{"id":29239,"date":"2022-04-13T14:49:00","date_gmt":"2022-04-13T12:49:00","guid":{"rendered":"https:\/\/naturzentrum-thurauen.ch\/?p=29239"},"modified":"2022-10-06T10:53:58","modified_gmt":"2022-10-06T08:53:58","slug":"oeufs-colores-doiseaux-des-oeuvres-dart-qui-ont-une-fonction","status":"publish","type":"post","link":"https:\/\/naturzentrum-thurauen.ch\/fr\/oeufs-colores-doiseaux-des-oeuvres-dart-qui-ont-une-fonction\/","title":{"rendered":"\u0152ufs color\u00e9s d\u2019oiseaux \u2013 des \u0153uvres d\u2019art qui ont une fonction"},"content":{"rendered":"\n

Presque invisibles<\/strong><\/p>\n\n\n\n

Une fonction importante des diff\u00e9rentes colorations des \u0153ufs consiste \u00e0 les camoufler sur le fond sur lequel ils reposent et \u00e0 les prot\u00e9ger ainsi contre les pr\u00e9dateurs. Ceci est par exemple essentiel pour le petit gravelot (Charadrius dubius), qui pond ses \u0153ufs mouchet\u00e9s de gris directement sur un banc de gravier\u00a0: \u00e0 l\u2019\u0153il nu, on les distingue \u00e0 peine, de sorte qu\u2019ils sont bien prot\u00e9g\u00e9s contre des ennemis tels que la martre, le renard ou la mouette. Pour les oiseaux qui construisent leur nid dans des cavit\u00e9s, comme le martin-p\u00eacheur (Alcedo atthis), le camouflage est moins important \u2013 car leurs \u0153ufs sont bien cach\u00e9s. Et puisque la production de pigments exige beaucoup d\u2019\u00e9nergie, les \u0153ufs des oiseaux nichant dans des cavit\u00e9s sont souvent sans couleur.<\/p>\n\n\n\n

\"\"
Pour d\u00e9couvrir les quatre \u0153ufs du petit gravelot, il faut y regarder de pr\u00e8s. (Photo\u00a0: Kevin Winterhoff)<\/em><\/figcaption><\/figure>\n\n\n\n
<\/div>\n\n\n\n

En s\u00e9curit\u00e9 et au chaud<\/strong><\/p>\n\n\n\n

Outre le camouflage, la coloration de la coquille a encore d\u2019autres avantages pour les oisillons en d\u00e9veloppement\u00a0: les \u0153ufs plus fonc\u00e9s absorbent mieux la chaleur du soleil, et sont donc surtout pondus par des esp\u00e8ces d\u2019oiseaux qui nichent dans des r\u00e9gions froides. En outre, les pigments \u00e9paississent la coquille de l\u2019\u0153uf et la rendent ainsi plus r\u00e9sistante. Sur les \u0153ufs mouchet\u00e9s, les taches sont donc souvent surtout rassembl\u00e9es \u00e0 l\u2019extr\u00e9mit\u00e9 inf\u00e9rieure de l\u2019\u0153uf, o\u00f9 il est particuli\u00e8rement fragile.<\/p>\n\n\n\n

\"\"
Les \u0153ufs du rouge-gorge (Erithacus rubecula) sont renforc\u00e9s par des pigments.<\/em><\/figcaption><\/figure>\n\n\n\n
<\/div>\n\n\n\n

Palette de couleurs<\/strong><\/p>\n\n\n\n

La coquille \u00e9tant calcaire, la couleur de base d\u2019un \u0153uf d\u2019oiseau est blanche. La coloration des \u0153ufs est obtenue au moyen de deux pigments seulement\u00a0: la protoporphyrine pour une coloration rouge-brun, la biliverdine pour une coloration vert-bleu. Diverses combinaisons cr\u00e9ent ainsi toutes sortes de nuances possibles. Si l\u2019objectif de la coloration semble \u00e9vident dans certains cas, la r\u00e9ponse pour des \u0153ufs d\u2019autres esp\u00e8ces d\u2019oiseaux n\u2019est pas si simple\u00a0: la remarquable couleur bleue des \u0153ufs du merle, par exemple, reste un myst\u00e8re pour la science.<\/p>\n","protected":false},"excerpt":{"rendered":"

Le lapin de P\u00e2ques n\u2019est pas le seul \u00e0 colorer ses \u0153ufs \u2013 chez nos oiseaux \u00e9galement, on trouve une \u00e9tonnante vari\u00e9t\u00e9 de couleurs pour les \u0153ufs. Mais pourquoi les oiseaux pondent-ils des \u0153ufs color\u00e9s ?<\/p>\n","protected":false},"author":11,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[261],"tags":[],"class_list":["post-29239","post","type-post","status-publish","format-standard","hentry","category-flore-faune-suisse"],"_links":{"self":[{"href":"https:\/\/naturzentrum-thurauen.ch\/fr\/wp-json\/wp\/v2\/posts\/29239","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/naturzentrum-thurauen.ch\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/naturzentrum-thurauen.ch\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/naturzentrum-thurauen.ch\/fr\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/naturzentrum-thurauen.ch\/fr\/wp-json\/wp\/v2\/comments?post=29239"}],"version-history":[{"count":1,"href":"https:\/\/naturzentrum-thurauen.ch\/fr\/wp-json\/wp\/v2\/posts\/29239\/revisions"}],"predecessor-version":[{"id":29249,"href":"https:\/\/naturzentrum-thurauen.ch\/fr\/wp-json\/wp\/v2\/posts\/29239\/revisions\/29249"}],"wp:attachment":[{"href":"https:\/\/naturzentrum-thurauen.ch\/fr\/wp-json\/wp\/v2\/media?parent=29239"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/naturzentrum-thurauen.ch\/fr\/wp-json\/wp\/v2\/categories?post=29239"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/naturzentrum-thurauen.ch\/fr\/wp-json\/wp\/v2\/tags?post=29239"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}