I photographed this nice 8 Point Whitetail Buck Lip Curling (flehmen response) at the Sequoyah National Wildlife Refuge in Oklahoma. Bucks lip curl to bring scent molecules from Doe urine into contact with the Vomeronasal Organ (Jacobson’s organ). They smell the air to determine if any estrous does are in their vicinity and ready to breed.

I photographed this 8-Point Buck from my pickup while parked on the auto tour road at the Sequoyah National Wildlife Refuge. I had my camera and lens resting on a bean bag draped over the open window of my pickup.
Gear Used:
- Camera: Canon EOS 1D Mark III
- Lens: Canon EF 500 mm f/4L IS
Technical:
- Location: Sequoyah National Wildlife Refuge (Oklahoma)
- Date and Time Taken: October 21, 2011 (07:34:42 A.M.)
- Aperture Priority
- Aperture: f4.0
- Shutter speed: 1/400 sec. (as determined by the camera)
- ISO: 2000
- White Balance: Auto
- Metering Mode: Evaluative
- Exposure Compensation: 0 EV
- Back-button Focus
- Single Point Continuous Auto Focus
- Focal Length: 500 mm
- Processed With Luminar 4