By Laura Podzikowski
Geographic Range
Akepas are found mainly on the island of Hawai'i. Hawai'ian populations are currently located mostly on the eastern slopes of Mauna Kea, the eastern and southern slopes of Mauna Loa, and the northern slope of Hualalai. There is one subspecies on the island of O'ahu and another one considered extinct on Maui. Akepas do not migrate. (Lepson and Freed, 1997; Walton Beacham, 1990)
Biogeographic Regions:
oceanic islands 
(native ); pacific ocean (native ).
Other Geographic Terms:
island endemic .
Habitat
(3608 to 6888 ft; avg. 5248 ft)
Akepas inhabit closed canopied forest composed of native trees, including ohia (Metrosideros collina) or koa (Acacia koa) trees. The densest populations of Hawai'ian akepas tend to be found above 1,500 m. Little is known about the specific locations of the Maui akepa populations, but they are believed to live in montane areas as well. (Lepson and Freed, 1997; Walton Beacham, 1990)
These animals are found in the following types of habitat:
tropical ; terrestrial .
Terrestrial Biomes:
rainforest .
Physical Description
(0.35 to 0.42 oz)
(3.94 to 5.12 in)
(2.32 to 2.72 in)
Akepas range in body length from 10 to 13 centimeters, have a wingspan of 59 to 69 millimeters, and weigh anywhere from 10 to 12 grams. The males tend to be bright red-orange with brown wings and tails. Females, on the other hand, tend to be green or grey with yellow on the underside. Their yellow bills are known for their lateral asymmetry, which is an adaptation to help obtain food. (Gale Research, 1999; Gale, 2003; Hatch, 1985; Lepson and Freed, 1995; Lepson and Freed, 1997; Walton Beacham, 1990)
Some key physical features:
endothermic ; homoiothermic; bilateral symmetry .
Sexual dimorphism: sexes colored or patterned differently, male more colorful.
Reproduction
Akepas usually breed once yearly.
Akepas breed from March until September.
Akepas search for a single partner, during which the male performs a mating ritual in order to attract a female. Akepas form monogamous pairs during July and August (the postbreeding flocking period) and bonds last several years. In a majority of observed pairs, the birds only obtained a new mate after the previous mate had disappeared. (Gale, 2003; Lepson and Freed, 1995; Lepson and Freed, 1997)
Mating systems:
monogamous .
In the prebreeding period, akepa males display their most aggressive behavior. Competitive groups have been seen in aerial displays that can reach up to 100 m off the ground. These males sometimes get into dogfights, in which two or more individuals will engage in twisting or circular chase fights. In addition, males engage in aggressive “song bouts”, where two or more individuals vigorously sing at the same time in close proximity to one another. (Lepson and Freed, 1995; Lepson and Freed, 1997)
The breeding period of akepas begins in March and ends by September. The male and female search for nesting sites after pairing. Females are responsible for nest construction. Once the clutch is laid the female incubates the eggs. After hatching, little is known about the young. Both parents feed the chicks, which develop their juvenile plumage by day 12. Young akepas are often dependent on parental care well after leaving the nest, and both parents participate in this stage of care. (Lepson and Freed, 1997)
Some females have been observed to breed successfully in their second year, although it is more common for females to commence breeding in the third year. Males have not been observed to breed successfully in their second year. Akepa juvenile plumage looks much like the female adult plumage: green or gray with a gray underside. Males usually do not obtain their full adult plumage until their fourth year. Nonetheless, some third year males successfully mate before they obtain full adult plumage. The delayed acquisition of adult male plumage in monogamous, non-territorial birds in which males perform parental care is highly unusual and only known in akepas. Researchers have hypothesized that it may be a result of the highly competitive and complicated mating rituals the males perform. These factors could have selected for males with delayed maturation because younger males are not capable of competing with the older males for a mate. (Lepson and Freed, 1995; Lepson and Freed, 1997)
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous .
Once the clutch is laid, typically with one or two eggs and in rare cases with three, the eggs are incubated for 14 to 16 days by the female. Throughout this period the males sometimes feed the females, although females also forage for themselves. After hatching little is known about the young. Females brood the hatchlings for up to 8 days. Males, in return, feed females until after the brooding period. Both males and females will feed the young after this stage of development. Young akepas leave the nest around 16 to 20 days after hatching. They remain near the parents during this period, following their parents and vocalizing to beg for food. They may remain dependent on their parents for up to ten weeks after hatching. (Lepson and Freed, 1997)
Parental investment:
altricial ; pre-fertilization (provisioning, protecting: female); pre-hatching/birth (provisioning: female, protecting: male, female); pre-weaning/fledging (provisioning: female, protecting: male, female); pre-independence (provisioning: male, female).
