Diamond Firetails – Gems of the Australian Bush

Life history and movements

Many aspects of the Diamond firetail life history are poorly understood. Undoubtedly the most comprehensive account of the biology and behaviour of this species in the field and in aviaries was provided by Brian O’Gorman in two articles published in Australian Aviculture in January 1980 and January 1981. O’Gorman’s field study focussed on the Grampians region of western Victoria where he spent 5 years documenting habitat use, feeding and nesting behaviours. Diamond Firetails are far more social than other Stagonopleura firetails (Beautiful and Red-eared) and may occur in small flocks (up to 30-40) during the non- breeding season.

Throughout their range Diamonds are regarded as being sedentary although several authors note seasonal movements between denser and more open environments. O’Gorman (1981) documented regular annual movements from their spring/summer breeding areas in the Grampians to the more open mallee plains to the north-west where the birds spent the winter often in large aggregations of up to 300 birds. They return to the Grampians in August/September. While there are no detailed accounts of the size of home ranges, densities of up to 1.2 birds/ha have been recorded in Eucalypt woodland near Armidale, NSW (Ford et al 1986) and 0.1 to 0.2 birds/ha in remnants and revegetation areas in South Australia (Paton et al 2004). These few density measurements certainly indicate substantial fluctuations in population size at most locations.

Availability of suitable seed throughout the year is of course an essential habitat requirement, although Diamond Firetails have an extremely wide diet in the wild. They are ground-feeders that predominantly eat ripe and half-ripe seeds of various native and introduced grasses but are also known to feed on seeds of herbs, bushes and trees, numerous types of green plant materials as well as insects (Immelmann 1965, O’Gorman 1981). Read (1994) quantified the diet of Diamond Firetails in the Mount Lofty Ranges of South Australia by analysing the crop contents of wild-caught birds. He found, not surprisingly, that grass and herb seeds dominated the diet, with 65.1% of crop samples containing only seeds. Identification of the seeds showed that Diamonds concentrated on weed and pasture grasses rather than native species, probably because introduced plants often produce abundant seeds. From 45 samples he identified 19 different plant species, many of which were not grasses. Although exotic grasses are a valuable seed source, the periodicity of this seed supply may be inadequate for maintaining populations. A diversity of native grasses with differing phenology and maturation patterns appears essential for their persistence in an area (Paton et al 2004).

Breeding behaviour in the wild

Diamonds in the wild have a loose breeding season in spring/summer (August to January) although they may also breed in autumn, taking advantage of appropriate conditions. O’Gorman (1981) noted double broods in 3 out of 5 years which seemed to be linked to higher rainfall. Breeding may occur in loose colonies, sometimes with several nests in the same tree (Immelmann 1965), where they build a domed nest with a long entrance tunnel constructed of long pieces of interwoven green grass. Nest heights vary considerably with some at 2metres and others up to 10 metres above the ground.

An interesting feature of nest site selection is a preference by Diamonds to nest in clumps of mistletoe growing in large eucalypts. O’Gorman (1981) first noted this preference and recent field studies have quantified this. Cooney and Watson (2005) found that while mistletoe made up only 0.5% of canopy volume in their woodland study area near Holbrook, NSW, some 30% of diamonds nests were located in mistletoe. All these nests were in mistletoe growing on Eucalyptus blakleyi and at an average height of 4.2 to 4.3 metres. This site preference is suggested to provide three benefits for nesting success of diamond firetails (Cooney et al 2006):

1. A sturdy location which helps the structural integrity of the nest
2. Protection from predation on the nest
3. Modifying the microclimate experienced by the nest and nestlings

In contrast to these findings Macguire and Kleindorfer (2007) in their study of diamonds in the Mount Lofty Ranges found most Diamond Firetail nests were in Banksia speciosa, even though mistletoe was abundant. Clearly any preference in nest-site selection varies between areas.

Nest Adornment: Diamond Firetails are also known to weave flowers into the entrance of their nests. McGuire and Kleindorfer (2007) conducted a study in the Mount Lofty Ranges to determine the occurrence of flowers and whether nests with flowers were more successful than nest without flowers. They found that 70% of nests studied had flowers woven into the entrance; however predation occurred irrespective of the number of flowers found on nests. They note that Diamond Firetails prefer long stems in building nests, due to its structural stability and being easier to weave, and suggest that the presence of flowers is merely a by- product of the preference of suitable nest-building material.

Nest Predation: While as aviculturists we become familiar with finch nests having high success rates we often don’t realise that the situation is very different in the field. The little data available indicates that the success rate for Diamond firetail nesting in the wild is very low. Macguire and Kleindorfer (2007) found that predation on nests averaged a staggering 96% (100% in 2004 and 91% in 2005).

Much of this predation is by birds (currawongs, kookaburras, butcherbirds) and the rate of predation is probably much higher today than before white settlement due to the fragmentation of the landscape. With increased fragmentation of habitat there has been an increase in edge effects which includes the increase of edge-specialists. The Department of Environment and Climate Change NSW (2005) state that nest predation of Diamond Firetails by Pied Currawongs has increased with the degradation of fragmented remnants. Weeds species with berries, such as Hawthorn and Cotoneaster, can invade remnants which has assisted an increase in the population of Pied Currawongs.

