Condition dependence of sexually selected signals in the European Starling (Sturnus vulgaris)

Since Darwin, evolutionary biologists envisaged various hypotheses to explain the advantages for males to exhibit exaggerated secondary sexual traits, also known as ornaments. One of these hypotheses proposes that male ornaments may signal to the females the benefits they can get by mating, and that female preference for ornamented males is one of the main selecting forces explaining the evolution of secondary sexual traits. The evolutionary scenario becomes more complex if we consider that in many species males bear multiple ornaments. Why multiple ornaments should evolve? Why and how do females base their choice among different male traits? Different ornaments could signal different aspects of male quality (=benefits). For example, individual condition at different stages of male’s life may by reflected by the expression of different ornaments, or diverse ornaments could respond differently to a similar stress experienced during a male life-history event due, for example, to a different response to carry-over effects. Condition dependence of male ornaments has been supported by a large number of studies on sexual secondary traits, yet whether and how different stresses at different life-history stages affect the expression of multiple ornaments has been investigated in a more limited number of cases. In my PhD project I used a passerine bird, the European starling (Sturnus vulgaris), as a model species given that males bear multiple secondary sexual traits. In this species it has been shown that females prefer males with long throat feathers that have high UV reflectance, that produce a complex song and, although with less empirical support, with more brightly colours on the beak. During my PhD I attempted to investigate the mechanisms that underlie the expression of male ornaments by experimentally manipulating individual condition during two energy-demanding life-history events, i.e. during nestling development and during the post-juvenile moult. Male attractiveness was directly evaluated in a female choice experiment. The first experimental manipulation aimed at investigating the effect of an immune challenge on growth and physiological responses on nestlings that were naturally infested with ectoparasites (manuscript 1), and to assess the temporal pattern of their first- and second-year moult (manuscript 2). The second experimental manipulation was used to test the effect of removing the stress caused by the nest ectoparasites on parental investment during the incubation (manuscript 3), and on parent-offspring communication during the nestling stage (manuscript 4). I then examined the temporal pattern of the post-juvenile moult in males from ectoparasite-free and naturally infested nests (manuscript 5). A third experimental manipulation consisted of supplementing with or depriving of carotenoids the diet of males in the course of their post-juvenile moult. I further tested the effect of nest ectoparasites and diet i) on the preening activity of males during winter, i.e. from the end of the moult to the start of the breeding period (manuscript 6), ii) on the expression of male ornaments and iii) on female preference (manuscript 7). My results suggest that an early stress, i.e. endotoxin or ectoparasites, does not significantly affect the nestling growth. Nestlings whose immune system was challenged with an endotoxin (LPS) showed similar antioxidant capacity and oxidative damage to those measured on control nestlings, whereas hematocrit was higher in second-brood LPS-nestlings than controls. Nestlings in ectoparasite-free nests produced a more conspicuous postural begging than that produced by nestlings in naturally infested nests. Parents were also sensitive to nest ectoparasites because they increased the time spent at the nest during the incubation period, although the provisioning effort during the nestling period was not different among deparasitized and control broods. Moult was advanced in birds injected with LPS and in those grown without nest ectoparasites, as they were probably in better condition than their counterparts and could therefore anticipate such costly life-history event. Birds from ectoparasite-free nests moulted over a longer period than controls, whereas moult duration of LPS and control birds was similar. The supplement of carotenoids during moult resulted in an increase of time invested in preening their plumage a few months after the end of the moult, and showed an increased yellow colouration of the beak in the following breeding season. As result, males that were grown in ectoparasite-free nests and were supplemented with carotenoids during the following moult were preferred by females in the mate choice experiment. In conclusion, the results of my PhD project provided an experimental evidence of carry-over effects in starlings. Males that experienced different stresses during the early stages of their life were less attractive for the females in their first breeding season. While I found a different colouration of the beak among birds from ectoparasite-free and control nests, the throat feathers were of similar length and colouration. This difference in attractiveness could be due to song characteristics during mate choice tests. Any attempt to individually record male song unfortunately failed and the effect of early stresses on song could not be assessed directly. Despite this, the resulting female preference for males that experienced favourable juvenile conditions suggests that male ornaments are considered as a whole during mate choice, and their expression is probably influenced by carry-over effects. These findings seem therefore in agreement with the redundant signal hypothesis, which suggests that female integrate the information of all male ornaments to assess the mate quality

