Friday, 30 November 2007

The outbreak of plumbism is spreading: dead Flamingos found in Comacchio and Dragojesolo

More corpses of Flamingos were collected recently both in Comacchio (south of the Po Delta) and in Dragojesolo (north of Venice). Moreover, today the newspaper "La Stampa" of Turin offer to the readers a whole reportage of the story. The title is "Flamingos are dying in Italy - Slaughter of birds in the Po Delta: poisoned by the hunter". The reporter states that dead Flamingos were collected "in dozens" and that all evidences are pointing out an epidemic of plumbism due to the high number of lead pellets on the bottom of the lagoons, where Flamingos are currently feeding. They are attracted by the artificial fodder offered by the lagoon owners to the ducks to make faithful them to be finally shot.

Sunday, 25 November 2007

The lead shot from a single shotshell may kill more than 60 Ducks or 23 Swans

The lead pellets from a unique shotgun shell is enough to poison mortally from 40 to more than 60 adult Mallard ducks. It depedes either from the other healthy conditions of the birds or the climate.

In the same way, a shotshell may kill 23 adult Swans with the effect of its lead bullets collected from the birds in the bottom of a lake.

Thursday, 22 November 2007

Collection of dead Flamingos in the Po Delta, november 2007

Pictures courtesy of Emilio Nessi

Repeated poisoning of Flamingos in the Po Delta

In November 2006, more than 20 Greater Flamingos (Phoenicopterus roseus) were found dead in the Po Delta, NE Italy, because of a severe event of lead shot poisoning. 16 of them were collected and several lead pellets were present in their gizzard cavities. Chemical and histopathological analyses confirmed the suspect of lead shot poisoning. The average of lead concentration in hepatic tissue was 108,41 ppm, a value higher than 8 ppm, the threshold in aquatic birds(*). This case confirms the importance to forbid the lead pellets used in hunting shotgun shells in Italian wetlands. Nevertheless, local regional government never agreed to stop using lead pellets in the protected wetlands, so more cases of dead Flamingos were registered in the same area exactly one year later.

Giuseppe ARCANGELI, Amedeo MANFRIN, Giovanni BINATO, Roberta DE NARDI, Stefano VOLPONI, Marta VASCELLARI, Franco MUTINELLI, Calogero TERREGINO., 2007. [Lead poisoning in wild birds - A research on Flamingos (Phoenicopterus roseus) in the Po river Delta. In Italian with English summary] Avvelenamento da piombo in uccelli selvatici - Indagine su Fenicotteri (Phoenicopoterus roseus) nel Delta del fiume Po. Obiettivi & Documenti Veterinari, 9:39-45.

The Dangers of Lead for Birds

How and where lead accumulates.
When a shotgun shell is fired, only a small fractionof the shot strikes the target. The rest of the pellets fall back to earth, where the pellets accumulate in the soil either on land or on the bottom of wetlands or other water bodies. Near waterfowl blinds or in agricultural fields where hunting activity is high, lead shot historically accumulated in substantial amounts.

The Dangers of Lead for Birds
Birds’ digestive systems

Birds are poisoned when they ingest lead shot found in the soil or in wetlands. Because birds lack teeth, they swallow their food whole. Along with their food, birds swallow small pebbles, called grit, which grind the food in the gizzard. Aquatic birds, particularly ducks, geese, and swans, use the sensitive tissues in their bills to detect particles of food and grit in the soil or in mud at the bottoms of lakes and wetlands – but waterfowl are unable to distinguish lead shot from pebbles, and may also ingest the toxic lead pellets.
Lead’s deadly effects.
Lead pellets enter the gizzard, where they are ground into smaller particles and partially dissolved by digestive acids. The dissolved lead combines with other elements in the bird’s digestive tract and is absorbed into the bloodstream, where it inhibits the ability of hemoglobin to carry oxygen, and reduces the number of red blood cells. Depending on the dose of lead, it may take only a few days for the bird to experience anemia, and its muscles weaken. If the anemia is severe enough, the bird may lack the strength to eat, and slowly starve to death or die from the failure of vital internal organs (Bellrose 1975), or from neurological damage. Furthermore, weakened birds are more vulnerable to accidents, hypothermia, and predators, so their ability to survive is reduced even if the dose of lead itself is not lethal.

Toxic doses and wildlife mortality.

Lead is extremely toxic if eaten and absorbed into the blood. Symptoms of lead poisoning can appear as soon as four days after ingestion of as few as two to three pellets, with death occurring in 17 to 21 days. A single pellet has been shown to be lethal to birds as large as swans. Controlled studies conducted in the 1950s showed that ducks that ingested four 0.11-inch-diameter lead shot pellets suffered a mortality rate 41% higher than those that were free of lead (Bellrose 1975). The Canadian Wildlife Service estimated that 250,000 waterfowl died per year from lead poisoning in Canada (Scheuhammer and Norris 1995). It estimated that several million more waterfowl suffer sub-lethal effects, resulting in lower survival rates and reduced breeding success. Before the 1991 prohibition on lead shot for waterfowl hunting, it was estimated that two to three percent of the autumn and winter populations of waterfowl across the U.S. fell victim to lead poisoning each year (Bellrose 1976, p. 73). Lead shot in the environment also causes secondary poisoning of wildlife. This may happen when scavengers or predators such as owls, hawks, and eagles ingest lead while feeding on prey containing lead pellets, or on prey with lead-contaminated muscles and internal organs. The high number of endangered Bald Eagles lost to secondary lead poisoning in the 1970s was one of the primary reasons for the federal ban on lead shot for waterfowl hunting.

Silent killing of Flamingos: the beginning of the story

Po Delta, S of Venice, NE Italy: a complex of wetlands and lagoons of high interest from the wildlife point of view. Flamingos start to visit the area early the nineties of last century and start to breed early this century. Finally they "discover" a "new food resource" constituted by seeds and other food made available in the inner lagoos by the owners for duck-hunting purpose. The picture shows Flamingos feeding among ducks in the Po Delta.