Friday, July 16, 2010

Hummingbird moths and muddy roads

A new Earthwatch team joined us here in Tarrazú yesterday; we kicked things off with our customary hike through the Fundacion Nubotropica, a protected area in the forested watershed high above Santa Maria. Among the highlights of our first day were repeated sightings of "hummingbird moths" pollinating the shrubs near the meeting/eating hall. These moths, lepidopterans in the Sphingidae family, look and behave very much like tiny hummingbirds - but upon closer examination their six dangling legs give them away! Their close relatives in the Old World, in fact, fill the niche that would be occupied by hummingbirds (which are restricted to the New World, and thus absent in the Old World) and are a common sight in the summer gardens of many countries in Europe.

We got caught by some pretty heavy rain in the field this morning - had a spot of trouble driving out of the steep muddy road leading to the farm, in fact....tomorrow when we return to the farm to harvest the hymenoptera in our yellow pan traps we'll likely have to leave the Land Rover on solid ground and walk the 1-2km down into the coffee farm in order to avoid getting stuck - the joys of doing fieldwork in the rainy season here in Tarrazú!

Sunday, July 11, 2010

Week’s end in Tarrazú

We have finished up a week of fieldwork in Tarrazú – Saturday evening we celebrated with a barbecue at a local farmer’s house, and the Earthwatch team departed early Sunday morning for San Jose. A second team will come in this next week, and we’ll resume work in the coffee fields…so far we have found, as might be expected, fewer bees in the coffee fields than we found during the coffee flowering season a few months ago. However, we have noticed quite a few bees in the forest habitats nearby some of the coffee fields – for instance, native stingless bees that like to make their nests in the knots of large trees. We’ll see if this trend holds up as we sample more farms and forests across the region.The Earthwatch team was treated to a private tour of one of the farms this week – Fernando, one of the coffee farmers with whom we’re working, stopped by his farm and showed us around, noting many of the non-coffee (shade) plants he has planted over the years. He noted especially several species of plants that “fix” atmospheric nitrogen, providing shade as well as natural fertilizer for the coffee shrubs. The forest habitat near his farm is particularly nice – the volunteers did a great job helping put in traps in the steep, dense forest!

Tuesday, July 6, 2010

Rainy season in Tarrazú

I’m back in San Marcos, Costa Rica, leading a few Earthwatch teams this month as we conduct more coffee sustainability research. This is a continuation of the work we started in April; the study is focused on better understanding the conservation value of forest fragments in and around coffee farms in the region in terms of an important ecosystem service: pollination. Building on recent research conducted elsewhere that indicates that having forests nearby coffee yields can enhance pollination, we are comparing pollinator diversity and abundance in both coffee farms that either have adjacent forest stands or are isolated from forest fragments. Coffee is able to self-fertilize, but can produce higher yields if it gets assistance from managed honeybees (imported European honeyebees, the same species commonly used in the U.S.) and other bees – these other bees, especially native stingless bees, are especially likely to be found nesting in forest fragments – hence the link between forest conservation and coffee yields. In April, we collected bees during coffee flowering season; now that the coffee flowering has ceased, we are trying to get a better idea of where the pollinators hang out during times when coffee is not flowering – hence we’re sampling in both coffee farms and nearby forest habitat.
This morning our first team of the month hit the field, helping set up yellow-pan traps to capture bees and wasps in both coffee fields and nearby forest areas. The team (six women from the U.S., Canada, and the U.K.) did a great job scrambling up and down the steeply terraced coffee fields…in addition to setting up bee traps, they also recorded timed observations of the number and type of pollinators flying through the fields, and measured ground cover (e.g., live plants, dead plants (mulch), and flowering plants that might serve as alternative resources for pollinators). Tomorrow we’ll go see what our traps have attracted; after we collected specimens from them, we’ll set up traps in another field – and then it’s back to the lab for an afternoon of sorting through specimens so that we can further identify the types of bees /wasps that we have captured.This afternoon, it is pouring rain, as is the norm for this time of year. As we head further into the rainy season, we’ll continue to do our work in the mornings, when we can generally expect at least a few hours of sunny, bee-friendly weather...
Yesterday as part of their orientation, the group was treated to a rare appearance of a male resplendent quetzal, famed trogon of Central America - lots of opportunity for close-up observation as he flitted from tree to tree alongside a dirt road we were descending after a hike through the forest at Fundacion Nubotropical - a terrific and auspicious start to the week!