Home, dirty home: effect of old nest material on nest-site selection and breeding performance in a cavity-nesting raptor

The quality of a breeding site may have major fitness consequences. A fundamental step to understanding the process of nest-site selection is the identification of the information individuals use to choose high-quality nest sites. For secondary cavity-nesting bird species that do not add nest lining material, organic remains (faeces, pellets) accumulated inside nest cavities during previous breeding events may be a cue for high-quality nest-sites, as they contain information about past successful breeding and may improve thermal insulation of eggs during incubation. However, cavities in which breeding was successful might also contain more nest-dwelling ectoparasites than unoccupied cavities, offering an incentive for prospective parents to avoid them. We exposed breeding cavity-nesting lesser kestrels (Falco naumanni) to nestbox dyads consisting of a dirty (with a thick layer of organic substrate) and a clean nestbox (without organic material). Dirty nestboxes were strongly preferred, being occupied earlier and more frequently than clean ones. Hatching success in dirty nestboxes was significantly higher than in clean ones, suggesting a positive effect of organic nest material on incubation efficiency, while nestbox dirtiness did not significantly affect clutch and brood size. Nestlings from dirty nestboxes had significantly higher ectoparasite load than those from clean nestboxes soon after egg hatching, but this difference was not evident a few days later. Nest substrate did not significantly affect nestling growth. We concluded that nest substrate is a key driver of nest-site choice in lesser kestrels, although the adaptive value of such a strong preference appears elusive and may be context-dependent

Analysis of Movement Recursions to Detect Reproductive Events and Estimate Their Fate in Central Place Foragers

Background Recursive movement patterns have been used to detect behavioral structure within individual movement trajectories in the context of foraging ecology, home-ranging behavior, and predator avoidance. Some animals exhibit movement recursions to locations that are tied to reproductive functions, including nests and dens; while existing literature recognizes that, no method is currently available to explicitly target different types of revisited locations. Moreover, the temporal persistence of recursive movements to a breeding location can carry information regarding the fate of breeding attempts, but it has never been used as a metric to quantify recursive movement patterns. Here, we introduce a method to locate breeding attempts and estimate their fate from GPS-tracking data of central place foragers. We tested the performance of our method in three bird species differing in breeding ecology (wood stork (Mycteria americana), lesser kestrel (Falco naumanni), Mediterranean gull (Ichthyaetus melanocephalus)) and implemented it in the R package ‘nestR’. Methods We identified breeding sites based on the analysis of recursive movements within individual tracks. Using trajectories with known breeding attempts, we estimated a set of species-specific criteria for the identification of nest sites, which we further validated using non-reproductive individuals as controls. We then estimated individual nest survival as a binary measure of reproductive fate (success, corresponding to fledging of at least one chick, or failure) from nest-site revisitation histories during breeding attempts, using a Bayesian hierarchical modeling approach that accounted for temporally variable revisitation patterns, probability of visit detection, and missing data. Results Across the three species, positive predictive value of the nest-site detection algorithm varied between 87 and 100% and sensitivity between 88 and 92%, and we correctly estimated the fate of 86–100% breeding attempts. Conclusions By providing a method to formally distinguish among revisited locations that serve different ecological functions and introducing a probabilistic framework to quantify temporal persistence of movement recursions, we demonstrated how the analysis of recursive movement patterns can be applied to estimate reproduction in central place foragers. Beyond avian species, the principles of our method can be applied to other central place foraging breeders such as denning mammals. Our method estimates a component of individual fitness from movement data and will help bridge the gap between movement behavior, environmental factors, and their fitness consequences

