Around the end of February 2017 the developers introduced a new type of timed quest challenge.

These challenges are prompted by a player reaching a particular level of experience in the game. Also, if a player has reached that level before the challenge is introduced, they will automatically be prompted to do the challenge.

Please report any new information in the comments section of this page.
LevelTimed Quest
25Rare Animals
26Wolf Pack
27The Arrival of Gorillas
28Spiny Animal
29Cat Paths
30Colorful Birds
33Four Legs
35Health Challenges (Series of 6)
36Biology Lesson
37Circus Act
38Rabbit Recon
40Animal love
41Fluffy Visit
43Snail Family
44Rabbit Family
45New Species
46Llama Family
47Lost Things
48Insect Collection
50Something Smells
51Festival of Colors
52Water Birds
53Ice-Breaking Party
54Crane Family
55Unusual Trees
56Boat Race
57Colorful Hedgerows
58Equipment for the Fire Department
59Chocolate Animals
60Raccoon Family!
61Music Bands
62Bear Family
63The Flower Guardians
64Australian Animals
65Iced Tea Stand
66Talent Show
67Turtle Family
71Seal Family
72Crocodile Family
73Book Fair
74Clothes Store
75Lemur Family
76Stationery Shop
77Sport Is Healthy
78Jelly Bean Shop