Holland Honeyeaters Research Articles

Nitrogen requirements of an old world nectarivore, the orange-tufted sunbird Nectarinia osea.

Nectarivorous birds are represented by three major radiations: honeyeaters and sunbirds in the Old World and hummingbirds in the New World. Costa's hummingbirds and New Holland honeyeaters have unusually low nitrogen requirements, which have been related to the species' low-protein, high-sugar diets. Therefore, we hypothesised that orange-tufted sunbirds (Nectarinia osea) would likewise have low-maintenance nitrogen requirements and low rates of endogenous nitrogen loss. To test this hypothesis, we measured nitrogen balance, total endogenous nitrogen loss, and body mass changes in captive birds, using insects as a nitrogen source. Nitrogen balance, estimated by regression analysis to be 3.9 mg d(-1), was less than one-half of that allometrically predicted, while total endogenous nitrogen loss (1.9+/-0.6 mg d(-1)) was less than one-third of the allometrically predicted value. Thus, orange-tufted sunbirds follow the same pattern of low nitrogen requirements found in hummingbirds and honeyeaters. Total endogenous losses of nitrogen in nectarivores are low because a fibreless, easily digestible liquid diet reduces nitrogen losses in the feces, while the protein-sparing effect of a diet containing largely sugar leads to low endogenous urinary nitrogen losses.

Aggression And Nectar Use in Territorial Non-Breeding New Holland Honeyeaters Phylidonyris novaehollandiae in Eastern Australia

Territorial non-breeding New Holland Honeyeaters Phylidonyris novaehollandiae were studied in an open forest in eastern Australia. During winter, birds maintained priority of access to nectar from Banksia inflorescences but the extent to which this use was exclusive was variable. I examined the aggressive responses of these birds to intruders of different sizes (interference behaviour), and their use of defended nectar (exploitation behaviour). Owners displayed interspecific discrimination with all honeyeater species being excluded except the much larger wattlebird which was harassed while feeding. Owners expelled a greater proportion of intruding conspecifics compared to other species and used more aggressive behaviour (chases) against them. Energy inexpensive aggression (displacements) was used against smaller intruder species who were also more likely to be attacked if they attempted to feed. The rate at which intruding honeyeaters were expelled (birds/h/m²) increased with both nectar abundance and intruder pressure but actual territory exclusiveness (proportion of intruders expelled) was highest only at moderate nectar levels (lower when nectar was poor or very rich). Owners visited inflorescences in their territories more often than intruding honeyeaters, and fed at the most productive inflorescence stages. Nectar within territories was depleted at a faster rate then undefended nectar. Consequently, the territories appeared to be operated as nectar 'sinks', rather than as the 'sources' typical of other nectarivorous birds.

Territorial Behaviour of Breeding White-Cheeked and New Holland Honeyeaters: Conspicuous Behaviour Does Not Reflect Aggressiveness

Breeding territoriality in birds is characterised not only by aggression, but also by a range of other behaviours making territory owners conspicuous. Birds perform displays and vocalisations, use exposed perches, and tend to confine their movements to well-defined centres of activity. Such behaviour may be advertisement to potential intruders, and may therefore tend to occur when territory owners are most aggressive. Alternatively, it may be associated with specific stages of breeding such as courtship or broodrearing. Distinguishing between these possibilities is difficult in breeding birds because changes in aggressiveness tend to be closely linked to breeding cycles. Male New Holland and White-cheeked Honeyeaters show pronounced seasonal changes in aggressiveness that are clearly not linked to breeding cycles. I monitored time budgets, displays and vocalisations of breeding males to determine whether the conspicuousness of their behaviour varied with changes in aggressiveness or with breeding cycles. No seasonal changes in behaviour suggested that males advertised their presence when they were aggressive. Changes in display and vocalisation rates with breeding cycles suggested that some aspects of these behaviours were advertisements to females. Both species performed song flight displays most frequently before egg laying, and White-cheeked Honeyeaters called most frequently when they were unpaired. The amount of time males spent on their territories also changed with breeding cycles and peaked when males were caring for young. I suggest that this pattern reflects demands of parenting rather than changes in advertisement behaviour. The extent to which males used exposed perches did not vary either seasonally or with breeding cycles.

