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Cited by 1melanin and skin pigmentationAvian ecology and behaviorBird parasitology and diseases

Colour Abberations in African Penguins Spheniscus Demersus

Open access
Traisnel, Gwendoline, Pichegru, Lorien, Visser, Henvik, Edwards, Lloyd·2018·Marine Ornithology
DOI 10.5038/2074-1235.46.1.1243
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Abstract

Colour aberrations in African Penguins Spheniscus demersus.Marine Ornithology 46: 19-22.Colour aberrations among wild birds are of long-time interest because they are uncommon, particularly in seabirds, although recent publications have revealed varying forms of aberrations in cormorants and penguins.In African Penguins Spheniscus demersus, there have been previous sightings of abnormal plumages, particularly in Algoa Bay, South Africa.This paper reveals new cases of plumage aberrations in African Penguins: leucism, "brown," and phaeomelanism, all within Algoa Bay.While all aberrations seemed of natural origin, one in the shape of a number eight may have resulted from human actions.

AI snapshot

Written from the paper’s full text.

TL;DR

This paper reports new cases of plumage aberrations—phaeomelanism, “brown,” and leucism—in African Penguins in Algoa Bay, South Africa, observed opportunistically between 2009 and 2017. Most appeared natural in origin, but one white figure-eight mark on a penguin’s back was thought likely to result from human action.

Key findings

  • Two unusual “blues” (fledgling-stage penguins) on St. Croix Island in 2011 showed reddish-brown colouration, possibly phaeomelanism; no parent was sighted, and it is unknown whether they retained the abnormal colour as adults.
  • Two “brown” penguins were sighted: one on St. Croix in 2009 and 2010 and possibly Bird Island in 2011, and another on Bird Island in 2017. The 2017 adult had a bleached gold-brown body, darker head, and two dark dots above the right eye; conspecifics showed no aggression toward it.
  • Leucism cases included a 2013 incubating bird with breast and face almost entirely white and a few black back feathers, re-sighted on the same nest the following year; a 2016 bird rearing two healthy chicks with light, almost white plumage over much of the body but normal black belly band and head; and a 2011 bird with a white figure-eight mark on its black back, re-sighted in April 2013 after two moulting seasons with the same pattern.
  • Only three previous wild African Penguins with plumage aberrations had been scientifically recorded, all in Algoa Bay and incorrectly named isabellinism; two were in fact “brown” and ino. All African Penguins spotted with a colour aberration in this study were seemingly in good health, and a few were breeding normally, but only three were re-sighted in a later year.

Methods

  • Opportunistic sightings of plumage aberrations were made by researchers and SANParks rangers between 2009 and 2017 on Bird Island and St. Croix Island in Algoa Bay, South Africa.
  • These islands host half of the world’s African Penguin population, and observations were part of a long-term monitoring project initiated in 2008; researchers spend three weeks to two months on the islands annually during the peak breeding season between March and June, with two SANParks rangers permanently based on Bird Island.
  • The paper describes and interprets individual sightings against known definitions of colour aberrations; no formal quantitative analysis is reported.

Limitations

  • Stated: For the two reddish-brown fledglings, no parent was sighted, so parental plumage and whether the birds retained abnormal colour as adults are unknown; for one leucistic bird, without knowing its history it was difficult to distinguish progressive greying from true leucism, so it was recorded as leucism; the mechanism behind the figure-eight mark remains unclear.
  • Stated: Only three of the reported birds were re-sighted in a later year, and low apparent survival in African Penguins with plumage aberrations may be indistinguishable from normal-plumage penguins because African Penguin adult and juvenile survival has recently dropped to <0.4.
  • Evident: The findings rely on opportunistic sightings of a small number of cases, with no systematic sampling, genetic confirmation, or physiological testing; identifications are visual and based partly on expert opinion.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.5038/2074-1235.46.1.1243

Cites

0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

3 of 24 cited sources checked · 1 supported · 0 flagged · accuracy not yet measured

  • Findingcitation

    Conspecifics did not show any aggressive behaviour towards the 2017 'brown' adult, as is often the case when conspecifics exhibit plumage differences.

