How do you make sure that your birds eat enough?
The weight of a bird is not necessarily the best or sole indicator to be used, when it comes to a proper health assessment. If you have got only a few resident or tame birds, or birds who are used to be handled, then you can certainly weigh them, or train them to weigh themselves. If you have got more birds to care for, or wild birds to be released at some point, then it is not practical and also not advisable to weigh them to often. Trying to catch birds in an aviary environment can cause more damage than good, unless there is concern that something is wrong. Even if we do catch a bird, we do not always weigh her or him. However, we always check the keel bone and breast muscles, which is the better indicator for nutritional condition and sufficient physical exercise, and is not dependent on how small or big a bird is, as there is quite often a considerable interspecies variation in size. However, hospitalised or nestling birds will be weight regularly to monitor sufficient weight gain, development and treatment response.
It is useful to observe birds regularly and closely, ideally without being noticed. One should monitor how the birds behave, how alert they are, how they interact, fly, socialise and preen. From the distance one can check the plumage condition, how the eyes look like and how birds eat. One should also check droppings and pellets, which will indicate if a bird eats enough. Droppings can also be easily analysed for parasites like worms or coccidia eggs.
It is also worth noting that food consumption can vary quite considerably. This can depend on the time of the year, weather, moulting, enrichment, mood and other factors. We feed our corvids once a day, and only during daylight hours. Then all food gets removed. They still have their food caches, if they want to eat more. Occasionally, we top food up at around noon, in particular when our birds have a phase, where they eat larger amounts.