Updated

The number of dead birds collected on the Gulf Coast has more than doubled in the past month as oil from BP's broken deepwater well continues to wash up on islands and beaches rich in bird colonies.

Officials say 2,599 dead birds had been collected on the Gulf Coast as of Thursday. A month ago, 1,046 dead birds had been collected, according to official death counts.

The number of other dead animals being reported by officials has not climbed as steeply. For example, in the past month the number of dead sea turtles has grown from 411 to 483 and dead mammals from 47 to 62.

Some bird conservation groups are stepping up criticism of the efforts to protect nesting areas and say government figures drastically under count the number of affected birds.