5 research outputs found
SzĂĽlĹ‘i hormonkoncentráciĂł Ă©s szĂĽlĹ‘i ráfordĂtás, Ă©lethossz reproduktĂv teljesĂtmĂ©ny Ă©s ivadĂ©kminĹ‘sĂ©g az Ă©jszakai ragadozĂł madarak szaporodásában. = Parental hormone concentration and parental investment, life-span reproductive perfomance and offspring quality in nocturnal raptors.
TeljesĂtett kutatási programunk nĂ©gy altĂ©mára kĂĽlönĂĽl el. 1) SzĂĽlĹ‘i tesztoszteron Ă©s ösztrogĂ©n koncentráciĂł a költĂ©si Ă©s a költĂ©sen kĂvĂĽli idĹ‘szak fĂĽggvĂ©nyĂ©ben. 2) RögzĂtett, vagy az utĂłdok igĂ©nyĂ©tĹ‘l fĂĽggĹ‘ szĂĽlĹ‘i ráfordĂtás? Egy teĂłria kĂsĂ©rleti elemzĂ©se. 3) A reproduktĂv kĂ©pessĂ©g emelkedĹ‘ Ă©s sĂĽllyedĹ‘ szakasza, az öregedĂ©s. 4) MennyisĂ©g versus minĹ‘sĂ©g, az utĂłdok minĹ‘sĂ©gĂ©t meghatározĂł tĂ©nyezĹ‘k. 1) Kimutattuk, hogy a tesztoszteron (T) koncentráciĂł a territĂłriumszerzĹ‘ tevĂ©kenysĂ©gben tĂĽkrözi a hĂmek eltĂ©rĹ‘ minĹ‘sĂ©gĂ©t, Ă©s fiĂłkagondozáskor a magasabb T szintűek intenzĂvebb táplálĂ©khordással magasabb reproduktĂv sikert Ă©rnek el. 2) TerepkĂsĂ©rletekkel igazoltuk, hogy az Ă©jszakai ragadozĂł madarak a fiĂłkák szĂĽksĂ©gletĂ©tĹ‘l fĂĽggetlenĂĽl rögzĂtett szĂĽlĹ‘i befektetĂ©ssel nevelik fel utĂłdaikat. 3) Feltártuk, hogy a szĂĽlĹ‘i T Ă©s ösztrogĂ©n koncentráciĂł korrellál az Ă©letkorfĂĽggĹ‘ költĂ©si sikerrel, - hogy idĹ‘s fĂ©szkelĹ‘ pároknak csökken a predáciĂłs kockázata - hogy elszenvedett predáciĂł növeli a szĂĽlĹ‘k predátorelhárĂtĂł tevĂ©kenysĂ©gĂ©t – Ă©s kimutattuk, hogy az idĹ‘s hĂmeket a közĂ©pkorosztály kiszorĂtja a jĂł minĹ‘sĂ©gű Ă©lĹ‘helyekrĹ‘l, Ă©s ezzel csökken reproduktĂv teljesĂtmĂ©nyĂĽk. 4) Ă–sszefĂĽggĂ©st mutattunk ki a kelĂ©s utáni fiĂłka T koncentráciĂł Ă©s az ivadĂ©kok kirepĂĽlĂ©si kondĂciĂłja között, valamint hogy kevĂ©s utĂłdot produkálĂł fĂ©szekaljakbĂłl több ivadĂ©k marad reproduktĂv tevĂ©kenysĂ©gre a helyi populáciĂłban, mint a sokfiĂłkájĂş fĂ©szekaljakbĂłl. (Cikkek: Acta Ornith. 2, Ornis Fenn. 2, Ardea 1, J. Ornith. 1, Folia Zool. 2) | The project was divided into four parts. 1) Annual cycle of testosterone and estradiol concentration in male and female tawny owls. 2) Fixed schedule or demand-dependent investment in parental care. An experimental test. 3) Increase and decline in the reproduction, the scenescence. 4) Quantity versus quality: factors determining offspring quality. 1) We have shown that different testosterone cencentrations (T) in males reflect different abilities to acquire territory and males with high T levels feed their nestlings more intensively and achieve higher breeding success. 2) We tested the ’Fixed schedule theory’ using brood size manipulation: male Tawny Owls regulate their feeding effort independently of the offspring’ needs. 3) We have found that parental T and estradiol levels correlate with age-dependent breeding success.- The predation risk for owl parents decreases as they acquire breeding experience.- Field experiment showed that after the owl parents have suffered brood predation they enhance their antipredator activity.- Old males are forced by males of middle age to vacate their high quality territories, hence their breeding performance declines. 4) A relationship was found between the post-hatching T concentration and the fledging condition of those offspring.- Moreover parents raise a greater proportion of high quality recruits from low fledgling production, than from high fledgling production. Articles: Acta Ornith. 2, Ornis Fenn. 2, Ardea 1, J. Ornith. 1, Folia Zool.