The Steady Decline in Abundance of Diamonds

In 1932 Neville Cayley commented that the Diamond Firetail “is freely distributed throughout the southern portions of Queensland, through NSW and Victoria and into the eastern parts of South Australia”. Cayley (1932) further reported that Gould had found this species was plentiful everywhere he visited in SA and NSW, being equally numerous west of the divide on the Liverpool Plains and the Namoi and Mooki river plains of NW NSW. While Diamonds are still present in these areas they are hardly plentiful.

Indeed since the early 1980s Diamond Firetails have experienced a significant decline in abundance relative to earlier times. Surveys of the Mount Lofty Ranges population in South Australia shows that average recording rate across the region declined from 27% to 6% of surveys for the pre-1980 to post-1995 periods (1). It has also declined in abundance throughout New South Wales and Victoria and in South Australia the Eyre Peninsula, Flinders Range and Mt Lofty Ranges sub-populations are all now likely to be isolated. Elsewhere populations are highly fragmented.

In the Mount Lofty ranges, Paton et al (2004) note that while Diamond Firetails breed well during summer and early autumn populations may comprise 70% juvenile birds, their populations decline dramatically during late autumn and winter. The majority of birds banded each summer simply disappear. They suggest that changed patterns of seed supply during winter due to the replacement of native grasses by summer seeding introduced grasses may be one factor explaining this seasonal loss.

Antos and Bennett (2006) showed clearly that foraging behaviour per se cannot explain the decline. They note that the Diamond Firetail and Yellowrumped Thornbill showed 80% similarity in foraging ecology – they both foraged on the ground on substrates such as leaf- litter and bare ground, although the Firetail foraged more frequently on grass. However they note that one species, the Diamond Firetail, is experiencing severe decline throughout much of its range, while the Yellow-rumped Thornbill is proliferating in most places. Clearly factors other than foraging behaviour are involved in the decline of diamonds.

In Queensland the species was once distributed north to Cardwell, Qld, mostly on the inland slopes of the Great Dividing Ra., but is no longer recorded north of Clermont (Qld) and indeed it may well be lost from much of southern Qld. For this northern part of its range, Woinarski and Caterall (2004) provide an interesting historical perspective. They describe an extended study of birds on Coomooboolaroo Station which lies just south of the Emerald to Rockhampton road within the Brigalow Belt bioregion in central Queensland. This property is unique in that well known ornithologist Charles Barnard (famed for his work with the Paradise parrot (see Olsen 2008 )) maintained a detailed record of bird fauna on the property from 1873 to 1933. More recent surveys can thus be compared with his records to track patterns of change. This analysis showed that the Diamond Firetail had been quite common in this region and in fact increased in abundance up to 1933, but it had disappeared altogether by 1999 when Woinarski and Caterall (2004) resurveyed the property.

So significant is the decline that the Diamond Firetail is now declared as “Vulnerable” in NSW, “Endangered” in Queensland, “near Threatened” in Victoria and “near threatened” in the Australian government’s “Action Plan for Australian Birds 2000” (2). These ratings clearly indicate that the species has declined dramatically throughout its range, although it is difficult to find quantitative information that demonstrates the decline (Ford et al 2005).

Another clear indication of decline is that numerous birding guides, landscape restoration projects and conservation guides now use the diamond firetail as a focal bird. Examples include the Murrumbidgee Catchment Management Authority (3), Liverpool Plains Bird Routes (4), Cotton Catchment Communities CRC booklet – Birds on Cotton Farms (5) which lists the Diamond Firetail as an “indicator species” linked to healthy functioning vegetation on farms, and Birds Australia’s “Woodland Birds Conservation Project” (6).

Threatening Processes

Diamond Firetails are threatened largely by the extensive clearance and fragmentation of habitat. Some 80% of Australia’s temperate woodlands have been cleared since European settlement. In some previous strongholds for diamonds in South Australia less that 7% of habitat remains intact (Macguire and Kleindorfer 2007). There seems to be good evidence that Diamond populations are unable to persist in areas where remnants of native vegetation are smaller than 200ha. Fragmentation of habitat leads to smaller, isolated populations where dispersal is inhibited and genetic variability may be lost, so increasing their vulnerability to local extinction.