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Condition dependence of sexually selected signals in the European Starling (Sturnus vulgaris)

Since Darwin, evolutionary biologists envisaged various hypotheses to explain the advantages for males to exhibit exaggerated secondary sexual traits, also known as ornaments. One of these hypotheses proposes that male ornaments may signal to the females the benefits they can get by mating, and that female preference for ornamented males is one of the main selecting forces explaining the evolution of secondary sexual traits. The evolutionary scenario becomes more complex if we consider that in many species males bear multiple ornaments. Why multiple ornaments should evolve? Why and how do females base their choice among different male traits? Different ornaments could signal different aspects of male quality (=benefits). For example, individual condition at different stages of male’s life may by reflected by the expression of different ornaments, or diverse ornaments could respond differently to a similar stress experienced during a male life-history event due, for example, to a different response to carry-over effects. Condition dependence of male ornaments has been supported by a large number of studies on sexual secondary traits, yet whether and how different stresses at different life-history stages affect the expression of multiple ornaments has been investigated in a more limited number of cases. In my PhD project I used a passerine bird, the European starling (Sturnus vulgaris), as a model species given that males bear multiple secondary sexual traits. In this species it has been shown that females prefer males with long throat feathers that have high UV reflectance, that produce a complex song and, although with less empirical support, with more brightly colours on the beak. During my PhD I attempted to investigate the mechanisms that underlie the expression of male ornaments by experimentally manipulating individual condition during two energy-demanding life-history events, i.e. during nestling development and during the post-juvenile moult. Male attractiveness was directly evaluated in a female choice experiment. The first experimental manipulation aimed at investigating the effect of an immune challenge on growth and physiological responses on nestlings that were naturally infested with ectoparasites (manuscript 1), and to assess the temporal pattern of their first- and second-year moult (manuscript 2). The second experimental manipulation was used to test the effect of removing the stress caused by the nest ectoparasites on parental investment during the incubation (manuscript 3), and on parent-offspring communication during the nestling stage (manuscript 4). I then examined the temporal pattern of the post-juvenile moult in males from ectoparasite-free and naturally infested nests (manuscript 5). A third experimental manipulation consisted of supplementing with or depriving of carotenoids the diet of males in the course of their post-juvenile moult. I further tested the effect of nest ectoparasites and diet i) on the preening activity of males during winter, i.e. from the end of the moult to the start of the breeding period (manuscript 6), ii) on the expression of male ornaments and iii) on female preference (manuscript 7). My results suggest that an early stress, i.e. endotoxin or ectoparasites, does not significantly affect the nestling growth. Nestlings whose immune system was challenged with an endotoxin (LPS) showed similar antioxidant capacity and oxidative damage to those measured on control nestlings, whereas hematocrit was higher in second-brood LPS-nestlings than controls. Nestlings in ectoparasite-free nests produced a more conspicuous postural begging than that produced by nestlings in naturally infested nests. Parents were also sensitive to nest ectoparasites because they increased the time spent at the nest during the incubation period, although the provisioning effort during the nestling period was not different among deparasitized and control broods. Moult was advanced in birds injected with LPS and in those grown without nest ectoparasites, as they were probably in better condition than their counterparts and could therefore anticipate such costly life-history event. Birds from ectoparasite-free nests moulted over a longer period than controls, whereas moult duration of LPS and control birds was similar. The supplement of carotenoids during moult resulted in an increase of time invested in preening their plumage a few months after the end of the moult, and showed an increased yellow colouration of the beak in the following breeding season. As result, males that were grown in ectoparasite-free nests and were supplemented with carotenoids during the following moult were preferred by females in the mate choice experiment. In conclusion, the results of my PhD project provided an experimental evidence of carry-over effects in starlings. Males that experienced different stresses during the early stages of their life were less attractive for the females in their first breeding season. While I found a different colouration of the beak among birds from ectoparasite-free and control nests, the throat feathers were of similar length and colouration. This difference in attractiveness could be due to song characteristics during mate choice tests. Any attempt to individually record male song unfortunately failed and the effect of early stresses on song could not be assessed directly. Despite this, the resulting female preference for males that experienced favourable juvenile conditions suggests that male ornaments are considered as a whole during mate choice, and their expression is probably influenced by carry-over effects. These findings seem therefore in agreement with the redundant signal hypothesis, which suggests that female integrate the information of all male ornaments to assess the mate quality.Sulla base delle teorie di Darwin, i biologi evoluzionisti hanno formulato diverse ipotesi per spiegare l’origine dei tratti sessuali secondari esibiti dai maschi, anche detti ornamenti. Una di queste ipotesi suggerisce che le femmine valutino gli ornamenti maschili per massimizzare