27 Oct 2015

El Changamé y la agricultura en Isla Gobernadora

By: Jorge Ventocilla

drriss / CC BY-NC-SA 2.0

 

Did you plant anything this year?” I asked Hernán while he was sailing us out of Gobernadora Island.  “Absolutely not! What for? The changamé eats it all…” was his answer.

In Panama’s countryside, the great-tailed grackle is called by its proper name in Spanish: changamé.  In Panama City we call it talingo, but that is the name of a different “tick-eater” species…well, actually of three species, all from the genus Crotophaga

In some other regions it is called zanate or chanate, chango, clarinero; sometimes it is called just thrush. They have more complex names in other places. In the northern coast of Colombia it is called maríamulata. In some regions in Venezuela it is called “Pedro Luis”.

Sometimes it is said to be a crow, but it is not related to real crows. Crows belong to the Corvidae family.  The changamé belongs to the Icteridae family. The latter includes orioles and troupials.

Gobernadora vista desde isla Cébaco. Foto de Jorge Ventocilla.

Quiscalus mexicanus is the scientific name of the great-tailed grackle. Many people wonder for how long does this bird live. You can tell the age of these birds by the rings that can be seen on their legs. One of these (recaptured) birds was determined to be 12 ½ years old.

We have already talked about the great-tailed grackle or changamé back in January 2013 (http://www.biomuseopanama.org/en/boletin/chango-mournful-singer); however, I would like to talk about it again.  The size of its population in Panama City is becoming a big problem and, on top of that, the great-tailed grackle seems to be giving the final blow to essential agricultural traditions in Gobernadora Island, in the Gulf of Montijo, Veraguas.

Ubaldino Castillo, another dweller of Gobernadora Island, also commented: “I have not planted anything in two or three years.  These days, probably just six farmers on the island have small agricultural plots: Vidal, Jose Maria… The rest of them don’t. They have to buy the rice and corn they eat…” 

Pilando arroz en la isla. Foto de Gregory Odry.

He was born in 1962 and he tells me that when he was 24 he saw a great-tailed grackle for the first time in Gobernadora Island.  Before that, he had only seen this bird in Panama City, during one of those trips islanders take with the purpose of making some money.

Compared to neighboring Island of Cébaco, Gobernadora Island is ten times smaller. It has a surface area of almost 3000 acres, and a population of approximately 350.  Last names like Castillo, Alfonso, and Guevara are quite common, and people on the island are mostly farmers or fishermen.  An interesting fact is that in the 70’s the islanders decided that it was not a good thing to have cows on the island, especially because of the impact on water sources.  They have not had any cows on the island ever since.  I don’t have references of any other similar communities in Panama.

 “Before the uncontrolled growth of the population of changamé birds, there was another type of bird here.  It was also a black bird, only smaller…we called it little thrush…” continued Ubaldino.  “It was somewhat harmful for the rice and corn plantations.  There are not many of them now on the island.  We don’t even have the white-tipped doves because the changamé ‘pecked them out’ of the island… Have you seen how they take hermit crabs and let them fall from high above just to crack their shells and eat them afterwards? …those little devils!

El arroz nuestro de cada día, en Gobernadora. Foto de Lucie Vilar.

The geographical distribution of the changamé used to be from Mexico down to northern Peru.  However, I have read that human intervention is the main cause for their habitat to be so widespread these days.  It now includes the United States and Canada.  In 1997, its range was determined to go as far north as Oregon, with some individuals found in Canada.  Two years later, it was reported to be “...as Far East as Western Arkansas”. 

The phenomenon of Gobernadora Island, and probably of other areas in the country, is directly related to the uncontrolled increase of its populations.  These birds travel in large flocks, and they are omnivorous.  They would eat anything: both the sprouts and grains of corn; rice in all of its stages, especially about two or three weeks before it is ready for harvest. The bird usually rests on the ears of the rice and breaks them. Its impact on agriculture is so significant that people in Gobernadora Island are no longer planting any of these products (rice and corn), which are essential for subsistence farming. 

At some point during the conversation, Ubaldino Castillo insisted: “…planting? what for?  …for feeding such a vermin?

The point is that it is not just about planting or not, but about all the things culturally related to farming.  I know, I know, this is not exactly my specialty, but I would like to let it all out… 

What can we do for handling a species that everybody acknowledges as a “smart” one? People have tried different strategies for getting rid of it with little success.  Their nests are usually built up above in tree palms, making it very difficult to control them.  

Should we use poison? Unfortunately, bird lovers, it does happen. People actually use poison to get rid of this bird. The changamé is, however, clever enough to avoid falling for it once it learns other birds from its flock have been poisoned.  

Ivo Leblet, a French artist who lives in Gobernadora Island since 2005, has thought about using fishnets for covering the plantations. Perhaps ultrasound may work. Airports in some countries use this technique for driving birds away and avoiding any risks related to these birds flying into plane engines.  While talking about these alternatives, Ivo takes a look at the three bundles of rice plants on display in his kitchen: “...this was all that we could get from our last harvest”. Valerie, his wife, also tells me that there is a relation between the growing populations of changamé and the decrease in the populations of blue jays and crimson-backed tanagers. I know this has happened in larger cities as well.

Right now I have no proposal for this issue but I would like to bring this to the attention of specialists from the different universities and scientific organizations that study Panama’s wildlife.  The truth is that, even though this is a very common species in both large cities and towns in this country, few people have studied it.  The best way of “handling” a species, and of controlling it whenever it turns into a pest, is to study it, know everything about it. It is that simple. 

Scientific investigation is crucial in our countries. Practical implementation of any scientific conclusions derived from the study of these species is essential too.