    “Surprisingly, conspecifics did not show any aggressive behaviour towards it, as is often the case when conspecifics exhibit plumage differences (Cook et al. 2012).”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites Cook et al. 2012 source

      In the paper’s main text (page not provided), Cook et al. say their albino cormorant may have been harassed by conspecifics and note that harassment has been observed in albinos of other flocking bird species. This supports the possibility of aggression toward birds with unusual plumage, but not the broader claim that it often occurs whenever conspecifics differ in plumage. The absence of aggression toward the 2017 brown adult is the citing authors’ observation, not one reported by Cook et al. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
  • Premisecitation

    Penguins have a generally high annual adult survival (0.8-0.9).

    “As long-lived species, penguins have a generally high annual adult survival (0.8-0.9; e.g., Le Bohec et al. 2007), favouring the re-sighting of individuals with plumage aberrations (Juáres et al. 2011).”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites Le Bohec et al. 2007 source

      Table 3 reports mean annual survival estimates of 0.844 for failed breeders, 0.902 for non-breeders and 0.971 for successful breeders, supporting the general point that adult survival is high. But these estimates are for king penguins, not penguins generally, and the successful-breeder estimate exceeds the stated 0.8–0.9 range. Page numbers are unavailable in our copy. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites Juáres et al. 2011 source
  • Findingown data

    Two 'brown' penguins were sighted in the study area.

    “Two “brown” penguins were sighted in the study area, although only one is discussed in detail here.”
    Quote in the paperNot a substantial claim
  • Findingown data

    Between April and June 2017, an adult exhibiting a bleached-brown plumage was sighted on Bird Island.

    “Between April and June 2017, an adult exhibiting a bleached-brown plumage was sighted on Bird Island.”
    Quote in the paperSubstantial claim
  • Findingown data

    In two cases, birds with strong partial leucism were recorded breeding on St. Croix Island.

    “In two interesting cases, birds with strong partial leucism were recorded breeding on St. Croix Island.”
    Quote in the paperNot a substantial claim
  • May combine two claims. 19
  • Classified as probably not a substantial claim. 9

  • May combine two claims.

    Premisecitation

    Sightings of birds with colour aberrations are rare, especially for albinos, because survival in the wild is relatively low, perhaps due to reduced abilities to hunt, higher risk of predation, or conspecific harassment and conflicts.

    “Sightings of birds with these aberrations are rare, especially for albinos, because survival in the wild is relatively low, perhaps due to reduced abilities to hunt (Cook et al. 2012), higher risk of predation, or conspecific harassment and conflicts (Alaja & Mikkola 1997).”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites Cook et al. 2012 source
    • cites Alaja & Mikkola 1997

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Findingown data

    The entire body of the 2017 'brown' adult was gold-brown, while the head was darker.

    “The entire body was gold-brown, while the head was darker (Fig. 1b).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The two unusual 'blues' were siblings and exhibited a reddish-brown colouration unlike other young of their age.

    “Unlike other young of their age, the siblings exhibited a reddish-brown colouration (Fig. 1a).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In 2013, a bird spotted incubating two eggs had breast and face almost entirely covered with white feathers, while a few black feathers were spread over its back.

    “In 2013, a bird spotted incubating two eggs had breast and face almost entirely covered with white feathers, while a few black feathers were spread over its back (Fig. 1c).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    This paper reports new cases of plumage aberrations in African Penguins: leucism, 'brown,' and phaeomelanism, all within Algoa Bay.

    “This paper reveals new cases of plumage aberrations in African Penguins: leucism, “brown,” and phaeomelanism, all within Algoa Bay.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The 2016 leucistic breeding bird was in good condition and had light, almost white, plumage covering a large part of the body.

    “This breeding bird, in good condition as well, had light, almost white, plumage covering a large part of the body (Fig. 1d).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    'Brown' is recessive and sex-linked in inheritance; as a result, in the wild this mutation is mainly found in female birds.

    ““Brown” is recessive and sex-linked in inheritance; as a result, in the wild this mutation is mainly found in female birds (van Grouw 2013).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites van Grouw 2013

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    In African Penguins, only three previous cases of colour aberrations have been scientifically recorded, all of them incorrectly named isabellinism.

