A test on within-individual changes in risk-taking behaviour due to experience to predation in the Collared Flycatcher (Ficedula albicollis)

Different experiences from the past may have influence on individual¿s behaviour through feedback mechanisms that can weaken or preserve the within-individual consistency of behavioural traits. Here, we aimed to find evidence for such feedback mechanisms that may operate on risk-taking behaviour via the effect of former experience to potential predation events in male Collared Flycatchers (Ficedula albicollis). We predicted that risk-taking of males would decrease after experiencing a predator¿s attack in previous breeding seasons (negative feedback). We assessed risk-taking by flight initiation distance (FID) that is the distance at which an individual flees from an approaching predator, which was estimated for 234 individuals from different breeding seasons. Information on predation experience (i.e. occurrence of nest predation, the incidence of capture by human observers) was available from our long-term database on individual life histories. In a horizontal approach, we found no difference in FID when comparing males with former experience to predation with males naive to predators. A longitudinal approach relying on the repeated tests of the same individuals from different years yielded analogous results, we could not show a significant change in the risk-taking behaviour of the males as a consequence of experience to predation in past years. However, we found that individuals systematically took less risk over the years, which might be a consequence of acquiring general experience with agePeer Reviewe

Individual differences in song plasticity in response to social stimuli and singing position

Individual animals can react to the changes in their environment by exhibiting behaviors in an individual‐specific way leading to individual differences in phenotypic plasticity. However, the effect of multiple environmental factors on multiple traits is rarely tested. Such a complex approach is necessary to assess the generality of plasticity and to understand how among‐individual differences in the ability to adapt to changing environments evolve. This study examined whether individuals adjust different song traits to varying environmental conditions in the collared flycatcher (Ficedula albicollis), a passerine with complex song. We also aimed to reveal among‐individual differences in behavioral responses by testing whether individual differences in plasticity were repeatable. The presence of general plasticity across traits and/or contexts was also tested. To assess plasticity, we documented (1) short‐scale temporal changes in song traits in different social contexts (after exposition to male stimulus, female stimulus or without stimuli), and (2) changes concerning the height from where the bird sang (singing position), used as a proxy of predation risk and acoustic transmission conditions. We found population‐level relationships between singing position and both song length (SL) and complexity, as well as social context‐dependent temporal changes in SL and maximum frequency (MF). We found among‐individual differences in plasticity of SL and MF along both the temporal and positional gradients. These among‐individual differences in plasticity were repeatable. Some of the plastic responses correlated across different song traits and environmental gradients. Overall, our results show that the plasticity of bird song (1) depends on the social context, (2) exists along different environmental gradients, and (3) there is evidence for trade‐offs between the responses of different traits to different environmental variables. Our results highlight the need to consider individual differences and to investigate multiple traits along multiple environmental axes when studying behavioral plasticity

A behavioural trait displayed in an artificial novel environment correlates with dispersal in a wild bird

Behaviour shown in a novel environment has important consequences for fitness in many animals. It is widely studied with standard tests by placing the individuals into an unfamiliar experimental area, that is the so-called open-field or novel environment test. The biological relevance of traits measured under such artificial conditions is questionable and could be validated by establishing a link with variables that truly reflect exploration in the wild. Our aim in this field study was to characterize behaviours measured in an artificial novel environment (an aviary) and assess the biological relevance of them in the collared flycatcher (Ficedula albicollis). Therefore, we measured the repeatability and the association of multiple behavioural traits, as well as their relationship with breeding dispersal (that reflects exploration in the wild). We found evidence for non-zero repeatability for number of crosses between the quarters, number of hops and perching latency in the aviary, and these repeatabilities were high when assessed at shorter time windows. Additionally, birds with short perching latency in the novel environment were more likely residents and bred closer to their breeding nest box in the previous year, which may suggest that latency to perch is connected to dispersal in the wild. In sum, our results indicate that behaviours assessed in an artificial environment are individual-specific at least on smaller timescales, and at least, one component of these behaviours is correlated with an ecologically relevant trait

Male territorial aggression and fitness in collared flycatchers: a long-term study

consequences for fitness. Here, we explored the relationship between aggression and fitness in a long-term database collected in a wild population of the collared flycatcher (Ficedula albicollis). We quantified the aggression of males during nest-site defence by conducting simulated territorial intrusions in the courtship period. We estimated the fitness of males based on their pairing success, breeding output and survival to next year. Earlier arriving and older males had a higher probability to establish pairbond, and males that started to breed earlier fledged more young. Aggression did not predict pairing and breeding performances. However, the probability of a male to return in the next year was significantly related to aggression in an age-dependent manner. Among subadult males, more aggressive individuals had higher chances to return, while among adult males, less aggressive ones did so. This finding is in harmony with our general observation that subadult collared flycatcher males behave more aggressively than adult males when confronted with a conspecific intruder. Subadult males may be socially inexperienced, so they should be more aggressive to be successful. In contrast, if adult males suffer from higher physiological costs, a lower level of aggression may be more advantageous for them. Our study shows that aggressive behaviour can be a fitness-related trait, and to understand its role in determining fitness, age should be taken into account

