Dragonfly Migration in Mexico
(Migración de libélulas en México)
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As the first snows make their appearance across the northern part of the continent and dragonflies on the wing become a summer memory, we look to the south for continued dragonfly activity. Since late summer, staff of MDP partner Pronatura Veracruz have been scanning the skies for migrating dragonflies, and the results for August and September are in. Pronatura Veracruz (www.pronaturaveracruz.org) has worked for over 16 years to conserve and protect the ecosystems of the southeastern state of Veracruz, and they are also the site of the stunning Rio de Rapaces (River of Raptors), one of the largest annual raptor migrations in the world. Pronatura staff collects daily data on this avian migration, and in a single season they may see as many as 4.5 million birds that include over 25 different species. In the course of many years of raptor observations, they have also noted the regular and concurrent movement of thousands of migrating dragonflies, and for the past two years, they have been collecting data on dragonfly migration as part of the Migratory Dragonfly Partnership, as well as conducting local outreach and education about dragonflies and wetlands.
The graphs in the sidebar show daily counts of the thousands of dragonflies sweeping past the Pronatura observatory in Chichicaxtle, a small town situated amid sugar cane fields of Veracruz, about 11 miles (18 kilometers) inland from the eastern coast. These data have not yet been examined in detail, but a quick glance reveals the expected pattern of large peaks of dragonfly movement followed by smaller pulses across several days, and days with no dragonfly sightings at all. Not all migration reports are accompanied by species data, but the majority of species identified in flight were Wandering Glider and Spot-Winged Glider (Pantala flavescens and P. hymenaea), with some Common Green Darners (Anax junius) earlier in the season and a small sprinkling of Black Saddlebags (Tramea lacerata) throughout.
When examined in conjunction with migration reports from eastern Canada and the United States, we will be able to get a better picture of the timing of dragonfly movement and investigate the climate data around days with large peaks versus no flight activity at all. Reports in 2013 of large movements of Common Green Darners in the northeast US, coupled with the low numbers of reports for this species in Veracruz suggest that Common Green Darners may begin to fall out of migratory flights further south. The continued movement of the western migrant, Variegated Meadowhawk (Sympetrum corruptum), remains even more questionable; 2013 saw a large increase in the number of reporters in California, especially from birders, but as yet we have no reports from western Mexico to help us elucidate the southern extent of meadowhawk movement in the west. MDP partner staff are planning new workshops in Mexico in winter 2013/spring 2014 to help engage additional partners and observers throughout Mexico to broaden our view of dragonfly migration. In the meantime, we are excited about the tremendous increase in the number of reports (and reporters!) in our 2nd season of data collection and our fruitful new relationships with birding organizations, and we are looking forward to analyzing all of the new data this winter as the story of dragonfly migration continues to unfold!
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Our partners at Pronatura Veracruz are collecting valuable migration data on dragonflies and raptors. Click on the graphs below to view dragonfly data from the summer and fall of 2013 in Veracruz, Mexico.
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The Migratory Dragonfly Partnership is composed of dragonfly experts, nongovernmental programs, academic institutions, and federal agencies from the U.S., Mexico, and Canada. Together, we are combining research, citizen science, and education and outreach to better understand North America's migrating dragonflies and promote conservation of their wetland habitat.
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