Where to find deer carcasses

I need a blacktail and whitetail carcass for my daily quest and I don't know where to look

I've encountered deer in Explore but that has never yielded me a carcass 

You can get them from hunting medium prey. While a collect quest is active you have a chance of your scouts bringing back what you need from rescouting, or certain explore encounters - such as the snake with the 'what's that' prompt, or tapping the tree for the woodpecker- may get the desired items.

Is there any specific area I need to be in?  My hunters mostly bring back birds or opossums

The snake should only be giving you quests for things you can find in your biome. Birds and opossums are critters though, while blacktail and whitetails are medium. If your hunters aren't good enough for medium trails you'll have to hope for the best in finding them in explore, or buy them off the TC.

Alright thank you for the information