The Palawan peacock-pheasant (''Polyplectron napoleonis'') is a medium-sized (up to 50 cm long) bird in the family
Phasianidae
The Phasianidae are a family of heavy, ground-living birds, which includes pheasants, partridges, junglefowl, chickens, turkeys, Old World quail, and peafowl. The family includes many of the most popular gamebirds. The family is a large one and i ...
.
It is featured prominently in the culture of the indigenous people of Palawan. The bird is also depicted in the official seal of the city of
Puerto Princesa
Puerto Princesa, officially the City of Puerto Princesa ( Cuyonon: ''Siyudad i'ang Puerto Princesa''; fil, Lungsod ng Puerto Princesa), is a 1st class highly urbanized city in the Mimaropa region of the Philippines. According to the 2020 census ...
.
Description
The adult male is the most
peacock
Peafowl is a common name for three bird species in the genera '' Pavo'' and '' Afropavo'' within the tribe Pavonini of the family Phasianidae, the pheasants and their allies. Male peafowl are referred to as peacocks, and female peafowl are r ...
-like member of the genus ''
Polyplectron
The peacock-pheasants are a bird genus, ''Polyplectron'', of the family Phasianidae, consisting of eight species. They are colored inconspicuously, relying on heavily on crypsis to avoid detection. When threatened, peacock-pheasants will alter t ...
'' in appearance. It has an erectile crest and highly
iridescent
Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change color as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, feathers, butterfly ...
electric blue-violet, metallic green-turquoise dorsal plumage. Its breast and ventral regions are dark black. The
rectrices
Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those on the tai ...
are wide, flat, and rigid. Their terminal edges are squared. Each tail plume and upper-tail covert is marked with highly iridescent, light reflective,
ocelli
A simple eye (sometimes called a pigment pit) refers to a form of eye or an optical arrangement composed of a single lens and without an elaborate retina such as occurs in most vertebrates. In this sense "simple eye" is distinct from a multi-le ...
. The tail is erected and expanded laterally together with the bodies of the birds. The males also raise one wing and lower the other, laterally compressing the body during pair-bonding, courtship displays as well and may also be
antipredator adaptation
Anti-predator adaptations are mechanisms developed through evolution that assist prey organisms in their constant struggle against predators. Throughout the animal kingdom, adaptations have evolved for every stage of this struggle, namely by av ...
.
The female is slightly smaller than the male. Its contour plumage is cloudy silt in colouration. The mantle and breast are a dark sepia in coloration. The rectrices are essentially similar to those of the male, exhibiting marked adumbrations and stunning ocelli. Throughout, their plumage is earthen and difficult to distinguish from the substrate and branches. While it has similar proportions of the tail to the male, its markings are not as visually arresting. Like the male, the female has a short crest and is whitish on the throat, cheeks and eyebrows.
Chicks are vivid ginger and cinnamon hued with prominent yellow markings. Juveniles of both sexes in the first year closely resemble their mothers. Subadult males in their second year more closely resemble their fathers but the mantle and wing coverts are marked with adumbrations analogous with the ocelli in the contour plumage of other peacock-pheasant species.
Like other peacock-pheasants, Palawan males and some females exhibit multiple spurs on the metatarsus. These are used in anti-predator defense, foraging in leaf litter and contests with other males. The male Palawan excavates slight depressions in which it orients its body during postural display behaviors. The bird vibrates loudly via stridulation of rectrice quills. This communicative signal is both audible and as a form of
seismic communication
Seismic or vibrational communication is a process of conveying information through mechanical (seismic) vibrations of the substrate. The substrate may be the earth, a plant stem or leaf, the surface of a body of water, a spider's web, a honeycomb, ...
.
Palawan peacock-pheasants are strong fliers. Their flight is swift, direct and sustained.
Distribution and habitat
Endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...
to the
Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
, the Palawan peacock-pheasant is found in the humid forests of
Palawan Island
Palawan is the largest island of the province of Palawan in the Philippines and fifth-largest by area and tenth-most populous island of the country, with a total population of 994,101 as of 2020 census. The north west coast of the island is alon ...
in the southern part of the Philippine
archipelago
An archipelago ( ), sometimes called an island group or island chain, is a chain, cluster, or collection of islands, or sometimes a sea containing a small number of scattered islands.