Fészekaljszabályzás és utód-szexarány, szülői minőség és párhűség az éjszakai ragadozó madarak szaporodásában = Brood size control and offspring sex-ratio, parental quality and mate fidelity in the breeding of nocturnal raptors
A teljesĂtett kutatási program nĂ©gy altĂ©mára kĂĽlönĂĽlt el: 1) SzĂĽlĹ‘ktĹ‘l irányĂtott hormonális fĂ©szekaljszabályzás. 2) Ivari preferencia az utĂłdgondozásban. 3) ParazitafertĹ‘zöttsĂ©g Ă©s az ösztrogĂ©n illetve tesztoszteron-koncentráciĂł összefĂĽggĂ©se, hatásuk a reproduktĂv teljesĂtmĂ©nyre Ă©s a párkötöttsĂ©gre. 4) A fĂ©szekaljakat Ă©rt predáciĂł mĂ©rtĂ©ke Ă©s következmĂ©nye. 1) Ă©s 2) altĂ©ma. - Kimutattuk a szĂĽlĹ‘i Ă©letkor Ă©s az idĹ‘járás hatását az ivadĂ©kok tesztoszteron koncentráciĂłjára Ă©s tĂşlĂ©lĂ©sĂ©re, kĂsĂ©rlettel megerĹ‘sĂtettĂĽk az anyai befolyást az utĂłdok tesztoszteron koncentráciĂłjára, megállapĂtottuk, hogy a szĂĽlĹ‘k kĂ©pesek az utĂłdok ivararányát az uralkodĂł környezeti feltĂ©telekhez Ă©s a demográfiai igĂ©nyekhez igazĂtani. PublikáciĂłk: Behav Ecol Sociobiol 2004, 56:306-303; Condor 2005, 107:323-328; Ethology 2006, 112: 1-7, közlĂ©sre leadva: J Avian Biol 3) altĂ©ma. - Vizsgálataink a szĂĽlĹ‘i minĹ‘sĂ©gen feltárták a tesztoszteron Ă©s az esztradiol koncentráciĂł pozitĂv korreláciĂłját a szĂĽlĹ‘i Ă©letkorral Ă©s a reproduktĂv teljesĂtmĂ©nnyel. PublikáciĂł: J Raptor Res 2005, 39:26-35; publikálásra leadva: J Field Ornithol. 4) altĂ©ma. - Kimutattuk , hogy a fĂ©szekaljpredáciĂłt szenvedett szĂĽlĹ‘k nagyobb arányban váltak el Ă©s változtattak fĂ©szkelĹ‘ helyet, mint a fĂ©szekaljat sikeresen felnevelĹ‘k, Ă©s többen váltak illetve változtattak fĂ©szket, ha idĹ‘sebb fiĂłkákat vesztettek el, mintha fiatalabbakat. Publikálásra leadva: Acta Oecol | Project was distinguished into four points. 1) Brood size control by parental hormones. 2) Offspring sex favour in parental care. - Relationships between the sex of offspring, hatching order, testosterone concentration and survival. 3) Relationships between the parasite infection, estrogene and testosterone concentration of the parents and their effects on reproductive performance and mate fidelity. 4) Brood predation and its consequence. Points 1) and 2) We have shown the effect of parental age and weather on testosterone concentration and nestling survival, confirmed the maternal influence on offspring testosterone concentration by experiments and found broods being male biased during adverse conditions but female biased during mild conditions. Publications: Behav Ecol Sociobiol 2004, 56:306-303; Condor 2005, 107:323-328; Ethology 2006, 112: 1-7, submission to J Avian Biol Point 3) Examinations on parental quality have revealed the positive relationships between the estradiol and testosterone concentration and parental age and breeding success. Publication: J Raptor Res 2005, 39:26-35; submission to J Field Ornithol Point 4) More parents whose broods were depredated changed mate and nest site than parents whose broods were raised. Increased divorces and shifts of nest sites, as a consequences of brood predation suffered in late breeding season, support the age investment hypothesis for temporal changes in brood defence. Submitted to Acta Oeco