Megadyptes antipodesyellow-eyed penguin

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Geographic Range

Yellow-eyed penguins (Megadyptes antipodes) are island endemic and are found in the southern regions of New Zealand, including Stewart Island, South Island, the Otago Peninsula and a few other islands in the same region. These penguins are not migratory and stay in this range year round. They only leave the island to hunt off the coast of New Zealand and the respective islands they inhabit. ("Penguins: Basic Facts", 2012; Croxall and Davis, 1999; McKay, et al., 1999; Moore and Wakelin, 1997; Moore, 1999)

Habitat

Yellow-eyed penguins inhabit island shorelines in New Zealand. Most of the shore is covered in coastal forest, where the penguins live and nest. These birds are primarily terrestrial and only enter the water to hunt. ("Penguins: Basic Facts", 2012; McKay, et al., 1999; Moore, 1999)

  • Average elevation
    0 m
    0.00 ft

Physical Description

Yellow-eyed penguins are relatively large in comparison to other penguins living in similar conditions. Their height ranges from 56 to 78 cm, with an average height of 70 cm. The mass of these penguins ranges from 5 to 8 kg. These physical characteristics make Megadyptes antipodes the largest penguin that does not live in the Antarctic. A defining trait of this particular penguin is their yellow eyes. The characteristic used to distinguish between adult and juvenile penguins is the presence of yellow plumage on the adult's heads. Yellow feathers are not present on juvenile penguins until they molt, around the age of one. Megadyptes antipodes exhibits sexual dimorphism: males have a carotenoid derived ornament. The difference in males and females can be seen in the pigmentation of the head feathers (plumage). Carotenoids are responsible for the bright yellow coloration of the male's head and are hypothesized to be a signal of parental quality, although few studies have been conducted on the subject. ("Penguins: Basic Facts", 2012; Massaro, et al., 2003; Moore and Wakelin, 1997; Van Heezik and Seddon, 1989)

  • Sexual Dimorphism
  • sexes colored or patterned differently
  • male more colorful
  • Range mass
    5 to 8 kg
    11.01 to 17.62 lb
  • Range length
    56 to 78 cm
    22.05 to 30.71 in
  • Average length
    70 cm
    27.56 in

Reproduction

Megadyptes antipodes is monogamous: a male has one female partner each breeding season. There is a great amount of parental care given by yellow-eyed penguins, which contributes to the monogamous mating system. This species exhibits sexual dimorphism, a difference in secondary characteristics between males and females, responsible for mate selection. In M. antipodes, the sexually dimorphic characteristic is the yellow plumage feathers found on males, females use the color for mate selection. This color pattern is believed to be indicative of mate quality; however, more evidence is required to determine how mates are chosen. Megadyptes antipodes exhibits nesting behavior that influences the social structure of the birds. Their nesting sites are typically very large and isolated. Research indicates that the more isolated the nesting site, the more effective the breeding. Most of their nesting sites are under the cover of surrounding plants, the optimal setting is a coastal forest. These isolated nests are one factor that prevents yellow-eyed penguins from being colonial birds. (Massaro, et al., 2003; McKay, et al., 1999; Seddon and Davis, 1989)

Megadyptes antipodes is a relative of crested penguins and has similar reproductive behavior. Yellow-eyed penguins reproduce during the same breeding season, every year. Their breeding season starts in the middle of August and typically lasts 28 weeks. During this time, penguins find a mate and build a nest where they will lay and incubate their eggs. This species lays only two eggs each year, this is a characteristic shared with other crested penguins. These eggs are laid at the same time, usually in September and October. Unlike many other penguin species, yellow-eyed penguins lay two similarly sized eggs that will both yield viable offspring. In contrast, many penguin species lay eggs of two different sizes. Since both eggs will yield viable offspring, they must incubate both. This is likely due to the amount of the hormone prolactin that is secreted. Once the eggs are laid, they take an average of 43 days to hatch; hatching typically occurs in November, after the incubation period. Juvenile yellow-eyed penguins usually reach sexually maturity after two to three years for females and three to four years for males. ("Penguins: Basic Facts", 2012; Massaro, et al., 2003; Setiawan, et al., 2006; Setiawan, et al., 2007)

