Noisy Miner

Noisy Miner 2Description

The noisy miner (Manorina melanocephala) is a bird in the honeyeater family, Meliphagidae, and is endemic to eastern and south-eastern Australia. This miner is a grey bird, with a black head, orange-yellow beak and feet, a distinctive yellow patch behind the eye and white tips on the tail feathers. The Tasmanian race has a more intense yellow panel in the wing, and a broader white tip to the tail. Males, females and juveniles are similar in appearance, though young birds are a brownish-grey. As the common name suggests, the noisy miner is a vocal species with a large range of songs, calls, scoldings and alarms, and almost constant vocalizations particularly from young birds. One of four species in the genus Manorina, the noisy miner itself is divided into four subspecies. The separation of the Tasmanian M. m. leachi is of long standing, and the mainland birds were further split in 1999.

Found in a broad arc from Far North Queensland through New South Wales and Victoria to Tasmania and southeastern South Australia, the noisy miner primarily inhabits dry, open eucalypt forests that lack understory shrubs. These include forests dominated by spotted gum, box and ironbark, as well as in degraded woodland where the understory has been cleared, such as recently burned areas, farming and grazing areas, roadside reserves, and suburban parks and gardens with trees and grass but without dense shrubbery. The density of noisy miner populations has significantly increased in many locations across its range, particularly human-dominated habitats. The popularity of nectar-producing garden plants such as the large-flowered grevilleaswas thought to play a role in its proliferation, but studies now show that the noisy miner has benefited primarily from landscaping practices that create open areas dominated by eucalypts.

Noisy miners are gregarious and territorial; they forage, bathe, roost, breed and defend territory communally, forming colonies that can contain several hundred birds. Each bird has an ‘activity space’ and birds with overlapping activity spaces form associations called ‘coteries’, the most stable units within the colony. The birds also form temporary flocks called ‘coalitions’ for specific activities such as mobbing a predator. Group cohesion is facilitated not only by vocalizations, but also through ritualised displayswhich have been categorised as flight displays, postural displays, and facial displays. The noisy miner is a notably aggressive bird, and chasing, pecking, fighting, scolding, and mobbing occur throughout the day, targeted at both intruders and colony members.

Foraging in the canopy of trees and on trunks and branches and on the ground, the noisy miner mainly eats nectar, fruit and insects. Most time is spent gleaning the foliage of eucalypts, and it can meet most of its nutritional needs from manna, honeydewand lerp gathered from the foliage. The noisy miner does not use a stereotyped courtship display, but copulation is a frenzied communal event. It breeds all year long, building a deep cup-shaped nest and laying two to four eggs. Incubation is by the female only, although up to twenty male helpers take care of the nestlings and fledglings. Noisy miners have a range of strategies to increase their breeding success including multiple broods and group mobbing of predators. The noisy miner’s population increase has been correlated with the reduction of avian diversity in human-affected landscapes. Its territoriality means that translocation is unlikely to be a solution to its overabundance, and culling has been proposed, although the noisy miner is currently a protected species across Australia.

Appearance

The noisy miner is a large honeyeater, 24–28 centimetres (9.4–11.0 in) in length, with a wingspan of 36–45 centimetres (14–18 in), and weighing 70–80 grams (2.5–2.8 oz). Male, female and juvenile birds all have similar plumage: grey on the back and tail and on the breast, and otherwise white underneath, with white scalloping on the nape and hind-neck and on the breast; off-white forehead and lores; a black band over the crown, bright orange-yellow bill and a distinctive patch of yellow skin behind the eye; a prominent white tip to the tail; a narrow olive-yellow panel in the folded wing; and orange-yellow legs and feet. A juvenile can be distinguished by softer plumage, a brownish tinge to the black on its head and the grey on its back, and a duller, greyish-yellow skin patch behind the eye.[12]

The noisy miner is similar in appearance to the yellow-throated miner and the black-eared miner; it has a dull white forehead and a black crown, while the others have grey heads.[14]

Geographical variations

Size variation in the noisy miner over its range follows Bergmann’s rule; namely, birds tend to be larger where the climate is colder.[11] Adults from central-eastern and northern Queensland tend to have little or no olive-yellow edging to the feathers of the back and wings, and have a wider white fringe on the feathers of the hind-neck and back, giving birds from Queensland the appearance of having more distinctive scalloping than other populations.[15] Wing length generally increases with latitude andM. m. leachi has measurably shorter wings than the nominate race, although no significant difference in wing length was found in a study of populations north of 30° S and south of the Murray River.[15] The subspecies leachi also has finer scalloping on the hind-neck than the nominate race, a more intense yellow tinge to the wing panels, and a slightly broader off-white tip to the tail.[12]

The far north Queensland subspecies titaniota has a shorter tail, paler crown, larger yellow skin patch, and paler upper parts without the yellow-olive of the nominate race; and lepidota, found in western New South Wales, is smaller than the nominate race with a black crown, and darker more mottled upperparts.[11]