il proprio successo riproduttivo nella scelta del partner e che la preferenza femminile sia una delle forze selettive principali alla base dell’evoluzione dei tratti sessuali secondari. Lo scenario evolutivo si complica se consideriamo che i maschi di molte specie esibiscono ornamenti multipli. E’ stato ipotizzato che diversi ornamenti possano segnalare differenti aspetti della qualità maschile. In questo caso la loro espressione potrebbe riflettere la condizione del maschio in fasi diverse della life-history, oppure differenti ornamenti potrebbero essere influenzati in modo diverso da uno stesso stress. Molti studi sui tratti sessuali secondari maschili hanno mostrato che i costi associati all’espressione di alcuni ornamenti sono correlati alla condizione dell’individuo, cioè sono condizione-dipendenti. Tuttavia, sono pochi gli studi sull’effetto di eventi di stress in fasi diverse del ciclo vitale sull’espressione di ornamenti multipli. Nel mio progetto di Dottorato ho studiato i meccanismi che regolano l’espressione dei tratti sessuali secondari di Storno (Sturnus vulgaris), un passeriforme di medie dimensioni in cui i maschi presentano ornamenti multipli. In questa specie, vi sono evidenze sperimentali che le femmine preferiscono penne della gola più lunghe e con un’alta brillantezza nella radiazione ultravioletta, canti complessi e (probabilmente) colori del becco più intensi. Nel corso del mio Dottorato ho effettuato tre manipolazioni sperimentalmente per modificare la condizione dei maschi in due fasi costose della life-history, durante lo sviluppo giovanile e nel corso della prima muta, per valutare l’effetto di stress precoci sull’espressione degli ornamenti nel corso della prima stagione riproduttiva. L’attrattività dei maschi manipolati è stata testata utilizzando un esperimento di scelta femminile. La prima manipolazione sperimentale aveva l’obiettivo di studiare l’effetto di uno stress immunitario sulla condizione dei pulcini in nidi naturali (manoscritto 1), oltre che sui tempi di muta del primo e del secondo anno di vita (manoscritto 2). Con la seconda manipolazione sperimentale ho testato l’effetto della rimozione dei parassiti del nido sull’investimento parentale durante il periodo d’incubazione (manoscritto 3) e sull’interazione genitori-prole (manoscritto 4). La terza manipolazione sperimentale è stata effettuata sulla dieta dei maschi nel periodo della muta giovanile; ad un gruppo di individui è stata somministrata una dieta ricca di carotenoidi, mentre un altro gruppo ha ricevuto una dieta priva di carotenoidi. Quindi ho esaminato i tempi della muta giovanile dei maschi involati da nidi con e senza parassiti che hanno ricevuto una dieta ricca o priva di carotenoidi (manoscritto 5). Ho analizzato l’effetto delle differenze di carico parassitario e di dieta i) sul tempo investito dai maschi nel mantenere in ordine il piumaggio (manoscritto 6), ii) sull’espressione degli ornamenti maschili e iii) sulla preferenza femminile (manoscritto 7). I risultati ottenuti suggeriscono che uno stress precoce, come un’infezione batterica o la presenza degli ectoparassiti nel nido, non abbia un effetto rilevante sulla crescita dei pulcini. Il potere antiossidante (Capacità Antiossidante Totale, TAC) e la concentrazione di metaboliti reattivi dell'ossigeno (ROM) non sono risultati significativamente differenti tra i pulcini trattati con lipopolisaccaridi (LPS) e i pulcini di controllo trattati con una soluzione salina. D’altra parte, l’ematocrito è risultato più alto nei pulcini trattati con LPS ma solo in quelli nati tardivamente. Nei nidi in cui sono stati rimossi gli ectoparassiti, i pulcini hanno eseguito un begging posturale mediamente più intenso, mentre le strategie di allocazione degli adulti non sono state influenzate dalla presenza dei parassiti nel nido, anche se durante la fase di incubazione delle uova gli adulti hanno trascorso un tempo significativamente maggiore nei nidi privi di parassiti. L’inizio della muta post-giovanile è stato anticipato dagli individui trattati con LPS e da quelli involatisi da nidi senza ectoparassiti, probabilmente perché in condizioni migliori rispetto agli individui di controllo (trattati con una soluzione salina, o involatisi da nidi infestati da parassiti). La muta è stata completata in tempi più lunghi dai maschi involatisi dai nidi senza parassiti, mentre il trattamento con LPS non ha prodotto differenze significative rispetto ai controlli nella durata della muta. La presenza dei carotenoidi nella dieta durante la muta non ha influenzato la colorazione delle penne della gola. Tuttavia i risultati suggeriscono che il trattamento abbia avuto un effetto positivo sulla condizione nei mesi successivi alla muta, poiché i maschi che hanno assunto carotenoidi nel corso della muta hanno investito più tempo nelle attività di mantenimento del piumaggio e hanno prodotto un becco più brillante nel corso della successiva stagione riproduttiva. Nell’esperimento di scelta, le femmine hanno mostrato una preferenza significativa per i maschi involatisi dai nidi senza parassiti e che hanno ricevuto una dieta ricca di carotenoidi durante la muta. In conclusione, i risultati del mio Dottorato forniscono prove sperimentali di effetti carry-over nello Storno. Infatti, due differenti stress giovanili hanno ridotto l’attrattività dei maschi nella prima stagione riproduttiva, anche se i dati ottenuti dalle misure strumentali hanno evidenziato differenze significative soltanto per la colorazione del becco e non per la lunghezza o la colorazione delle penne della gola. E’ noto che l’attrattività dei maschi è legata alle caratteristiche del canto, ma nel corso del mio Dottorato non è stato possibile stimare l’effetto delle manipolazioni sperimentali su tale ornamento. Ad ogni modo il risultato ottenuto dall’esperimento di scelta femminile suggerisce che le femmine considerano in modo complessivo gli ornamenti multipli del maschio, la cui espressione è influenzata da effetti carry-over. Questi risultati sembrano in accordo con l’ipotesi del segnale ridondante (Redundant Signal Hypothesys), secondo cui le femmine integrano le informazioni ottenute dagli ornamenti maschili per valutare la qualità dei potenziali partner

