{"id":260768,"date":"2022-08-17T12:23:31","date_gmt":"2022-08-17T11:23:31","guid":{"rendered":"https:\/\/zakrasnejsivimperk.cz\/?p=260768"},"modified":"2022-08-17T12:24:57","modified_gmt":"2022-08-17T11:24:57","slug":"veda-neni-nuda-uklizeni-hnizda-pomaha-vlastovkam-zbavit-se-cizich-vajec","status":"publish","type":"post","link":"https:\/\/zakrasnejsivimperk.cz\/?p=260768","title":{"rendered":"V\u011aDA NEN\u00cd NUDA: Ukl\u00edzen\u00ed hn\u00edzda pom\u00e1h\u00e1 vla\u0161tovk\u00e1m, aby se zbavily ciz\u00edch vajec"},"content":{"rendered":"<figure id=\"attachment_260769\" aria-describedby=\"caption-attachment-260769\" style=\"width: 960px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-260769 size-full\" src=\"https:\/\/zakrasnejsivimperk.cz\/wp-content\/uploads\/2022\/08\/10\/vla\u0161tovka-hn\u00edzdo.jpg\" alt=\"\" width=\"960\" height=\"640\" srcset=\"https:\/\/zakrasnejsivimperk.cz\/wp-content\/uploads\/2022\/08\/10\/vla\u0161tovka-hn\u00edzdo.jpg 960w, https:\/\/zakrasnejsivimperk.cz\/wp-content\/uploads\/2022\/08\/10\/vla\u0161tovka-hn\u00edzdo-300x200.jpg 300w, https:\/\/zakrasnejsivimperk.cz\/wp-content\/uploads\/2022\/08\/10\/vla\u0161tovka-hn\u00edzdo-768x512.jpg 768w, https:\/\/zakrasnejsivimperk.cz\/wp-content\/uploads\/2022\/08\/10\/vla\u0161tovka-hn\u00edzdo-536x357.jpg 536w, https:\/\/zakrasnejsivimperk.cz\/wp-content\/uploads\/2022\/08\/10\/vla\u0161tovka-hn\u00edzdo-725x483.jpg 725w\" sizes=\"(max-width: 960px) 100vw, 960px\" \/><figcaption id=\"caption-attachment-260769\" class=\"wp-caption-text\">Ilustra\u010dn\u00ed foto: pixabay<\/figcaption><\/figure>\n<hr \/>\n<p>&nbsp;<\/p>\n<h6>Pozorov\u00e1n\u00ed zhruba 150 p\u00e1r\u016f vla\u0161tovek v ji\u017en\u00edch \u010cech\u00e1ch objasnilo v\u011bdc\u016fm z \u00dastavu biologie obratlovc\u016f AV \u010cR ot\u00e1zku, zda jsou tito pt\u00e1ci jen pe\u010dliv\u00ed ukl\u00edze\u010di vlastn\u00edch hn\u00edzd, nebo si vyvinuli zvl\u00e1\u0161tn\u00ed strategii, jak se br\u00e1nit hn\u00edzdn\u00edmu parazitismu. Vyhazuj\u00ed toti\u017e z vlastn\u00edch hn\u00edzd ciz\u00ed vejce. Experiment v\u011bdc\u016f uk\u00e1zal, \u017ee vla\u0161tovky p\u0159ed n\u00e1kladn\u00fdm vychov\u00e1v\u00e1n\u00edm ciz\u00edch pt\u00e1\u010dat zachra\u0148uje po\u0159\u00e1dkumilovnost.<\/h6>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-243085 alignright\" src=\"https:\/\/zakrasnejsivimperk.cz\/wp-content\/uploads\/2021\/12\/19\/akademie-v\u011bd-av-cr-logo-300x80.png\" alt=\"\" width=\"300\" height=\"80\" srcset=\"https:\/\/zakrasnejsivimperk.cz\/wp-content\/uploads\/2021\/12\/19\/akademie-v\u011bd-av-cr-logo-300x80.png 300w, https:\/\/zakrasnejsivimperk.cz\/wp-content\/uploads\/2021\/12\/19\/akademie-v\u011bd-av-cr-logo-768x206.png 768w, https:\/\/zakrasnejsivimperk.cz\/wp-content\/uploads\/2021\/12\/19\/akademie-v\u011bd-av-cr-logo-1024x275.png 1024w, https:\/\/zakrasnejsivimperk.cz\/wp-content\/uploads\/2021\/12\/19\/akademie-v\u011bd-av-cr-logo-1331x357.png 1331w, https:\/\/zakrasnejsivimperk.cz\/wp-content\/uploads\/2021\/12\/19\/akademie-v\u011bd-av-cr-logo-1801x483.png 1801w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/>Jeden ze sou\u010dasn\u00fdch projekt\u016f, ve kter\u00e9m experti z \u00dastavu biologie obratlovc\u016f AV \u010cR sleduj\u00ed vla\u0161tovky, se zam\u011b\u0159uje na v\u00fdzkum hn\u00edzdn\u00edho parazitismu, tedy zp\u016fsob