Unfortunately we aren't certain what this object/residue is. Since this is outside of the realm of our expertise, you could inquire with wildlife biologists at the MD Department of Natural Resources. An email can be sent to <personal data hidden> (especially if you want to share this or other photos) or, if you would like to speak to someone, they have a Wildlife and Heritage Service phone number at<personal data hidden>. The phone line is staffed during regular business hours, 8:00 am to 4:30 pm, except state holidays and weekends.

Miri