Eastern spinebills often produce high-pitched, rapid "pip" vocalizations. During courtship, pairs perform flight displays in which the male flies behind the female and they chase in an undulating motion. To initiate this courtship flight, a male will touch his beak to a female's tail. When feeding on flower nectar, eastern spinebills sing a piping territorial song to defend the flower. They raise feathers on their throat and crown and flick their tails 2 to 3 times per second if they feel threatened or when they are ready to fight. Eastern spinebills also perform broken-wing, distraction displays when their nestlings are threatened. Like all birds, eastern spinebills perceive their environment through audio, visual, tactile, and chemical stimuli.
Communication Channels: visual ; tactile ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
The increase in feral cat populations has led to population declines in eastern spinebills. Despite population declines of over 30% in recent years, the IUCN Red List labels the species as least concern.
CITES: no special status
IUCN Red List of Threatened Species: least concern
There are no known adverse effects of Acanthorhynchus tenuirostris on humans.
Although humans are not affected directly, pollination by eastern spinebills allows for greater diversity of flowers not only in the wild but also in gardens and urban parks.
Like all honeyeaters, eastern spinebills are very effective pollinators for nectar-producing plant species. While feeding on nectar, their heads often brush against the flower and collect pollen which is then transferred to the next flower they feed on. Due to their specialized bills, eastern spinebills forage from a limited group of flowering species, therefore reducing the amount of cross-pollination and resulting in very effective pollination. During winter or low nectar resources, eastern spinebills also prey on insects and likely impact their populations as well.
Several species of cuckoos including pallid cuckoos (Cuculus pallidus) and shining bronze-cuckoos (Chrysococcyx lucidus) are brood parasites known to use eastern spinebills as hosts. Brood parasitism can result in lower productivity for host species, as the parasitic young often eject other hatchlings out of the nest or out-compete them for food.
Eastern spinebills are also known to be hosts for some flower mites including Hattena cometis and H. floricola. The flower mites may negatively affect eastern spinebills by consuming nectar and therefore reducing food availability for spinebills.
Ecosystem Impact: pollinates
Commensal/Parasitic Species:
Eastern spinebills are primarily nectar-feeders and use their highly-adapted, tubular beak to forage from tubular flowers. Their highly specialized beaks are hypothesized to be the result of a close co-evolution with the tubular flowers they feed upon. Eastern spinebills select flowers based on available nectar rather than size of the flower. Young are mainly fed on insects, differing from adults who depend on insects only during or prior to their breeding periods or when nectar availability decreases during winter.
These birds are most active during the day because the amount of nectar peaks at dawn and more insects are active at that time. Their nectar consumptions peaks in autumn, from August to October, mainly to store fat and increase their body mass to prepare for upcoming winter.
Animal Foods: insects
Plant Foods: nectar
Primary Diet: herbivore (Nectarivore )
Eastern spinebills are native to eastern and south-eastern Australia. They are widespread, ranging from east of the Great Divide to west of Carnarvon Gorge, passing through North Queensland. The range of eastern spinebills extends from the coast, inland to Boggabilla in the northwestern Plains Region. Acanthorhynchus tenuirostris is also found in Tasmania. These birds may migrate during cold months but they are usually within one region, depending on food source availability.
Biogeographic Regions: australian (Native )
Eastern spinebills mainly inhabit dense forest and woodlands with thick underbrush. They nest on a small tree or bush from a few to more than ten meters above the ground. They are common in low-altitude and near-coastal, dry heathland but they are sometimes present in the higher altitudes as well. They are occasionally found in rainforests, and less often in wet sclerophyll forest. Eastern spinebills are also common in urban gardens and parks. Eastern spinebills can be solitary or gregarious, and they show regular seasonal movements within a limited area depending on resource availability.
Habitat Regions: temperate ; tropical ; terrestrial
Terrestrial Biomes: rainforest ; scrub forest
Other Habitat Features: urban
Currently there is no data available on the lifespan of Acanthorhynchus tenuirostris.
