Alibardi, L. 2009. Follicular patterns during feather morphogenesis in relation to the formation of asymmetric feathers, filoplumes and bristles. Italian Journal of Zoology 76: 279-290.

Alibardi, L., and R.H. Sawyer 2006. Cell structure of developing downfeathers in the zebrafinch with emphasis on barb ridge morphogenesis. Journal of Anatomy 208: 621-642.

Anonymous. Learn about birds: Feathers and Pumages: Molting. (The Cornell Lab of Ornithology).

Arenholtz, A. 2001 Identifying the sub-adult Bald Eagle. Friends of the Bosque Newsletter 8: 1-3.

Arroyo, B.K., J.R. 1996. Age and sex differences in molt of the Montagu’s Harrier. Journal of Raptor Research 30: 224–233.

Austin-Smith, P. 1985. Current status of Bald Eagles in Nova Scotia. In J.M. Gerrard and T.N. Ingram (eds.) The Bald Eagle in Canada: Proceedings of Bald Eagle Days, Winnipeg, August 18-20, 1983 (White Horse Plains Publishers and Eagle Foundation: Headingley, Manitoba and Apple River, WI), pp. 39-43.

Bachmann, T.W. 2010. Anatomical, morphometrical and biomechanical studies of Barn owls’ and Pigeons’ wings. Ph.D. dissertation, Aachen University.

Billington, M., and J. Payne n.d. A microscopic look at contour feathers from a Bald Eagle, Barn Owl, Peregrine Falcon, and a Blue and Yellow Macaw. The Raptor Center, University of Minnesota’s College of Veterinary Medicine.

Bloom, P.H., and W.S. Clark 2001. Molt and sequence of plumages of Golden Eagles and a technique for in-hand ageing. North American Bird Bander Jul.-Sept.: 97-116.

Bluhm, C.K. 1988. Temporal patterns of pair formation and reproduction in annual cycles and associated endocrinology in waterfowl. Current Ornithology 5: 123-185.

Bortolotti, G.R. 1984. Age and sex size variation in Golden Eagles. Journal of Field Ornithology 55: 54-66.

——— 1984. Criteria for determining age and sex of nestling Bald Eagles. Journal of Field Ornithology 55: 467-481.

Bortolotti, G.R., R.D. Dawson, and G.L. Murza 2002. Stress during feather development predicts fitness potential. Journal of Animal Ecology 71: 333-342.

Bortolotti, G.R., and V. Honeyman 1985. Flight feather molt in breeding Bald Eagles in Saskatchewan. In J.M. Gerrard and T.N. Ingram (eds.) The Bald Eagle in Canada: Proceedings of Bald Eagle Days, Winnipeg, August 18-20, 1983 (White Horse Plains Publishers and Eagle Foundation: Headingley, Manitoba and Apple River, WI), pp. 166-179.

Bortolotti, G.R., T. Marchant, J. Blas, and S. Cabezas 2009. Tracking stress: localisation, deposition and stability of corticosterone in feathers. Journal of Experimental Biology 212: 1477-1482.

Brodkorb, P. 1948-1949. The number of feathers in some birds. Quarterly Journal of the Florida Academy of Sciences 11-12: 241-245.

——— 1955. Number of feathers and weights of various Systems in a Bald Eagle. The Wilson Bulletin 67: 142.

Brommer, J.E., Pihlajamäki, O., Kolunen, H. & Pietiäinen, H 2003. Life-history consequences of partial moult asymmetry. Journal of Animal Ecology 72: 1057–1063.

Buehler, D.A. 2022. Bald Eagle (Haliaeetus leucocephalus). Birds of the World, ed. P.G. Rodewald and S.G. Mlodinow (Cornell Lab of Ornithology).

Chandler, R.M., Pyle, P., Flannery, M.E., Long, D.J. & Howell, S.G.354–360 2010. Flight feather molt of turkey vultures. The Wilson Journal of Ornithology 122: 354–360.

