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001-es BibID:	BIBFORM010634
Első szerző:	Lengyel Szabolcs (biológus)
Cím:	Clutch size determination in shorebirds: revisiting incubation limitation in the pied avocet (Recurvirostra avosetta) / Szabolcs Lengyel, Béla Kiss, C. Richard Tracy
Dátum:	2009
Megjegyzések:	1. Traits strongly related to fitness, such as offspring number, are expected to show intraspecific variation among individuals. However, offspring number is invariant in several reptiles, birds, and mammals. Most shorebirds (210+ species), for example, have an invariant clutch size of four eggs, which is unexpected in such an ecologically, behaviourally and socially diverse group. 2. The incubation-limitation hypothesis (ILH) suggests that shorebird clutch size is limited by the inability of adults to incubate clutches larger than four eggs. Several recent studies reported no overall costs of incubating experimentally enlarged clutches and concluded no support for the traditional ILH. However, most studies have not measured all potential costs, and none has quantified costs beyond egg hatching. We conducted a clutch-enlargement experiment and measured potential costs both during incubation and chick rearing in pied avocets ( Recurvirostra avosetta L.). 3. Hatching was more asynchronous and egg hatchability was marginally lower in enlarged clutches than in controls. Nonetheless, more young hatched from enlarged clutches (mean: 4·2 ± 0·17 SE) than from controls (3·4 ± 0·09), and the two groups did not differ in incubation period, complete or partial clutch failure, or hatchling body size, apparently refuting the ILH. 4. However, pairs incubating enlarged clutches occupied poorer feeding territories during chick rearing, experienced higher chick mortality, and eventually raised fewer young to independence (mean adjusted for season: 0·7 ± 0·16 SE juveniles) than did control pairs (1·2 ± 0·13). Chick survival was primarily associated with prey availability, and predation risks were not higher in larger broods. 5. Our results provide evidence that incubating unusually large clutches can affect post-hatching performance and lead to lower annual reproductive success in shorebirds. This study, therefore, supports the ILH and points to the importance of monitoring reproductive success beyond the hatching of the chicks.
Tárgyszavak:	Természettudományok Környezettudományok idegen nyelvű folyóiratközlemény külföldi lapban clutch manipulation cost of reproduction life history optimal clutch size precocial birds
Megjelenés:	Journal of Animal Ecology. - 78 (2009), p. 396-405. -
További szerzők:	Kiss Béla Tracy, C. Richard
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM135557
035-os BibID:	(WoS)001678261800001
Első szerző:	Ouyang, Jenny Q.
Cím:	Hormonal plasticity to food restriction is heritable in the house sparrow, Passer domesticus / Jenny Q. Ouyang, Ádám Z. Lendvai
Dátum:	2026
ISSN:	0021-8790
Megjegyzések:	1. Theoretical and empirical studies agree that populations harbour extensive among-individual variation in phenotypic plasticity, but the mechanisms generating and maintaining this variation are often unknown. 2. Endocrine systems, which can change plastically in response to environmental variation, may be shaped by natural selection, but their evolution requires heritable variation. It is currently unknown if endocrine plasticity in response to environmental challenges is heritable. 3. We investigated this question in house sparrows, Passer domesticus, by testing glucocorticoid responsiveness to food restriction. We alternated restricted (70% of individual daily food intake) and adequate (110%) treatments twice, drawing blood samples at the end of each treatment. Based on glucocorticoid responsiveness, we classified individuals into high-plasticity, low-plasticity and medium (control) groups by selecting the 20 most responsive, least responsive and random individuals, respectively. We transferred these groups into separate aviaries and let them reproduce. In the next generation, we measured hormonal responsiveness using identical methods. 4. Using a cross-foster design and quantitative genetic models, we partitioned the heritability of glucocorticoid responsiveness into genetic and environmental components. We found moderate heritability (h2 > 30%) of glucocorticoid plasticity in response to food availability. The environmental and residual variances of glucocorticoid responsiveness were smaller than those for the intercept. 5. Our findings provide empirical evidence for the existence of heritable individual variation in glucocorticoid plasticity, highlighting its potential to evolve under natural selection, particularly in dynamic and rapidly changing environments.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk corticosterone, evolution house sparrows HPA axis Passer domesticus phenotypic plasticity
Megjelenés:	Journal Of Animal Ecology. - [Epub ahead of print] (2026), p. 1-12. -
További szerzők:	Lendvai Ádám Zoltán (1977-) (biológus)
Pályázati támogatás:	K139021 OTKA ADVANCED 153291 Egyéb
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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