Economic assessment of wild bird mortality induced by the use of lead gunshot in European wetlands.

In European wetlands, at least 40 bird species are exposed to the risk of lead poisoning caused by ingestion of spent lead gunshot. Adopting a methodology developed in North America, we estimated that about 700,000 individuals of 16 waterbird species die annually in the European Union (EU) (6.1% of the wintering population) and one million in whole Europe (7.0%) due to acute effects of lead poisoning. Furthermore, threefold more birds suffer sub-lethal effects. We assessed the economic loss due to this lead-induced mortality of these 16 species by calculating the costs of replacing lethally poisoned wild birds by releasing captive-bred ones. We assessed the cost of buying captive-bred waterbirds for release from market surveys and calculated how many captive-bred birds would have to be released to compensate for the loss, taking into account the high mortality rate of captive birds (72.7%) in the months following release into the wild. Following this approach, the annual cost of waterbird mortality induced by lead shot ingestion is estimated at 105 million euros per year in the EU countries and 142 million euros in the whole of Europe. An alternative method, based upon lost opportunities for hunting caused by deaths due to lead poisoning, gave similar results of 129 million euros per year in the EU countries and 185 million euros per year in the whole of Europe. For several reasons these figures should be regarded as conservative. Inclusion of deaths of species for which there were insufficient data and delayed deaths caused indirectly by lead poisoning and effects on reproduction would probably increase the estimated losses substantially. Nevertheless, our results suggest that the benefits of a restriction on the use of lead gunshot over wetlands could exceed the cost of adapting to non-lead ammunition