Cieslak, M.K., Z. 2009. Moult and breeding of captive Northern Hawk Owls Surnia ulula. Ardea 97: 571–579.

Clark, W.S. 1983. The field identification of North American eagles. American Birds 37: 822-826.

——— 1983. The field identification of North American eagles. American Birds: 822-826.

——— 1996. Ageing Steppe Eagles. Birding World 9: 269-274.

——— 2001. Aging Bald Eagles. Birding February: 19-28.

——— 2004. Wave moult of the primaries in accitripid raptors, and its use in ageing immatures. In R.D. Chancellor and B.-U. Meyburg (eds.) Raptors Worldwide: Proceedings of the 6th World Conference on Birds of Prey and Owls, May 2003, Budapest, Hungary (World Working Group on Birds of Prey and owls: Berlin), pp. 795-804.

——— 2007 Raptor identification, ageing, and sexing. In D.M. Bird and K.L. Bildstein (eds.) Raptor Research and Management Techniques (Institue for Wildlife Research, National Wildlife Federation: Washington, DC), pp. 47-55.

Compton, L.V. 1938. The pterylosis of the Falconiformes with Special Attention to the Taxonomic Position of the Osprey. University of California Publications in Zoology (University of California Press: Berkeley, CA).

Dawson, A. 1997. Plasma-luteinizing hormone and prolactin during circannual rhythms of gonadal maturation and molt in male and female European Starlings. Journal of Biological Rhythms 12: 371-377.

——— 2008. Control of the annual cycle in birds: endocrine constraints and plasticity in response to ecological variability. Philosophical Transactions of the Royal Society of London B: Biological Sciences 363: 1621-1633.

Dietz, M.W., Rogers, K.G. & Piersma, T. 2013. When the seasons don’t fit: speedy molt as a routine carry-over cost of reproduction. PLoS ONE 8: e53890.

Edelstam, C. 1984. Patterns of moult in large birds of prey. Annales Zoologici Fennici 21: 271-276.

——— 2010. Raptor moult patterns and age criteria. In D.A. Christie and J. Ferguson-Lees (eds.) Raptors of the World (A.C. Black: London), pp. 50-53.

Ellis, D.H., V.G. Rohwer, and S. Rohwer 2016. Experimental evidence that a large raptor can detect and replace heavily damaged flight feathers long before their scheduled moult dates. Ibis 159: 217-220.

Espie, R.H., James, P.C., Warkentin, I.G. & Oliphant, L.W. 1996. Ecological correlates of molt in Merlins (Falco columbarius). Auk 113: 363–369.

Gerrard, J.M., and T.N. Ingram 1985. The Bald Eagle in Canada: Proceedings of Bald Eagle Days, Winnipeg, August 18-20, 1983 (White Horse Plains Publishers and Eagle Foundation: Headingley, Manitoba and Apple River, WI).

Gerrard, J.M., D.W.A. Whitfield, P. Gerrard, P.N. Gerrard, and W.J. Maher 1978. Migratory movements and plumage of subadult Saskatchewan Bald Eagles. Canadian Field-Naturalist 92: 375-382.

Gill, F.B. 2007. Feathers. In Ornithology (W. H. Freeman and Company: New York), Ch. 4, pp. 79-113.

Ginn, H.B.M., D.S. 2000. Moult in birds. BTO Guide (Norwich, U.K.).

Hanson, T. 2011. Feathers: The Evolution of a Natural Miracle (Basic Books: New York).

Harris, M.P., J.F. Fallon, and R.O. Prum 2002. Shh-Bmp2 signaling module and the evolutionary origin and diversification of feathers. Journal of Experimental Zoology 294: 160-176.

Hedenström, A. 2006. Scaling of migration and the annual cycle of birds. Ardea 94: 399–408.