    “In African Penguins Spheniscus demersus, only three previous cases of colour aberrations have been scientifically recorded, all of them incorrectly named isabellinism (Everitt & Miskelly 2003, Smith & Voogt 2014).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Everitt & Miskelly 2003 source
    • cites Smith & Voogt 2014

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Incomplete oxidized eumelanin is extremely susceptible to sunlight, and mutation 'brown' produces a plumage that bleaches rapidly.

    “Incomplete oxidized eumelanin is extremely susceptible to sunlight, and mutation “brown” produces a plumage that bleaches rapidly (van Grouw 2013).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites van Grouw 2013

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Study design and conductcitation

    Without knowing the bird's history, it is difficult to distinguish progressive greying from true leucism in such a case, and therefore the observation was recorded as leucism.

    “However, without knowing the bird's history, it is difficult to distinguish one aberration from the other in such a case (van Grouw 2013), and therefore we have recorded this observation as leucism.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites van Grouw 2013

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    This agrees with phaeomelanism, as defined above.

    “This agrees with phaeomelanism, as defined above.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    One aberration, in the shape of a number eight, may have resulted from human actions.

    “While all aberrations seemed of natural origin, one in the shape of a number eight may have resulted from human actions.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Bird Island and St. Croix Island in Algoa Bay host half of the world's population of African Penguins.

    “Bird Island (33°50′S, 26°17′E) and St. Croix Island (33°48′S, 25°46′E) in Algoa Bay, South Africa, host half of the world's population of African Penguins (Crawford et al. 2011).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Crawford et al. 2011 source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Phaeomelanism, 'brown,' and leucism are more common than albinism, but they remain rare events in seabirds.

    “Although phaeomelanism, “brown,” and leucism are more common than albinism (van Grouw 2006), they remain rare events in seabirds (e.g., Oosthuizen & de Bruyn 2009).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites van Grouw 2006

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Oosthuizen & de Bruyn 2009

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationreasoning

    The figure-eight mark most likely resulted from some sort of injury that had permanently damaged the pigment-producing cells of the skin, as the bird was re-sighted in April 2013 after two moulting seasons with exactly the same pattern.

    “Most likely it resulted from some sort of injury that had permanently damaged the pigment-producing cells of the skin, as the bird was re-sighted in April 2013 after two moulting seasons with exactly the same pattern.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    The random distribution of white feathers observed on the 2016 leucistic bird could indicate a case of progressive greying, i.e., loss of pigment cells with age.

    “The random distribution of white feathers observed (Fig. 1d) could indicate a case of progressive greying, i.e., loss of pigment cells with age.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationown data

    Leucism may be even more common in African Penguins than the 'brown' mutation, as more cases of leucism were recorded on the two islands.

    “Although the mutation “brown” is fairly common in the wild, leucism may be even more common in African Penguins, as more cases of leucism were recorded on the two islands.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisenone given

    When individuals with phaeomelanism reach adult stages, they usually recover a natural plumage.

    “When they reach adult stages, the individuals usually recover a natural plumage.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    'Brown' is a mutation more commonly observed but often misinterpreted as leucism, isabellinism, or albinism.

    ““Brown” is a mutation more commonly observed but often misinterpreted as leucism, isabellinism, or albinism (van Grouw 2012).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites van Grouw 2012

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    The 2017 'brown' adult was likely hatched on Bird Island, as this species has high site fidelity.

    “This adult was likely hatched on the island, as this species has high site fidelity.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: African Penguins have high site fidelity.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisereasoning

    Most sightings of plumage aberrations are recorded in penguin species, probably reflecting the ease of sighting aberrations in this seabird family, as these species systematically exhibit a dark plumage and breed in large numbers.