rozmno\u017eov\u00e1n\u00ed, kter\u00fdm se proslavila p\u0159edev\u0161\u00edm kuka\u010dka obecn\u00e1. \u201e<em>Je to strategie, kdy parazitick\u00e1 samice naklade sv\u00e9 vejce do ciz\u00edho hn\u00edzda a p\u0159enech\u00e1 tak inkubaci vejce a p\u00e9\u010di o jej\u00edho potomka nevlastn\u00edm rodi\u010d\u016fm. To bylo pozorov\u00e1no nejen u kuka\u010dek a jim podobn\u00fdm oblig\u00e1tn\u00edm hn\u00edzdn\u00edm parazit\u016fm, kte\u0159\u00ed to ani jinak d\u011blat neum\u00ed, ale tak\u00e9 u klasicky &#8216;slu\u0161n\u011b&#8217; hn\u00edzd\u00edc\u00edch druh\u016f pt\u00e1k\u016f, jako jsou t\u0159eba vla\u0161tovky obecn\u00e9,\u201c<\/em> vysv\u011btluje Michal \u0160ulc z \u00dastavu biologie obratlovc\u016f AV \u010cR (\u00daBO AV \u010cR), hlavn\u00ed autor studie.<\/p>\n<p>Tou nej\u010dast\u011bj\u0161\u00ed a nej\u00fa\u010dinn\u011bj\u0161\u00ed obranou je rozpozn\u00e1n\u00ed a vyhozen\u00ed parazitick\u00e9ho vejce z hn\u00edzda. <em>\u201eToto chov\u00e1n\u00ed m\u016f\u017eeme pozorovat i u vla\u0161tovek, kter\u00e9 z hn\u00edzda vyhazuj\u00ed ciz\u00ed vla\u0161tov\u010d\u00ed vejce, a to p\u0159edev\u0161\u00edm ta, kter\u00e1 se v hn\u00edzd\u011b objevila p\u0159ed snesen\u00edm prvn\u00edho vlastn\u00edho vejce. Dosud nebylo ov\u0161em v\u016fbec jasn\u00e9, zda toto chov\u00e1n\u00ed skute\u010dn\u011b vzniklo jako obrana proti parazitismu, nebo se jedn\u00e1 &#8216;pouze&#8217; o odstra\u0148ov\u00e1n\u00ed ciz\u00edch p\u0159edm\u011bt\u016f z hn\u00edzda souvisej\u00edc\u00ed s jeho \u00faklidem,\u201c<\/em> dod\u00e1v\u00e1 V\u00e1clav Jel\u00ednek (\u00daBO AV \u010cR). Mnoho druh\u016f pt\u00e1k\u016f, hlavn\u011b p\u011bvc\u016f, toti\u017e udr\u017euje sv\u00e1 hn\u00edzda \u010dist\u00e1 a odstra\u0148uj\u00ed z nich nap\u0159. spadan\u00e9 list\u00ed, v\u011btvi\u010dky nebo trus ml\u00e1\u010fat. To rodi\u010d\u016fm umo\u017e\u0148uje bezpe\u010dn\u011b sv\u00e1 vejce ot\u00e1\u010det b\u011bhem inkubace nebo udr\u017eovat hn\u00edzdo bez patogen\u016f a parazit\u016f. Takhle \u010distotn\u011b se chovaj\u00ed i rodi\u010de vla\u0161tovky obecn\u00e9.<\/p>\n<h6>Tvar je pro vla\u0161tovky d\u016fle\u017eit\u011bj\u0161\u00ed sign\u00e1l ne\u017e barva<\/h6>\n<p>Aby zjistili, zda se vla\u0161tovky vyhazov\u00e1n\u00edm vajec p\u0159\u00edmo br\u00e1n\u00ed parazitismu, nebo tak jen ukl\u00edzej\u00ed sv\u00e9 hn\u00edzdo, provedli v\u011bdci z \u00daBO AV \u010cR d\u016fmysln\u00fd experiment. Vla\u0161tovk\u00e1m do hn\u00edzda vkl\u00e1dali um\u011bl\u00e9 p\u0159edm\u011bty, kter\u00e9 se li\u0161ily tvarem \u010di barvou od jejich vlastn\u00edch vajec. <em>\u201ePokud by se vla\u0161tovky p\u0159i rozpozn\u00e1v\u00e1n\u00ed p\u0159edm\u011bt\u016f \u0159\u00eddily odli\u0161nost\u00ed ve zbarven\u00ed, pak by se toto chov\u00e1n\u00ed skute\u010dn\u011b dalo pova\u017eovat za obranu proti parazitismu, proto\u017ee parazitick\u00e1 vejce se od t\u011bch vlastn\u00edch li\u0161\u00ed p\u0159edev\u0161\u00edm barvou. Naopak pokud by se vla\u0161tovky p\u0159i vyhazov\u00e1n\u00ed \u0159\u00eddily p\u0159edev\u0161\u00edm tvarem p\u0159edm\u011bt\u016f, nikoli jejich barvou, pak se pravd\u011bpodobn\u011b jedn\u00e1 pouze o chov\u00e1n\u00ed spojen\u00e9 s \u00faklidem hn\u00edzda. A to je p\u0159esn\u011b to, co jsme pozorovali \u2013 vla\u0161tovky se \u0159\u00eddily pouze tvarem p\u0159edm\u011bt\u016f, ne jejich zbarven\u00edm,\u201c<\/em> \u0159\u00edk\u00e1 Michal \u0160ulc.