Is the nikon af s 80 400mm f 4 5 5 6g ed vr long enough for birds?

Here is what the site says about that.

From Nikon AF-S 80-400mm f/4.5-5.6G ED VR: Nikon AF-S 80-400mm f/4.5-5.6G ED VR: A zoom lens by Nikon for Full frame cameras, 80-400mm f/4.5-5.6. Specs - Maker: Nikon - Focal length: 80-400mm (zoom) - Maximum aperture: f/4.5-5.6 (it gets darker as you zoom in) - Made for: Full frame sensors - Mounts: Nikon F - Stabilised: yes - Autofocus: yes What it frames like - On full frame (Nikon F): as marked, 80-400mm. - On APS-C (Nikon F): like 120-600mm on full frame; ...

From Wildlife and sport: Reach: Focal length is the first thing to sort out. - Sport from the sideline and larger animals: 70-200mm to 100-400mm on full frame. - Birds: 600mm full-frame equivalent and beyond. Birds are small and far away; a common saying is that you never have enough reach for them. Smaller sensors help here. A 100-400mm lens on APS-C gives the view of about 150-600mm on full frame, and on Micro Four ...

Quoted from this site's pages.