Complex sentence: Since 1988, the brown pelican has been rated as least concern on the IUCN Red List of Endangered species based on its large range--greater than 20,000 km 2 (7700 mi 2)--and an increasing population trend.
Split into simpler sentences: Since 1988, the brown pelican has been rated as least concern on the IUCN Red List of Endangered species. This was on the basis of its large range--greater than 20,000 km 2 (7700 mi 2)--and an increasing population trend.