Hello, and welcome to the forum! Have a look at the app:
Merlin Bird ID - Home, and the website:
https://ebird.org/explore (you'll probably need an account to view that one). These should help with both of your questions. Regarding Merlin, it will probably prompt you to install a bird pack containing all the birds of Nigeria with their descriptions, ranges, photos and sounds, so even if the 'Explore Lists of Birds Near You' is inaccurate due to there not being enough birdwatchers collecting data, you can always have a look at the 696 species in the bird pack for Nigeria. With enough data, the bar chart showing frequency should contain bars of varying height--here you only have a high dark bar (= present) or no bar at all (= absent).
If you have any questions about bird ID, don't hesitate to ask at:
Bird Identification Q&A. You can share your photos/videos here:
Gallery, if you want, too. I'm afraid the said Collins bird guide only covers Europe and adjacent regions--if you're looking for a guide covering Nigeria, have a look at:
Best bird guides by region...Africa, or start a new thread in:
Books, Magazines, Publications, Video & DVD. BirdForum is quite huge, so it will take you some time to explore all the subforums--I feel I'm still in the process of discovering new places here myself.
EDIT: Does '80 miles south of Bonny Island' mean you work on an oil platform? Here's a thread by a person who spends half of the time at sea about what birds he sees, although--obviously--most of the species you'd get in Southern Nigeria would be different than those:
North Sea Thread.