  • Breeding interval
    Yellow-eyed penguins breed annually.
  • Breeding season
    Yellow-eyed penguins breed August through March.
  • Range eggs per season
    2 to 2
  • Range time to hatching
    38 to 54 days
  • Average time to hatching
    43 days
  • Range fledging age
    3 to 4.5 months
  • Average fledging age
    3.5 months
  • Range age at sexual or reproductive maturity (female)
    2 to 3 years
  • Range age at sexual or reproductive maturity (male)
    3 to 4 years

Parental care in Megadyptes antipodes is displayed by both the male and female parent. Parental care can be seen in yellow-eyed penguins starting at the incubation period, through the growing of the juvenile, until it reaches about six weeks old. Both the male and female parent takes part in the incubation period. Once the eggs are incubated and hatch, a new form of parental investment begins, involving the protection of the young and providing the necessary resources for them. This period is known as brooding and usually takes about six weeks. Neither the role of protecting the young, nor finding food is reserved for a specific parent; one parent guards the newly hatched penguins, while the other hunts. After this six week brooding period, parental protection is reduced, but provisioning is increased. Juveniles will ultimately fledge and leave the nest area to provide for themselves. ("Penguins: Basic Facts", 2012; Massaro, et al., 2003; Setiawan, et al., 2006; Setiawan, et al., 2007)

  • Parental Investment
  • male parental care
  • female parental care
  • pre-hatching/birth
    • protecting
      • male
      • female
  • pre-weaning/fledging
    • provisioning
      • male
      • female
    • protecting
      • male
      • female
  • pre-independence
    • provisioning
      • male
      • female

Lifespan/Longevity

The average lifespan of Megadyptes antipodes is 23 years. Male yellow-eyed penguins typically live longer than females. Predation does not play a big role in determining their lifespan. The factor with the most influence is the amount of breeding, those who do not or cannot breed typically live longer than those that do breed. ("Penguins: Basic Facts", 2012; Ainley and DeMaster, 1980)

  • Average lifespan
    Status: wild
    23 years
  • Average lifespan
    Status: wild
    23 years

Behavior

Yellow-eyed penguins are sedentary birds that usually stay in one area, except when hunting. Megadyptes antipodes is not a colonial penguin, meaning it does not live in large groups with other penguins. ("Penguins: Basic Facts", 2012; Ainley and DeMaster, 1980; Moore, 1999; Setiawan, et al., 2006)

Home Range

These birds typically stay on the shore. When they do forage, they only travel about 7 to 13 km offshore and they hunt off the continental shelf. (Ainley and DeMaster, 1980; Moore, 1999)

Communication and Perception

Potential mates communicate acoustically, via shrill calls. Their nest sites are usually well hidden, this call is used for mates to find each other, as well as juveniles. They do not receive much social stimuli from other penguins due to their isolated nature and are easily startled by humans. ("Penguins: Basic Facts", 2012; Setiawan, et al., 2007)

Food Habits

Megadyptes antipodes has a diet that consists mostly of small prey, either juveniles or species whose adults are small. Yellow-eyed penguins are carnivores. Their diet is mainly composed of fishes including opalfish Hemerocoetes monopterygius, red cods Pseudophycis bachus, blue cods Parapercis colias, silversides Argentina elongata and spats Sprattus antipodum. However, they also eat mollusks and some crustaceans including Nototodarus sloani and Nyctiphanes australis, respectively. Most of their hunting occurs off the coast of New Zealand at the edge of the continental shelf, making them marine predators. Their foraging behavior depends on the breeding season. Penguins that have not bred successfully travelled greater distances to hunt. Their trips off shore are relatively shorter than trips of other penguins of a similar size. (Croxall and Davis, 1999; Moore and Wakelin, 1997; Moore, 1999; Van Heezik and Seddon, 1989)

  • Animal Foods
  • fish
  • eggs
  • mollusks
  • aquatic crustaceans

Predation

Predation is important to all animals and crucial to those animals that are threatened or endangered. Megadyptes antipodes falls under the crucial category because they are a threatened species. The key predators that threaten M. antipodes are terrestrial mammals that were introduced by humans. These predators include ferrets Mustela furo, feral house cats Felis catus, humans, and domestic dogs Canis lupus familiaris. Mustela furo and F. catus are responsible for predation of newly born penguins, while humans and C. lupus familiaris are the only terrestrial mammals that are capable of predation on adult yellow-eyed penguins. However, non-terrestrial predators include New Zealand sea lions Phocarctos hookeri. Yellow-eyed penguins do not have any anti-predator mechanisms against terrestrial mammals because they are a relatively new predator, although their conservation status does help serve as an anti-predator mechanism. (Lalas, et al., 2007; McKay, et al., 1999)

