Coastie

There is actually no such thing as a yearling at this time of year, they will be 5 months old, 17 months old, 29 months old etc. Most fawns are born in June to insure that they will be large enough to survive a winter. There are exceptions to the rule as there are exceptions to every rule, but for the most part all fawns will be born within 7-10 days of each other during June. A small deer by itself at this time of year could be a 5 month old seperated from its mother due to any number of circumstances or could be a 17 month old likewise seperated from its normal running mates. Does will chase this years fawn away for a short time during estrus, but will normally get back together with them afterward. Bucks at this time of year,especially those in the 17 month old category, will be with bachelor groups of 2-5 animals as a general rule. Again, all rules have exceptions. The bachelor bucks will begin to break up into singles in the next week or so depending on the area of the country you live in for the rut. The advice in the other posts is excellent information on aging deer on the hoof and experience will help. There is an issue of the American Whitetail (I believe) that has a good pictorial layout of deer, bucks in particular, at various ages which could be helpful to you.