There has been an overall decline through the years on the IUNC Red List od Index of species survival. Birds being the most stable species to remain on the most healthy numbers spectrum with a slight 0.05 change over 20 years and mammals similarly, on the other hand corals having the most rapid decline from 0.99 in 1995
However the species with the most increasing survival concern is Amphibians in 1980 they were already at the end of spectrum however over 30 years they have continued to plummet into the concern of survival spectrum and they hold the lowest index of species survival with 0.74 in 2010. The reasons for this will be later discussed. ] The proportion of warm-water coral, bird, mammal and amphibian species expected to survive into the near future without additional conservation actions has declined over time. The
Red List Index (RLI) for all these species groups is decreasing.
Coral species are moving most rapidly towards greater extinction risk, while amphibians are, on average, the group most threatened. A Red List Index value of 1.0 indicates that all species in a group would be considered as being of Least Concern, that is not expected to become extinct in the near future. At the other extreme, a value of 0 indicates that all species in a group have gone extinct. A constant level of the index over time implies that the extinction risk of species is constant, and if the rate of biodiversity loss were reducing, the lines on this figure would show an upward slope.
Species of birds and mammals used for food and medicines are on average facing a greater extinction risk than species as a whole, through a combination of over-exploitation, habitat loss and other factors.