<\/p>\n<p>V\u011bdci p\u0159i experimentu zjistili, \u017ee p\u0159edm\u011bty, kter\u00e9 sv\u00fdm tvarem napodobovaly vejce, p\u0159ij\u00edmaly vla\u0161tovky mnohem ochotn\u011bji ne\u017e p\u0159edm\u011bty stejn\u00e9 hmotnosti a objemu, ov\u0161em tvaru hv\u011bzdi\u010dky. Naopak p\u0159edm\u011bty, kter\u00e9 m\u011bly podobnou barvu, dokonce i skvrny jako vla\u0161tov\u010d\u00ed vejce, nebyly p\u0159ij\u00edm\u00e1ny \u010dast\u011bji ne\u017e n\u00e1padn\u011b modr\u00e9 p\u0159edm\u011bty. V\u00fdsledky v\u00fdzkumu tak ukazuj\u00ed, \u017ee pozorovan\u00e9 chov\u00e1n\u00ed (nap\u0159. odstra\u0148ov\u00e1n\u00ed ciz\u00edch vajec), kter\u00e9 se m\u016f\u017ee na prvn\u00ed pohled zd\u00e1t jako d\u016fmysln\u011b vyvinut\u00e1 evolu\u010dn\u00ed strategie slou\u017e\u00edc\u00ed k jednozna\u010dn\u00e9mu \u00fa\u010delu (k obran\u011b proti hn\u00edzdn\u00edmu parazitismu), m\u016f\u017ee ve skute\u010dnosti slou\u017eit k n\u011b\u010demu \u00fapln\u011b jin\u00e9mu (ukl\u00edzen\u00ed hn\u00edzda). To ov\u0161em nic nem\u011bn\u00ed na tom, \u017ee n\u011bkter\u00e9 samice vla\u0161tovek se dok\u00e1\u017eou zbavit parazitick\u00e9ho vejce, ani\u017e by tu\u0161ily, jak\u00e9 riziko skr\u00fdv\u00e1.<\/p>\n<h6>Drah\u00e1 p\u00e9\u010de o ciz\u00edho potomka<\/h6>\n<p>V\u00fdskyt hn\u00edzdn\u00edho parazitismu klade na hostitelsk\u00e9 p\u011bstouny vysok\u00e9 energetick\u00e9 n\u00e1klady, nejen zm\u00edn\u011bnou vy\u0161\u0161\u00ed m\u00edru inkubace ciz\u00edho vejce, ale hlavn\u011b n\u00e1slednou p\u00e9\u010di o vyl\u00edhl\u00e9ho ciz\u00edho potomka, kter\u00e9ho je pot\u0159eba na za\u010d\u00e1tku zah\u0159\u00edvat, a p\u0159edev\u0161\u00edm minim\u00e1ln\u011b t\u0159i t\u00fddny krmit. Tyto extra n\u00e1klady maj\u00ed \u010dasto nep\u0159\u00edzniv\u00fd vliv na vlastn\u00ed rozmno\u017eov\u00e1n\u00ed hostitel\u016f. Inu, m\u00edt po\u0159\u00e1dek v hn\u00edzd\u011b se vypl\u00e1c\u00ed, vla\u0161tovk\u00e1m n\u011bkdy dvojn\u00e1sob.<\/p>\n<p><strong>(tz-av\u010dr)<\/strong><\/p>\n<hr \/>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&nbsp; Pozorov\u00e1n\u00ed <\/p>\n","protected":false},"author":2,"featured_media":260769,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"gallery","meta":{"footnotes":""},"categories":[24,174],"tags":[],"jetpack_featured_media_url":"https:\/\/zakrasnejsivimperk.cz\/wp-content\/uploads\/2022\/08\/10\/vla\u0161tovka-hn\u00edzdo.jpg","_links":{"self":[{"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=\/wp\/v2\/posts\/260768"}],"collection":[{"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=260768"}],"version-history":[{"count":3,"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=\/wp\/v2\/posts\/260768\/revisions"}],"predecessor-version":[{"id":261163,"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=\/wp\/v2\/posts\/260768\/revisions\/261163"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=\/wp\/v2\/media\/260769"}],"wp:attachment":[{"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=260768"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=260768"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zakrasnejsivimperk.cz\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=260768"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}