Field Metabolic Rate and Water Flux of Nectarivorous Honeyeaters

Field metabolic rate (FMR) and water influx of New Holland honeyeaters (Phylidonyris novaehollandiae), eastern spinebills (Acanthorhynchus tenuirostris) and a crescent honeyeater (P. pyrrhoptera) were measured by the doubly labelled water technique. New Holland honeyeaters had just finished breeding and were beginning their summer moult. They ranged in mass from 15.4 to 21.0 g (mean = 17.3 g, n = 12) and had FMRs averaging 8.8 mt CO2 g(-1) h(-1) or 77.6 kJ day(-1), which was 2.8 times their measured basal metabolic rate (BMR). Their water influx rate averaged 10.7 mL day(-1). Eastern spinebills were still feeding young and had yet to begin moulting. They ranged in mass from 8.0 to 10.7 g (mean = 9.7 g, n = 6), had FMRs averaging 10.9 mL CO2 g(-1) h(-1) or 52.9 kJ day(-1) (2.5 times their measured BMR), and had an average water influx rate of 8.7 mL day(-1). FMR and water influx of a single 14.6-g crescent honeyeater, which was in late primary moult, were 75.9 kJ day(-1) (2.7 times measured BMR) and 12.5 mL day(-1). The FMR of New Holland honeyeaters varied inversely with mean standard operative temperature (T-es) calculated for values of T-es below 20 degrees C as follows: FMR (kJ day(-1)) = 134 - 5.47 T-es (n = 12, r(2) = 0.52). Honeyeater FMRs were much lower than would be predicted allometrically for hummingbirds of the same mass, reflecting the honeyeaters' low-cost foraging tactic of consuming nectar while perched.

Responses of Territorial New Holland Honeyeaters Phylidonyris novaehollandiae to Short-term Fluctuations in Nectar Productivity

New Holland Honeyeaters Phylidonyris novaehollandiae occupying feeding territories during the nonbreeding season were studied in an open forest in northeastern New South Wales. The energy content of these territories fluctuated from day-to-day both naturally and as a result of experimental manipulations. In response to artificial increases in nectar, territory owners did not alter territory area but did exclude a greater proportion of intruders, reduced the level of interspecific discrimination in aggression, and employed more energetically expensive aggression. However, at very high levels of nectar productivity the owners expelled fewer intruders. The results indicated a graded aggressive behaviour dependent on the prevailing nectar productivity and intruder rate. There was no increase in intruder pressure as productivity was increased during the experiments.

The Vocal Repertoires of Six Honeyeater (Meliphagidae) Species from Adelaide, South Australia

Honeyeaters (Meliphagidae) are prominent members of the avifauna in Australia, typically with four to five resident species in any area. We recorded vocalisations from six species resident around Adelaide in South Australia: the Red Wattlebird Anthochaera carunculata, Little Wattlebird Anthochaera chrysoptera, Noisy Miner Manorina melanocephala, White-plumed Honeyeater Lichenostomus penicillatus, New Holland Honeyeater Phylidonyris novaehollandiae and Crescent Honeyeater Phylidonyris pyrrhoptera. The larger honeyeaters (Red and Little Wattlebird) produced characteristically harsh vocalisations covering a wide range of frequencies. Crescent and White-plumed Honeyeaters had a varied and complex repertoire of calls and songs which were quite musical in nature. Noisy Miners and New Holland Honeyeaters produced vocalisations dominated by simple single note whistles. Each species had specific vocalisations emitted in different contexts: alarm, distress, begging and contact calls as well as song. Alarm and distress calls of the six species had common characteristics and typically induced responses from other honeyeater species.

Can Nest Predation Explain the Timing of the Breeding Season and the Pattern of Nest Dispersion of New Holland Honeyeaters?

We tested the following two predictions of the hypotheses that predation rate may select for nest spacing and winter breeding in New Holland honeyeaters: (a) the level of nest predation should be lower during the breeding season than outside it, and (b) clumped nests should show a higher predation rate than more dispersed nests. Artificial nests, containing budgerigar and artificial eggs, were set out in four different seasons and in two different configurations: clumped and spaced. Clumped nests suffered higher predation than spaced nests but there was no seasonal difference in total predation rates. Birds accounted for 67% of predation events for which the predator was identified

An inexpensive photographic technique for identifying nest predators at active nests of birds.