Henny, C.J., R.A. Olson, and T.L. Fleming 1985. Breeding chronology, mol, and measurements of Accipiter hawks in northeastern Oregon. Journal of Field Ornithology 56: 97-112.

Herremans, M. 2000. The “chaotic” flight feather moult of the Steppe Buzzard Buteo buteo vulpinus. Bird Study 47: 332–343.

Hörnfeldt, B., Carlsson, B-G. & Nordström, A. 1985. Molt of primaries and age determination in Tengmalm’s Owl (Aegolius funereus). Auk 105: 783–789.

Houston, D.C. 1975. The moult of the Whitebacked and Rüppell’s Griffon Vultures Gyps africanus and G. rueppellii. Ibis 117: 474–488.

Howell, S.N.G. 2003. All you ever wanted to know about molt but were afraid to ask, Part I: the variety of molt strategies. Birding October: 490-496.

——— 2003. All you ever wanted to know about molt but were afraid to ask, Part II: finding order amid the chaos. Birding December: 640-650.

Howell, S.N.G. 2010. Peterson Reference Guide to Molt in North American Birds (Houghton Mifflin Harcourt Company: Boston, MA).

Humphrey, P.S., and K.C. Parkes 1959. An Approach to the Study of Molts and Plumages. Auk 76: 1-31.

Iñigo, Z., Z. Jabi, and M. José Enrique 2018. Moult in birds of prey: a review of current knowledge and future challenges for research. Ardeola 65: 183-207.

Jenni, L., K. Ganz, P. Milanesi, and R. Winkler 2020. Determinants and constraints of feather growth. PLoS ONE 15: e0231925.

Jiang, T.-X., R.B. Widelitz, W.-M. Shen, P. Will, D.-Y. Wu, C.-M. Lin, H.-S. Jung, and C.-M. Chuong 2004 Integument pattern formation involves genetic and epigenetic controls: feather arrays simulated by digital hormone models. International Journal of Developmental Biology 48: 117-136.

Johnson, L.G. 1968. Endocrine influences on growth and pigmentation of embryonic down feather cells. Journal of Embryology and Experimental Morphology 20: 319-327.

Jollie, M. 1947. Plumage changes in the Golden Eagle. Auk 64: 549-576.

Kaiser, G.W. 2007. Inner Bird: Anatomy and Evolution (UBC Press: Vancouver, BC).

Kang, S.-G., and W.-H. Hur 2016. New moult pattern in diurnal raptors: primary moult pattern of the Japanese Sparrowhawk Accipiter gularis. Ringing and Migration 32: 28–36.

Krüger, O. 2005. The evolution of reversed sexual size dimorphism in hawks, falcons and owls: a comparative study. Evolution and Ecology 19: 467–486.

Liguori, J. 2004. How to age Golden Eagles. American Birding 2004: 278-283.

Lovette, I.J., and J.W. Fitzpatrick (eds.) 2016. Handbook of Bird Biology, 3rd ed. (Cornell Lab of Ornithology: Ithaca, NY).

Lucas, A.M., and P.R. Stettenheim 1972. Avian Anatomy: Integument Part I. Agriculture Handbook (U.S. Department of Agriculture: Washington, DC). 2 vols.

——— 1972. Avian Anatomy: Integument Part II. Agriculture Handbook (U.S. Department of Agriculture: Washington, DC). 2 vols.

McCollough, M.A. 1989. Molting sequence and aging of Bald Eagles. The Wilson Bulletin 101: 1-10.

Miller, A.H. 1941. The significance of molt centers among the secondary remiges in the falconiformes. The Condor 43: 113-115.

Newton, I. 1979. Population Ecology of Raptors (T. & A. D. Poyser Ltd. and Buteo Books: Berkhamsted, Hertfordshire, England and Vermillion, SD).

Newton, I. 2009. Moult and plumage. Ringing & Migration 24: 220–226.

Newton, I., and M. Marquiss 1982. Moult in the Sparrowhawk. Ardea 70: 163–172.

