THE IMAGES (#1, #2, #3) are mislabeled. The earliest version of the caption, dated March 2009, claims the monster boar was bagged in Texas. An August 2011 version says it was shot in Missouri. Yet another version claims it was killed in Florida. The truth of the matter is that these photos weren't taken anywhere on the North American continent.
According to a March 3, 2009 article in the Conroe Courier, no 1,800-pound wild boar has ever been seen near Conroe, Texas, let alone hunted, bagged, and photographed for posterity. Your average Texan feral hog weighs in at approximately 150 lbs., says a Texas Parks and Wildlife game warden quoted in the Courier. An exceptionally large one might tip the scales at 300. It's rare to find a wild boar exceeding 400 pounds anywhere in the United States.
In point of fact, it's doubtful there's a wild boar anywhere in the world that weighs 1,800 pounds. There have been reports of domestic hogs approaching or exceeding that size, but the largest documented specimens in the wild have topped out at 1,100 pounds or less.
Citing a report in a French hunting magazine, the Courier reveals that the boar in these pictures was actually a 781-pounder killed in Turkey in 2005 (the EXIF data embedded in the images confirms the photos were snapped on June 3 of that year). One visual clue — the "Nature Tours" logo on the side of a vehicle in one of the photos — indeed points to a Turkish hunting website on which the same images are displayed.
Sources and further reading:
Rumors of Giant Hog Turn Out to Be Bull
Conroe Courier, 3 March 2009
Nature Tours Turkey
Website of Turkish hunting tour company
Wild Boar (Sus Scrofa)
General info from Animal Diversity Web
Last updated: 03/20/13