The last hike that we did in Joshua Tree NP was a 3-mile (4.8 km) long hike to the 49 Palm Oasis. Anil decided not to go with us as his knees were hurting, and he was waiting for us next to the car. It was a hot day, so Bartek and I did not want him to wait for us for too long, so we did speed-hiking and were back at the parking lot in 1h 15min. Even though we hurried so much, we still saw many lizards, a beautiful green zebra snake, and several cacti.
Still, if you have time for only one longer hike in the park, I would recommend the Lost Palm Hike over this one. It seems the latter is less traveled, and probably that's why it is way easier to encounter animals there.
Some of the lizards that we met during our hike:
Chuckwallas are huge!
49 Palm Oasis:
A short, uncut, unedited movie shot during the hike (we are breathing heavily as we just walked up a bigger hill):