Change in rate of nest predation due to environmental modification is considered a major cause of population decline of many bird species. Our ability to adequately understand and effectively manage this effect is limited by our ability to identify the relative roles of individual nest predators. This is because nest predation is seldom witnessed despite its high frequency. We describe and evaluate an inexpensive photographic technique for identifying nest predators at active nests. Each camera unit (A$220) was triggered by circuitry (A$30), using a magnetic reed switch attached to a supplementary egg. A total of 51 nests of New Holland honeyeaters (Phylidonyris novaehollandiae) was monitored with the equipment. Of these, 39 were preyed upon. Predation was never witnessed, but predators were captured on film for 72% of nests at which predation occurred.

Correlation between nectar supply and aggression in territorial honeyeaters: causation or coincidence?

A fundamental prediction of food-based economic models of territoriality is that animals will not defend territories if food is so abundant that defense will not improve access to food. Several studies of nectar-feeding birds support this prediction, with territoriality being rare or absent in years when nectar was particularly abundant. However, these results could potentially be an artefact of changes in bird density with nectar availability, and in at least some cases the correlations between territory defense and nectar availability could be purely coincidental. This paper reports the first experimental test of whether cessation of territory defense in nectar-feeding birds results from a direct response to abundance of nectar. New holland honeyeaters Phylidonyris novaehollandiae and white-cheeked honeyeaters P. nigra show pronounced changes in their levels of territorial aggression over the 7–8 months that they breed. These changes are predictable from economic considerations in that the birds are least aggressive in the months when nectar is extremely abundant. I tested whether the birds were responding to changes in nectar availability by providing sugar-water feeders at “neutral” locations that were easily accessible to territory holders, but far enough away from territories that intrusion rates were unaffected. I tested for responses at two time scales feeders were put out for 48-h periods in 1987, and were left out continuously from January to October 1988. The only effect was that territory holders visited feeders instead of flowers when floral nectar was scarce. They continued to defend their territories aggressively at those times, showed seasonal changes in aggressiveness similar to birds on a site without feeders, and did not shift their territories toward feeders. I conclude that the observed changes in aggressiveness are not responses to changes in nectar availability, and suggest alternative explanations.

Effects of nectar volume and concentration on sugar intake rates of Australian honeyeaters (Meliphagidae)

Sugar intake rates of captive Australian honeyeaters (Meliphagidae) feeding at artificial flowers varied across species, and as a function of nectar volume and concentration within each species. Red Wattlebirds (Anthochaera carunculata, 110 g), achieved higher intake rates than New Holland Honeyeaters (Phylidonyris novaehollandiae, 20 g), and both achieved higher rates than Eastern Spinebills (Acanthorhynchus tenuirostris, 10 g). These results reflect differences in bill and tongue dimensions as well as in body mass. Sugar intake rates for all three species increased with volume (5-50 μl) at any given concentration (10-60% mass/mass sucrose). For a given volume, sugar intake rates peaked at intermediate concentrations: 40-50% for the two larger species, and 30-40% for the smallest species. Published studies for other nectarivores foraging at unlimited volume feeders also show optimal nectar concentrations of 30-50%. However, biophysical theory predicts optima at 20-26% for small volumes, and plants presumed to be adapted for bird-pollination often have dilute nectar (20-30%). To explore this discrepancy further, we presented New Holland Honeyeaters with a range of sucrose concentrations (10-50%) using two presentation schemes. In the first we varied concentration but kept volume constant, thus varying gross sugar reward available in each concentration. This gave maximum sugar intake rates at 50%. In the second we varied both volume and concentration so that gross sugar rewards were equal for all solutions, decoupling high concentrations and large sugar rewards. This gave optima at 20%. We argue that variation among plants in nature more closely resembles the latter, "equal sugar presentation" scheme, and therefore, that dilute nectars may indeed represent adaptations for bird pollination.

Co-operative Care of Fledglings by New Holland Honeyeaters

Co-operative Care of Fledglings by New Holland Honeyeaters

The seasonal abundance and foraging behaviour of honeyeaters and their potential role in the pollination ofBanksia menziesii

