Yesterday, October 27, 2014 I witnessed one of the most amazing spectacles of nature, the migration of birds of prey that since I know this phenomenon that has fascinated thousands, I still remain with the mouth open as thousands, millions of birds fly southward on one of the longest migration routes on the Neotropics, the Transamerican Flyway as defined by Bildstein (Fig. 1).

Figure 1. Trans-American Flyway on the Mesoamerican Land Corridor

It all started with my return from San Marcos de Colon (SMC) to southern Honduras and border with Nicaragua (Fig 2). The road leading from Choluteca, one of the largest cities in southern Honduras to San Marcos de Colon, flies from the municipality from 1100 meters to 100 meters, from here the height to Pespire will not vary above 100 meters , arriving at 20 masl (Fig. 3).

Figure 2. Geographic location from SMC to Pespire, Honduras.

As at 08:30 I have my first encounter with one of the endless hot springs that awaited me that day. The interesting thing about this first stop was that I am directly in front of one of the most important power generation plants in Honduras, about 22 km from Choluteca, which consists of two groups of chimneys that throw hot air towards the sky and that is what migrating raptors are looking for, rising hot air currents. It was amazing to see how they grouped together to make the most of this artificial thermal and that the smog produced by chimneys was almost unimportant for birds (Fig. 4).

Mixed thermal of birds of prey migrated.

Sometimes the hot springs were so large and low in height that you could see the shadows of the birds on the pavement of the street turning around you, simply amazing. Maybe if 25 times stop to see, photograph and take videos of the hot springs was little.

After seeing this and thinking where all this had happened, I argue what we have talked to many colleagues about migration in these latitudes, that after Veracruz in Mexico the Gulf of Fonseca could be a second funnel only bigger because it was crazy, there were hot springs everywhere you looked, a nightmare for a single accountant, even for two or three. It was so much the migration that there were currents that were mixed making a kind of knot, like this famous corner in Tokyo where hundreds of people converge, only in this case they are birds and form a knot. It would be a titanic task to try to count what I observe that day.

Hypothetical map of the Gulf of Fonseca bottleneck. maps

Convergence of flocks

I finish this little note with one hour of uninterrupted observation and with the satisfaction of having witnessed another year of this incredible movement of birds through Central America on their journey south.

Related news