Adding zeros when not found

Hello everyone!
I am working with some bird survey data (see attached document). I did about 800 surveys at some 80 locations. I want to analyze the data, but I have an issue I am hoping someone can help me with.

See document attached: I didn't survey every place every day, but I want to know what species I DIDN'T see at locations on days that I did surveys. The way the data is structured, I recorded only the number of individuals of species detected, what I need is 0's for all the species I DIDN'T see. For example, I did a survey at location 33 on 5/15/11 and found a bunch of species, but I didn't see an AMRO (American Robin) - in my pivot table I want it to show that I found 0 AMRO individuals (& show 0's for all the other species I didn't find). Basically, I want the pivot table to show me a 0 for all species I DIDN'T see when I did do a survey at a specific location on a specific date. Make sense? Happy to clarify if not. I would be very grateful for your help. I need the data in this format for my analyses.

The only solution I have thought of is to copy all the sp. names for each combination of location and date (800+!) and then put the number found 0, this would work but it would take a long long time, I am hoping someone is much more clever than me and is willing to help me out! Thanks!

Thanks - here it is again, hopefully this time it will work!

Thanks, but I am afraid that doesn't work. I want the pivot table to show me a 0 for all species I DIDN'T see when I DID a survey at a specific location on a specific date. If I just fill the tables with 0's it will show 0's on dates that I didn't do surveys. Do you follow?

anybody have any ideas here?

BUMP.... I'd REALLY appreciate some help here