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001-es BibID:BIBFORM065614
Első szerző:Szabó Krisztián (zoológus)
Cím:Adaptive Host-Abandonment of Ectoparasites Before Fledging? Within-Brood Distribution of Nest Mites in House Sparrow Broods / Krisztián Szabó, Anita Szalmás, András Liker, Zoltán Barta
Dátum:2008
ISSN:0022-3395
Megjegyzések:We studied the within-brood distribution of a haematophagous mite Pellonyssus reedi living on nestling house sparrows (Passer domesticus) near the time of fledging. We measured the natural level of infestation of individual nestlings, and determined the feeding efficiency of mites, by scoring their feeding status. Within-brood distribution of mite loads was unrelated to nestling body mass, tarsus length, or immunocompetence. These results did not support parasite preference for large or susceptible hosts. Mite feeding-efficiency was also unrelated to these nestling characteristics, confirming that large nestlings or nestlings with less-developed immunocompetence did not provide superior feeding conditions for mites. Therefore, our results do not support the hypothesis that within-brood distribution of avian ectoparasites is explained by the parasites' preferences for characteristics, such as large body size or low immunocompetence, that make nestlings suitable hosts. On the other hand, we found that mite loads were negatively correlated with nestling age and feather length, suggesting that nestlings closer to fledging harbored fewer mites then their less-developed nestmates. Furthermore, feather length had a stronger relationship with parasite distribution than did nestling age. We presume, therefore, that feather characteristics, i.e., length, may serve as a signal for mites to perceive the ready-to-fledge state of nestlings, inducing abandonment behavior. These results support another, largely neglected hypothesis, i.e., that the avoidance or abandonment of those nestlings that are close to fledging may also explain the parasites' distribution in a brood. This hypothesis is based on the argument that many nest-dwelling ectoparasites breed in the nest material and emerge only periodically to feed on nestlings. In such parasites, the ability to recognize and avoid mature fledglings can be adaptive because this may help the parasites to avoid their removal from the nest so they can continue to reproduce by feeding on unfledged chicks of the current or later broods. Our results suggest that adaptive host-abandonment by nest-dwelling ectoparasites can influence within-brood parasite distributions around the time of fledging.
Tárgyszavak:Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
house sparrow
haematophagous mite
ectoparasite
nest mites
Pellonyssus reedi
abandonment behaviour
within-brood distribution
Megjelenés:Journal Of Parasitology 94 : 5 (2008), p. 1038-1043. -
További szerzők:Szalmás Anita (1978-) (biológus, mikrobiológus, klinikai mikrobiológus) Liker András Barta Zoltán (1967-) (biológus, zoológus)
Pályázati támogatás:T046661
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2.

001-es BibID:BIBFORM022989
Első szerző:Szabó Krisztián (zoológus)
Cím:Effects of haematophagous mites on nestling house sparrows (Passer domesticus) / Krisztián Szabó, Anita Szalmás, András Liker, Zoltán Barta
Dátum:2002
ISSN:1230-2821
Megjegyzések:Haematophagous mites are frequently found on nestling house sparrows (Passer domesticus), but their effects are poorly known. In this study we investigated whether natural levels of infection by two mite species Pellonyssus reedi and Ornithonyssus sylviarum have any fitness consequences on their hosts, including some physiological indices of chick health, body condition and fledging success. Among the haematological variables, thrombocytes and heterophils, but not lymphocytes and eosinophil granulocytes showed positive correlations with mite loads. There was also a significant decrease in the haematocrit values of the nestling sparrows with increasing mite intensity. We found no significant effect of ectoparasites on shortterm indices of nestling fitness, such as body mass or fledging success. These results suggest that the bloodfeeding mites of the studied house sparrow population mainly affected the haematological parameters of their hosts: They generated a nonspecific immune response, with inflammatory processes and anaemia. On the other hand, parasite infestation seemingly has only weak influence on feather and skeletal growth of nestling sparrows, and no effect on fledging success and body mass.
Tárgyszavak:Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Passer domesticus
Pellonyssus reedi
Ornithonyssus sylviarum
haematophagous mites
haematological variables
anaemia
immune response
body mass
fitness effects
Megjelenés:Acta Parasitologica 47 : 4 (2002), p. 318-322. -
További szerzők:Szalmás Anita (1978-) (biológus, mikrobiológus, klinikai mikrobiológus) Liker András Barta Zoltán (1967-) (biológus, zoológus)
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
Borító:
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