    “Interestingly, most of the sightings of plumage aberrations are recorded in penguin species (Oosthuizen & De Bruyn 2009, Juáres et al. 2011, Smith & Voogt 2014, Carpenter-Kling et al. 2017), probably reflecting the ease of sighting aberrations in this seabird family, as these species systematically exhibit a dark plumage and breed in large numbers.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Oosthuizen & De Bruyn 2009

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Juáres et al. 2011 source
    • cites Smith & Voogt 2014

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    The figure-eight mark on the 2011 penguin was believed to be a result of some human action because of the complexity of the pattern.

    “Because of the complexity of the pattern on this bird with partial-leucism, we believe this mark to be a result of some human action.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Only three wild African Penguins with plumage aberrations ('brown,' ino, and phaeomelanism) have been scientifically recorded to date, all within Algoa Bay.

    “However, only three wild African Penguins with plumage aberrations (“brown,” ino, and phaeomelanism) have been scientifically recorded to date, all within Algoa Bay (Everitt & Miskelly 2003, Smith & Voogt 2014), although these aberrations may occur through the entire range of this species.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Everitt & Miskelly 2003 source
    • cites Smith & Voogt 2014

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    African Penguin adult and juvenile survival probabilities fluctuate and have recently dropped to <0.4.

    “However, African Penguin adult and juvenile survival probabilities fluctuate and have recently dropped to <0.4 (Sherley et al. 2014).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Sherley et al. 2014 source

  • May combine two claims.

    Interpretationreasoning

    Penguins naturally do not have phaeomelanin in their plumage, so they cannot exhibit an isabel mutation.

    “As penguins naturally do not have phaeomelanin in their plumage, they cannot exhibit such a mutation.”
    Quote in the paperNot a substantial claim
25 of 25

  • The paper relies on this without support.

    African Penguins have high site fidelity.

    “This adult was likely hatched on the island, as this species has high site fidelity.”

  • The paper relies on this without support.

    Colour aberrations may occur through the entire range of the African Penguin species.

    “although these aberrations may occur through the entire range of this species.”
2 of 2

Cites

The publisher hasn’t deposited this paper’s reference list.

Research works printed but not linked: 3

  1. ALAJA, P. & MIKKOLA, H. 1997. Albinism in the great gray owl (Strix nebulosa) and other owls. In: DUNCAN, J.R., JOHNSON, D.H. & NICHOLLS, T.H. (Eds.). Biology and Conservation of Owls of the Northern Hemisphere. General Technical Report NC 190. Washington, DC: United States Department of Agriculture Forest Service. pp. 33-37.
  2. HOCKEY, P.A.R., DEAN, W.R.J. & RYAN, P.G. 2005. African Penguin Jackass Penguin Sphenisucs demersus. Roberts Birds of Southern Africa, 7th ed. Cape Town: The Trustees of the John Voelcker Bird Book Fund. Pp. 631-634.
  3. WILSON, E.A. 1907. "Aves." In: National Antarctic Expedition 1901-04, Vol. 2: Zoology, Part 2, pp. 1-121. London: British Museum.

Cited by

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Related

Authors
Traisnel, G., Pichegru, L., Visser, H., & Edwards, L.
Affiliations
None
ORCID
Venue
Marine Ornithology
Publisher
University of South Florida Libraries
Published
2018
Volume
46
Issue
1
ISSN
  • 1018-3337 (ISSN-L)
  • 2074-1235
DOI
10.5038/2074-1235.46.1.1243
OpenAlex
W4409760520
Semantic Scholar
2657e1df9a42c5c5314e6d7c8397fa51fc1dce41
Cited by
1
References
0
Citations by year
2025: 1
FWCI
0.00
Type
journal article
Language
en
Open access
Licence
cc-by
Locations
  • Marine ornithology (publishedVersion, cc-by)
  • Digital Commons - University of South Florida (University of South Florida) (submittedVersion)
  • Nelson Mandela University Research Repository (submittedVersion)
Funders
  • Department of Science and Technology, Ministry of Science and Technology, India
  • Nelson Mandela University
  • South African National Parks
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › melanin and skin pigmentation
  • Physical Sciences › Environmental Science › Ecology › Avian ecology and behavior
  • Life Sciences › Immunology and Microbiology › Parasitology › Bird parasitology and diseases
Keywords
African penguin, Spheniscus demersus, leucism, Algoa Bay

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