Several months ago, parts of the Amazon rainforest were in the grip of one of the most severe droughts on record. River levels were at historic lows and the impact on wildlife was severe.
The number of pink river dolphins in a remote part of the Peruvian Amazon dropped by nearly half in October compared with 2009, as the level of the Samiria River fell, a major tributary of the Amazon. Along a 20km stretch of the river, a population of 250 pink dolphins declined to about 140.
But now a team of conservation experts working in the region has found that many species have recovered more quickly than expected. This includes the pink dolphins, which, according to surveys conducted in March, have seen their numbers increased by nearly 10%, compared to the same period last year, prior to the drought. The number of grey dolphins is also up from March 2010 - by 30%.
"This is a very good sign and suggests that the Samiria River is recovering from the drought of 2010," says Dr Richard Bodmer from the University of Kent, who has published extensively on the area for the last 25 years.
The research is being carried out in the Pacaya Samiria national reserve in the upper reaches of the Amazon, an area covering more than 20,000 sq km (700 sq miles). It falls within one of the three regions worst affected by the 2010 drought, when parts of the Amazon and its tributaries reached their lowest levels for half a century.
Now the water levels are extremely high again and local officials have declared a state of emergency. "We are being hit on both sides - extremely high levels of water or droughts," says Dr Bodmer.
Source - BBC News