The eBird Team has in the past mentioned that birders tend to report their bird sightings less often during the summer. I can think of a few reasons that this behavior pattern might be occurring:
1. Birders get excited about Spring and Fall migrations and therefore are out birding more often and are more excited about reporting their sightings.
2. By the time mid-June rolls around, birders (and their non-birding friends and family) might be a bit burned out.
3. It's often hot outside and their are tons of mosquitoes and the lure of the outdoors is tempered.
4. If other families are similar to mine, July is one busy month, with family reunions, scout camps, etc. Maybe people just don't have as much time to be birding.
Well, I hope to encourage all of you to buck that trend of the Summer birding blues. Live the mantra of "Always be Birding" and please take on my challenge of submitting an average of at least one birding checklist to eBird per day. Why don't you test out the new eBird data entry system!