AbstractSeasonal changes in the abundances of five species of honey‐eaters were assessed in relation to the flowering phenology of Banksia menziesii in banksia woodland near Perth, Western Australia. The total number of honeyeaters was significantly correlated to the number of inflorescences ofB. menziesii. New Holland Honeyeaters. Brown Honeyeaters and Western Spinebills were present throughout the year, whereas the larger honeyeaters (Red and Little Wattlebirds) were observed when B. menziesii was flowering.The foraging behaviours of the Little Wattlebirds, New Holland Honeyeaters, Brown Honeyeaters and Western Spinebills were similar and all were likely to effect pollination of B. menziesii florets. Differences in their foraging position at an inflorescence, number and direction of foraging probes, and the time spent at an inflorescence were minimal. Western Spinebills used inflorescences lower in the tree crown than the other species. Movements to inflorescences on different plants were inversely related to honeyeater size. Smaller honeyeaters were frequently chased from inflorescences by the larger species, increasing the proportion of distant foraging movements made by the smaller species. Also these interrupted visits were of shorter duration than uninterrupted visits. Visitation by smaller species, especially the Brown Honeyeater, may result in more cross pollinations although the effect on the reproductive success of B, menziesii is unknown.

Patterns of Residency and Movement Among Honeyeaters in Heathland near Sydney

We present patterns of residency and movement derived from the results of a five-year program of banding birds and a three- year program of observing the location and behaviour of individually colour-banded birds in heathland in Brisbane Water National Park, near Sydney. New Holland and White-cheeked Honeyeaters account for most birds captured or observed in our study area. We define a resident bird to be one that is observed nesting andlor is repeatedly sighted in about the same area over a period of at least two days and then categorise species on the basis of whether or not resident individuals are present throughout most of the year. Those species that satisfy the latter criterion also exhibit high recapture rates whereas other species have relatively low recapture rates. We argue that our definitions are more useful than others in the literature. Based on the above definition and on recapture data, most individual New Holland and White-cheeked Honeyeaters are either transients that are captured just once and are never mapped as resident; or occasional residents that are captured more than once, visit our study area throughout their lives but satisfy our definition of resident only some of the time. Future residents, for example, spend some of their time on our grids for an average of eight months before being mapped as residents. There are also gaps of about three to five months between periods of residency. During summer, the residents appear to spend less time in our study areas than during the rest of the year. However, there appears to be no regular, seasonal movement of New Holland and White-cheeked Honeyeaters into and out of our study area. Residents show little variation over time in the locations of their centres of activity in the heathland and do not move far from these areas. Consequently, emigration of resident birds is negligible and departures of residents must be due to mortality. This mortality of residents, which averages about 54% p.a., is associated with low availability of nectar, the principal source of energy to these birds. Individuals often change partners but not unless their partner vanishes, presumed dead.

The Digestion of Pollen by Some Australian Birds

About one-third of all banksia pollen grains excreted 1-2 hours after ingestion by captive New Holland honeyeaters (Phylidonyris novaehollandiae), zebra finches (Poephila guttata) and budgerigars (Melopsittacus undulatus), had lost their protoplasmic contents. Most pollen passed through the digestive systems of these birds in 4-5 hours and up to 44% of grains were digested. The faeces of wild purple- crowned lorikeets (Glossopsitta porphyrocephala) showed a similar proportion of empty grains. In the budgerigar, honeyeater and lorikeet, loss of contents of pollen grains occurred, not in the stomach, but progressively along the intestine.

Radio-tracking Honeyeater Movements

In heathland areas near Sydney honeyeaters (mostly New Holland Honeyeaters Phylidonyris novaehollandiae and White-cheeked Honeyeaters R nigra) are either residents that can be observed repeatedly near the same location for at least two days or transients that are not seen again after initial capture and banding (Pyke & Recher, unpubl.). To understand what determines the distribution and abundance of resident honeyeaters it is necessary to know how and where individuals spend their time during the day. It is thus desirable to be able to follow their daily pattern of movements.

Determinants of Feeding Territory Size in the New Holland Honeyeater Phylidonyris Novaehollandiae

Territorial New Holland Honeyeaters were studied in an open-layered forest in north-eastern N.S.W. between 1981 and 1983. The birds aggressively defended productive inflorescences of both Banksia integrifolia and B. spinulosa. The size of feeding territories occupied by New Hollands (either alone or in pairs) decreased significantly as the density of inflorescences and the abundance of honeyeaters in the study area increased. Multivariate analyses suggested that changes in food density (inflorescence density) determine territory size while changes in intruder pressure (honeyeater numbers) have no significant effect except through the intervening variable of food density. Feeding territories may be held for only a few days but most last a number of weeks.

