Case studies (continued)

     7) Black Robin

          - Endemic to Islands off the coast of New Zealand (quite a ways).

          - Had been reduced to 1 breeding pair before recovery.

          - Although a large part of the native fauna had been exterminated by the 14th
          century (18 taxa of birds), the Black Robin was generally unaffected until the
          arrival of Europeans in the 19th century.

               - usual story of cats, rats, etc., though this time rabbits were also
               introduced.  These were apparently creating a problem, so cats were
               introduced to control the rabbits.  The cats did exterminate the rabbits, but
               also exterminated an additional 12 species of bird.  The black robin hung
               on on one of the smaller islands (though habitat was not ideal).

               - They were thought to be stable until color banding showed that the same
               few birds were consistently sighted.  

               - An eventual transfer of the remaining birds back to a larger island proved
               successful.

               - Important - a big reason for the success was cross-fostering.  Basically
               placing the eggs into the nests of other birds, and letting them raise the
               young. 

                    - Initially this created imprinting problems until the young were
                    removed as fledglings.  

               - The population has since increased to over 140 birds when the text was
               published, and now 250 birds .  The New Zealand Department of
               Conservation is attempting to set up another population.

               - All birds descended from a single female that didn't even breed until she
               was eight years old!

     8) African Elephant

          - Note: the Asian elephant is probably in worse danger (at least the wild
          populations - the domestic ones are doing fine).

          - Range used to include most of Africa, but has been getting smaller for centuries. 
          Even early Roman writers noted that it's population was shrinking (locally, of
          course).

          - Several factors are driving the elephant populations down:

               - habitat loss - where human populations are expanding, the elephant loses
               out.  East Africa had a growth rate of 3% for much of the 20th century
               (that's a doubling time of less than 23 years!!).

               - illegal hunting - ivory is very valuable, and generally the case is made
               that it's poaching that impacts elephant populations the most.  Because of
               this, all ivory trade was banned in 1990.  This had an immediate positive
               effect.  Some elephants were still killed for food, and not all countries had
               adequate funds to control trade/poaching.

               - the text makes a case for habitat loss being more important, but several
               indicators seem to show otherwise:

                    - poaching in Kenya was reversed after the introduction (believe it
                    or not) of helicopter gun ships to control poaching.  Elephant
                    populations have recovered somewhat, or at least have stopped
                    declining as fast (poachers were using automatic weapons).

                    - attempts by some countries to be allowed to export ivory legally
                    have been consistently turned down.  It is felt that any legal ivory
                    on the market would spur poaching.  A one time sale of stockpiled
                    ivory was permitted recently (2000).

                    - sometimes one government agency doesn't know what another
                    one is doing.  While in the Sudan in 1985, I was told that the ivory
                    in Khartoum could be legally exported to the United States
                    (according to the State Department).  The elephant was already
                    recognized as being endangered by the Fish and Wildlife Service,
                    so obviously importing the ivory (and there was lots of it!) was
                    illegal.

               - however, with the reduction in the ivory trade, habitat destruction is
               becoming more important as the major threat to elephant populations.

                    - in some countries, elephants are now real pests.  The
                    governments must cull herds to keep down human-elephant
                    conflicts.

               - one could spend an entire semester on this species alone.