{"id":1474,"date":"2022-08-07T12:13:39","date_gmt":"2022-08-07T16:13:39","guid":{"rendered":"https:\/\/web.colby.edu\/mainebirds\/?p=1474"},"modified":"2022-08-07T12:13:40","modified_gmt":"2022-08-07T16:13:40","slug":"vocal-mimicry-philadelphia-and-red-eyed-vireos","status":"publish","type":"post","link":"https:\/\/web.colby.edu\/mainebirds\/2022\/08\/07\/vocal-mimicry-philadelphia-and-red-eyed-vireos\/","title":{"rendered":"Vocal Mimicry &#8211; Philadelphia and Red-eyed Vireos"},"content":{"rendered":"<!--themify_builder_content-->\n<div id=\"themify_builder_content-1474\" data-postid=\"1474\" class=\"themify_builder_content themify_builder_content-1474 themify_builder tf_clear\">\n    <\/div>\n<!--\/themify_builder_content-->\n\n\n<p>We see an almost synchronous arrival of a guild of songbirds collectively called the leaf-gleaning insectivores.&nbsp; These birds include our vireos, warblers and tanagers.&nbsp; All of them make a living by preying on caterpillars and other herbivores that attack the leaves of deciduous trees.&nbsp; The leaf-gleaning herbivores are the friends of the trees, gobbling up the leaf-eating insects. A cascade of events occurs in spring allowing the warblers and vireos to return: leaf-out, followed by emergence of caterpillars, followed by the arrival of the leaf-gleaning birds.&nbsp; In central and southern Maine, the first ten days of May capture the arrival of many of these birds.<\/p>\n\n\n\n<p>Among these arrivals are Red-eyed Vireos.&nbsp; I daresay that Red-eyed Vireos vie for the title of most common woodland bird in eastern North America.&nbsp; A bird of treetops, Red-eyed Vireos are much more often heard than seen.&nbsp;<\/p>\n\n\n\n<p>Hearing a Red-eyed Vireo is a snap because they sing vigorously all through the day.&nbsp; Their song is a series of two- and three-note phrases. An effective mnemonic for learning the song is \u201chere-I-am, where-are-you, over-here, in-the-tree.\u201d<\/p>\n\n\n\n<p>The song is rather monotonous and dry. Despite the seeming monotony of their song, Red-eyed Vireos show remarkable diversity in their two- and three-note phrases.&nbsp; A typical Red-eyed sings around 45 phrases.&nbsp; Those phrases are strung together to make a distinctive song type.&nbsp; Each song type consists of the same one to five phrases.&nbsp; A typical male sings about 30 song types.<\/p>\n\n\n\n<p>A less common vireo breeding in Maine, the Philadelphia Vireo, needs to be considered in this column.&nbsp; Red-eyed and Philadelphia vireos share an intriguing overlap in their songs.<\/p>\n\n\n\n<p>The Philadelphia Vireo closely resembles the Red-eyed Vireo but has a less distinct line above the eye and has a yellow wash on the underparts.&nbsp; The Philadelphia Vireo is also smaller, averaging 12 grams in weight to the 17-gram weight of a typical Red-eyed Vireo.&nbsp;<\/p>\n\n\n\n<p>Most nesting male songbirds defend their territories against other males of its species, but not against males of other species. However, Red-eyed Vireos and Philadelphia Vireos defend their territories against their own species and against the other species.&nbsp;<\/p>\n\n\n\n<p>The song of the Philadelphia Vireo is very similar to the song of the Red-eyed Vireo song.&nbsp; Even highly experienced birders pass off singing Philadelphia Vireos as the more common Red-eyed Vireo.&nbsp; The reason for the similarity will soon be apparent.<\/p>\n\n\n\n<p>In northern New England forests, insect prey may become quite hard to find during the breeding season.&nbsp; Because both vireos eat the same insects, there is an advantage for a territorial vireo to keep a member of its own species and members of the other vireo species away from its food sources.<\/p>\n\n\n\n<p>In most cases, the vireos avoid direct confrontations over the boundaries of a territory.&nbsp; Instead, a territorial bird proclaims his ownership of a territory by singing from perches throughout his territory.&nbsp; Similarly adjacent territory owners sing throughout their territory.&nbsp; The neighboring birds recognize unseen but real boundaries, avoiding physical interactions.<\/p>\n\n\n\n<p>The problem the Philadelphia Vireo has is how to maintain exclusive ownership of a territory, defending against a larger and stronger Red-eyed Vireo that may be trying to expand his territory.&nbsp; Philadelphia Vireos have solved the problem by becoming a social mimic.&nbsp; These birds mimic the song of the Red-eyed Vireo.&nbsp;&nbsp;<\/p>\n\n\n\n<p>Play-back experiments have shown that Red-eyed Vireos cannot tell the difference between a Red-eyed Vireo song and a Philadelphia song.&nbsp; No wonder birders have trouble telling the two species apart by song!&nbsp; On the other hand, Philadelphia Vireos can distinguish between a Philadelphia Vireo song and a Red-eyed Vireo song. Philadelphia Vireos mimic the song of the Red-eyed Vireo to level the playing field; it\u2019s a case of deception over brawn.<\/p>","protected":false},"excerpt":{"rendered":"<p>We see an almost synchronous arrival of a guild of songbirds collectively called the leaf-gleaning insectivores.&nbsp; These birds include our vireos, warblers and tanagers.&nbsp; All of them make a living by preying on caterpillars and other herbivores that attack the leaves of deciduous trees.&nbsp; The leaf-gleaning herbivores are the friends of the trees, gobbling up [&hellip;]<\/p>\n","protected":false},"author":146,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_s2mail":"yes","ngg_post_thumbnail":0,"footnotes":""},"categories":[1],"tags":[],"builder_content":"","_links":{"self":[{"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/posts\/1474"}],"collection":[{"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/users\/146"}],"replies":[{"embeddable":true,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/comments?post=1474"}],"version-history":[{"count":3,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/posts\/1474\/revisions"}],"predecessor-version":[{"id":1478,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/posts\/1474\/revisions\/1478"}],"wp:attachment":[{"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/media?parent=1474"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/categories?post=1474"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/tags?post=1474"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}