To commemorate World Rhino Day (Sept. 22), a day bringing awareness to the ongoing battle to stop poachers from killing rhinos for their horns, we’re highlighting these terrific photos of rhino species.

“The white rhinoceros or square-lipped rhinoceros (Ceratotherium simum) is the largest and most numerous species of rhinoceros that exists. It has a wide mouth used for grazing and is the most social of all rhino species. The white rhinoceros consists of two subspecies: the southern white rhinoceros, with an estimated 17,460 wild-living animals at the end of 2007 (IUCN 2008), and the much rarer northern white rhinoceros. The northern subspecies has very few remaining, with seven confirmed individuals left, with only four still able to reproduce (Including those in captivity).”

“22 September is International Rhino Day. Almost 800 Rhino have been poached in South Africa this year. Let’s help put an end to this senseless killing!” – Lea Duckitt

“4-week-old greater one-horned rhino named Petunia cools off in the Asian Plains with her mom, Tanaya. The calf is the 67th greater one-horned rhino born at the Safari Park.” – Jenn Beening

“Petunia, born on August 1 to mother Tanaya, weighed only 128 pounds (greater one-horned rhino calves usually weigh between 132 and 176 pounds at birth), so animal care staff had to keep a 24-hour watch on the newborn rhino. After growing and gaining some strength, Petunia was ready to leave her protected yard and meet the rest of the rhino family.”

“The young rhino seemed eager to explore her new habitat and kept up with her mother, following closely behind her as she observed other rhinos and animals living in the Asian Plains habitat.”

“Once widespread in Southeast Asia, the greater one-horned rhinoceros is now found only in India and Nepal. This species is listed as endangered by the International Union for Conservation of Nature. There are an estimated 3,250 greater one-horned rhinos remaining in the wild.” – San Diego Zoo

The Wilds Safari – Cumberland, Ohio.

Shamwair Game Reserve, South Africa.

A white rhino in Solio ranch, Kenya.

Woburn, England, United Kingdom.

Madikwe, South Africa.

“After spending days looking for these guys we were rewarded on a gray, misty, early morning and this guy was moving really fast. Severely hunted to almost extinction, this is one of a few left.” – Sandra’s Weeds

Paula Froelich from Yahoo Travel visited South Africa to meet the men fighting to save South Africa’s rhinos from poaching. Check out her video and explore 8 Ways to Save a Rhino Today.

This photo selection is inspired by the Rhino Pictures group.

To join this series, tweet @flickr with your favorite wildlife photos, and include the hashtag #WildlifeWednesday. And if you’d rather not tweet, simply include the same hashtag in your Flickr photo title, or tag it with WildlifeWednesday.

We look forward to seeing your contributions and featuring a new selection of your photo submissions every Wednesday here on our blog.

Previously featured for this series: Wildlife Wednesday: Marine mammals