Vocalisations

As the common name suggests, the noisy miner is an unusually vocal species. Previously known as the garrulous honeyeater, it has a large and varied repertoire of songs, calls, scoldings and alarms.[16] Most are loud and penetrating, and consist of harsh single notes.[17] It has two broad-frequency alarm calls that are used when mobbing intruders into their territory, or when predators (including humans) are sighted; and a narrow-frequency alarm call that is primarily used when airborne predators are seen, such as the brown falcon (Falco berigora), or other large flying birds including the Australian magpie (Cracticus tibicen) and the pied currawong (Strepera graculina).[18] The aerial predator alarm call is a series of high-pitched, slurred whistling notes. The broad-frequency alarm calls are a series of ‘churr’ notes, low pitched and harsh, occurring at low and high levels of intensity.[16] The narrow-band call is used in situations where the bird signals the presence of a predator and restricts information about its own location, while the broad-band alarm is used to attract attention,[19] and can initiate mobbing behaviour. These churring calls vary between individuals,[20] and laboratory tests show noisy miners can distinguish calls by different birds. Hence, this may be integral to the complex social structure of the species.Distribution and habitat

Distribution

Noisy miner mapThe noisy miner is endemic to eastern and south-eastern Australia, occupying a broad arc from Far North Queensland where there are scattered populations, to New South Wales where it is widespread and common from the coast to a line from Angledool to Balranald, through Victoria into south-eastern South Australia, and eastern Tasmania. Its range in South Australia has been steadily expanding since it was first recorded near Adelaide in the early 1890s.[25] It is sedentary over its entire range.[26]The noisy miner is territorial, and the territory of a colony is aggressively defended—which has led to a significant reduction in avian diversity in areas occupied by the noisy miner, with smaller species excluded.[27]

The noisy miner primarily inhabits dry, open eucalypt forests without understory shrubs. It is commonly found in open sclerophyllforests, including those on coastal dunes or granite outcrops; forests dominated by spotted gum on mountain ridges and exposed slopes; box and ironbark forests on the foothills of the Great Dividing Range; mixed forests of eucalypts and cypress (Callitris); forests dominated by yapunya, mulga, gidgee, brigalow or emu bush; in stands of belah and scattered clumps of boree; on the edges of woodlands of river red gum including swamp woodlands bordering floodplains, and areas dominated by exotic species such as European ash and willow. It regularly inhabits degraded patches of forest where the understory has been cleared, including recently burned areas, and modified habitats such as lightly-timbered farming and grazing areas, roadside reserves, bushland remnants in towns and cities, and suburban parks and gardens with trees and grass but without dense shrubbery.[28]

The noisy miner has benefited from the thinning of woodland on rural properties, heavy grazing that removes the understory, fragmentation of woodland that increases the percentage of edge habitat, and urban landscaping practices that increase open eucalypt environments.[26] It has been described as a ‘reverse keystone’ species, as it is colonizing an ever-increasing range of human-dominated habitats, and aggressively excluding smaller bird species from urban environments.[27] This phenomenon has been also observed in rural areas. A field study across the South West Slopes of New South Wales, showed that the noisy miner’s presence corresponded with reduced numbers of insectivorous birds such as fantails, whistlers, the restless flycatcher (Myiagra inquieta), and other honeyeater species, and that this decrease was most marked in sites with better access to water and nutrients.[29] While it has been hypothesized that the proliferation of large-flowering grevillea cultivars has contributed to the abundance of noisy miners, recent research has identified the proliferation of lightly treed open areas, and the presence of eucalypt species as the most significant factors in the population increase.[27] Large-flowered grevillea hybrids such as Grevillea ‘Robyn Gordon’ can benefit the noisy miner, in that an abundance of resources is usually dominated by larger aggressive honeyeaters,[30] and a continuous nectar source could provide an advantage for the non-migratory species.[31] A field study in box-ironbark country in central Victoria found miner numbers were correlated with the occurrence of yellow gum (Eucalyptus leucoxylon), which reliably produces flowers (and nectar) each year.[32] The abundance of the noisy miner is primarily determined by habitat structure.[33][34]

FeedingNoisy Miner 1

 The noisy miner primarily eats nectar, fruit and insects, and occasionally it feeds on small reptiles or amphibians. It is both arboreal and terrestrial, feeding in the canopy of trees and on trunks and branches and on the ground. It forages within the colony’s territory throughout the year, usually in groups of five to eight birds although hundreds may gather at a stand of flowering trees such as banksia. The noisy miner collects nectar directly from flowers, hanging upside down or straddling thin branches acrobatically to access the nectar; it takes fruit from trees or fallen on the ground; gleans or hawks for invertebrates; and picks through leaf litter for insects. It has been recorded turning over the dried droppings of emu (Dromaius novaehollandiae) and eastern grey kangaroo (Macropus giganteus) searching for insects.[50]

In a study of birds foraging in suburban gardens, the noisy miner was seen to spend more time in banksia, grevillea and eucalypt species, and when in flower, callistemon, than in other plants including exotics. Most time was spent gleaning the foliage of eucalypts, and noisy miners were significantly more abundant in sites where eucalypts were present. The noisy miner can meet most of its nutritional needs from manna, honeydew and lerp gathered from the foliage of eucalypts.[27] 

Detailed studies of the diet of the noisy miner record it eating a range of foods including: spiders; insects (leaf beetles, ladybirds,stink bugs, ants, moth and butterfly larvae); nectar (from Jacaranda mimosifolia, Erythrina variegata, Lagunaria patersonia,Callistemon salignus, Callistemon viminalis, eucalypts Argyle apple, sugar gum, yellow gum, grey ironbark, and grey gum,Banksia ericifolia, B. integrifolia, B. serrata, Grevillea aspleniifolia, G. banksii, G. hookeriana, G. juniperina, G. rosmarinifolia, and flowering quince); seeds from oats,wheat and pepper tree; fruit from saltbush, mistletoe and crabapple; frogs and skinks; and other matter such as bread, pieces of meat and cheese, and food scraps.[50]

{Click to hear call}