Tuesday, March 26, 2013

Shaving brushes on trees









Species name: Pseudobombax ellipticum

Common name: shaving brush tree

Location: Dominican Republic

The shaving brush tree, by far my favourite tropical tree that I saw in the Dominican, is native to southern Mexico and further south to the "left half" of Central America. It is still relatively common there in the wild, but will likely soon be threatened by habitat loss.

The tree has many traditional uses, from native medicines (the trunk of the tree is succulent-like and so stores water; it was believed that the water exuded from the stem when the tree was cut had healing properties) to construction materials (the wood is very soft and so easy to carve into shapes) to decorative material (the flowers are very popular church decorations in Central America). It is also sometimes used as firewood, but because the stems store so much water the wood must dry out first (and so other species are often favoured). The plant, for obvious reasons, is also a preferred ornamental species almost everywhere it grows, and has now been introduced to Florida, Hawaii and Arizona in the United States where it struggles along (never quite reaching its fullest potential as a tree, but certainly not dying, either). The flowers are, by far, the most spectacular flowers I have ever seen on a tree. Before the flowers are ready to open, they look like small acorns on the tips of all of the branches, sometimes in clusters of 2 or more "acorns". When my mom and I first saw the tree, we both wondered why the grounds staff were keeping a very dead-looking tree so prominently displayed outside the balcony of our hotel room since the tree didn't even have any leaves. The rounded parts of the acorns elongate and turn from a dark maroon-brown to a much lighter brown. Then a seam forms along the elongated acorn, where the flower can emerge through. The protective covering of the flower, that "acorn," then curls down around itself, contributing to those decorative curls at the bottom of the flower. Depending on the variety (some argue depending on the subspecies or even the species), the flowers that open will either be white or pink, as in the pictures above.

Me, being who I am, saw the flowers the first day and wondered what type of animal would be coerced into pollinating a flower like that. Since each individual flower in the inflorescence is so darn tiny, I figured the only possible animal that could pollinate it (or enjoy any of its nectar) would have to be either a moth or a butterfly, since they would be the only animals with styles (or "tongues") long enough to get down to the nectaries. Since the flowers seemed to open at night (only because I didn't get up at the crack of dawn to watch them be opened, as I discovered later), I figured it had to be moths. Not a bad guess, but an incredibly incorrect one.

One morning, my mom and I were awoken by a wonderful racket outside, with what sounded like a bunch of birds being mauled by a bunch of other birds. By the time I grabbed my camera (and put on clothing that wouldn't look like I was in my pyjamas) and ran downstairs the show was almost over, but this is what I saw:



Can you see what causes the flowers to open? No? Look a little closer...



See him yet? Still don't know what you're looking for?



Yes, that's right. Woodpeckers. Woodpeckers opening flowers! I though this was mind-boggling, and had never heard of woodpeckers doing anything other than pecking trees. Apparently they are multi-talented! They drill into the bottom of the flower through the protective covering (what used to be that "acorn") to drink all of the nectar at the bottom of the flower. By the time the flower splits open along the holes that the woodpecker made, its a moot point what else comes along since they would only be getting the woodpecker's leftovers. Every morning there were 5 or 6 of these birds that would congregate on this tree and fight each other for the optimal flowers. There were other birds, sparrows, that would wait around until the nasty woodpeckers were done before moving in on the flowers, and then once the flowers were fully open there were always a swarm of insects flying around the tops of the flowers, collecting pollen and any nectar that was left over. Interestingly enough, I didn't ever see a butterfly around the flowers. Hummingbirds did come visit the flowers during the day, but they didn't usually last long. They were probably disappointed with their nectar haul, and there seemed to be many, many other flowers that they could exploit for food elsewhere.


Our friend the woodpecker is right in the middle of this shot, drinking from the elongated 
"flower acorn". Click to enlarge...