The Changing Plumage of the King vultures

The king vulture (Sarcoramphus papa) goes through several plumages before acquiring its familiar adult plumage. Birds in various stages of molting can be confusing. This article provides illustrations and a brief explanation to help you determine the age and properly identify young and immature king vultures.

King Vulture Plumage

Variation in the plumage of vulture species is largely unexplained. What are the reasons for differences in plumage patterns and why do some species have a single plumage while others undergo multiple molts to achieve the adult plumage? 

Although we do not yet know all of the answers, the identification of plumage pattern variation among king vultures marks the beginning of our understanding of how to identify them.

Generally, people are used to the single plumage of most vultures, but they are surprised at how the king vulture’s plumage changes between the juvenile and adult stages.

King vulture plumage types

King vultures exhibit three types of plumages including:

  • The natal plumage of a young king vulture is that it wears while it is in the nest from the time it hatches until several weeks later. Almost all bird natal plumages are made of down.  
  • The juvenile plumage replaces the natal plumage (coat of down). After fledging, most birds leave their nest in their juvenile plumage and keep it for about a year. 
  • The basic plumage is the mature plumage of many birds. King vultures have multiple plumages before acquiring their adult basic plumage. Basic I, II, and III in this context refer to plumages before the definitive basic. 

After fledging, king vultures acquire the more familiar adult plumage after 4 to 5 years. There are several kinds of plumage that birds go through before they acquire a definitive basic plumage. Here you will find illustrations and a brief description to help you figure out how to tell the possible age of a king vulture.

Hours after hatching

At hatch, chick king vultures have a white coat of down. The unfeathered head and neck are dark with pink tones. The feet are pink. Within a week or so, the head and neck turn black. 

Chicks hatch with their eyes semi-open and are only able to half stand on their elbows. The first coat of down is thin and the parents need to brood the young through the first two weeks.


Hatching through the 4th week

In the first two weeks, the chick grows rapidly and the thin coat of down becomes more noticeable. Within the first two weeks, the young vulture begins to grow a second thicker and whiter coat of down. During the first 4 weeks after hatching, the chick begins to stand on its feet and take short steps.


Weeks 4 through 8

The young king vulture has developed a new layer of down. It is able to comfortably stand up and walk around the nest area.

Within this period the chick begins to grow its flight feathers (pins), which are not visible yet under the thick coat of down. By the seventh week, the tail feathers (rectrices) begin to emerge under the coat of down.
Photo: ~Ealasaid~


Week 9 through 15

Between weeks 9 and 15th, the wing feathers, wing coverts, and tail feathers have emerged and are visible. The body (contour) feathers are also emerging but are still under the coat of down.

Through this period, the chick gains size and weight, and the black juvenile plumage continues to become more visible.
Photo: Leandro Moreira.


Fledging through the first year

By approximately week 19 the juvenile leaves the nest in the black juvenile plumage. Some white tufts of down may still pesist. The juvenile plumage is all black with white mottling on the thighs and on the underside of the wings, which is noticeable in flight. The unfeathered neck and head are black. The beak is dark reddish.
Photo: Danilo Mota.


Basic-I plumage – second year

By end of the first year the juvenile vulture begins to replace its breast and belly feathers. By the end of the second year, the breast and belly are mostly white with scattered black mottling.

The back and wing coverts are still dark. The neck and beak begin to show colors. The iris also change color. The wattle grows bigger but it is still dark.
Photo: Raul Vega.


Basic II plumage – third-year

By the end of the 3rd year, the sub-adult king vulture has a pure white breast and belly. The underside of the wings is mostly white. The back is still solid black. 

The neck, head, and beak colors become more saturated. The wattle begins to change colors. The iris becomes paler.
Photo: Christian Sanchez.


Basic III plumage – fourth-year

By the end of the fourth year, the back and wing coverts are mostly white with black mottling. The ruff turns lighter gray and appears to reduce in size exposing more of the neck.

The head has the appearance of an adult bird. The yellow and orange on the neck are bright. The bald crown is red, beak color, and yellow-orange wattle are indistinguishable from those of an adult bird.
Photo: Jose Illanes.


Fifth Year – Definite basic (adult) plumage

By the end of the fifth year, a king vulture has acquired the adult plumage. Some individuals may still have some dark mottling in the back into the 6th year. Male and female king vultures have the same plumage.

The adult plumage will be the same for the rest of the bird’s life without a noticeable variation in breeding and nonbreeding seasons.
Photo: Raul Vega.

Conclusions:

Despite their size and striking appearance, little is known about the king vulture’s breeding habits and aspects of its plumage and natural history.

A handful of publications about the nesting biology of the species provide most of the information for this article.

As a result of the recent availability of photographic material shared on social networks and citizen science websites, we are beginning to understand some aspects of the king vulture’s natural history.

References:

  • Carvalho Filho, E.P.M., Zorzin, G. and Specht, G.V.A. (2004). Breeding biology of the King Vulture (Sarcoramphus papa) in southeastern Brazil. Ornitología Neotropical. 15(2): 219-224.
  • Holste, M., J. M. Ruth, and J. C. Eitniear (2020). King Vulture (Sarcoramphus papa), version 1.0. In Birds of the World (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA.
  • Wallace, M.P., and S.A. Temple. 1987. Competitive interactions within and between species in a guild of avian scavengers. Auk 104: 290-295.