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001-es BibID:BIBFORM022848
Első szerző:Lendvai Ádám Zoltán (biológus)
Cím:The effect of energy reserves on social foraging: hungry sparrows scrounge more / Ádám Z. Lendvai, Zoltán Barta, András Liker, Veronika Bókony
Dátum:2004
ISSN:0962-8452
Megjegyzések:Animals often use alternative strategies when they compete for resources, but it is unclear in most cases what factors determine the actual tactic followed by individuals. Although recent models suggest that the internal state of animals may be particularly important in tactic choice, the effects of state variables on the use of alternative behavioural forms have rarely been demonstrated. In this study, using experimental wind exposure to increase overnight energy expenditure, we show that flock-feeding house sparrows (Passer domesticus) with lowered energy reserves increase their use of scrounging (exploiting others' food findings) during their first feed of the day. This result is in accordance with the prediction of a state-dependent model of use of social foraging tactics. We also show that scrounging provides less variable feeding rates and patch finding times than the alternative tactic. These latter results support the theoretical assumption that scrounging is a risk-averse tactic, i.e. it reduces the risk of immediate starvation. As the level of energy reserves predicts the use of social foraging tactics, we propose that selection should favour individuals that monitor the internal state of flock mates and use this information to adjust their own tactic choice.
Tárgyszavak:Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
producer-scrounger game
state-variables
starvation risk
foraging strategies
house sparrow
Passer domesticus
Megjelenés:Proceedings of the Royal Society. Series B. Biological sciences. - 271 : 1556 (2004), p. 2467-2472. -
További szerzők:Barta Zoltán (1967-) (biológus, zoológus) Liker András Bókony Veronika (alkalmazott zoológus)
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2.

001-es BibID:BIBFORM021571
Első szerző:Lendvai Ádám Zoltán (biológus)
Cím:The effects of energy reserves and dominance on the use of social-foraging strategies in the house sparrow / Ádám Z. Lendvai, András Liker, Zoltán Barta
Dátum:2006
Megjegyzések:In social animals, dominance rank often influences individuals' behaviour, but in most cases it is unknown how dominance modulates the effects of other phenotypic traits. We investigated the mutual effects of social dominance and the level of energy reserves on the use of social-foraging strategies in captive flocks of house sparrows, Passer domesticus.We used experimental wind exposure to manipulate overnight energy expenditure of dominant and subordinate individuals. In response to the experimental treatment dominants used scrounging (exploiting others' food finding) significantly more, whereas for subordinates there was only a moderate and nonsignificant increase in scrounging. Individual variability in the frequency of scrounging was higher in subordinates than in dominants and this difference between the dominance groups was unaffected by the treatment. These results suggest that individuals of different dominance status adopt different strategies: to cope with an energetically challenging situation, dominants behave rather uniformly by increasing further their preference for scrounging, whereas subordinates do not alter their tactic, but may rely on using scrounging opportunistically.
Tárgyszavak:Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Animal behaviour. - 72 : 4 (2006), p. 747-752. -
További szerzők:Liker András Barta Zoltán (1967-) (biológus, zoológus)
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3.

001-es BibID:BIBFORM018785
Első szerző:Lendvai Ádám Zoltán (biológus)
Cím:Conflict over parental care in house sparrows : do females use a negotiation rule? / Ádám Z. Lendvai, Zoltán Barta, Olivier Chastel
Dátum:2009
ISSN:1045-2249
Megjegyzések:Ho do parents resolve their conflict over parental care? The classical "sealed-bid" model of biparental care suggested that parents use a fixed best effort given the partner's effort. Alternatively, parents may "negotiate" their actual effort until the efforts of both partners settle down to limiting values, but in this case, the resulting efforts will not be the best responses to one another. Consequently, under the best response scenario, the response of 1 parent to the removal of its mate can be predicted from the response to a reduction in its partner's effort, whereas the "negotiation" model predicts that such an extrapolation will underestimate the effort of a parent caring alone. We tested this prediction in free-living house sparrows (Passer domesticus). We experimentally manipulated the males' parental care as follows: males' care in group 1) was reduced by using a capture-handling-release stress protocol, 2) stopped by removing the male, and 3) left as control. In response to these manipulations, control females kept their feeding rate constant, whereas male-stressed-released females showed a moderate increase of feeding rate. When this response was extrapolated to zero male effort, their effort was still significantly lower than the observed effort of male-removed females. These results suggest that females may use the negotiation rule to determine their actual parental effort.
Tárgyszavak:Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
biparental care
handicapping
mate removal
Passer domesticus
sexual conflict.
Megjelenés:Behavioral Ecology. - 20 : 3 (2009), p. 651-656. -
További szerzők:Barta Zoltán (1967-) (biológus, zoológus) Chastel, Olivier
Internet cím:DOI
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4.

