Understanding the ecological and evolutionary function of stopover in migrating birds

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Journal Year: 2022, Volume and Issue: 97(4), P. 1231 - 1252

Published: Feb. 8, 2022

ABSTRACT Global movement patterns of migratory birds illustrate their fascinating physical and physiological abilities to cross continents oceans. During voyages, most land multiple times make so‐called ‘stopovers’. Our current knowledge on the functions stopover is mainly based proximate study departure decisions. However, such studies are insufficient gauge fully ecological evolutionary stopover. If we how a focal trait, e.g. changes in energy stores, affects decision depart from without considering trait(s) that actually caused bird land, unfavourable environmental conditions for flight, misinterpret function It thus important realise acknowledge stopovers have many different functions, not every migrant has same (set of) reasons stop‐over. Additionally, may obtain contradictory results because significance traits context dependent. For instance, late spring migrants be more prone risk‐taking with lower stores than early migrants. Thus, neglect decisions subject selection minimise immediate (mortality risk) and/or delayed (low future reproductive output) fitness costs. To alleviate these issues, first define as an interruption endurance flight costs . Second, review all probable stopover, which include accumulating energy, various forms recovery avoiding adverse list potential other less well studied, minimising predation, exhaustion spatiotemporal adjustments migration. Third, derived aspects, argue paradigm shift ecology research. This includes focusing why individual interrupts its likely identify individual‐specific function(s) correctly departure‐decision studies. Moreover, highlight selective forces acting dependent expected differ between, K −/ r ‐selected species, sexes migration strategies. example, else being equal, species survival rate, high rate) should stronger urge continue or resume increase suffered offset by higher success subsequent breeding season. Finally, propose focus mechanisms controlling landing decisions, ultimate shaping ideas limited but can applied any species. revised definition proposed stimulate fruitful discussion towards better understanding Furthermore, identifying will support targeted measures conserve restore functionality sites threatened anthropogenic changes. especially long‐distance migrants, currently alarming decline.

Language: Английский

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Multiple factors contribute to female dominance in migratory bioflows

Open Biology, Journal Year: 2025, Volume and Issue: 15(2)

Published: Feb. 1, 2025

Migration is a widely observed phenomenon supported by morphological, physiological and behavioural traits that vary with season sex in many species. Recently, the genetic components underpinning migration marmalade hoverfly (Diptera: Syrphidae) have been unpacked through detection of differentially expressed genes between migrant non-migrant females. Males also migrate, but changing ratios during autumn migration, from around 50% female northern Europe to 90% southern Europe, suggests males are poor long-distance fliers. To elucidate mechanisms this difference, we performed transcriptomic characterization actively migrating females males. Both sexes show similar adaptations including hyperphagia starvation resistance, display higher tolerance cold, lower wing loading values greater flight capacity. In addition, modulate expression involved immunity, hypoxia longevity while suppressing hormonal pathways maintaining reproductive diapause. These contribute success migrants underlie diminishing pool males, influencing population dynamics across huge geographic areas whole migratory overwintering period.

Language: Английский

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Interactive effects of rising temperatures and urbanisation on birds across different climate zones: A mechanistic perspective

Global Change Biology, Journal Year: 2023, Volume and Issue: 29(9), P. 2399 - 2420

Published: March 13, 2023

Abstract Climate change and urbanisation are among the most pervasive rapidly growing threats to biodiversity worldwide. However, their impacts usually considered in isolation, interactions rarely examined. Predicting species' responses combined effects of climate urbanisation, therefore, represents a pressing challenge global biology. Birds important model taxa for exploring both behaviour physiology have been well studied urban non‐urban systems. This understanding should allow interactive rising temperatures be inferred, yet considerations these almost entirely lacking from empirical research. Here, we synthesise our current potential mechanisms that could affect how species respond with focus on avian taxa. We discuss motivate future in‐depth research this critically important, overlooked, aspect Increased pronounced consequence (through heat island effect) change. The biological impact warming systems will likely differ magnitude direction when interacting other factors typically vary between habitats, such as resource availability (e.g. water, food microsites) pollution levels. Furthermore, nature may cities situated different types, example, tropical, arid, temperate, continental polar. Within article, highlight drivers mechanistic birds, identify knowledge gaps propose promising avenues. A deeper behavioural physiological mediating provide novel insights into ecology evolution under help better predict population responses.