Breeding Behaviour of the New Holland HoneyeaterPhylidonyris Novaehollandiae

The breeding of New Holland Honeyeaters was studied in New England National Park, N.S.W., between June 1981 and December 1983. New Hollands bred in the autumn and spring of each year. Of the 57 eggs found, only 36.8% survived to become fledglings, with most of the losses being attributed to predation. Nest sites were defended and the owners discriminated between different intruder species. In terms of energy from nectar, these territories were uneconomical for most of the reproductive cycle in autumn. Males undertook most of the nest defence while only females built nests and incubated eggs. During incubation, females used the territory's nectar resources more than the males.

Seasonal changes in a honeyeater assemblage inBanksiawoodland near Perth, Western Australia

Abstract Honeyeaters were the most numerous birds in banksia woodland near Perth, Western Australia, throughout the year. Numbers were greatest in a Banksia littoralis swamp, but only during those few months when it contained large amounts of nectar. In the surrounding woodland, numbers were lower but fairly constant during the year. This reflects the smaller amounts of nectar produced throughout the year, by the overlapping flowering patterns of several Banksia and Adenanthos species. Large and medium-sized honeyeaters (wattlebirds and New Holland Honeyeaters) and flocking silvereyes dominated the swamp when it flowered. In contrast, small honeyeaters (spinebills and Brown Honeyeaters), many of whom were highly territorial residents, comprised the majority of the woodland assemblage throughout the year. These observations support a model based upon aggressive defence of rich nectar sources by the larger honeyeater species, and more efficient exploitation of dispersed flowers by smaller honeyeaters.

The diet of the New Holland honeyeater, Phylidonyris novaehollandiae

AbstractNew Holland honeyeaters collect nectar, manna or honeydew for energy and hawk small flying insects for protein. The insects taken were usually Diptera and Hymenoptera weighing 0.7 mg dry weight or less. Net rates of energy gain from hawking small flying insects were usually less than 20 J min−1 and sometimes negative and insufficient to meet the bird's daily energy requirements. Those from feeding on nectar, manna or honeydew were usually above 40J min−1 and often above 400J min−1 at dawn and the birds depended on these carbohydrates for energy. Nectar, manna and honeydew contained negligible amounts of protein, and the birds used small flying insects as sources of protein, and presumably other nutrients. Given that carbohydrate resources supply better rates of energy gain than insects. New Holland honeyeaters should collect their energy requirements from carbohydrates and only collect sufficient insects to satisfy their protein requirements. Estimates of the food intakes of both non‐breeding and breedig birds showed that they did this. Non‐breeding New Holland honeyeaters collected from 72 to 125 (mean 92) kJ of carbohydrates per day and 17 to 58 (mean 31) mg of protein per day. These meet the daily energy (75 kJ) and protein (20 mg) requirements of the birds. Breedig birds collected more carbohydrates and more insects, but in proportion to their increased energy and protein requirements respectively.New Holland honeyeaters are probably limited by their ability to meet their energy requirements from nectar, manna or honeydew and not by insects. Non‐breeding birds collected their protein requirements in about 10 min of insect‐feeding, but spent from 33 to 90% of the day collecting carbohydrates to meet their energy requirements. The maintenance requirement of 20 mg of protein per day for New Holland honeyeaters is about 25% of that estimated from standard equations for a bird of the same size. This low level may have evolved in response to low energy availability.

Partitioning of nectar sources in an Australian honeyeater community

AbstractFeeding by honeyeaters was found to maintain nectar at low levels at three sites studied on Kangaroo Island in May‐June 1978. The productivity of nectar at a site and position in a dominance hierarchy appeared to determine which bird species used each site. Correa was the main nectar source in the poorest area and produced 0.05 kJ m−2 per day. The small eastern spinebill was the most abundant honeyeater. The purple‐gaped honeyeater also occurred but fed mostly on honeydew. The medium sized New Holland honeyeater was common and territorial in the second area, where Banksia marginata and B. ornata inflorescences and Adenanthos flowers produced 0.7 kJ m−2 of nectar per day. Spinebills and crescent honeyeaters also visited flowers and were sometimes chased by New Holland honeyeaters. The richest site was a flowering Eucalyptus cosmophylla tree (5.1 kJ m−2 of nectar per day). A red wattlebird, the largest honeyeater, held a territory in part of this tree and chased other honeyeaters from the territory. New Holland, crescent and purple‐gaped honeyeaters fed on flowers in other parts of the tree. The spinebill was absent. We conclude that nectar was partitioned along a spectrum of rich to poor sources. Larger more aggressive species used and sometimes defended the richest sources while the smaller birds used the poorer sources.