The sexual dimorphism of eastern spinebills is not significant. Male eastern spinebills have an overall glossy black body about 13 to 16 cm long. Upper tail and inner wings are gray. They feature a white throat and bib that extends to the belly, and have a smaller, brown bib that covers only the throat. The lower breast and belly are a light brown to yellow-brown color. Males have feet and legs that are either black or dark red-brown. Females are similar to males but have more of an olive-grayish appearance and less intense brown on the throat. Along with the light, yellow-brown belly, females often have white feathers dispersed throughout plumage. Unlike male spinebills, females have paler, grayish-pink feet and legs. Whereas the juveniles' eyes are black, the adults tend to have bright red eyes. Their wing span ranges from 18 to 23 cm and their long, thin bills range from 2 to 5 cm. The average body weight is 11 g although it increases during the winter months due to the storing of fat to conserve energy. Eastern spinebills go through two moulting stages sometime between early December and late April.
Acanthorhynchus tenuirostris can be distinguished from Acanthorhynchus superciliosus, or western spinebills, by differences in body size and appearance. A. superciliosus, slightly smaller than A. tenuirostris, has white supercilium and an overall appearance of olive-gray rather than black.
Average mass: 11 g.
Range length: 13 to 16 cm.
Range wingspan: 18 to 23 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike; sexes colored or patterned differently; male more colorful
In public parks and gardens, feral cats and occasionally some domestic dogs kill these birds. Bird feeders that provide manufactured "nectar" can be detrimental to birds' health, due to the lack of thiamine in the refined sugar. Predation rate increases during the breeding season when helpless nestlings are vulnerable to attack. When adult birds sense a predator approaching, they perform broken-wing distraction displays and lure the predators away from the nest. If nestlings have fledged or are near fledging, they may flutter or explode from the nest when predators come near which often proves fatal.
Known Predators:
The exact mating system of eastern spinebills is unknown, but they are likely socially monogamous. A specific pair will nest and tend their brood, but individuals have been observed to make extra-pair copulations. To initiate a courtship flight, a male flies over to a female and either touches the female's tail with his bill or calls loudly. The display lasts for 15 to 30 seconds. They fly in an undulating pattern with the male pursuing the female. Sometimes the female turns around suddenly to face her pursuer and they hover briefly, touching each others' bills. In the end, they land near the location where they began. The courtship can last for over a week with feeding and resting occurring in between. There is no mate defense during courtship, so other male spinebills can come and initiate flight with the same female while the other male is resting or feeding.
Mating System: monogamous
The breeding season occurs from August to December. Both the male and female collect materials suitable for their nest, however only the female actually builds the nest. Females can lay up to 4 eggs, with an average of 2 eggs per clutch, and can lay up to 5 clutches per season. The approximate interval time between two clutches ranges from 37 to 41 days. The average incubation period last 14 days after which the nestlings are born, weighing around 8 g each. It takes an average of 14 days for young to fledge, and they become independent and begin foraging 8 days later. Information on when the young reach sexual maturity is not known, but once the young reach independence they leave the territory while the adults remain.
Breeding interval: Eastern spinebills can breed up to 5 times per season, with a 37 to 41 day interval between clutches.
Breeding season: Eastern spinebills breed between August and December.
Range eggs per season: 1 to 4.
Average eggs per season: 2.
Average time to hatching: 14.4 days.
Average fledging age: 13.7 days.
Average time to independence: 3 weeks.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; oviparous
Incubation is primarily performed by female eastern spinebills, but males will occasionally assist. Both sexes remove fecal sacs when naked nestlings hatch from the eggs and feed the young every 5 to 10 minutes. Although the young occasionally are fed nectar, most of them are fed insects until they are capable of independently feeding on nectar. Nestlings are known to be very noisy while they are fed. After less than 2 weeks the parents encourage the young to fledge. The adults prepare for their subsequent nest 1 to 9 days after the young fledge. While the parents remain in the territory to make a new nest, juveniles leave the territory after being chased by their parents or voluntarily when they become independent.
