EPOW - Ecology Picture of the Week

Of Red Flowers and Green Hummingbirds

Botellita (Mitraria coccinea) flowers
Green-backed Firecrown (Sephanoides sephanoides)
Puyehue National Park, Chile

Explanation:  This week we find ourselves in Patagonia of South America, enjoying an unusual exploration of red flowers and green hummingbirds.

Flowering plants of Patagonia are pollinated by many agents, including insects, wind, self-pollination, and birds.  One of the most common bird pollinators of the region is the Green-backed Firecrown (Sephanoides sephanoides, locally named Picaflor Rubí, "Ruby Hummingbird"), a tiny but prolific hummingbird.  Like hummingbirds in other areas, this one specializes on taking nectar from plants with long, red, tubular flowers ("sympetalous corollas").

Although it is the only hummingbird regularly appearing in the area, the Firecrown is such a vital pollinator that an amazing array of at least 16 species of plants among 14 botanical families apparently have specifically evolved red, tubular flowers to be pollinated by this master of flight:
   

Green-backed Firecrowns are ubiquitous and abundant in the region but migrate north during winter (except on the Quetrihue Peninsula in the Andean lake Lago Nahuel Huapi in adjacent Argentina, where they are year-round residents, found with the winter-blooming mistletoe Tristerix).  Accordingly, the numbers of these red-flowering plants in bloom generally follow the bird’s appearance and relative abundance, as shown in this week's main ecology picture, above.  
 

Shown above is an example of the red, tubular flower of Mitraria coccinea.  Note the downward angle of the flower and the extruding stamens.  As the Firecrown seeks nectar deep within the flower, the sticky pollen gets transferred to the bird’s head and back, and thence to pollinate another flower as the bird moves on. 

Here is another example of a local plant that has apparently co-evolved to be pollinated by Green-backed Firecrowns.  These are the striking blooms of Fuschia magellanica, a regional endemic.  

Note the long, extruding stamens on the bottom that carry the pollen.  As with the other plants in this amazing array, it hides its nectar prize deep within the tube of its corolla, so that when the hummingbird feeds, the pollen transfers to the bird's head, to be then transported to other plants of the same species.  

Studies have shown that Firecrowns also seek out the red tubular flowers of the proteaceous tree Embothrium coccineum in equal frequency whether the tree is in large or small remnant forest fragments or isolated in pastures.  This suggests that the tree, and its blooms, also play a key role in the bird's feeding.

So, overall, In this amazing example of coadaptation, so many plants may depend upon this tiny bird of the far southern forests for their reproductive survival, just as the bird relies on their nectar for its survival.  

Can you spot the Green-backed Firecrown?  
It is amazing how ecologically important a role that 
such a seemingly insignificant bird can play.

Information:
     Fraga, R. M., A. E. Ruffini, and D. Grigera. 1997. Interacciones entre el Picaflor Rubi Sephanoides sephanoides y plantas del Bosque Subantartico en al Parque Nacional Nahuel Huapi, Argentina . Hornero 14:224-234.
     Smith-Ramirez, C., and J. J. Armesto. 2003. Foraging behavior of bird pollinators on Embothrium coccineum (Proteaceae) trees in forest fragments and pastures in southern Chile . Austral Ecology 28:53-60.

Acknowledgment:
     My thanks to botanist Andy MacKinnon for helping identify the array of plants listed in the table above.