research worker have puzzle together hundreds of songster fossils excavated from what ’s now a Peruvian desert dotted by just a twosome coinage of chick . harmonise to their finding print inThe Auk : Ornithological Advances , some 15,000 age ago , these tar seeps were grassy , forested areas home to horrific wolves , saber - toothed cats , and at least 21 mintage of songbird .
now , more than half of the boo species on the planet are passeriform bird , a radical that admit songbird , and they ’re especially diverse in the Neotropics , which includes Central and South America . Yet , they have a panty front in the fogy track record . To see how the skirt were affected by the last ice historic period , Jessica Oswald and David Steadman from theFlorida Museum of Natural Historyidentified 625 fossilise bones excavated from the now arid Talara Tar Seeps in northwestern Peru ( pictured below ) . The fossils are between 15,000 and 18,000 years previous , and the identifiable birds let in antbird , crescentchests , flycatchers , swallows , mockingbirds , finch , sparrows , and blackbirds .
Of the 21 passerine coinage identified , only two of them seem to live at the web site today : the long - tag mockingbird , Mimus longicaudatus , and the cinereous finch , Piezorina cinerea . The other 19 species are either extinct or require wetter experimental condition , although some of them still likely contain by during El Niño effect . Furthermore , closely half of all the private fossils and eight of the 21 mintage were blackbirds , including three out species : one antecedently described , two new to science . These razz run to form communal roosts near water .
This songbird community at Talara suggests that the site supported savannah , grassland and woodland during the last frigid interval – all of which are absent there today . Climate fluctuations and the collapse of big mammal communities ( which blackbirds take form commensal relationships with ) had a massive influence on the composition and geographical range of a function of passeriform bird birds . “ Species answer idiosyncratically to historical change , which mean that or else of full communities shifting their distribution in reply to climate change , some mintage became nonextant or extirpated in certain areas , some moved to track shift imagination , and others adapted , ” Oswald say in astatement . “ I think understanding how some species responded to diachronic change can help predict how a species will respond to forward-looking change . "
15,000 days ago , the arid landscape regard here at Peru ’s Talara Tar Seeps was grassland and forest . J. Oswald
