Feather Moulting Sequence


Staff member
Feather molt sequence is easy really dependent on the species of bird owned naturally some birds are slightly different to others such as burrowing parrots are different to amazons which in turn are different to greys and then there is the difference between the “baby moult” and the adult full cycle moult.

The vast majority of parrots with a few exceptions have 10 primary feathers attached to what would be the human hand, 12 secondaries which are attached to what would be your forearm. The feathers are given numbers, the primaries are known by P numbers ie P1 to P10, with the P10 being the outermost feather called a distal feather and P1 the inner most one. The feathers that are known as Secondaries lay alongside the primaries running inwards with their numbers ie P1 has S1 alongside it so from the outside of the wing running to the inside of the wing where it joins the body it goes P10, P9, P8, P7, P6, P5, P4, P3, P2, P1, S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12. See diagram below of this rather cracking picture of a grey with all the little body anatomy parts labelled.
grey anatomy.jpg
The following picture shows you that the feathers from the right wing and the left wing mirror image each other and you can tell if it’s a right wing feather or a left wing feather as one side of the feather is longer than the other in the feathery bits that come away from the quill which is the central long white shaft area. You can see the feathers on the left arch one way with longer feathering one side and the ones on the right are a mirror image of them, left are left wing feathers and right are the right ones.
macaw feathers.jpg

Healthy parrots moult in a set way and this is very different from the moulting sequence in birds like hawks, ducks, foul and pheasants. With our parrots, a central primary, usually P6 is the first feather to be dropped from both wings and growth of the new replacement feathers start immediately. How long does it take to grow a feather in a healthy bird usually at a rather of between 3 to 4 mm a day. Okay so once this P6 is partially grown, P5 and sometimes its P7 will be moulted and start to regrow. Then numbers P3 and P7 this happens in both directions along both wings at the same time. When the bird finishes growing the majority of the primaries the bird starts to do the same with the Secondaries. The full moulting sequence for most parrots is as follows, brackets indicate feathers being moulted at the same time in pairs: P6, (P5+7) (P8+4) (P3+9) (P2+10) P1. Then the Secondaries: S1, straight through to S12 at the end of the moult. The birds do it this way so they can continue to fly and are not grounded. Ok so the number P1 refers to primary feather in position one and S1 secondary feather in position one in case your confused with the P and S being in front of the numbers

feather numbers.gif
Right so that’s the Primaries and Secondaries covered. The feathers above those are called the coverts these are called minor coverts and major coverts and the lovely dinky ones that trim the edge are sometimes called the antebrachial coverts.

Right on to the other stuff! A healthy bird will not moult more than 3 feathers from the wing at once. Since the rate of growth is much the same in parrots, regardless of their size, large birds take longer to replace all their flight feathers. It may take a large macaw or cockatoo more than 18 months to complete a full moult. But a small parakeet can take less than 3 months to do the same sequence.

There is another document on this site reference moulting one which is more in the determination of whether a feather is shed naturally or not. https://theparrotclub.co.uk/community/index.php?threads/feathers.15107/

Basically depending on the species of bird you own the feathers moult in opposite pairs on the wings so that the bird always is able to fly. An odd damaged feather is replaced faster than others more especially if it is removed it will be replaced faster.

A wing clipped bird due to the imbalance of the clipping removal of weight takes longer to replace the feathers and more feathers are damaged and it’s a vicious cycle when a bird is clipped incorrectly.

Each feather has a group name and a number in its location the under-down doesn’t its just basically the stuff that keeps your bird warm and is used as a shock absorber.

Amazon parrots are slightly different they don’t have the oil glands nor do they have the gall bladder of other birds of their topographic genome!! Lets just say they are individuals lol.

Moulting can take time and also be dependent on the nutrition, temperature, amount of natural uva/uvb light and a number of other things such as age and general wellness of the bird.

For a bird to synthesize enough D3 from broad-spectrum light to perform correct absorption of the calcium takes a minimum exposure of daylight (not sunshine) outside of approximately 40 minutes indoors under uva/uvb lighting the same however to keep your bird at its optimum levels its always better to endure that the bird has access to broad-spectrum as and when it desires or for a minimum of 4 hours a day structured throughout the day. I just leave my uva/uvb lights on its easier!!

Here are references to a couple of really good reads below. The best read I have had for a while was the restudy of the molting of parrots by Howell et al. (2003) if you can get access to it and read it it will tell you everything you ever wanted to know and a heap load besides….errrr the terminology does get a bit “thick and syrupy” at times though be warned!

Distribution of unique red feather pigments in parrots by Kevin J McGraw & Mary G Nogare

]“In many birds, red, orange and yellow feathers are coloured by carotenoid pigments, but parrots are an exception. For over a century, biochemists have known that parrots use an unusual set of pigments to produce their rainbow of plumage colours, but their biochemical identity has remained elusive until recently. Here, we use high-performance liquid chromatography to survey the pigments present in the red feathers of 44 species of parrots representing each of the three psittaciform families. We found that all species used the same suite of five polyenal lipochromes (or psittacofulvins) to colour their plumage red, indicating that this unique system of pigmentation is remarkably conserved evolutionarily in parrots.

Species with redder feathers had higher concentrations of psittacofulvins in their plumage, but neither feather coloration nor historical relatedness predicted the ratios in which the different pigments appeared. These polyenes were absent from blood at the time when birds were replacing their colorful feathers, suggesting that parrots do not acquire red plumage pigments from the diet, but instead manufacture them endogenously at growing feathers.”

Ibis International Journal Of Avian Medicine

]In captive Budgerigars Melopsitticus undulatus moult of primaries started in the middle of the tract and moved progressively inwards and outwards, the inner feathers being replaced faster than the outer ones. Full replacement of primaries took six to eight months and a new cycle of moult usually started before completion of the old cycle. Molt of secondaries followed no clear pattern and occurred less frequently than molt of primaries. Molt of rectrices started with the middle pair and moved progressively outwards on both sides. Complete molt of rectrices took about six months and a new cycle often started before completion of the old. Molt of the head and body occurred intermittently throughout the year. Birds fledged in juvenal plumage, they passed into first basic plumage with a partial molt (head and body feathers) and into definitive basic plumage with a molt of all contour feathers.

In the field in inland mid-eastern Australia, there were some birds replacing feathers and some with complete plumage in most months of the year. Birds with complete plumage may have been between molts or within a molt and between replacement of feathers. The proportion of birds in molt did not increase in intensity after breeding, or cease during breeding or before movements. Some birds of both sexes with gonads in a reproductive condition were replacing feathers. Birds that were replacing feathers had similar lipid deposits to birds that had a complete plumage.

Below is the feather structure of an outer feather (not the inner fluffy heat retaining ones) so you can see how its actually held together with little barbs that hook over each other to make the feather hold shape and how it attaches into the skin from where it’s grown.
feather structure.jpg
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