Elanus scriptus

Abstract: Letter-winged Kites Elanus scriptus were studied in western Queensland from 1972 to 1983, and the trends in their distribution and population level closely paralleled those of the rats on which they preyed. The Kite population peaked in 1975 and then declined, but a few Kites remained and resumed breeding after many of them had left the inland and irrupted into coastal regions in 1977. The Kites appeared to breed continuously while the rat plague lasted, and they hunted the rats at night. Data on nest site and construction, nesting habits and clutch and brood sizes were obtained .

Abstract: There have been few quantified studies of the diet of the Letter-winged Kite Elanus scriptus. Previous literature has emphasised the importance of native rodents, particularly the Long-haired Rat Rattus villosissimus, in the kite's breeding diet within its normal range in the eastern interior of Australia. However, the introduced House Mouse Mus musclus is important during extralimital (non-breeding) occurrences of the kite in irruption years, and in its breeding and non-breeding diet in central Australia during mouse plagues (see Baker-Gabb and Pettigrew 1982, Hollands 1984, Marchant and Higgins 1993). It has been suggested that the kite may be switching successfully to a diet of House Mice (Baker-Gabb and Pettigrew 1982), or that House Mice are a nutritionally inferior diet not permitting the kite's long-term persistence in extralimital areas nor successful breeding (Hollands 1984).

Abstract: This paper is the third in a series in which new interesing and doubtful records of birds in the Northern Territory are detailed and discussed; see Parker (1969, 1970) for previous papers. The following noses contain remarks on Anas castanea, Elanus scriptus, Polytelis alexandrae, Halcyon sanctu, Hirundo tahitica, Megalurus gramineus, Acanthiza iredalei and Pardalotus striatus.

Abstract: In environments driven by unpredictable resource pulses, populations of many consumer species experience dramatic fluctuations in abundance and spatial extent. Predator–prey relationships in these acyclic systems are poorly understood in particular with respect to the level of prey specialisation shown by nomadic predators. To understand the dynamics of such a system I examined the response to rodent outbreaks by the letter-winged kite (Elanus scriptus) in the Simpson Desert, Australia; a region that experiences major pulses in primary productivity, driven by unpredictable rainfall events. The kite feeds on small mammals and is the only night-hunting species in the Accipitridae. Letter-winged kites irrupted in the area on only three occasions during 20 years of sampling (1999–2019) and remained for a maximum of 20 months. Each period of kite occupation occurred only during the increase and/or peak phase of rodent population cycles (which occurred three times during the study). During each period kite diet was dominated by small (10–50 g body mass) quadrupedal rodents (Pseudomys australis, P. hermannsburgensis, Mus musculus). Abundance of these species varied across the three outbreaks and kites typically captured them in proportion to availability. The large body mass (134 g) long-haired rat (Rattus villosissimus) was abundant during one outbreak but was infrequently consumed. The bipedal spinifex hopping-mouse (Notomys alexis) was within the kites’ favoured prey size range (35 g) but was consistently avoided. The flexibility in prey selection by letter-winged kites appears to be an important adaptation for survival and reproduction by species exploiting acyclic rodent outbreaks.