From tigers to dolphins, animal populations in many of China\'s ecosystems have plummeted under decades of development and urbanisation, a World Wildlife Fund study said. The conservation group highlighted about a dozen species in different natural habitats across the country in its third China Ecological Footprint Report, saying numbers have fallen dramatically over the years. \"The populations of more than 10 flagship and keystone species in China have undergone marked decline that was particularly severe between the 1960s and 1980s,\" the report said. According to findings compiled by WWF from various sources, the Yangtze river dolphin population crashed by 99.4 percent from 1980 to 2006, while that of the Chinese alligator fell by 97 percent from 1955 to 2010. Amur tiger numbers slumped by 92 percent from 1975 to 2009 due to hunting, deforestation, habitat loss and intensified human activities, it said. But the study noted that a few animal types, including China\'s \"star species\", the giant panda, had seen gradual recovery due to long term protection efforts. The study is part of a broader effort to compile decades of population data -- including size, density and capture rates -- for hundreds of species to build a \"living planet index\" for the country. In a separate set of indicators updated since the previous report in 2010, the group noted that China\'s per capita \"ecological footprint\" -- or impact on the ecosystem -- ranked 74th highest of 150 nations, at 2.1. That per capita footprint exceeded China\'s \"biocapacity\", or the ability of the ecosystem to bear human activity, of 0.87 per capita, creating what the report called an ecological \"deficit\". By comparison the global per capita footprint came in at 2.7 and its biocapacity at 1.8. \"China like many other countries in the world, is in a state of biocapacity deficit,\" the report said. The factors behind China\'s ecological footprint reflected its economic growth, urbanisation, and spending on infrastructure. The per capita ecological footprint in cities was double that of rural areas, and higher in the east -- which is more developed with greater population densities -- than in the rest of the country.