Weighing in at only 6-9 g this small, but very active, fantail provides hours of entertainment as it tumbles, twists, loops, dives and almost turns itself inside out in the pursuit of insect prey. Together with its persistent call, these behaviours have earned it many alternative names including Cranky Fantail, Mad Fan, Snapper and Fanny Devil Bird.
The Grey Fantail is found throughout most of Australia, New Zealand, the Solomon Islands, New Caledonia, southern New Guinea, Vanuatu and formerly on Lord Howe Island.
Seasonal movement of this species is poorly understood. Throughout its range Grey Fantails can be partly resident (i.e. many don't migrate) and partly migratory and in some locations the local population can be wholly or partly replaced or augmented by migrants from other regions. During autumn and winter fantails tend to move north and west, returning south to breed in spring to summer. Although small, some of these birds even cross Bass Strait. Altitudinal migration, movement from higher to lower elevations, is also thought to occur during autumn-winter.
Ron and Win Thoday, keen birdwatchers, recorded when Grey Fantails were present on their property in Langwarrin, south of Melbourne for over 30 years (1976-1997). The fantails often arrived in January or February and left again in May or June. Although they saw no trends towards earlier or later arrival over time, the birds generally disappeared earlier in years of warmer autumn minimium temperatures and lower summer rainfall, i.e. warmer and drier years. Unfortunately they were unable to continue recording during the recent dry decades.
Another keen birdwatcher has been recording the birds using Albert Park Lake (APL), Melbourne for many years (1981-2006). The Grey Fantail uses this park as a stop-over point on both its spring and autumn migration. Since 1981 autumn arrival has became later and departure earlier - shortening the time spent at APL. Spring arrival timing did not change though spring departure became later, again shortening the season. This suggests that the fantails might be spending longer at their breeding grounds by delaying their departure.
Figure 1. Changes in arrival and departure timing of Grey Fantails during their autumn migration through APL. Since 1991 there is a shift towards shorter stop-overs at APL and this corresponds to a reduced variability in autumn minimum temperatures (Fig. 2).
Figure 2. Arrival timing of Grey Fantails at APL and autumn mean minimum temperature at Melbourne.
Daily bird records, from the southern semi-arid regions of Western Australia, have revealed that the winter visiting Grey Fantail, who appears in April to May, has been arriving earlier over time (~ 0.6 days/year).
These three examples highlight the value of long-term observations and move us toward understanding Australian bird movement and how this might alter under a changing climate.
During autumn remember to look out for the Grey Fantail as it moves north, record when and where you see it (http://www.climatewatch.org.au/ ), and help us better understand this charismatic species.