Language: Английский

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Endocrine and molecular regulation of seasonal avian immune function

Philosophical Transactions of the Royal Society B Biological Sciences, Journal Year: 2025, Volume and Issue: 380(1918)

Published: Jan. 23, 2025

Birds have evolved seasonal adaptations in multiple aspects of the innate and adaptive immune systems. Seasonal immunological are crucial for survival harsh environmental conditions response to increased prevalence acute chronic diseases. Similar other vertebrates, birds exhibit remarkable plasticity cytokine production, chemotaxis, phagocytosis inflammation across year. In this review, we provide a comparative perspective on rhythms bird function. We describe advances our understanding annual changes cells responses challenges. Then, role glucocorticoids, sex steroids, thyroid hormones (THs) melatonin act as immunomodulators is described. then discuss impact major emerging disease, high pathogenicity avian influenza, one most critical diseases with significant implications poultry wild populations. The review identifies need enhance knowledge tissues birds, at molecular, cellular hormonal levels Moreover, there absence information sex-specific variation Understanding system dynamics will aid addressing negative impacts pathogenic diseases, minimize global economic losses conservation efforts.This article part Theo Murphy meeting issue 'Circadian infection immunity'.

Language: Английский

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Why the superb physiological capacity of birds matters

Journal of Experimental Biology, Journal Year: 2025, Volume and Issue: 228(Suppl_1)

Published: Feb. 15, 2025

ABSTRACT Among vertebrates, birds undertake the longest, fastest and highest migrations of any taxonomic group, largely due to their unique cardiorespiratory system, which permits for very large rates gas exchange. Managing resultant elevated production reactive oxygen species, thus oxidative stress, has meant that can avoid pathologies relating major medical challenges now probably account majority global healthcare spending. Hypoxia underlies most critical illnesses faced by humans, but avian system supply far more per unit time than mammal. Birds have high circulating glucose levels, adaptations cope with stress brought about hyperglycaemia. also inflammatory responses obesity in humans when they seasonally gain huge fat stores. Lastly, live four times longer similarly sized mammals, seasonal endogenous muscle hypertrophy, some even increase telomere length age. A new frontier ‘physiologging’ is emerging, making use technologies use, provide novel parameters better understanding biomechanics, energetics ecology a range species. These physiologging tools are likely insight into physiology, biomechanics including ability spread disease, as well each detailed this Commentary. By virtue physiological capacity, study physiology area future discovery research using applied interdisciplinary areas physiology.

Language: Английский

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Recovery of constitutive immune function after migratory endurance flight in free-living birds

Biology Letters, Journal Year: 2023, Volume and Issue: 19(2)

Published: Feb. 1, 2023

Strenuous physical activity can negatively affect constitutive innate immune function (CIF), the always present first line of defence against pathogens. CIF is non-specific, and thus vital when encountering novel A lowered likely increases risk infection disease. Migratory birds engage in truly extreme during their endurance flights, however, little known about how they deal with negative impact this has on function. By collecting both between- within-individual data we show, for time, that free-flying migratory recover several parameters stopovers, which are stationary periods between flights. With this, provide an important piece puzzle migrating cope physiological challenges face biannual journeys. Furthermore, our study stresses importance stopovers beyond fuel accumulation.