When to measure plumage reflectance: a lesson from Collared Flycatchers Ficedula albicollis

Sexually selected colour traits of bird plumage are widely studied. Although the plumage is replaced only at one or two yearly moults, plumage colour has long been shown to change between moults. Nevertheless, most studies measure colour weeks to months after the courtship period, typically at nestling rearing, and it is unclear whether these measurements yield relevant data concerning the primary process of sexual selection. Here we analyse repeated spectrometric data taken from male Collared Flycatchers during social courtship and nestling rearing. We show that some spectral traits are not correlated between the two measurements and that within-individual correlation declines significantly with the likely exposure of the plumage area to damage and soiling. There is an overall decline in spectral trait exaggeration during breeding, but trait decline is not closely related to measurement latency, especially not in the damage-exposed areas. Finally, sexual selection estimates differ depending on whether they are derived from spectra measured during courtship or during nestling rearing. These results suggest that, contrary to current practice, measurements of plumage reflectance should be made during the primary period of sexual signalling. Spectral trait decline during breeding could also be studied as a possible signal for mates and neighbours.Peer Reviewe

Ornaments and condition: plumage patch sizes, nutritional reserve state, reserve accumulation, and reserve depletion

Abstract: Condition-dependence is considered as a dominant mechanism ensuring the fitness benefits of continued mate choice for heritable sexual signal traits, but crucial questions remain concerning the underlying physiological pathways. For example, it is unclear whether condition-dependence is mediated by the different amount of resource obtained, some uncheatable functional link with nutritional status, or the adverse effect of nutritional stress experienced by some individuals. Furthermore, the pattern of change in nutritional reserves in relation to ornamental traits has recently been proposed as a critical pillar of the condition-dependence concept, but this pattern is virtually unknown in natural populations. We quantified separate measures for actual body condition, lipid reserve accumulation rate, and lipid reserve depletion, and applied these measures to two white plumage ornaments of male collared flycatchers during courtship, during nestling rearing, and before the summer moult. Neither actual condition nor reserve accumulation rate before moult predicted the subsequent change of ornament sizes, but reserve depletion was accompanied by the reduction of forehead patch size to the following year. Wing patch size, a trait important in territoriality, was negatively related to both reserve accumulation and reserve depletion in the courtship period, but not related to current condition. Finally, irrespective of breeding phase, measures of current condition, and recent nutritional reserve depletion were negatively correlated, but both were unrelated to resource accumulation rate. These results indicate that measuring nutritional reserve trajectories in addition to actual condition may reveal functionally important processes underlying signal-condition correlations. Significance statement: Ornamental signal characters are known to convey honest information to signal receivers through their dependence on nutritional condition. Here, we show that such signals can also indicate the temporal trends of condition. We examine plumage patch sizes and separate measures of actual condition, nutritional reserve accumulation, and nutritional reserve depletion in three contexts: during courtship, during nestling rearing, and before the summer moult. The results suggest nutritional stress effects on signal expression, and predictable reserve dynamics in relation to signal expression, thereby highlighting the usefulness of dynamic nutritional measures in clarifying the fundamental concept of condition-dependent signalling.Peer Reviewe

A margit-szigeti sünök és kullancsaik szerepe a Borrelia burgdorferi sensu lato baktériumok fenntartásában