Lifespan/Longevity
Tagged females in the wild have lived for at least 10 years. No information on akepas living in captivity could be found. Little is known about the causes of mortality. Juveniles have a lower survivorship than adults, and most hypothesized causes of mortality relate to juveniles. Predation from introduced species is one of these possible causes, as well as diseases transported through mosquitos. (Lepson and Freed, 1997)
Behavior
Akepas are generally tolerant of others of their own species. Most aggressive interactions occur during the pre-breeding season as a result of competition between males. In the post-breeding time period, akepas can be found foraging in flocks consisting of family members, non-breeders, and unsuccessful breeders. Akepas are not territorial birds and can be found in interspecific flocks that include endangered Hawai'ian creepers (Oreomystis mana), amakihis (Hemignathus) and endangered akiapoloa'aus (Hemignathus munroi). Within these flocks there is typically little interaction between akepas and the other species. Akepas are regularly chased by more aggressive territorial birds including i'iwis (Vestiaria coccinea), apapanes (Himatione sanguinea) and Hawai'i amakihis (Hemignathus virens). Akepa females have been known to steal nest materials from other species. (Lepson and Freed, 1997)
Home Range
Akepas are not territorial. Little is known about precise ranges of adult akepas except that they return to the same breeding sites each year. Akepas are philopatric, breeding within 250 m of their natal nest, but males have been observed to travel 5 km in search of a mate. One adult akepa was also recorded traveling about 5 km in search of a lost juvenile. The home range of juveniles can be greater than 300 m from the nest, though these larger distances are mostly observed while young akepas are part of a mixed-species feeding flock. (Lepson and Freed, 1997)
Communication and Perception
Akepas are songbirds that use vocalizations to communicate in most cases. Little is understood about the functions of akepa vocalizations, although these birds vocalize throughout all months of the year. The male call is a high-pitched, descending trill. Juvenile communication is used mainly as a means of obtaining the attention of the parents and maintaining contact with parents. Akepas are not known to make any nonvocal sounds. (Gale Research, 1999; Gale, 2003; Lepson and Freed, 1997)
Food Habits
The odd, asymmetrical bills of akepas help them to pry apart scales of buds in search of their prey. They feed on insects and spiders, though their main diet consists of caterpillars. They have been seen feeding on nectar to a lesser extent. They may take nectar incidentally while searching for insect prey but the brushy tip of the tongue and the capability to role it up into a tube suggest adaptations for nectar feeding. (Gale Research, 1999; Gale, 2003; Hatch, 1985; Lepson and Freed, 1997)
Primary Diet:
carnivore (insectivore , eats non-insect arthropods); herbivore (nectarivore ).
Animal Foods:
insects; terrestrial non-insect arthropods.
Plant Foods:
nectar.
Predation
- pueos (Asio flammeus sandwichensis)
- 'los (Buteo solitarius)
- domestic cats (Felis silvestris)
- Polynesian rats (Rattus exulans)
- brown rats (Rattus norvegicus)
- black or roof rats (Rattus rattus)
- Indian mongooses (Herpestes javanicus)
- common mynas (Acridotheres tristis)
Little is known about predation pressures on akepas. Introduced species, such as domestic cats (Felis silvestris), Polynesian rats (Rattus exulans), black or roof rats (Rattus rattus), brown rats (Rattus norvegicus), Indian mongooses (Herpestes javanicus), and common mynas (Acridotheres tristis), are believed to be potential predators. Natural predators are thought to be bird-eating owls, pueos (Asio flammeus sandwichensis), and Hawaiian hawks, or 'los (Buteo solitarius). (Lepson and Freed, 1997; Walton Beacham, 1990)
Ecosystem Roles
Akepas may help to pollinate flowers when they eat nectar. They may also impact the populations of insects on which they prey. (Lepson and Freed, 1997)
Economic Importance for Humans: Negative
Hawaiian akepas have no negative economic impact on humans. (Gale, 2003; Lepson and Freed, 1997)
Economic Importance for Humans: Positive
Akepas are an important part of the native Hawai'ian avifauna and attract ecotourism. (Gale, 2003; Lepson and Freed, 1997)
Ways that people benefit from these animals:
ecotourism .
Conservation Status
IUCN Red List: [link]:
Endangered.
US Migratory Bird Act: [link]:
No special status.
US Federal List: [link]:
Endangered.
CITES: [link]:
No special status.
Both extant subspecies of akepas are listed as endangered according to the IUCN Red List, the United States Endangered Species Act list, and the state of Hawai'i. The largest threat for the species is habitat destruction as a result of logging and forest clearing for animal grazing. Other reasons include predation of akepas by introduced species and declining numbers of ohia trees, in which akepas build their nests. Currently much of the lands akepas inhabit have become state or national parks, but more is needed to save their dwindling populations. (Gale Research, 1999; Gale, 2003; Lepson and Freed, 1997; Walton Beacham, 1990)
Other Comments
The genus name Loxops comes from the Greek word Loxia, which means "to look like a crossbill", and is given to the akepa because of its asymmetrical bill shape. The species epithet coccineus comes from the Latin word coccinus, which means scarlet, in reference to the adult male plumage color. The common name, akepa, in Hawaiian means "lively" or "nimble" which describes their restless behavior. Also, the word "kepa" means "to cut obliquely" or "turn to one side", which could be a reference to the distinguishing asymmetrical bill shape. (Holloway, 2003; Lepson and Freed, 1997)
For More Information
Find Loxops coccineus information at
Contributors
Tanya Dewey (editor), Animal Diversity Web, University of Michigan Museum of Zoology.
Laura Podzikowski (author), Kalamazoo College. Ann Fraser (editor, instructor), Kalamazoo College.
