Galapagos finch are jazz for their wondrous diversity of bill shape . Their variety of bill are outstandingly well adapted to their different feeding habits , which range from crack seeds to sipping nectar to extracting insect from tiny offer using cactus spines . Just last month , thegenomes of all of Darwin ’s finches were sequenced , allowing researchers to nail the genetic ground of their bill version . And now , a newstudypublished inNature Communicationsadds a previously look out over item to their regular carte du jour : efflorescence . Turns out , 83 percent of land wench in the Galapagos Islands have dilate their diet to now admit nectar and pollen .
Compared to mainland habitats , isolated islands typically harbor a lower diversity of works and insect species , since dispersing over immense watery expanses of ocean can be difficult for them . Birds , however , can flee to these different regions , but then they ’re face up with a special buffet of bugs and plant matter . As a result , insect- and ejaculate - feeder begin to widen their dieting to include floral resources . They end up interacting with more coinage than their mainland counterparts in a phenomenon call “ interaction release . ” Until now , it ’s never been report for an entire residential area before .
For four yr , a team led byAnna Traveset of the Spanish Research Councilmeasured flower visits and pollen transport by birds on 12 Galapagos island during peak flowering time of year . Their study represents 19 out of the total 23 land bird species on the island , and in addition to finches , these included warblers and New World flycatcher .
Every metal money they observed interact straight off with flowering plant , suggesting that birds act as key pollinator all across the archipelago . Such a large expanding upon of a feed niche has never before been report among craniate . To the right is a small ground finch ( Geospiza fuliginosa ) pollinate the flowers of the uncouth shrubBursera graveolensin the Galapagos .
Furthermore , when they compare the bird - flower interaction of this island ecosystem to that of the South America mainland , they find that the Galapagos web is more highly associate — propose a not bad degree of diet generalization . That means that birds do n’t know apart between native or invasive industrial plant mintage : Of the 106 flora mintage the wench visited , 29 percent were exotic to the Galapagos . Expanding their dieting may have help their survival upon arrival , but it may have also led to the unwanted pollination of invasive plant .
image : Ruben H. Heleno
