Massive attacks on birds with other birds are ocurances when lots of birds fight poo or egg on each other very hyperactivly. These fights normally occur on one specific location, especially by the two bins near the brick houses on the Cityscape.
These big attacks can take a whole birds lives off of it with 5 continuous poops or eggs. Nests can be a base for watching birds that don't want to risk losing their lives by taking part. Hackers are mostly present at these attacks, too. This can cause continuous egging or pooeing and normally cover the floor with egg splotches mixed with bird poo.
These attacks can be offically caused by 2 birds pooeing on each other continuously and randomly, which can lead to numerous birds joining in, which therefore causes the fight. The Cityscape witnesses these attacks more than any other scene. In addition, the Islands can have these attacks on the wooden port with buildings on as well. This doesn't, however, happen as much as the Cityscape fights do.
They are quite fun to watch and sometimes fun to join in, but like mentioned earlier, they can take several or all lives off of you, so be careful.
Other places that these happen are between the two roads in front of the 4 brick houses on Cityscape,on the field fenced with hedges. Birds normally watch the fight on the hedges surrounding the green and can sometimes feel like joining in. Eagles don't normally survive these fights because of their takeoff times that compared to other small birds like the Robins, are quite slow. This means that they cannot takeoff and exit the fight as easily. Robins therefore, are mostly the main attackers, along with some other small birds too.
For more information on the birds flying capabilities, see the Category Birds page.