Zoolife Photography.... i never really liked it before, but now that i've discovered it, im having incredible fun with it.
From the moment you have a child and they start to experience things consciously, it's really nice to get a subscription to a zoo. We did this and the first time we went to the zoo with our little one, we took our camera with us. The lens that I had with me at the time was totally not zoo-worthy due to its short range, namely the 24-105mm lens.
As you can imagine, I was a bit short on zoom range but still managed to take some nice shots.
Since I experienced this as very nice, I immediately looked for a telephoto lens and quickly found the Sigma 100-400 F5-6.3 DG DN OSS Contemporary. Not the most lightsensative lens, but with a awesome built-in image stabilizer. Most of the Zoolife photos on my website were shot with this lens.