conservation, Delaware Bay, Delaware Bay 2011

Starting a new dialogue on shorebird conservation- come to our celebration on May 9th

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Mean horseshoe crab densities in Delaware bay from 2006 to 2010. The Delaware data excludes Mispillion Harbor which had far higher densities but also showed no increase.This January, we learned that a whole suite of artic-nesting shorebirds have plummeted in numbers including red knots, semipalmated sandpipers, ruddy turnstones and lesser yellowlegs.  The magnitude of this problem is still unknown, but real declines of 35 to 90% have been documented.  The reasons are unclear but we know Delaware Bay stopover, the lynchpin place where many shorebirds prepare themselves for breeding, is still in the same miserable condition it was 10 years ago.  Horseshoe crab numbers have not increased and neither has crab egg densities.

Survey of horseshoe crabs from ocean Trawl conducted by Virginia Tech. This survey is sanctioned by the Atlantic States Marine Fish Commission but not supported by them or any other agency. This year Eric Hallerman, a marine science professor at V Tech had to personally raise funds to keep the trawl active.Adding to the mismanagement of crabs, we are slowly uncovering other problems for shorebirds.  Most US wintering areas like southwest gulf coast of Florida are so crowded with people that where there were once 10,000 birds, there are now only a few hundred.  We also know that the number of threatening storms moving through the equatorial Atlantic are increasing dramatically.  These storms can wipe whole flocks of shorebirds at once as they try to reach South American wintering area.   There is more.

Projection of the number of Hurricanes in the tropical Atlantic based on the present climate and a warmed climate.

 

The worst of it is that these problems will be with us for decades because it is written in the genetic code of migratory shorebirds.  In ecological terms, most shorebirds are K-selected — their life history strategy is to invest less in making eggs and more in taking care of young.  Adults usually live longer so less young are necessary to maintain the population.  Humans are also K-selected species.   Species like bobwhite quail and other hunted species are R-selected, their strategy is to lay more eggs and invest less in post-fledging care.   Adults are short lived so the population needs to produce more young to maintain the population.

 

The practical difference between R and K species is their ability to bounce back from catastrophe.  R-selected species can reproduce their way out of severe declines once the problem causing the decline is fixed.  Over-hunt rabbits and, within a few years, protection will bring them back.  When K species decline they can be destroyed forever.

Author banding eagles along the Cohansey River in early 2000’sWe are in a time when shorebirds species, like the red knot, can be destroyed forever.  Losing a species is not like losing a shoe.  I spent a significant part of my career restoring bald eagles to Delaware Bay.   When we started there was only one pair on Delaware Bay.  Now 25 years later, there are over 100.  Bald Eagles are a K-selected species so the population grew slowly, but they had only one  big problem, loss of young from the insidious effect of DDT and other persistent chemicals.  Once we cleared that up, the work focused on protecting nests from disturbance.   In retrospect, the restoration of this species was a glorious undertaking that had to be done. Imagine life without eagles.  Imagine trying to describe to your grandchildren the glory of a mighty bird that commands both sky and water, afraid of nothing, and yet as humble as a child.  Then imagine the hubris that almost allowed this species to be lost from the world.

 

This hubris is destroying Arctic-nesting shorebirds.  We are fast closing on a new world where only pictures and movies will help us understand the thrill of hearing one flock of 10,000 shorebirds, their sound like a jet engine, their movements with the precision of marching soldiers, but flowing like water around a rock.  These birds are hardy, but the odds are against them especially in a world where only a few people care.

 

But the fate of species is not preordained it is a choice.  This May we hope to restart the dialogue on the recovery of shorebirds.  On May 9th we will celebrate the recognition of Delaware Bay as a Site of Hemispheric Importance to shorebirds.   I was there at the inaugural event in 1986 where Governors Tom Kean of NJ and Mike Castle of DE signed an agreement to designate Delaware Bay as the first shorebird stopover in the Western Hemisphere Shorebird Reserve Network (WHSRN).  Now the network includes 88 sites.  We have high hopes that this celebration will change  the fate of shorebirds.  All people with a love for birds are invited.