<\/a>An American robin sits on a nest. (Courtesy Photo \/ Bob Armstrong)<\/p><\/div>\n\t\t\t\t
As fruit-eaters, both species can disperse seeds (and sometimes associated mutualistic mycorrhizal fungi). American robins disgorge large seeds and defecate smaller ones; they can store fruit overnight in an extensible esophagus (like a crop, but somewhat different). They are not efficient at digesting fruits, which pass through the gut quickly; furthermore, this species lacks the necessary enzyme for digesting sucrose (common sugar, a disaccharide), although other sugars (monosaccharides such as fructose and glucose) are digestible. I have not found such information for the European robin.<\/p>\n\t\t\t\t
Their nesting habits are quite different. The American species makes a bulky, open-cup nest of grasses and small twigs held together with mud; it is placed on a branch, or building, or stump, or occasionally on the ground, often with some protection such as thick foliage overhead. The European robin commonly nests in tree cavities, holes in stone walls, under tussocks or roots, making the nest of moss, grass, and twigs, placed on a mat of dead leaves.<\/p>\n\t\t\t\t
Both species are socially monogamous, but there can be variations on that theme: As many song birds do, the American robin indulges in frequent extra-pair copulations, so that a brood of nestlings often has two or more fathers. This practice is known in the European species, but I found no information on how commonly.<\/p>\n\t\t\t\t
Incidentally, the name ‘robin’ has been applied to many other birds in other places, including the Central American rufous-collared thrush (or rufous-collared robin; family Turdidae), the robin-chats of Africa (Musicapidae), the Australian robins (in an altogether different taxonomic family, Petroicidae), and — by early settlers in Australia — the Australian rufous whistler (‘robin redbreast’, in yet a different family, Pachycephalidae), among others. Most of these have reddish feathers on the chest.<\/p>\n\t\t\t\t
Common names in English can be very confusing.<\/p>\n\t\t\t\t
• Mary F. Willson is a retired professor of ecology. “On the Trails” appears every Wednesday in the Juneau Empire.<\/em><\/p>\n\t\t\t","protected":false},"excerpt":{"rendered":"A tale of two (or more) robins. <\/p>\n","protected":false},"author":106,"featured_media":84383,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_stopmodifiedupdate":false,"_modified_date":"","wds_primary_category":11,"footnotes":""},"categories":[11,4],"tags":[149,568,123],"yst_prominent_words":[],"class_list":["post-84382","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-home2","category-news","tag-outdoors","tag-column","tag-science"],"_links":{"self":[{"href":"https:\/\/www.juneauempire.com\/wp-json\/wp\/v2\/posts\/84382","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.juneauempire.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.juneauempire.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.juneauempire.com\/wp-json\/wp\/v2\/users\/106"}],"replies":[{"embeddable":true,"href":"https:\/\/www.juneauempire.com\/wp-json\/wp\/v2\/comments?post=84382"}],"version-history":[{"count":0,"href":"https:\/\/www.juneauempire.com\/wp-json\/wp\/v2\/posts\/84382\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.juneauempire.com\/wp-json\/wp\/v2\/media\/84383"}],"wp:attachment":[{"href":"https:\/\/www.juneauempire.com\/wp-json\/wp\/v2\/media?parent=84382"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.juneauempire.com\/wp-json\/wp\/v2\/categories?post=84382"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.juneauempire.com\/wp-json\/wp\/v2\/tags?post=84382"},{"taxonomy":"yst_prominent_words","embeddable":true,"href":"https:\/\/www.juneauempire.com\/wp-json\/wp\/v2\/yst_prominent_words?post=84382"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}