Ecosystem Roles

Plasmodium relictum is a parasite that has been found on wild yellow-eyed penguins. There is not much information on the ecosystem role of Megadyptes antipodes. Their foraging range is off the continental shelf and they are predators to various fish species. When on land, their only major predators are mammals introduced by humans. They are also prey to New Zealand sea lions, but they are not a major component of the sea lion's diet. (Jones and Shellam, 1999; Lalas, et al., 2007; McKay, et al., 1999)

Commensal/Parasitic Species
  • Plasmodium relictum (class Aconoidasida; phylum Apicomplexa)

Economic Importance for Humans: Positive

Yellow-eyed penguins provide a positive impact on the New Zealand economy because of the tourism industry built upon viewing them. However, the birds are not as cooperative as some other animals involved in ecotourism because they are shy and easily scared by humans. When humans view yellow-eyed penguins, they are required to hide and remain quiet, so the birds are not startled. This ecotourism allows for increased awareness and knowledge about the penguins and helps in their conservation. Ecotourism has a positive effect on the local economy and it helps with the conservation effort. Conservation efforts are partially funded by the fees charged for such tours. (McClung, et al., 2004; "Conservation Project", 2012; Ratz and Thompson, 1999)

Economic Importance for Humans: Negative

There are no known adverse affects of Megadyptes antipodes on humans.

Conservation Status

Megadyptes antipodes is endangered according to the IUCN Red List and is threatened according to the United States Federal list. The main cause contributing to the status of yellow-eyed penguins is deforestation on the coast of New Zealand. There are various conservation efforts, including penguin reserves, such as Penguin Place in Dunedin, New Zealand. These reserves allow visitors to view the penguins for a fee, which helps conserve M. antipodes. Another conservation effort is the Yellow-eyed Penguin Trust, which teaches people about the penguins and collects funds for their conservation. There are only a few thousand yellow-eyed penguins living in the world today. (Houston and McKinlay, 2012; McClung, et al., 2004; "Conservation Project", 2012)

Contributors

William Wardell (author), The College of New Jersey, Matthew Wund (editor), The College of New Jersey, Leila Siciliano Martina (editor), Animal Diversity Web Staff.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

island endemic

animals that live only on an island or set of islands.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

male parental care

parental care is carried out by males

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

piscivore

an animal that mainly eats fish

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

threatened

The term is used in the 1994 IUCN Red List of Threatened Animals to refer collectively to species categorized as Endangered (E), Vulnerable (V), Rare (R), Indeterminate (I), or Insufficiently Known (K) and in the 1996 IUCN Red List of Threatened Animals to refer collectively to species categorized as Critically Endangered (CR), Endangered (EN), or Vulnerable (VU).

visual

uses sight to communicate

References

Penguin Place. 2012. "Conservation Project" (On-line). Penguin Place Conservation Reserve. Accessed November 13, 2012 at http://www.penguinplace.co.nz/.

2012. "Penguins: Basic Facts" (On-line). Yellow-Eyed Penguin Trust. Accessed October 17, 2012 at http://yellow-eyedpenguin.org.nz/.

Ainley, D., D. DeMaster. 1980. Survival and mortality in a population Adelie Penguins. Ecology, 61: 522-530. Accessed October 24, 2012 at http://swfsc.noaa.gov/publications/cr/1980/8004.pdf.

Croxall, J., L. Davis. 1999. Penguins: Paradoxes and Patterns. Marine Ornithology, 27: 1-12. Accessed October 15, 2012 at http://www.marineornithology.org/PDF/27/27_1.pdf.

Darby, J., S. Dawson. 2000. Bycatch of yellow-eyed penguins (Megadyptes antipodes) in gillnets in New Zealand waters 1979-1997. Biological Conservation, 93: 327-332. Accessed October 17, 2012 at http://www.sciencedirect.com/science/article/pii/S0006320799001482.

Houston, D., B. McKinlay. 2012. "Megadyptes antipodes" (On-line). IUCN Red List. Accessed November 14, 2012 at http://www.iucnredlist.org/details/106003859/0.

Jones, H., G. Shellam. 1999. Blood parasites in penguins, and their potential impact on conservation. Marine Ornithology, 27: 181-184. Accessed October 14, 2012 at http://marineornithology.org/PDF/27/27_23.pdf.

