Dawn W. Frith

Seasonality of litter invertebrate populations in an Australian upland tropical rain forest.

Monthly samples, taken over 19 months, examined the composition, density, and seasonality of invertebrate litter faunas in an upland tropical rain forest. Arthropods represented 96.0 percent of the total sample number. Numbers of invertebrates increased with an increase in precipitation and there were significantly more individuals in samples during the wetter months. Numbers declined when litter became dry and/or sparse or oversaturated. Fluctuations in invertebrate litter populations appeared to relate to rainfall, litter moisture content, leaf fall, and rates of decomposition. Comparisons were made with similar studies carried out elsewhere in tropical rain forests. The present investigation is part of a study of the breeding and foraging ecology seasonality of Australian upland tropical forest birds. THIS STUDY REPRESENTS some of the first available data on tropical rain forest litter invertebrates in

Nesting biology of the spotted catbird, Ailuroedus melanotis, a monogamous bowerbird (Ptilonorhynchidae), in Australian Wet Tropics upland rainforests

Spotted catbird, Ailuroedus melanotis, nests (104 active and 59 old) were studied on the Paluma Range, north Queensland during 1978–89. Nesting began in September: 97% of clutches were incubated during October–December, 83% of nests had nestlings during November–December, and 70% of nestlings fledged in December. Nests were 3.1 1.3 m (n = 119) above ground. Nest dispersion was clumped, reflecting preference for particular topography and traditional use of a site over years. Four individuals used the same nest location for at least four consecutive seasons. Mean nearest-neighbour distance between 30 nests, built at 11 traditional locations over different seasons, averaged 42.0 31.4 m. At least 32 pairs nested within 50 ha in season 1980–81, at an average of one pair per 1.6 ha (home range) and at a mean nearest-neighbour nest distance of 96.9 24.8 m. Parents foraged at a mean of 68 36 m from their nests. Two replacement nests were built and laid in within 16 days of the loss of a brood. Eggs were laid 9–29 days after nest completion. Mean clutch size was 2.0 and eggs were laid on alternate days. At laying, eggs averaged 11% of mean adult female weight. Only females built nests, incubated, and brooded. Males fed females and nestlings. Females sometimes incubated before clutch completion. Median and mean incubation periods were 22–23 days. Eggs were incubated for 62% of total diurnal time, bouts averaging 19 min at a frequency of 2.0 per hour. Median nestling period was 19–20 days, the mean 20 days, when parents spent an average of 48% of diurnal time at their nest. Visits to nestlings averaged 4.9 min at a frequency of 5.9 per hour. During the first 15 days of nestling life, females spent 12% more time brooding a single nestling than a larger brood. A single nestling was provided with an average of 3.9 meals per hour and a larger brood 5.7 meals per hour. On average, females delivered 63% of all meals (n = 602) to broods at a rate of 3.3 per hour, males doing so at an average of 2.0 meals per hour. Of 323 identified nestling meals, 80% were of fruit (at least 33 plant species, of which 29 were identifiable) and 20% animal (of 182 meals 54% were insects, 21% pieces of birds). Proportionately more fruit was fed to older nestlings. Of 137 eggs laid in 72 nests, 88% hatched and 60% of nestlings left the nest; 46% of all eggs produced fledglings, averaging 1.0 per nest. Overall nest success rate was 51%, but of only those nests for which the fate was known it was 57%. The success rate of nests for which the fate was known during an exceptionally dry breeding season was 8%, with only 5% of eggs laid producing fledglings, at a rate of 0.1 per nest The nesting biology of the spotted catbird is compared with that of the green catbird, A. crassirostris, and found to be similar except in mean nest height and in proportions of fruit/animal foods fed to nestlings. The nesting biology of these two monogamous species is compared with that of the polygynous bowerbirds, and the significance of Ficus figs to the evolution of catbird monogamy discussed. The limited extent of nest attendance by the male catbird is discussed in the context of the evolution of contrasting bowerbird mating systems.

The unique type specimen of the bird of paradiseLophorina superba pseudoparotia Stresemann 1934 (Paradisaeidae): a hybrid ofLophorina superba xParotia carolae

The unique female-plumaged type specimen (Zoologisches Museum Berlin 49.296) of the Superb Bird of ParadiseLophorina superba pseudoparotia Stresemann 1934 is in fact a hybrid. It is the product of the first recorded hybridization betweenL. superba andParotia carolae (Paradisaeidae), and the first hybrid known to involve the latter species. Morphological and biometrical comparisons are presented to demonstrate that the hybrid individual is nearly perfectly intermediate between the putative parent species in colouring and dimensions, indicating that, like other recorded hybrid birds of paradise, it is a first generation cross. Das einzigartige weibchenfarbene Typus-Exemplar der Kragenparadiesvogel-UnterartLophorina superba pseudoparotia (Stresemann 1934) im Zoologischen Museum Berlin (49.296) ist in Wirklichkeit ein Bastard. Es repräsentiert den ersten bekannten Fall einer Hybridisierung der beiden ArtenL. superba undParotia carolae (Paradisaeidae) und den ersten bekannten Bastard, der letztere Art einbezieht. Morphologische und biometrische Vergleichsdaten werden vorgelegt, um zu zeigen, daß das Hybrid-Individuum in seiner Färbung und seinen Körpermaßen eine nahezu perfekte Zwischenform zwischen den mutmaßlichen Elternarten darstellt; des deutet darauf hin, daß es sich — wie bei anderen Paradiesvogel-Hybriden — um einen Angehörigen der ersten Filialgeneration handelt.

Short Communication: Additional Notes on the Nesting Biology of Victoria¿s Riflebird Ptiloris victoriae

An earlier study (Frith & Frith 1995) reported details of the little-known breeding biology of Victoria’s Riflebird Ptiloris victoriae at two nests. Since then, four further nests have been found, only one of which had eggs laid in it (a clutch of two) and fledged two young. Here we compare our observations of parental incubation attendance, feeding rates, nestling periods and diet at a nest containing two young with our previous observations of a nest with only one young in it. We also compare the structures and materials used in five nests.