Seagull cub

This one is our office pet. From my office I can see this roof and there a Seagull is having a nest. I have followed 3 egs in here. I think that one was eated by magpies, but there is two seagull cubs. I did not dare to open window and they were about 4 meters away from me.

My wife ordered new camera to her work and I did pit it up from store. It had enough zoom, to take a photo of this seagull cub. 85mm might be correct for this camera, but in my Nikon D5100 (crop sensor) it would be 300...400mm lens. But PowerShot fits in pocket.