Skin and flange colour, but not ectoparasites, predict condition and survival in starling nestlings

Parents are expected to strategically partition their limited resources among the current and future progeny in order to maximize their fitness. Since an equal investment in offspring of different reproductive value entails fitness costs, natural selection has promoted the evolution of reliable signals of offspring condition, allowing parents to invest in their progeny accordingly. In birds, mouth and skin colouration are hypothesized to be honest signals of offspring condition, because they are affected by diverse factors. Among these, ectoparasite load has been shown to affect nestling condition, but its influence on visual components of begging is poorly known. We experimentally investigated whether nest ectoparasite removal affected flange and skin reflectance of first- and second-brood European starling (Sturnus vulgaris) nestlings. We also tested whether high reflectance in visual components of begging mirrored other aspects of nestling condition, such as morphological (high stature) and physiological (high haematocrit and immune response) traits, and pre-fledging mortality. Ectoparasite removal did not affect visual components of begging in first or second broods. However, larger nestlings from both broods displayed higher ultraviolet (UV) reflectance of skin and higher flange reflectance in the visible-wavelength region (but lower flange UV reflectance) than their siblings. A higher skin UV reflectance relative to siblings also positively predicted pre-fledging survival within-brood. Therefore, visual components of begging did not mirror ectoparasite infestation in this species. However, they provide parents with reliable information about individual quality, thus affecting resource allocation and promoting survival of the most valuable offspring during the entire breeding season. Significance statement: In species with parental care, natural selection favours the evolution of reliable signals of offspring quality, thus allowing parents to invest in their progeny accordingly. We experimentally show that skin and beak flange colour does not mirror ectoparasite infection in European starling nestlings. However, begging visual signals predict nestling body size and survival until fledging. A seasonal variation in the strength of the association between begging visual signals and nestling condition is also shown, indicating that change ecological conditions can affect the association between different condition-dependent traits

Data from: Early exposure to a bacterial endotoxin advances the onset of moult in the European starling

In animals, events occurring early in life can have profound effects on subsequent life-history events. Early developmental stresses often produce negative long-lasting impacts, although positive effects of mild stressors have also been documented. Most studies of birds have investigated the effects of events occurring at early developmental stages on the timing of migration or reproduction, but little is known on the long-term effects of these early events on moulting and plumage quality. We exposed European starling (Sturnus vulgaris) nestlings to an immune challenge to assess the effects of a developmental stress on the timing of the first (post-juvenile) and second (post-breeding) complete annual moult, the length of the flight feathers, and the length and colouration of ornamental throat feathers. The nestlings were transferred to indoor aviaries before fledgling and kept in captivity until the end of post-breeding moult. Individuals treated with Escherichia coli lypopolysaccharide (LPS) started both moult cyclesing earlier compared to control siblings in either years. Moult duration was unaffected by the immune challenge, but an advanced moult onset resulted in a longer moult duration. Moreover, female (but not male) throat feather colouration of LPS-injected -exposed individuals showed a reduced UV chroma. We argue that an early activation of the immune system caused by LPS may allow nestlings to better cope with post-fledging stresses and possibly lead to improved body condition and earlier moult onset. The effect of early LPS exposure was remarkably persistent, as it was still visible more than one year after the treatment, and highlighted the importance of early developmental stresses in shaping subsequent major life-history traits, including the timing of moult in birds