The NSW Threatened Species website (7) identifies a broad range of factors leading to decline of the diamond firetail:

• Clearing and fragmentation of woodland, open forest, grassland and mallee habitat  for agriculture and residential development, and firewood collection.
• Poor regeneration of open forest and woodland habitats.
• Invasion of weeds, resulting in the loss of important food plants.
• Modification and destruction of ground- and shrub layers within habitat through:removal of native plants, litter and fallen timber; introduction of exotic pasturegrasses; heavy grazing and compaction by stock; and frequent fire.
• Predation of eggs and nestlings by increased populations of native predators such as the Pied Currawong Strepera graculina.
• Risk of local extinction due to small, isolated populations.
• Ongoing illegal trapping – it is noteworthy that the populations studied by BrianO’Gorman were essentially trapped out soon after his article with their locations was published (G. Hyde pers. comm.).Birds Australia also emphasises the plight of the Diamond Firetail by including it in the BA Woodland Birds Conservation Project (6), along with the Regent Honeyeater and the Swift Parrot as species requiring conservation efforts. This project aims to benefit all these species through:
• Improved on-ground management and protection of woodland habitat on both public and private land
• Improved habitat connectivity and extent through restoration and revegetation initiatives
• Monitoring of the effectiveness of habitat restoration on both private and public land
• Ongoing monitoring to determine population trends and priority sites for woodlandbirds across south-eastern Australia
• Increased community survey effort for a greater diversity of species
•  Identification and monitoring of the potential impacts of climate change on woodland birds and their habitats

Droughts can also compound the effects of clearing and grazing. Ford et al (2001) noted that the red-browed finch and double-barred finch disappeared from a well-studied remnant in the New England tablelands while diamond firetails changed from being common to rare during a drought in the early 1980s.

Conclusions

The Diamond Firetail is a species we should treasure in our aviaries and in the wild. The species is clearly under significant pressure and we can only hope that efforts to redress extensive modification of Australia’s woodland systems can help to stem the decline. While the Diamond Firetail is perhaps not as threatened as the Blackthroated finch (Poephila cincta) (8) or the much higher profile Gouldian finch (Erythrura gouldiae) (9), Diamonds are nonetheless under real pressure and the species is a worthy symbol for the plight of many woodland birds and the ecosystems they depend on. Perhaps for the future we could consider the Diamond Firetail as the “Gouldian of the western woodlands” in an effort to further raise its profile and help with restoration efforts for these landscapes.

References

Antos, M. J., and Bennett, A. F. (2006). Foraging ecology of ground-feeding woodland birds in temperate woodlands of southern Australia. Emu 106: 29–40.

Antos M.J., Bennett A.F. and White J.G. (2008) Where exactly do ground-foraging woodland birds forage? Foraging sites and microhabitat selection in temperate
woodlands of southern Australia. Emu 108: 201–211

Cayley N. W. (1932) Australian Finches in Bush and Aviary. Angus and Robinson Sydney. Cooney S.J.N., Watson D.M. and Young J. (2006) Mistletoe nesting in Australian birds: a

review. Emu 106: 1–12.
Cooney S.J.N. and Watson D.M. (2005) Diamond Firetails (Stagonopleura guttata)

preferentially nest in Mistletoe. Emu 105: 317–322
Ford, H.A., Noske, S. and Bridges, L. (1986). Foraging of birds in eucalypt woodland in

north-eastern New South Wales. Emu 86:168-179
Ford H.A., Barrett G., Saunders D.A. and Recher H.F (2001). Why have birds in the

woodlands of Southern Australia declined? Biological Conservation 97: 71-88.

Immelmann (1965) Australian Finches in Bush and Aviary. Angus and Robertson, Sydney.

McGuire A. and Kleindorfer S. (2007) Nesting success and apparent nest-adornment in Diamond Firetails (Stagonopleura guttata). Emu 107: 44–51

Olsen P. (2007) “Glimpses of paradise – the quest for the beautiful parakeet”. National Library of Australia, ACT.

O’Gorman B. (1981) A prolonged field study of the Diamond Firetail. Australian Aviculture January 1981. pp. 14-27

Paton D.C., Rogers D.J., and Harris W. (2004) Birdscaping the environment: restoring the woodland systems of the Mt Lofty region, South Australia. Pp 331-358 in “Conservation of Australia’s forest fauna. 2nd Edition”. Royal Zoological Society of New South Wales; Mosman

Read J.L. (1994) The Diet of Three Species of Firetail Finches in Temperate South Australia. Emu 94: 1-8

Woinarski J.C.Z. and Catterall C. (2004) Historical changes in the bird fauna at Coomooboolaroo, northeastern Australia, from the early years of pastoral settlement (1873) to 1999. Biological Conservation 116: 379–401

Weblinks

1. http://www.environment.sa.gov.au/biodiversity/pdfs/regional_recovery/fauna/birds/diamond- firetail.pdf
2. http://www.environment.gov.au/biodiversity/threatened/publications/action/birds2000/index.html
3. http://www.murrumbidgee.cma.nsw.gov.au/uploads/media/Diamond_Firetail.pdf
4. http://www.visitquirindi.com.au/attractions/bird_routes.html
5. http://www.cottonaustralia.com.au/environment/resources/Birds_On_Cotton_Farms.pdf
6. http://www.birdsaustralia.com.au/our-projects/woodland-bird-conservation.html
7. http://www.threatenedspecies.environment.nsw.gov.au/
8. http://www.blackthroatedfinch.com/
9. http://www.savethegouldian.org/[Copyright remains with the Author]