Nitzsch, C.L., W.S. Dallas, and P.L. Sciater 1867. Nitzsch’s Pterylography, tr. from the German. Ed. by Philip Lutley Sclater.

Palmer, R.S. 1972. Patterns of molting. In D.S. Farner, J.R. King and K.C. Parkes (eds.) Avian Biology (Academic Press: New York and London), II, Ch. 2, pp. 65-102.

——— 1988. Bald Eagle Haliaeetus leucocephalus (Linnaeus). In R.S. Palmer (ed.) Handbook of North American Birds: Diurnal Raptors (Part 1): Family Cathartidae, New World Condors and Vultures; Family Accipitridae (first part), Osprey, Kites, Bald Eagle and allies, Accipiters, Harrier, buteo allies (Yale University Press: New Haven, CT), pp. 187-237.

Paris, P. 1913 Recherches sur la glande uropygienne des oiseaux. Archives de zoologie expérimentale et générale 53: 139-276.

Payne, R.B. 1972. Mechanisms and control of molt. In D.S. Farner, J.R. King and K.C. Parkes (eds.) Avian Biology (Academic Press: New York and London), II, Ch. 3, pp. 104-155.

Pietiäinen, A., Saurola, P. & Kolunen, A. 1984. The reproductive constraints on molt in the Ural Owl (Strix uralensis). Annales Zoologia Fennici 21: 277–281.

Pittaway, R. 2000. Plumage and molt terminology. Ontario Birds 18: 27-43.

Prevost, Y. 1983. Moult in the Osprey Pandion haliaetus. Ardea 71: 199–209.

Proctor, N.S., and P.J. Lynch 1993. Manual of Ornithology: Avian Structure & Function (Yale University Press: New Haven).

Prum, R.O. 1999. Development and Evolutionary Origin of Feathers. Journal of Experimental Zoology 285: 291-306.

——— 1999. Development and evolutionary origin of feathers. Journal of Experimental Zoology 285: 291-306.

Prum, R.O. 2005. Evolution of the morphological innovations of feathers. Journal of Experimental Zoology, Part B: Molecular and Developmental Evolution 304: 570-579.

Prum, R.O., and A.H. Brush 2002. The evolutionary origin and diversification of feathers. The Quarterly Review of Biology 77: 261-295.

——— 2003. Which came first, the feather or the bird? Scientific American 288: 84-93.

Prum, R.O., and J. Dyck 2003. A hierarchical model of plumage: morphology, development, and evolution. Journal of Experimental Zoology 298B: 73-90.

Pyle, P. 2005. First-cycle molts in North American falconiformes. Journal of Raptor Research 39: 378–385.

——— 2005. Remigial molt patterns in North American falconiformes as related to age, sex, breeding status, and life-history strategies. The Condor 107: 823–834.

——— 2006. Staffelmauser and other adaptative strategies for wing molt in larger birds. Western Birds 37: 179–185.

Rohwer, S. 2008. A primer on summarizing molt data for flight feathers. The Condor 110: 799–806.

Rohwer, S., Ricklefs, R.E., Rohwer, V.G. & Copple, M.M. 2009. Allometry of the duration of flight feather molt in birds. PLoS Biology 7: e1000132.

Rohwer, V.G., and S. Rohwer 2013. How do birds adjust the time required to replace their flight feathers? Auk 130: 699–707.

Schumtz, J.K. 1992. The molt of flight feathers in Ferruginous and Swainson’s hawks. Journal of Raptor Research 26: 124–135.

Snyder, N.F.R., Johnson, E.V. & Clendenen, D.A. 1987. Primary molt of California Condors. The Condor 89: 468–485.

Solheim, R. 2012. Wing feather moult and age determination of Snowy Owls Bubo scandiacus. Ornis Norvegica 35: 48-67.

Southern, W.E. 1967. Further comments on subadult Bald Eagle plumage. The Jack-Pine Warbler 45: 70-80.

