Publications (3)4.36 Total impact
Article: Daily and seasonal activity patterns of partially migratory and nonmigratory subspecies of the Australian silvereye, Zosterops lateralis, in captivity[show abstract] [hide abstract]
ABSTRACT: We recorded the locomotor activity of the partially migratory Tasmanian silvereye, Zosterops l. lateralis, and the nonmigratory mainland silvereye, Z. l. familiaris, continuously over 17 and 15months, respectively, to identify daily and seasonal patterns. While graphing the data showed several trends, statistical analysis did not reveal a significant difference between subspecies, making this study mainly descriptive in nature. The lack of statistical differentiation was possibly due to the low number of study animals and similarities between them. During the first year in captivity, the Tasmanian birds displayed heightened activity during the migratory periods, which was most likely migratory restlessness. The Tasmanian birds did not show any nocturnal activity as in previous laboratory and field studies, rather their activity patterns were similar to those of diurnal migrants, possibly reflecting the temporally variable nature of their migration. Although the Tasmanian birds displayed higher overall activity levels than the mainland birds during the first year in captivity, the activity patterns were similar between the subspecies. Captivity appeared to influence the activity of both subspecies in the second year of the study; following the onset of molt, neither subspecies regained the activity levels of the previous year, nor did activity follow the same pattern. Possible reasons (e.g., prevention of breeding) for this are discussed. This is the most detailed study to date on the daily and seasonal activity patterns of an Australian bird in captivity. KeywordsSilvereye- Zosterops lateralis -Locomotor activity-Migratory restlessness-Daily activity-Seasonal activityJournal of Ethology 04/2012; 28(3):471-482. · 1.18 Impact Factor
Article: Orientation in captive migratory and sedentary Australian silvereyes Zosterops lateralis (Zosteropidae)[show abstract] [hide abstract]
ABSTRACT: The orientation of two closely related subspecies of Australian silvereye Zosterops lateralis was studied in captivity over 14months. Migratory silvereyes Z. lateralis lateralis showed significant directional preferences during the spring and autumn migration periods and also displayed orientated behaviour during the breeding period. In contrast, the non-migratory subspecies Z. lateralis familiaris did not display any significant directional preferences at any time. This is the first time that the orientation behaviour of a migratory and non-migratory subspecies has been compared over the duration of an annual cycle, both during and outside the migratory periods. The results suggest that migratory silvereyes possess an endogenous program determining the timing and direction of autumn and spring migration and that this program is unique to the migratory subspecies. This is also the first comparison of this nature on southern hemisphere birds and demonstrates that the migratory behaviour of southern hemisphere migrants may be more similar to that of northern hemisphere migrants than previously thought.Behavioral Ecology and Sociobiology 04/2012; 61(3):337-345. · 3.18 Impact Factor
Article: Moult in captive partially migratory and sedentary Australian silvereyes (Zosterops lateralis) (Zosteropidae)[show abstract] [hide abstract]
ABSTRACT: In this study, we describe and compare the duration and timing of post-breeding moult of primary and secondary wing feathers, tail feathers, wing coverts and body feathers in captive partially migratory and non-migratory Australian silvereyes (Zosterops lateralis). This study allowed us to follow individual birds through the course of their moult and record the progression of moult in two populations. Both groups of birds underwent a conventional (or basic) post-breeding moult. While all birds followed a similar pattern of feather replacement, differences were found in the timing and duration of moult between migratory and non-migratory birds. The migratory birds generally started their moult earlier in the year and completed it before the non-migratory birds. The migratory birds revealed an overall uniformity in the timing and duration of their moult, while the non-migratory birds showed a greater degree of variability between individuals.04/2012; 147(2):287-297.