The tail is the headline entry every week
A fat-tailed gerbil's weekly diary leads with the tail, because in this species — also called the duprasi — the tail is a visible fuel gauge. A healthy, well-fed gerbil carries a plump, smooth tail; reserves are stored there, and a tail that looks thinner or more wrinkled than last week is information. Record it in plain words each week, ideally with a quick photo from the same angle, and pair it with a gram weight from a digital scale. Either measure alone can mislead; together, week on week, they show whether your gerbil is holding condition or quietly drawing on reserves, which is exactly the pattern a vet will ask about first.
Food, including the protein line
A fat-tailed gerbil's diary should record the seed or pellet base, the vegetables offered and eaten, and a specific line for protein foods — this species relishes insects and other animal protein more than many small pets, and intake there is worth tracking separately. Note appetite honestly: bowls emptied, food buried in the bedding, or food ignored. Sand-bath use belongs in the food-adjacent notes too, since a gerbil who stops rolling in his sand often shows a greasy, unkempt coat soon after, and the diary connects those two facts. Water gets a level check: mark the bottle weekly so a change in drinking is a comparison, not a guess.
Digging, tunnels and the state of the deep bedding
A fat-tailed gerbil is a burrower, so the diary should record the habitat work of the week: how deep the bedding is, whether tunnels are holding, and whether he is digging with his usual enthusiasm. Note bedding top-ups and any rearrangement, and how he responded — a gerbil who rebuilds immediately is a gerbil feeling well. Record full clean-outs precisely, because destroying a tunnel system and its scent marks is a real event in a burrowing animal's life, and spacing them deliberately is easier with dates in front of you. A week of little digging from a keen burrower is a behaviour change to write down the day you notice it.
Sleep notes — including the very deep kind
A fat-tailed gerbil can sleep extraordinarily deeply when cool, sometimes entering a torpor-like state where he feels cold and limp and wakes slowly. The diary should note room temperature alongside any episode of unusually deep sleep, how long he took to warm and move normally, and whether eating followed as usual. That record protects you both ways: it stops one cold nap becoming a panic, and it shows a vet the pattern if episodes multiply. Note his general rhythm too — this species is often active in bursts at dawn, dusk and through the night rather than in one block, and your entries define his personal normal.
Keep the whole run, for his whole life
A fat-tailed gerbil's past entries are worth keeping for his entire life rather than pruning them seasonally, because the questions this species raises are trend questions — is the tail thinner than spring, is the weight drifting, are the deep sleeps more frequent — and trends need the early baseline to be readable. A gerbil's diary stays small enough that keeping everything costs nothing. Any single alarming entry — a tail suddenly thin, weight dropping across two weeks, torpor episodes lengthening — is a prompt exotics-vet call, with the diary itself as the evidence you bring. Storing the full sequence in a KinsLe Pet Passport keeps your fat-tailed gerbil's tail, weight and sleep history together in one portable record.