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001-es BibID:	BIBFORM013320
Első szerző:	Pap Péter László (ökológus)
Cím:	Variation in haematological indices and immune function during the annual cycle in the Great Tit Parus major / Péter L. Pap, Csongor I. Vágási, Jácint Tökölyi, Gábor Á. Czirják, Zoltán Barta
Dátum:	2010
ISSN:	0373-2266
Megjegyzések:	We investigated seasonal variation in haematological indices and immune function in the non-migratory Great Tit Parus major over a complete annual cycle. The haematocrit value showed a marked reduction in spring and summer, reaching a lowest value during moult, after which it increased to reach a maximum in winter and spring. The peak in the heterophil to lymphocyte ratio (H/L) during July indicated that Great Tits were the most stressed during the first half of the moulting period. The increase in heterophils and H/L ratio, concurrent with a reduced number of lymphocytes during the breeding season, probably reflected the cost of reproduction in terms of physiological stress and immune suppression. After breeding the number of heterophils and the H/L ratio decreased, reaching a lowest value during winter. The concentration of immunoglobulins followed the seasonal pattern in the number of heterophils, though highest values occurred somewhat later, in July?September during the second part of the moulting period. Our observations indicated large differences in activity throughout the year of different components of the immune system. This suggests differences in function among the components and possibly differences in susceptibility to stress, parasitism and hormones during the annual cycle. When juveniles became independent of their parents, the immunoglobulin concentration increased, whereas other immune measures did not show a significant change. This indicates a rapid increase of at least one component of the immune system after the young fledge.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Ardea. - 98 : 1 (2010), p. 105-112. -
További szerzők:	Vágási Csongor István Tökölyi Jácint (1984-) (biológus) Czirják Gábor Á. Barta Zoltán (1967-) (biológus, zoológus)
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat DOI
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001-es BibID:	BIBFORM030386
Első szerző:	Vágási Csongor István
Cím:	Correlates of variation in flight feather quality in the Great Tit Parus major / Csongor I. Vágási, Péter L. Pap, Jácint Tökölyi, Edina Székely, Zoltán Barta
Dátum:	2011
Megjegyzések:	The most important function of moult in birds is the renewal of deteriorated feathers. Worn and holey remiges may incur fitness costs, yet little is known about the factors responsible for the degree of feather wear and sources of variation in feather hole incidence. Here, we report results on variation in feather quality based on a study of three consecutive annual cycles of a Great Tit Parus major population. We found that month, age, sex, weight and the presence of feather holes are the main sources of variation in degree of wear. Juveniles and individuals with lower feather quality (measured through rachis diameter) and with fault bars present had higher feather hole loads. Feather abrasion peaked in the breeding season and was higher in females probably due to higher workload. The lower feather quality of juveniles compared to adults probably arises because of fast ontogeny in contrast to adults' prolonged moult. Our results indicate that feather deformities are positively interrelated and can be used as proxies of feather quality. Our findings on the correlates of feather holes seem partially contradictory with the widespread view that holes are feeding marks of chewing lice. We propose that feather holes are instead minor feather handicaps, at least in Great Tits.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban annual cycle fault bar feather deformities feather hole feather wear flight feather quality Parus major
Megjelenés:	Ardea. - 99 : 1 (2011), p. 53-60. -
További szerzők:	Pap Péter László (ökológus) Tökölyi Jácint (1984-) (biológus) Székely Edina Barta Zoltán (1967-) (biológus, zoológus)
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat
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