In response to questions about Caspian terns and possible interference 
from ring-billed gulls on Young Island:  Caspian terns are big, 
aggressive terns and hold their own nicely among ring-bills.  In fact, 
they seem to "bully" ring-bills for space.  On Four Bros islands, where 
I have watched nesting Caspians in the midst of 8000+ pairs of 
ring-bills for the last 5 years, the two species seem to be quite 
compatible.  However, daytime disturbances of the terns by humans allow 
ring-bills to prey on the tern eggs; they seem to do this more as an act 
of aggression than for food (their chance to be the bully?).

I don't believe that reducing populations of ring-bills will enhance the 
island for Caspians, but I do believe that avoidance of disruptive 
activities, such as shooting of cormorants and gulls and planting trees 
during the peak of the nesting season (two days after I observed the 
Caspians starting a nest!) will encourage the terns to expand their 
successful pioneering back to Young Island.

For more on the proposed [ongoing] management of this island by VFWD, 
read the management plan:  http://www.vtfpr.org/lands/islands.cfm