Stalmaster, M.V. 1987. The Bald Eagle (Universe Books: New York).

Terrill, R.S. 2018. Feather growth rate increases with latitude in four species of widespread resident Neotropical birds. Auk 135: 1055-1063.

Trail, P.W. 2003. Identification of Eagle Feathers and Feet. In Identification Guides for Wildlife Law Enforcement. Ashland, OR: USFWS National Fish and Wildlife Forensics Laboratory.

Tucker, V.A. 1991. The effect of molting on the gliding performance of a Harris Hawk (Parabuteo unicinctus). Auk 108: 108–113.

Vincent-Martin, N., and C. Ponchon 2013. Some elements for the help to the identification of the age of Bonelli’s Eagles Aquila fasciata (Vieillot, 1822). Nature de Provence – Revue du CEN PACA 2: 71–78.

Wegner, P.K., G. 2016. Can we reliably identify arctic Peregrine Falcons wintering in Central Europe? Ornitholische Jh. Bad.-Württ 32: 53–62.

Wingfield, J.C., J.D. Jacobs, A.D. Tramontin, N. Perfito, S. Meddle, D.L. Maney, and K. Soma 1999. Toward an ecological basis of hormone-behavior interactions in reproduction of birds. In K. Wallen and J.E. Schneider (eds.) Reproduction in Context: Social and Environmental Influences on Reproduction (The MIT Press: Cambridge, MA), pp. 85-128.

——— 1999. Toward an ecological basis of hormone-behavior interactions in reproduction of birds. In K. Wallen and J.E. Schneider (eds.) Reproduction in context (The MIT Press: Cambridge, MA), pp. 85-128.

Wingfield, J.C., and B. Silverin 2009. Ecophysiological studies of hormone–behavior relations in birds. In D.W. Pfaff, A.P. Arnold, A.M. Etgen, S.E. Fahrbach and R.T. Rubin (eds.) Hormones, Brain and Behavior. 2nd ed. (Academic Press: San Diego), Ch. 24, pp. 817-855.

Wolfe, J.D., Johnson, E.I. & Terrill, R.S. 2014. Searching for consensus in molt terminology 11 years after Howell et al. “first basic problem.” Auk: Ornithological Advances 131: 371–377.

Woodward, A.M. 2023. Morphometrics as a tool for the species identification of North American Bald and Golden Eagle primary feathers. Journal of Raptor Research 57: 468-474.

Ydenberg, R.C., Butler, R.W. & Lank, D.B. 2007. Effects of predator landscapes on the evolutionary ecology of routing, timming and molt by long-distance migrants. Journal of Avian Biology 38: 523–529.

Yue, Z., T.X. Jiang, R.B. Widelitz, and C.M. Chuong 2005. Mapping stem cell activities in the feather follicle. Nature 438: 1026-1029.

Zuberogoitia, I., Martínez, J.A., Zabala, J., Martínez, J.E., Castillo, I. & Hidalgo, S. 2005. Sexing, ageing and moult of Common Buzzards Buteo buteo in a southern Europe area. Ringing and Migration 22: 153–158.

Zuberogoitia, I., Alonso, R., Elorriaga, J., Palomares, L.E. & Martínez, J.A. 2009. Moult and age determination of Eurasian sparrowhawk Accipiter nisus in Spain. Ardeola 56: 241–251.

Zuberogoitia, I., De la Puente, J., Elorriaga, J., Alonso, R., Palomares, L.E. & Martínez, J.E. 2013. The flight feathers molt of Griffon Vultures Gyps fulvus and associated biological consequences. Journal of Raptor Research 47: 292–303.

Zuberogoitia, I., Gil, J.A., Martínez, J.E., Erni, B., Aniz, B. & López-López, P. 2016. The flight feather moult pattern of the bearded vulture (Gypaetus barbatus). Journal of Ornithology 157: 209–217.