Stunning Nature Shots in 2013 National Geographic Traveler Photo Contest

It's that time again! National Geographic is calling out to all of the world's photographers to enter the 2013 National Geographic Traveler Photo Contest. Submit your photos in any or all of these four categories: Travel Portraits; Outdoor Scenes; Sense of Place; and Spontaneous Moments. (Love that last one.)

“Our photo contest turns 25 this year, making it, we believe, the longest-running travel photo contest in the world,” said Keith Bellows, National Geographic Traveler magazine editor in chief. “In the last few years it seems as if the quality of shots has taken a quantum leap forward. The pictures increasingly reflect a more sophisticated way of seeing and interpreting the world, making the judging process more difficult. We encourage photographers to enter their work and compete against the best.”

The contest is now open and will end on Sunday, June 30. The grand prize winner receives a once-in-a-lifetime trip! Ready for this? It's a 10-day National Geographic Expedition to the Galápagos for two aboard the National Geographic Endeavour. Photographers, that means you'll get up-close and personal with unique species like flightless cormorants, marine iguanas and domed giant tortoises.

Though the contest just kicked off, National Geographic has already received hundreds of amazing entries that could very well claim that top spot. Among the photo editor's picks, we were asked to select our favorites. Today, we're spotlighting the best nature photos submitted so far - from a hilarious photo of an chilled-out kangaroo to a stunning portrait of an iceberg. Check out our top 13 and then submit your best shots!

Above: Walk With Me

Photo and caption by Douglas Croft/National Geographic Traveler Photo Contest

It was amazing to watch several family groups of elephants around the river. The little ones run around and play like puppies, but the tiny ones stay very close to their mothers. We were fortunate to capture this magical moment with mother and baby.

Portrait of One Chilled Out Kangaroo

Photo and caption by Graham McGeorge/National Geographic Traveler Photo Contest

"Jeez Louise...Those cookies were good"

Portrait of an Eastern Screech Owl

Photo and caption by Graham McGeorge/National Geographic Traveler Photo Contest

Masters of disguise. The Eastern Screech Owl is seen here doing what they do best. You better have a sharp eye to spot these little birds of prey.

One Mother's Love

Photo and caption by Graham McGeorge/National Geographic Traveler Photo Contest

I love watching the affection and attention that Bonobos have for their young. They truly are a wonderful species of ape.

King of the Penquins

Photo and caption by Nancy Dowling/National Geographic Traveler Photo Contest

Taken at Booth Island in Antarctica.

Mount Erebus Ice Cave

Photo and caption by Alasdair Turner/National Geographic Traveler Photo Contest

A scientist climbs out of an ice cave formed by volcanic vents near the summit of Mt. Erebus, Antarctica.

The Power of the Criollo

Photo and caption by Chris Schmid/National Geographic Traveler Photo Contest

The power of the Criollo horses at the Cabanha Ipu„ located in Paran‡, Brazil. The Criollo is the native horse of Uruguay (1910), Argentina (1918), Brazil (1932) and Paraguay. It may have the best endurance of any horse breed in the world next to the Arabian.

The Galactic Squid

Photo and caption by Cameron Knudsen/National Geographic Traveler Photo Contest

While on a night dive in the waters off Okinawa, Japan, this reef squid showed up. The time and air I spent trying to get close to him paid off.

Goðafoss

Photo and caption by Joshua Holko/National Geographic Traveler Photo Contest

Goðafoss is one of the most spectacular waterfalls in Iceland. Located in the central north of the island, translucent aqua water cascades over the horseshoe shaped falls and races down the canyon. Icicles cling to its rock ledges and fresh snow lies across the landscape under soft diffuse light of the type that only Iceland can deliver.

Ghostly Waterfall

Photo and caption by Charlotte Ralph/National Geographic Traveler Photo Contest

This photo was taken from a boat of Stirling Falls at Milford Sound in New Zealand in April 2013. Lord of the Rings territory! I used a Canon 5D Mark III using a Canon EF 24-105mm f/4L IS lens and a polarizer. Details: f/5.6, 1/60, ISO 250, 0.7 EV, 50mm. Have you ever been right in front of a huge waterfall? It's ethereal and ghostly and I feel (and hope!) that this image captures that feeling. I couldn't use a tripod on the moving boat, but got exactly the shot I wanted.

Barranco Camp at Night, Kilimanjaro

Photo and caption by Trevor Booth/National Geographic Traveler Photo Contest

Barranco camp was our third on our seven-day hike to the summit of Mount Kilimanjaro. Taken after dinner, while the group was getting ready to get a good night's rest, before tackling infamous Barranco Wall in the morning.

Iceberg Beauty

Photo and caption by Nancy Dowling/National Geographic Traveler Photo Contest

Brilliant color reflected in an iceberg.

Door to Hell

Photo and caption by Priscilla Locke/National Geographic Traveler Photo Contest

Standing at the edge of the Darvaza Crater in Turkmenistan. Known as the Door to Hell, this flaming crater has been burning for decades, fueled by the rich natural gas reserves found below the surface.

2013 National Geographic Traveler Photo Contest website