Lalas, C., H. Ratz, K. McEwan, S. McConkey. 2007. Predation by New Zealand sea lions (Phocarctos hookeri) as a threat to the viability of yellow-eyed penguins (Megadyptes antipodes) at Otago Peninsula, New Zealand. Biological Conservation, 135: 235-246. Accessed October 17, 2012 at http://www.sciencedirect.com/science/article/pii/S0006320706004496.

Massaro, M., L. Davis, J. Darby. 2003. Carotenoid-derived ornaments reflect parental quality in male and female yellow-eyed penguins (Megadyptes antipodes). Behavioral Ecology and Sociobiology, 55: 169-175. Accessed October 14, 2012 at http://georgealozano.com/papers/carotenoids/Massaro2003.pdf.

McClung, M., P. Seddon, M. Massaro, A. Setiawan. 2004. Nature-based tourism impacts on yellow-eyed penguins Megadyptes antipodes: does unregulated visitor access affect fledging weight and juvenile survival?. Biological Conservation, 119: 279-285. Accessed October 14, 2012 at http://comp.uark.edu/~mrm06/YEP.pdf.

McKay, R., C. Lalas, D. McKay, S. McConkey. 1999. Nest-Site Selection by Yellow-Eyed Penguins Megadyptes antipodes on grazed farmland. Marine Ornithology, 27: 29-35. Accessed October 14, 2012 at http://www.marineornithology.org/PDF/27/27_4.pdf.

Moore, P. 1999. Foraging Range of the Yellow-Eyed Penguin Megadyptes antipodes. Marine Ornithology, 27: 49-58. Accessed October 14, 2012 at http://www.marineornithology.org/PDF/27/27_7.pdf.

Moore, P., M. Wakelin. 1997. Diet of the Yellow-Eyed Penguin Megadyptes antipodes, South Island, New Zealand, 1991-1993. Marine Ornithology, 25: 17-29. Accessed October 14, 2012 at http://marineornithology.org/PDF/25/25_5.pdf.

Moore, P. 2001. Historical records of yellow-eyed penguin (Megadyptes antipodes) in Southern New Zealand. Notornis, 48: 145-156. Accessed October 17, 2012 at http://notornis.osnz.org.nz/system/files/Notornis_48_3_145.pdf.

Ratz, H., C. Thompson. 1999. Who is Watching Whom? Checks for Impacts of Tourists on Yellow-Eyed Penguins Megadyptes antipodes. Marine Ornithology, 27: 205-210. Accessed October 14, 2012 at http://marineornithology.org/PDF/27/27_28.pdf.

Reid, W. 1988. Age correlations within pair of breeding birds. The Auk, 105: 278-285. Accessed October 15, 2012 at http://elibrary.unm.edu/sora/Auk/v105n02/p0278-p0285.pdf.

Seddon, P., L. Davis. 1989. Nest-site selection by Yellow-eyed Penguins. The Condor, 91: 653-659. Accessed November 08, 2012 at http://elibrary.unm.edu/sora/Condor/files/issues/v091n03/p0653-p0659.pdf.

Setiawan, A., L. Davis, J. Darby, P. Lohman, G. Young, M. Blackberry, B. Cannell, G. Martin. 2006. Hormonal correlates of parental behavior in yellow-eyed penguins. Comparative Biochemistry and Physiology, 145: 357-362. Accessed October 14, 2012 at http://fish.washington.edu/research/younglab/graham_young/setiawan_et_al_2006.pdf.

Setiawan, A., L. Davis, J. Darby, P. Lokman, G. Young, M. Blackberry, B. Cannell, G. Martin. 2007. Effects of artificial social stimuli on the reproductive schedule and hormone levels of yellow-eyed penguins (Megadyptes antipodes). Hormones and Behavior, 51: 46-53. Accessed October 14, 2012 at http://fish.washington.edu/research/younglab/graham_young/setiawan_et_al_2007.pdf.

Sullivan, D., M. Sullivan. 1975. Transport Defects as the Physiological Basis for Eye Color Mutants of Drosophila melanogaster. Biochemical Genetics, 13: 603-613. Accessed November 17, 2012 at http://www.springerlink.com/content/l321q43r98426150/.

Van Heezik, Y., P. Seddon. 1989. Stomach Sampling in the Yellow-Eyed Penguin: Erosion of Otoliths and Squid Beaks. Journal of Field Ornithology, 60: 451-458. Accessed October 14, 2012 at https://elibrary.unm.edu/sora/JFO/v060n04/p0451-p0458.pdf.