the challege of the rice fields of Mana


Knots in a rice field lost to the sea

Our work in French Guiana has proven to be fruitful.   We found over 1700 red knots and at least 1000 turnstones in one location, in the rice fields of Mana.   Moreover we resighted knots with a disproportionately high number of red flags indicating they were heading to the Bahia Lomas wintering grounds in Tierra del Fuego.  We know these birds because we banded them.  With the data collected by Alexandre Vinot, a volunteer from French Guiana, and data from our geolocators caught in Delaware Bay, we can be fairly certain that French Guiana plays a signficant role in the lives of Brazilian, Argentine and Chilean red knots.

Shotgun shells collected along one dike

The key place, the rice fields of Mana, presents a monumental management challedge.  First and foremost is the hunting.  While walking the dikes I picked up all the shotgun shells I could find along dikes that border the sea or project out into the sea.  I found about 30 newish shotguns shells per kilometer of dike.  This is a minimum as some of the dikes were being swept by the tides and most were overgrown with a tangle of vegetation.  We saw two people with guns in our 4 days in the field.   Although whimbrels are the most liklely targets because they are big, knots too are vulerable because they are the only bird to occur in dense groups, and thus more can be killed with one shot.  We can’t be certain how much a threat hunting presents to shorebirds in the rice fields of Mana, but most of the people working here believe it is.  I agree.

The eroded beach front of the Mana rice fields.

In the left side of the photo are about 800 knots. But the second challege is the rapidly shifting rice fields.  In a brief review of google earth imagery one can see that the area has lost nearly a kilometer of area to the sea since 2000.  Curiously the rice fields were stable until then.  Why?  Did the shift in ownership, and the uncertainies this creates in management, cause fields to be lost to the sea or did the power of the sea change in the last decade?  In any case the erosion has helped knots, turnstones, whimbrels and other species because the erosion has laid bare new habitat for an abundance of invertebrates eagerly consumed by shorebirds.The rice fields at Mana, French Guiana. The points were the locations of our beach surveys. The red line represents .86 km in length, the distance lost to erosion since 2000.

How to manage this situation?  The rice fields create jobs and habitat for many shorebirds like semi-palmated sandpiper, greater and lesser yellowlegs, pectoral sandpipers, stilt sandpipers and others.  The eroded rice banks create habitat for knots and the other species mentioned above.

Above all is the welfare of the people of this land.  They need food and jobs, both provided by the rice fields and hunting.  Is this an intractable problem?