Waterfowl (ducks and geese) have a simultaneous molt of all primary flight feathers (10 in each wing) and thus are flightless in part of the summer (non breeding season). Thus, they tend to move to larger bodies of water in mid summer prior to this flightless period. Most major books on waterfowl describe the molt of the primaries. A good reference would be texts by Peter Pyle.

Yes, Clait E. Braun is right. Not only the primaries, but also the secondaries are molted simultaneously leaving the birds flightless until the new feathers come in. Ducks and other waterfowl are in Volume 2 of Pyle (there are two volumes), basically a bander's manual.

http://www.buteobooks.com/product/PYLE2.html

I quote Braun and Allen. The knowledge on moult in ducks started long time ago: Dean, W. R. J. 1978. Moult seasons of some Anatidae in the western Transvaal. Ostrich 49:76-84.

A recent work, Gehrold 2014 - Species-specific habitat use of wing-moulting waterbirds in response to temporary flightlessness. ,  may report some basic literature.

However, due to the simple strategy in respect to most of birds, you really will don't find dozens of works on moult in waterbirds. Rather, you can find ecological consequences of flightless periods. Also general handbooks on bird biology should be ok.

Also, take a look at BTO Guide 24 - Identification Guide to European Non-Passerines by Kevin Baker which gives reasonable summaries of moult for a range of non-passerines, including waterfowl.

Good suggestion, Matt. Just to be honest, some ageing criteria in that Guide are outdated, but general concepts on moulting will be useful to Mahdi Sadeghi.

Agreed Fabrizio, some of the ageing criteria in Baker's book are outdated but I considered that, overall, this would have little impact on the basic moult summary info for Mahdi

I think the BTO Guide 24 is out-of-print.

All of the responses are very helpful. Good luck with your studies.

      Clait

Thanks for all. Actually, I don't have access to mentioned book. By the way, I have read Dean, W. R. J. (1978) paper which not mention about the regrow sequences. How about the feathers regrow pattern after moulting? Are the primaries grow simultaneous like the moult?

Yes, replacement of primaries is also simultaneous but most waterfowl species can fly (somewhat poorly and for shorter distances) before the primaries are fully grown.

      Clait

Good. but how can I understand the molting effects (effects of molting in decrease heavy metals accumulation in feathers) in waterfowls by determine the heavy metals in adult in compare with the young species?

Ok, Mahdi, you are approaching an experimental study on metals in waterbird feathers. It is proved that the concentration in primaries decreases along the moult process only for Hg, and that the last grown feather is less enriched of Hg than the first one. For all other metals this pattern is not proved. Ducklings have simoultaneous feather growth (as all young birds), so, in theory, in young ducks you should measure the distal part of the feathers and compare such concentration with the concentration at the base of the feather, in order to assess if storing of metals decreases. The same in full adults, because the moult is again simultaneous. But you have the big challenge of external contamination (not bioaccumulated), normally higher on the tip. You should read a lot of literature on metals in feathers, more than articles on moult (very simple in ducks).

You may check the book Moult in Birds by Ginn and Melv (http://www.bto.org/volunteer-surveys/ringing/publications/moult-birds-ginn-and-melv).

Depends on the size of the bird and the condition of the bird how moult is developing. For example pelicans and cranes could have two generations primaries and secondaries.

Hi,

I reopen this discussion as I am trying to have some information about the duration of remex moulting in mallards. Specifically, it is possible to know how many days do the feathers take to growth from stage 1, just the calamus to stage 4, when 75% of the feathers is already grown? And how many days does the growth take in each stage (1,2,3,4)? I guess that growth should be aproximately linear.

Thank you in advance for help me out of this issue.

Best,

Gianluca