Hunted up in panhandle since 97 on ranches with both, never seen a cross, it was just a huge wt/ they have no interest in each other have been on ranches with both with them at feeder together muleys chase muley and wt chase wt and no aggression between the two even with hot does there.

whitetails bucks are much more aggressive breeders than muley bucks.

This is from a paper from TPWD, "Mule Deer Management in Texas."

"Antler characteristics, tail coloration and ear length are not reliable in recognizing hybrids. Hybrids can be identified by the length of the metatarsal gland that is located on the outside of the rear leg between the hock and the hoof. It typically will measure about 3/4 inch long in whitetails and about 4 inches long in mule deer. The metatarsal gland of hybrids is intermediate in length, measuring about 2 inches long. It has been theorized that occurrences of hybridization are initiated by white-tailed bucks, but interbreeding also can occur between mule deer bucks and white-tailed does. Hybrids appear to have at least a limited degree of fertility (Stubblefield 1985)."

This is from a paper from TPWD, "Mule Deer Management in Texas."

"Antler characteristics, tail coloration and ear length are not reliable in recognizing hybrids. Hybrids can be identified by the length of the metatarsal gland that is located on the outside of the rear leg between the hock and the hoof. It typically will measure about 3/4 inch long in whitetails and about 4 inches long in mule deer. The metatarsal gland of hybrids is intermediate in length, measuring about 2 inches long. It has been theorized that occurrences of hybridization are initiated by white-tailed bucks, but interbreeding also can occur between mule deer bucks and white-tailed does. Hybrids appear to have at least a limited degree of fertility (Stubblefield 1985)."

The paragraph above that one is pretty interesting as well:

"Where mule deer and white-tailed deer coexist, interbreeding does occur. The long-term effects are unknown, and for most areas, the extent of hybridization is not known. The highest incidence of hybridization in the Trans-Pecos occurs in the eastern part of the region where high populations of mule deer and white-tailed deer coexist. Using a technique called “polyacrylamidel electrophoresis,” Stubblefield et al. (1986) estimated that up to 14 percent of deer may be hybrids where both species occupy the same range, although the average occurrence of hybrids was only about 5%. Many ranches where the 2 species overlapped showed no evidence of hybridization. Using a more accurate technique (DNA sequencing), Cathey et al. (1998) found that 7.7% of 26 deer sampled were hybrids in the West Texas zone of contact (Terrell, Pecos, and Brewster counties). DNA sequencing was also used to determine the extent of hybridization in the Panhandle (Donley County) where the ranges of both species overlap. The results of a small sample of deer (n= 40) indicated a hybridization frequency of 8% (F. Bryant, pers. comm.). Observations by Texas Parks and Wildlife biologists during the hunting season indicate that true hybrids are extremely rare. Out of several hundred deer that are checked each year, it is rare to find a single hybrid."

from TPWD website.

This subject is really interesting to me right now, we have been talking about this in my biology class this week and I meant to bring up the subject in class but did not have time. Most hybrids are either infertile, die before birth, or have some type of defect and die early. I had thought that the hybrids were completely infertile but not according to what TPWD has to say. So this makes me curious if the hybrids are defected in some kind of way or if we could be seeing the beginning of a new species being developed...only the future will tell us.

Here's one more pic.

This is a confirmed hybrid shot near Fritch in '09. Notice the muley body size, head and ears vs the white tail rear end.

The tarsal gland is the key to identifing a true hybrid. In a mule deer it's 3 to 6 inches long. On a white tail it's only an inch or so. Hybrids will always split the difference and come in around 2 inches. This is what most biologists and Game Wardens use to confirm a cross (as well as DNA sampling if someone wants to spend the $$)
That is very cool, also very informative.I will keep the metatarsal in mind.
I can say that after observing this herd over the last 30 years, and the appearance of whitetail about 20 years ago, there has been a marked difference. Used to all the mulie racks were typical forking racks. All this single tine off a main beam stuff started later. Like I said, I have seen big ears, white tails and throat patches on the same deer. I have seen black tipped tails with whitetail racks and other combinations. I have watched whitetail does come to the feeder with mule deer does, eat, and leave together. I am all for science, I believe the tarsal gland thing, but the deer are ahead of the biologists, IMO.
Racks are never an indication of cross breeding. Just because a muley has a "whitetail looking rack" means nothing. In most cases DNA tests show these bucks to be 100% mule deer. Shooting one and putting a white tail tag on it could be a very costly mistake.

This is a confirmed hybrid shot near Fritch in '09. Notice the muley body size, head and ears vs the white tail rear end.

The tarsal gland is the key to identifing a true hybrid. In a mule deer it's 3 to 6 inches long. On a white tail it's only an inch or so. Hybrids will always split the difference and come in around 2 inches. This is what most biologists and Game Wardens use to confirm a cross (as well as DNA sampling if someone wants to spend the $$)
That is very cool, also very informative.I will keep the metatarsal in mind.
I can say that after observing this herd over the last 30 years, and the appearance of whitetail about 20 years ago, there has been a marked difference. Used to all the mulie racks were typical forking racks. All this single tine off a main beam stuff started later. Like I said, I have seen big ears, white tails and throat patches on the same deer. I have seen black tipped tails with whitetail racks and other combinations. I have watched whitetail does come to the feeder with mule deer does, eat, and leave together. I am all for science, I believe the tarsal gland thing, but the deer are ahead of the biologists, IMO.
Racks are never an indication of cross breeding. Just because a muley has a "whitetail looking rack" means nothing. In most cases DNA tests show these bucks to be 100% mule deer. Shooting one and putting a white tail tag on it could be a very costly mistake.