hollandmin

Have you download all 5 zip files? Since the PDF file size is quite big(829MB), which is separated into 5 zip files. If you just download 1 file, it's incomplete and you can't open it.

Handbook_of_Bird_Biology.zip.001 (200MB)
Handbook_of_Bird_Biology.zip.002 (200MB)
Handbook_of_Bird_Biology.zip.003 (200MB)
Handbook_of_Bird_Biology.zip.004 (200MB)
Handbook_of_Bird_Biology.zip.005 (27.9MB)