Examples of archipelagos include: the Indonesian Arch ...
.
Taxonomy
The Palawan peacock-pheasant, with its unique male plumage and distant range, represents a basal (Early?
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58mya)
Note that the
molecular clock
The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. The biomolecular data used for such calculations are usually nucleotid ...
calibration method used by Kimball ''et al.'' (2001) is now known to be inappropriate, yielding far too low estimates in galliform birds. offshoot of the
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial no ...
''Polyplectron'' (Kimball ''et al.'' 2001). The species is widely accepted to be monotypic, but while some males have white supercillia, giving a "double-barred" or masked appearance, others lack this trait, exhibiting dark faces, taller, denser crests and prominent white cheek spots. The birds with white supercillia are sometimes classified as a distinct subspecies, ''nehrkornae''. The white-cheeked form may inhabit deep forest habitat with low ambient light in rolling terrain whilst the masked form appears to inhabit taller, more open forest on flatter terrain with higher ambient light. This masked form exhibits an abbreviated, more tightly compacted and highly iridescent crest. Females of the two respective forms exhibit analogous differentiation. The female of the masked form is more prominently patterned and densely crested with paler contour plumage.
It was long known as ''Polyplectron emphanum'', but the name ''Polyplectron napoleonis'' was given one year before and takes priority over the newer name (Dickinson 2001).
Behavior and ecology
Peacock-pheasants are highly invertivorous, taking
isopod
Isopoda is an order of crustaceans that includes woodlice and their relatives. Isopods live in the sea, in fresh water, or on land. All have rigid, segmented exoskeletons, two pairs of antennae, seven pairs of jointed limbs on the thorax, an ...
s,
earwig
Earwigs make up the insect order Dermaptera. With about 2,000 species in 12 families, they are one of the smaller insect orders. Earwigs have characteristic cerci, a pair of forcep-like pincers on their abdomen, and membranous wings folded ...
mollusk
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is es ...
s,
centipede
Centipedes (from New Latin , "hundred", and Latin , "foot") are predatory arthropods belonging to the class Chilopoda (Ancient Greek , ''kheilos'', lip, and New Latin suffix , "foot", describing the forcipules) of the subphylum Myriapoda, an a ...
s and
termite
Termites are small insects that live in colonies and have distinct castes (eusocial) and feed on wood or other dead plant matter. Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitoidae, within the order Blattode ...
s as well as small
frog
A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" ''Triadobatrachus'' is ...
s,
drupe
In botany, a drupe (or stone fruit) is an indehiscent fruit in which an outer fleshy part ( exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pit'', ''stone'', or ''pyrena'') of hardened endocarp with a seed (''kernel'' ...
s,
seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
s and
berries
A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit, although many pips or seeds may be present. Common examples are strawberries, raspb ...
.
They are strictly monogamous, renesting yearly. The female usually lays up to two eggs. Both parents rearing chicks for up to two years. Males act as sentinels of nest sites and are highly pugnacious during the reproductive cycle.
Status and conservation
Due to ongoing habitat loss, small population size and limited range as well as hunting and capture for trade, the Palawan peacock-pheasant is classified as Vulnerable in the
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biolog ...
of Threatened Species. It is listed on Appendix I of
CITES
CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...
.
Gallery
File:Stavenn Polyplectron napoleonis 01.jpg, male
File:Polyplectron napoleonis-female-Lisbon.jpg, female
File:palawan_peacock.jpg, male
References
Footnotes
Works cited
*Dickinson, E. C. (2001): The correct scientific name of the Palawan Peacock-Pheasant is ''Polyplectron napoleonis'' (Lesson, 1831). '' Bull. B. O. C.'' 121(4): 266–272.
*Kimball, Rebecca T.; Braun, Edward L.; Ligon, J. David; Lucchini, Vittorio & Randi, Ettore (2001): A molecular phylogeny of the peacock-pheasants (Galliformes: ''Polyplectron'' spp.) indicates loss and reduction of ornamental traits and display behaviour. '' Biol. J. Linn. Soc.'' 73(2): 187–198 HTML abstract *Lesson, René-Primevère (1831): ''Traite d'Ornithologie'' 7:487; 8: 650.
*Temminck, Coenraad Jacob (1832): ''Nouveau Recueil de Planches coloriées d'Oiseaux'' 88 plate 540.