The photo shows the python stretching its jaws monstrously to devour the prey.
African pythons, which can grow up to 16 feet, usually prey on smaller animals such as rabbits.
Hulshof said the sight of the python swallowing a hefty two-month old wildebeest left him "speechless."
He came across the incident by chance while looking for lions and leopard, the Daily Mail
reports. He said: "I decided to investigate the area... and scanned the area with my binoculars, seeing only a few scattered Wildebeest, and a herd of Impala. The impala were staring down the back of a ridge drop off about 150 metres away, and it was enough for me to think there could have been a leopard or pride of lions feeding on something just out of sight. I took my rifle, left the guests on the vehicle and walked in to try and establish if it was in fact what I thought, and if I would be able to walk clients in safely to view the action."
He added: "I however found nothing, and just as I turned to return to my guests, I saw this snake lying on the ground. Moving closer I saw that it was swallowing the Wildebeest calf, aged about two months old.
"I almost could not believe what I was seeing, and being someone normally really composed, my guests must have thought the worst, because I sprinted back to the road as fast as my legs would allow.
"I simply had to retrieve my camera and get pictures, and allow my guests to get pictures, before the sun set, which was only a few minutes away.
"We watched for about 30 minutes, before descending darkness forced us to leave, and return to the car, all speechless at what we had just witnessed."
Hulshof had feared that the python had bitten into more than it could chew, but when he returned the following morning: "[We] found nothing, no tracks, no scuff marks, no python and no prey. Everything was gone, and because it had rained, we could not read any tracks to see which way the snake may have slithered off."
Hulshof explained the significance of the photo: "This was the first time I had ever seen something like this, and I have been working as a game ranger for 15 years already in South Africa, and have also traveled to other African Countries.
"This is an incredibly rare sighting, and is by my knowledge the first time that it has been recorded, let alone photographed and documented that a Southern African python catches prey as big as the blue wildebeest, albeit a wildebeest calf."
He said he showed the photo to snake experts. "Herpetologists I have consulted are all impressed, and dumbfounded by the images when they have seen them.
"It is not uncommon for pythons to catch live mammal prey, but this would usually consist of smaller species like hares, rabbits, impala lambs, duiker antelope, squirrels, birds, rats, cane rats and rodents etc.
"But to have managed something so big is mind boggling. This can be seen by how the python needed to really stretch its mouth to the limits to try and swallow the prey.
"I have been photographing wildlife for the past 15 years while I have been working in the industry, at various lodges and game reserves spread around South Africa."
The Welgevonden game reserve is located in the north eastern part of South Africa. The game reserve is malaria free. That makes it ideal spot for Western nature tourists.