From ancient trees and strange sea slugs to odd and adorable insects plus more, our most popular reader's photos of the year are a tribute to Mother Nature.
Readers submit nature photos to our Flickr pool and by email – and our readers are really talented. Photos come from all over the world and feature everything from the vast night sky to the minutiae of an insect's antennae. Each one is a wonder unto itself. While there are no bad ones, the following ten were extra great ... and earned the most views over the course of the year. Which one is your favorite?
Click on the image to read more about each photo.
20. Sea otter saves the day
19. The Needles at sunset
8. Baby stick insect proves that Mother Nature is a mad genius (video)
17. Every circle is a tiny animal
16. Fuzzy bee sleeps in a flower© marlin harms / Flickr
15. Pika gathers up the grass
14. Pirate spider or alien, you decide
13. Beautiful ravens show off their smarts
12, How are seashells formed?
11, Why are cardinals so conspicuous?
10. White Mountains hold an ancient secret
9. 170-year-old fig tree is a majestic beauty
8. Rainforest hoverfly has crazy moves (video)
7. See the tortoise beetle's adorable walk (video)
6. Sideways glance, owl-style
5. Meanwhile in Sweden...
4. Seagoing slug proves truth is stranger than fiction
3. Spiny devil katydid is strange and adorable
2. Jackrabbit isn't a rabbit at all
1. This is what the world's oldest tree looks like
Would you like to see your nature photo featured as the TreeHugger photo of the day? Join TreeHugger’s Reader Photo Pool on Flickr and add your pictures to the group. Alternatively, send it to firstname.lastname@example.org with "photo of the day" in the subject line.