Parental Investment: altricial ; male parental care ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female)
The eastern spinebill (Acanthorhynchus tenuirostris) is a species of honeyeater found in south-eastern Australia in forest and woodland areas, as well as gardens in urban areas of Canberra, Sydney, Melbourne, Adelaide and Hobart. It is around 15 cm long, and has a distinctive black, white and chestnut plumage, a red eye, and a long downcurved bill.
Originally described as Certhia tenuirostris by the English ornithologist John Latham in 1801,[2] it is a member of the small genus Acanthorhynchus with one other, the western spinebill of Western Australia. The generic name is derived from the Greek translation of spinebill, namely acantho-/ακανθο- 'spine' and rhynchos/ρυνχος 'bill'.[3] Its specific epithet is from Latin tenuis 'narrow' and rostrum 'bill'. Other English names include spine-billed honeyeater and awl-bird or cobbler's awl bird.[4] The eastern spinebill is polytypic, consisting of the subspecies A. t. cairnsensis, A. t. dubius, A. t. halmaturinus, and the nominate subspecies A. t. tenuirostris.[4]
The eastern spinebill forms a superspecies with the closely related western spinebill.[5] Scientists believe the two sister species are descended from a shared ancestor whose once widespread populations were separated by climate change. During a past period of desertification, that ancestor species retreated to refuges in the southwestern and southeastern corners of the continent, and evolved into the two present-day spinebill species.[6] Recent DNA studies have shown that the two spinebills belong to a clade which is a sister taxon to all other honeyeaters.[7]
The male eastern spinebill is 13–16 cm (5–6.5 in) long, and has a long thin downcurved black bill with a black head, white throat with a chestnut patch and red iris.[8] It has a brownish-red nape, a grey-brown back and pale cinnamon underparts.[8] The dark tail is tipped with white laterally.[8] Females are smaller with olive-grey crown, similar in colouring to male but slightly duller; and juveniles are pale warm cinnamon below with grey to olive-brown upperparts, a brown-red eye and orange base to the bill.[9][8][10] The call is a clear, high-pitched, staccato piping "chip-chip-chip", sometimes repeated for lengthy periods.[11][8][9]
Eastern spinebills are found in dry sclerophyll forest, scrub and heathland from the Cooktown area in North Queensland south through New South Wales east of the Great Dividing Range, through Victoria and into the Flinders Ranges in eastern South Australia as well as throughout Tasmania.[11] Adaptable, they can be found in urban gardens with sufficient vegetation to act as cover and a food source.
Breeding season is from August to January, with one or two broods raised. The nest is a deep cup-shaped structure of grass and bark strips, lined with feathers and soft plant fibres, hanging by the rim in the fork of a small bushy tree or shrub, 1–15 m (3–49 ft) above ground.[8] The clutch is one to four, with two being the average, pinkish eggs with dark reddish-brown blotches and spots, 17 mm × 13 mm (0.7 in × 0.5 in) in size.[12] The female incubates the eggs for 13 to 16 days before hatching. Both parents feed the chicks and remove the faecal sacs from the nest.
The eastern spinebill feeds on nectar from many plants, including the blooms of gum trees, mistletoes Amyema spp., Epacris longiflora,[13] Epacris impressa (common heath), Correa reflexa, and various members of the Proteaceae such as Banksia ericifolia,[14] Banksia integrifolia, Lambertia formosa and Grevillea speciosa, as well as small insects and other invertebrates. A 1982 study in the New England National Park in north-eastern New South Wales found that there was a large influx of birds coinciding with the start of flowering of Banksia spinulosa there.[13] They have been known to feed from exotic plants such as fuchsias.[15]
During periods of abundant flowering there may be periods of low nectar production, and it appears that the eastern spinebill responds to these periodic shortages by storing fat during periods of high nectar production, increasing the amount of time spent feeding, or dropping its day-time metabolic rate to night-time levels.[16]
The eastern spinebill (Acanthorhynchus tenuirostris) is a species of honeyeater found in south-eastern Australia in forest and woodland areas, as well as gardens in urban areas of Canberra, Sydney, Melbourne, Adelaide and Hobart. It is around 15 cm long, and has a distinctive black, white and chestnut plumage, a red eye, and a long downcurved bill.