001-es BibID:BIBFORM073444
035-os BibID:(Scopus)85026906262 (WOS)000406789200009
Első szerző:Sebestyén Flóra (biológus)
Cím:Insulin/IGF Signaling and Life History Traits in Response to Food Availability and Perceived Density in the Cnidarian Hydra vulgaris / Sebestyén Flóra, Póliska Szilárd, Rácz Rita, Bereczki Judit, Lénárt Kinga, Barta Zoltán, Lendvai Z. Ádám, Tökölyi Jácint
Dátum:2017
ISSN:0289-0003
Megjegyzések:Insulin/insulin-like growth factor signaling (IIS) is thought to be a central mediator of life history traits, but the generality of its role is not clear. Here, we investigated mRNA expression levels of three insulin-like peptide genes, the insulin-like receptor htk7, as well as several antioxidant genes, and the heat-shock protein hsp70 in the freshwater cnidarian Hydra vulgaris. Hydra polyps were exposed to a combination of different levels of food and perceived population density to manipulate life history traits (asexual reproduction and oxidative stress tolerance). We found that stress tolerance and the rate of asexual reproduction increased with food, and that these two effects were in significant interaction. Exposing animals to high perceived density resulted in increased stress tolerance or reduced reproduction only on lower food levels, but not on high food. The insulin-like receptor htk7 and the antioxidant gene catalase were significantly upregulated in the high density treatments. However, the expression level of insulin-like peptide genes, most antioxidant genes, and hsp70 were not affected by the experimental treatments. The higher expression level of htk7 may suggest that animals maintain a higher level of preparedness for insulin-like ligands at high population densities. However, the lack of difference between food levels suggests that IIS is not involved in regulating asexual reproduction and stress tolerance in hydra, or that its role is more subtle than a simple model of life history regulation would suggest.
Tárgyszavak:Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Insulin signaling, Hydra vulgaris
Megjelenés:Zoological Science. - 34 : 4 (2017), p. 318-325. -
További szerzők:Póliska Szilárd (1978-) (biológus) Rácz Rita (1989-) (biológus) Bereczki Judit (1979-) (biológus) Lénárt Kinga (1994-) (biológus) Barta Zoltán (1967-) (biológus, zoológus) Lendvai Ádám Zoltán (1977-) (biológus) Tökölyi Jácint (1984-) (biológus)
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5.

001-es BibID:BIBFORM091444
035-os BibID:(cikkazonosító)20203092 (WoS)000613752100015 (Scopus)85100477046
Első szerző:Vágási Csongor István
Cím:Social groups with diverse personalities mitigate physiological stress in a songbird / Csongor I. Vágási, Attila Fülöp, Gergely Osváth, Péter L. Pap, Janka Pénzes, Zoltán Benkő, Ádám Z. Lendvai, Zoltán Barta
Dátum:2021
ISSN:0962-8452
Tárgyszavak:Természettudományok Környezettudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Proceedings Of The Royal Society B-Biological Sciences. - 288 : 1943 (2021), p. 1-8. -
További szerzők:Fülöp Attila (1987-) (biológus) Osváth Gergely (1985-) (biológus) Pap Péter László (ökológus) Pénzes Janka Benkő Zoltán Lendvai Ádám Zoltán (1977-) (biológus) Barta Zoltán (1967-) (biológus, zoológus)
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