What are the causes of the sparrow decline?

Answer 1

The natural salt marshes of Merritt Island and the St. Johns River west of Titusville, once were home to a non-migratory songbird known as the dusky seaside sparrow. The dusky was not discovered until 1872, and this was the only place in the world they have ever been observed. The dusky seaside sparrow was declared extinct in December, 1990. The dusky's demise began in the 1940's when man began spraying the marshes with DDT for mosquito control. The pesticide entered the birds' food chain, and the dusky population plummeted from 2,000 to 600 breeding pairs. From the mid-1950's to 1963, dikes were constructed to impound the marsh. The ground-feeding dusky could not tolerate prolonged periods of flooding, and their population dwindled to 70 pairs. In 1963, the refuge began managing a small portion of NASA's lands including the joint management of the marshes with the mosquito control district. During this era, America was caught up in a "race for space" and any movement to curtail mosquito control was met with resistance. Despite support of the local mosquito control director to do something for the dusky, little was accomplished by the refuge and the downward spiral continued. In 1969, with only 35 pairs reported, the refuge began a joint management program with the mosquito control district, which allowed for the removal of three dikes to restore the marsh. The marsh was restored, but the dusky could not recover from the previous habitat disturbance. In 1977, biologists observed what was believed to be the last dusky on Merritt Island in the marsh to your left.

Answer 2

The Savannah sparrow is not an endangered species, rather listed as a species of least concern by the IUCN, which means it is currently still a common bird.

Answer 3

Sparrow species are far from extinct. The various sparrows are common species.