It’s half past seven in an overcast morning in the Ecuadorian cloud forest. The mist is dense, and we are sitting under a plastic tarp wearing thick layers. We start taking the birds out of the cloth bags after the first round to the mist nets.
We have set up
a series of long and almost invisible nets deep inside
the forest, which birds will fly into and get caught.
“We have to
process the hummingbirds first” I say to my three field assistants, “I
don’t want the birds to go into torpor”.
Torpor is the term for the hibernation state exhibited by some bird species as a physiological adaptation to cope with the low ambient temperature during the night by shutting down most of their vital functions. Their hearts pump blood less frequently, they breathe sporadically, and their body temperature drops close the ambient temperature - all this to save energy and make it through the night.
Eriocnemis alinae, or Emerald-bellied Puffleg
The problem occurs when hummingbirds go into torpor in your hands due to stress and cold temperatures. Then you have to perform what I call the resuscitation procedure by feeding them water with sugar and warming their bodies with your hands. This rarely happens, but in cold mornings, as they mostly are in the cloud forests, we want to avoid this process at any cost.
By now, I have my hand inside the bag and I can feel the little critter flapping around my fingers. No matter how many hundreds of times I have taken out a hummingbird from these bags, I always feel the same excitement as if it were the first time. Every time is a surprise; it’s like opening a present, you don’t know which species you have caught this time on the nets. Will this one be the violet-tailed sylph with its long blue metallic tail feathers, or the gorgeted sunangel, with its pink glowing throat?
Boissonneaua jardini or Velvet-purple Coronet.
“Nice! We caught a male velvet-purple coronet” I say, a shining metallic bluish-green backed and glittering purplish-blue bellied hummingbird. “Beautiful” my assistants reply. With the bird in my hand, I start measuring its bill length, wing and tail, and examine the plumage for parasites and molting feathers. This will tell me something about variation in size between other species, the habitats they live in, the age of the bird, and how healthy it is.
Using a small needle, I look in its tiny legs for an even smaller vein, from which I will collect few drops of blood to study its DNA. This procedure will provide important information about the specie’s relationship to other hummingbirds, as well as help us to reconstruct their evolutionary history. It’s like looking back in time, revisiting past events that might have influenced the life history of these hummingbird populations. All this is contained in the different combinations of the four letters of its genetic code.
Processing an Adelomyia melanogenys, Speckled Hummingbird.
I have visited the cloud forest in South America every year for five years now because this region harbors the highest diversity of hummingbirds compared to any other region in the Americas. With every field season, I am adding new evidence to help decipher why and how this impressive number of species originated, and what might happen in the future if their habitats keep changing as a result of climate warming, as they have in the recent years.
One strategy to cope with the transformation of habitats due to global warming in montane species is to move higher up in elevation to cooler temperatures. But what would happen with the intricate interactions that these species have developed in their long evolutionary history when stepping into a new scenario, with newer players, with a different script?
Hummingbirds, for example, are one of many groups of species that have close ecological interactions with the environment, as they depend on floral resources for their existence: their bills match particular flower shapes, their flight capabilities are tuned to a particular elevation, and their social behavior is influenced by other hummingbird species. Moving up in elevation would be like moving to another country for us, where a different language is spoken, unusual food is served, and strange behaviors are exhibited in an alien climate. In this new environment you either learn and adapt, or perish.
Eutoxeres condamini or Buff-tailed Sicklebill.
Adaptation to a particular environment is a rather long process that has been tuned by natural selection in thousands or millions of years; the “survival of the fittest,” as Darwin first called it. However, the environmental change in the present times is occurring too fast - too fast for evolution to shape species to these new scenarios, too fast for the fit individuals to survive. The situation is even more complicated for hummingbirds and montane species in the Andes where the forests are vanishing so rapidly due to human impact, since this fragments these habitats, and blocks the routes for this migration to higher sites with grasslands and cows.
What can be done to halt the decline of hummingbird species? First, conservation purposes in this region have to help local communities create economically sustainable land practices, implement reforestation efforts in degraded areas, and preserve the few patches of forest left. These actions, combined with effective global effort to stop warming gases in the rest of world, would partially help the subsistence and evolution of this region’s impressive biodiversity.
Back under the tarp, I check to see if the leg of the hummingbird has stopped bleeding. After feeling the energetic flapping of its wings in my hand, I open my fingers. The bird flies away and sits in a nearby branch where it starts preening its feathers and spreading its wings, almost like if he were examining that everything was okay after those uncomfortable minutes of processing. Then, after a few seconds, the hummingbird takes off to the depth of the cloud forest like a dart. It’s almost eight a.m. and the mist has vanished from the forest. “It already feels much warmer than a few minutes ago” my assistant notes, “it’s easy for us to adapt to this new temperature” he jokes while removing his thick jacket. By now, we are all only wearing t-shirts while taking down the tarp. Once again, it’s time for another round to the mist nets. “Who wants to go?”
Heliodoxa jacula or Green-fronted Brilliant.
Hummingbird photos taken by Jaime Chaves.
Aglaiocercus kingi, or Long-tailed Sylph.
For more information about Jaime's research visit www.ioe.ucla.edu/ctr/staff/chaves.html
or snail mail him at:
The Center for Tropical ResearchUniversity of California, Los Angeles-UCLA
Department of Ecology and Evolutionary Biology
621 Charles E. Young Drive South, Box 951606
Los Angeles, CA 90095-1606