A Lyme-borreliosis az északi félteke leggyakoribb vektorok által terjesztett betegsége. Az ezt okozó baktériumok, a Borrelia burgdorferi sensu lato fajcsoport egyes tagjai sokféle gerinces gazdában fennmaradhatnak a természetben: egyes rágcsálókban, madarakban, gyíkokban és sünökben is. Vizsgálatunk célja az volt, hogy megállapítsuk, hogy a margit-szigeti sünökben és az ezekről gyűjtött különböző fajú kullancsokban is jelen van-e a fertőzés. 2009-ben áprilistól októberig, 2010-ben márciustól novemberig gyűjtöttünk sünöket, havonta egy alkalommal. Az állatokat ezután lemértük és eltávolítottuk róluk a kullancsokat és a bolhákat, illetve 2010-ben szövetmintát is vettünk a fülükből. Az ektoparazitákat és a szövetmintákat további felhasználásig 70%-os alkoholban tároltuk. Zászlózással a növényzetről is gyűjtöttünk kullancsokat. A kullancsokat és a bolhákat később meghatároztuk, a kullancsokból alkalikus hidrolízissel, a szövetmintákból pedig DNS kivonó kittel kivontuk a DNS-t és polimeráz lánreakció illetve gél-elektroforézis segítségével megállapítottuk, hogy fertőzöttek-e Borrelia-val. A pozitív minták egy részét megszekvenáltattuk, hogy meghatározzuk a kimutatott baktériumok pontos faji hovatartozását. A két év folyamán 247 sünről 5063 kullancsot és 785 bolhát gyűjtöttünk össze. A kullancsok közül 4746 Ixodes ricinus-nak, 57 Ixodes hexagonus-nak, egy Ixodes acuminatus-nak és egy Hyalomma marginatum-nak bizonyult . A két évre viszonyítva a kullancsok prevalenciája a sünökön 77,3%, medián intenzitásuk pedig 12 volt. A meghatározott bolhákból 779 az Archaeopsylla erinacei, 6 a Ctenocephalides canis fajba tartozott. A bolhák prevalenciája 50,41%, medián intenzitásuk 3,5 volt. A növényzetről 152 az I. ricinus fajba tartozónak bizonyuló kullancsot szedtünk össze. A sünökről 2009-ben gyűjtött kullancsokban 139 poolból 68 lett pozitív B. burgdorferi s. l.-ra, a minimum prevalencia 15%-os volt. A területen zászlózással összegyűjtött kullancsokból 7 poolt állítottunk össze, ezekből 6 lett pozitív. Itt a minimum prevalencia 3,9% volt. A növényzetről gyűjtött kullancsokból és a szövetmintákból kimutatott baktériumok mind Borrelia afzelii-nek bizonyultak, a sünökről gyűjtött kullancsokból azonban Borrelia garinii-t is találtunk. Más sünökön végzett vizsgálatokkal ellentétben mi jóval több I. ricinus-t találtunk az állatokon, mint I. hexagonus-t. Ennek valószínűleg az a magyarázata, hogy a szigetre potenciálisan kullancsokat behurcoló kutyákon és madarakon inkább az előbbi, Magyarországon igen gyakori faj szív vért. Érdekes a két, hazánkban nem jellemző, egy-egy példányban talált kullancsfaj előfordulása. A Margit-sziget kedvelt városi parkja Budapestnek, amelyet hetente több ezer magyar és külföldi látogat. Az itt élő sünök vizsgálataink alapján fertőzhetik a rajtuk gyakran vért szívó kullancslárvákat és –nimfákat, melyek vedlés után, a következő stádiumukba jutva nagy valószínűséggel emberre is kerülhetnek, és betegséget okozhatnak.Lyme borreliosis is the most common vector-borne disease on the Northern hemisphere. The causative agents, namely certain members of the group Borrelia burgdorferi sensu lato can be maintained in nature by several vertebrate hosts: certain rodents, birds, lizards and hedgehogs. The aim of our study was to find out if the infection is present in the hedgehogs and in ticks collected from the hedgehogs and the vegetation. We collected hedgehogs from April to October in 2009 and from March to November in 2010, once a month. The animals were measured, the ticks and fleas were removed and in 2010 tissue samples were taken from the ears of the hedgehogs. The ectoparasites and the tissue samples were stored in 70% ethanol until further investigation. Questing ticks were collected by flagging. Later the ticks and fleas were identified, the DNA was extracted from the ticks by alcaline hydrolysis and from the tissue samples with a commercial DNA-extraction kit, and the Borrelia infection was investigated with the help of polymerase chain reaction and gel electrophoresis. Some of the positive samples were sequenced to identify the detected Borrelia species. In the two-year study, we collected 5063 ticks and 785 fleas from 247 hedgehogs. Among the ticks there were 4746 Ixodes ricinus, 57 Ixodes hexagonus, one Ixodes acuminatus and one Hyalomma marginatum. The prevalence of the ticks from hedgehogs was 77.3% and the median intensity was 12. 779 of the identified fleas were Archaeopsylla erinacei and six were Ctenocephalides canis. The prevalence of the fleas was 50.41%, the median intensity was 3.5. We collected 152 I. ricinus from the vegetation. 68 of 139 pools made from the ticks collected from hedgehogs in 2009 were positive for B. burgdorferi s. l., the minimum prevalence was 15%. We created 7 pools from the ticks collected by flagging and of these 6 were positive. The minimum prevalence in questing ticks was 3.9%. The bacteria detected in questing ticks and tissue samples were Borrelia afzelii, but in the ticks collected from hedgehogs we found Borrelia garinii, too. In contrast with other studies on hedgehogs we found more I. ricinus on the animals than I. hexagonus. The possible explanation for this is that mostly the former species that is very common in Hungary feeds on dogs and birds that can potentially transport ticks to the island. The occurrence of the two tick species, that are not characteristic for Hungary, is interesting. The Margaret Island is a popular city park in Budapest with several thousands of visitors every week. We have shown that hedgehogs can infect the nymphs and larvae feeding on them and in their next stage after moulting, ticks can infect people and cause disease