Michael T. — February 04, 10:57PM
Why do people list 0 next to a species?
Sometimes I come across a list and the person has put 0 as the number observed for just one or two species. Why? If you just leave it blank isn't it automatically assumed to be zero anyway? There are usually no comments to explain why either.
Caleb Marshall — February 04, 08:08PM
The only expinations I can think of are:
1. A mistake. Maybe some people enter an incorrect species, then see their mistake and change the count to a 0 instead of backspacing. Deleting a species on EBird Mobile can be inconspicious.
2. They may have seen tracks or a nest of a bird, but didn't see or hear any. But hopefully they'd mention something in the comments.
J — February 05, 12:38AM
Some people mark a 0 when they were looking for a specific bird that has been reported but they did not find it.
Menlo — February 05, 10:21AM
I agree with the above, but the proper usage (as per eBird instructions) would be in conjunction with breading code, for example Osprey - Occupied nest (known to be used in that season) however at the moment of the observation the next was empty = 0 birds seen. This usage should be reserved for the specific case otulined above (inappropriate, I think, to enter 0 and occupied nest if, say, one sees an old Bald Eagle's nest that is empty and no longer used. or a nest of uncertain usasge)
Dave H. — February 05, 01:12PM
I agree with all of the previous responses. I also use zero to report dead birds (assuming I didn’t see any of that species that were alive) since you aren’t supposed to count dead birds. From what I’ve seen, it appears most zeros are mistakes, so as the others mentioned, a description of why you reported zero is very helpful.
Caleb — February 06, 11:44AM
There are 4 reasons I can think of, only one of which wasn't mentioned above.
1. Traces of bird presence (Tracks, feathers, old nests)
2. Dead bird
3. You looked for or expected to see a species but didn't (helps other users researching for a twitch)
4. Recording a bird (such as an exotic breeder like parrots) that you don't want on your life list
Ideally eBird will add a better way of recording all of the 2nd and 3rd options; a way of doing those has either been promised in help articles or is requested extremely often.
Jonathan Landon — February 22, 07:41AM
Entering a 0 is also utilized in tracking a bird. For example, lets say you have been observing a rare bird in your birding area for the past few days.
For example, you see rare bird 'A' on Monday, Tuesday, and Wednesday, logging in a '1' for that bird. Then, Thursday, you can no longer find the bird. You would enter '0' for that bird, and NOTE: rare bird 'A' noted over the past 3 days has now departed. This is utilized for tracking purposes, as well as notifying those in your area whom you bird with as to the status of that rare bird. It is really the only way of letting everyone know that the bird has departed.