Bamboo, that massive grass, is a common component of eastern Asian forests. When I was in Thailand in 2007, the huge clumps of bamboo that made up much of the understory in the forests around Doi Chiang Dao gave them an otherworldy, prehistoric appearance. Green Magpies, Lesser Yellownapes, drongos, and a bunch of other super cool birds searched the papery strips of bamboo “bark” for arthropodic goodies. It was impressive how those birds could still hide themselves and be so unobtrusive in such an open understory.
Over on the other side of the world in the American tropics, bamboo is also an important component of many tropical forests. Most of the bamboo isn’t as big as that elephantine stuff in Asia but its easily recognizable as bamboo nonetheless. You do see some tall huge bamboo clumps in Costa Rica but this is introduced Common Bamboo from Asia. The native bamboo species are thinner, daintier plants that mostly occur in highland forests. It’s pretty common but you hardly ever get to see it produce seeds. Unlike many other plants, bamboo doesn’t do the annual seed and fruit thing. It just grows and grows until an entire patch (which can be massive in size) unexpectedly produces seeds. For neotropical birders, this occurrence is somewhat akin to finding an army antswarm except that it’s an even bigger event. There might not be as many bird species as an antswarm, but it’s even more difficult to happen upon and attracts some super sweet rarities.
For example, seeding bamboo is one of your only chances at seeing Maroon-chested Ground-Dove. These birds will sometimes show up at seed spread on the ground near highland forest but what they truly relish are bamboo seeding events. The only time I have ever come across this species in Costa Rica (or anywhere else) was at a seeding event on Chirripo Mountain. Although it happened so long ago that the memory of the event is becoming fuzzy, I recall not just one bird scampering away but several individuals that were singing, feeding, and having themselves nothing short of a ground-dove jamboree. As this was my second trip to Costa Rica, I had no idea that I had hit one of those avian jackpots we always dream of.
I don’t expect to see those beautiful little pigeons like that again but maybe I’ll get lucky and watch one or two at the seeding bamboo I found this past weekend on the road to Volcan Barva! Yes, a nice sized bamboo patch was seeding on Saturday and it looked like it was just getting started. I didn’t hear or see any ground-doves (did hear one Buff-fronted Quail-Dove) but I did catch up with one female Blue Seedeater! This is another bamboo associated bird that is always so darn uncommon. Although skulking behavior certainly plays a role in their apparent scarcity, they are too infrequently seen to not be genuinely rare. Since they are usually seen in or near bamboo, they might also be tied to seeding events. Other birds in Costa Rica that could show up at seeding events are Barred Parakeet, Slaty Finch, and Peg-billed Finch.
I could definitely use all three for my year list so I hope they show up at that patch somewhere on the mountain that looms near the house. If you take the main road up to Volcan Barva, the bamboo patch is in a riparian zone after where a light green sign points the way to “Volcan Barva”. It starts just past another sign that warns against dumping garbage. None of those special birds are guaranteed to show up but I think there’s a fair chance they will given that the seeding bamboo patch represents such an important and scarce resource. Although much of the surrounding area is deforested, the connection that the riparian corridor provides to intact forest at higher elevations will hopefully act as a highway those target birds just can’t resist taking.