My Rainbow Lorikeets. Dori is on the left, Lori is on the right. Almost identical they can be hard to tell apart if you don't know them.

The textbook average weight for a Rainbow Lorikeet is approximately 130 grams and they don’t tend to fluctuate much more than 5 grams away from their personal average weight unless there is something wrong. So if I were to tell you that my Rainbow Lorikeet “Lori” weighs 120 grams, would you think that’s something to worry about? Or how about my other Rainbow Lorikeet “Dori”? She weighs 155grams. Is she fat?

On paper, it looks like I have one underweight and one overweight bird. In reality, they live in the same aviary so they get exactly the same amount of exercise. They are both on the same (very healthy) diet. If you look at them, they’re extremely difficult to tell apart. Their body condition and size is pretty much identical. Neither of them have fluctuated more than 3 grams from those weights in over 2 years. Neither one of them is showing any signs of illness. Their current weights do not concern me at all, even though they’re both significantly different from their species’ average. Textbooks are a guide only they don’t always get it right.

Lori is on the left, Dori is on the right. Dori came to me unweaned, Lori adopted her. Even as a juvenile (why her colour is different) Dori quickly exceeded Lori's weight.

It’s important to realise that average species weight is quite possibly very different to your own bird’s healthy average weight. Many things can influence what a bird’s healthy weight might be. Different sexes, different sub species and different breeding lines may all have different average weights. A bird that had health issues when it was young may not have developed to be the same size as one who didn’t have issues. We’ve talked before about why weighing your bird could save your bird’s life. When weight dramatically changes, it’s one of the easiest ways to tell if something is wrong with your bird. It’s a good reason to make sure you’re aware of your own bird’s average and aren’t relying on generalised species weights to tell you when something is wrong.

So how do you tell if your bird is a healthy average weight? The answer isn’t necessarily actually found on the scales. The scales are mostly there to monitor changes in weight to help expose a hidden illness. The answer to whether or not your bird is a healthy average weight can be found in your bird’s body condition. The easiest way to do this is to look at the shape of your bird’s chest around its keel bone.

Transverse sections of a bird’s chest/pectoral muscles for 5 different body conditions: 1 - The chest is concave is shape 2 - The chest is has a flat contour line 3 - The chest is convex in shape 4 - The chest is semi-circular in shape 5 – The muscles extend beyond the keel bone

The keel bone runs down the centre of a bird’s chest and is represented in the above pictures by the black line in the centre of each picture.  A parrot that is a healthy weight should have a curved chest.  In terms of the pictures above most healthy parrots should be somewhere around or between body conditions 3 and 4.  Condition 5 is common enough in pet birds, but it is an overweight condition and poses some serious health risks.  Conditions 1 and 2 are underweight and if it were my bird I’d be very worried that the bird is either malnourished or has some sort of illness that is preventing the bird from gaining/holding its weight.

Some estimates say that a male Eclectus should average 430g. Pepi is one of the larger subspecies and consequently weighs a lot more than that estimate. His body condition would rank as a high 4 in the above pictures. 

At a checkup a vet would assess a bird’s body condition by examining the birds chest as described above.  The first step to solving weight issues is usually to get the bird’s diet right.  If you’re looking for help with that, check out the natural feeding course.  If your bird’s diet is healthy and you’re still concerned about your bird’s body condition I wouldn’t hesitate to take it to a vet and have the bird checked for illness or some advice on how to resolve any issues.

I have 4 galahs in my flock. Their weights range from 350g - 460g. Nemo (upper bird) weighs 40 grams less than Merlin (lower bird). Yet they look almost the same. 

It definitely helps if you have kept a journal of weights and to take it with you to any vet appointment so that the vet doesn’t have to compare to a generalisation. It wouldn’t hurt to keep a record of your bird’s body condition score (1-5) too.

Mel Vincent works as an animal rehabilitator out of Australia.