Language: Английский

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Migration tactics and connectivity of a Nearctic–Neotropical migratory shorebird

Journal of Animal Ecology, Journal Year: 2022, Volume and Issue: 91(4), P. 819 - 830

Published: Feb. 4, 2022

Abstract During long‐distance spring migrations, birds may rest and refuel at numerous stopover sites while minimizing the time to reach breeding grounds. If habitat is limited along migration route, pre‐breeding optimize flight range by having longer stopovers higher quality compared poorer sites. Stopover duration also depends on distance remaining grounds, ecological barriers individual characteristics. We assessed tactics connectivity of a Nearctic–Neotropical migratory shorebird, semipalmated sandpiper Calidris pusilla , two with known relative northern Gulf Mexico (NGOM) coast, first land encountered after crossing (GOM). used automated radio telemetry (Motus) estimate probability departure. Migration speed was estimated for individuals detected subsequent receivers Motus network. To measure connectivity, we morphometrics network assign general regions. Additionally, feather stable isotope ratios C N provided coarse information about overwintering declined fuel loads capture as expected under time‐minimizing strategy. After accounting load, approximately 40% site. found no detectable effect age, sex or location behaviour. The departure strongly affected humidity tailwind weather conditions. Birds stopping site had earlier apparent arrival Louisiana coast an hub this species, since were departing range‐wide regions values suggested using widespread wintering Our study shows how high‐quality, coastal wetlands NGOM serve critical role in annual cycle shorebird. behaviour indicated that high‐quality be species during migration. As threats GOM increase, protection these already vitally important.

Language: Английский

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Corticosterone's roles in avian migration: Assessment of three hypotheses

Hormones and Behavior, Journal Year: 2021, Volume and Issue: 135, P. 105033 - 105033

Published: July 14, 2021

Language: Английский

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Do departure and flight route decisions correlate with immune parameters in migratory songbirds?

Functional Ecology, Journal Year: 2022, Volume and Issue: 36(12), P. 3007 - 3021

Published: Sept. 23, 2022

Abstract Many songbirds migrate twice a year to exploit seasonally available resources. These journeys are energetically demanding and energy reserves of these small birds limited. Accordingly, most the time migrating is spent during stopovers that serve rest, replenish resources recover. While external influences, like prevailing weather conditions resource availability, well studied with regard stopover behaviour departure decisions, studies on how birds' individual physiological condition decisions may be linked scarce. We used large‐scale radio‐telemetry network covering German Bight (SE North Sea) study immunological constitution at correlate flight in five species short‐ medium‐distance migratory songbirds. measured markers innate (bacterial killing activity, lysozyme concentration, natural antibodies complement titres) acquired immune function (immunoglobulin Y) plasma. After sampling, we tracked terms duration as routes distances within telemetry after departure. found durations were positively related immunoglobulin Y across bacterial activity solely song thrushes spring, while no relations became apparent fall. Flight concentrations both spring fall, though not all investigated species. Coastal offshore‐oriented taken independent status. Our for first shows wild correlated their status, only but also beyond stopover. Furthermore, increased titres Immunoglobulin concentrations, either due recent infection or greater investment function, took additional sites, probably reach breeding grounds good condition. During less time‐constrained fall season, generally prolonged, from status any delays improve likely detrimental fitness. Read free Plain Language Summary this article Journal blog.

Language: Английский

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Controlled expression of avian pre-migratory fattening influences indices of innate immunity

Biology Open, Journal Year: 2024, Volume and Issue: 13(1)

Published: Jan. 15, 2024

ABSTRACT While immunity is frequently dampened when birds engage in strenuous migratory flights, whether and how changes during the rapid accumulation of energy stores preparation for migration remains largely unknown. Here we induced pre-migratory fattening through controlled daylight common quails (Coturnix coturnix) regularly assessed three markers constitutive innate (leukocyte coping capacity or LCC, hemagglutination hemolysis titres) measures body composition (lean fat mass). All showed similar over process. LCC responses, titres, were on average higher mid-fattening phase compared to peak-fattening phase, values those observed prior start fattening. At mid-fattening, found that a larger mass (as % mass) had lower peak responses titres. Reversibly, at also kept proportion lean highest peaks. Our results indicate undergo immune indices (over 8 weeks) as they accumulate propose this could be due competing trade-off processes between metabolic remodelling system function.

Language: Английский

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