Declines of Species

Wildlife in ‘Catastrophic Decline' due to Human Destruction, Scientists Warn 0920.rtf

Human Society under Urgent Threat from Loss of Earth's Natural Life 0519.rtf

Living Planet Repot Update - WWF 0914.pdf 180 pp.  update of 2012 report farther below

     The global Living Planet Index (LPI) reveals a continual decline in vertebrate populations over the last 40 years. This global trend shows no sign of slowing down.  For this 10th edition of the Living Planet Report, the LPI methodology has been updated and fine-tuned to give a better representation of the global distribution of vertebrate species.
    The weighted LPI (LPI-D) shows that the size of populations (the number of individual animals) decreased by 52% from 1970 to 2010.  This 52% includes 56% declines in tropical populations and 36% in temperate zone populationss.  It includes 39% declines for terrestrial species populations, 76% for fresh water ones, and 39% for marine ones.  Populations in protected areas declined only 18%.
    For terrestrial species, habitat loss to human land use – notably agriculture, cities and energy – is the major threat.  For freshwater ones, habitat loss and fragmentation, connectivity (water level changes from dams, irrigation, etc.), pollution, and invasive species are the threats.  For marine ones, stability followed a steep drop to till the mid-80s, with the largest declines in the tropics and Southern Ocean.

    This is a steeper decline than the 28% reported in the previous edition, when data from North America and Europe  – where long-term trend information has been more readily available –  dominated the global LPI.

     The LPI is calculated using trends in 10,380 populations of over 3,038 vertebrate species (fishes, amphibians, reptiles, birds and mammals).  These species groups have been comprehensively researched and monitored by scientists and the general public for many years, meaning that a lot of data is available to assess the state of specific populations and their trends over time.

Why Monarch Butterfly Numbers Are in Freefall 0713.rtf

updated from Brower et al., Insect Conser. & Diver., 5, 95, 2011