Delayed breeding in Little Penguins – evidence of climate change?

In the past few years there has been a resurgence of interest in the possibility of detecting climate change using natural systems (see, for example, Crick and Sparks 1999; Sparks and Menzel 2002; Hughes 2003; Parmesan and Yohe 2003; Root et al. 2003). The study of recurring natural (or biological) events, often in relation to climate, is known as phenology. These studies typically record events such as the arrival of migratory birds, first egg-laying or the commencement of flowering (e.g. Crick and Sparks 1999; Keatley et al. 2002; Root et al. 2003). Early studies of meteorology were strongly linked with phenology, with the timings of events in nature being used, for example, by the British Royal Meteorological Society (RMS), as measures of variations in climate (Sparks et al. 2002; Sparks and Smithers 2002). The RMS used a phenological network to study the timing of the seasons from 1875 to 1947, when the last coordinator retired (Sparks and Smithers 2002). During the same period many other countries in the northern hemisphere also had phenological schemes. In the subsequent 40 years phenology became less popular with meteorological agencies in many countries, often being regarded as not ‘real science’ (Keatley et al. 2002; Sparks and Menzel, 2002). This image of phenology has largely been altered by growing concerns over global warming and its potential impact on natural ecosystems. Sparks and Smithers (2002), summarise why phenology is now seen by many governments as important: (a) ‘The growing consensus that greenhouse-gas emissions are causing global climate change.’ (b)‘The realisation that phenological events can be very sensitive to climate fluctuations.’ (c) ‘Phenological events are cheap and easy to record.’ (d)‘Phenology can motivate and enthuse a large body of committed recorders.’ (e) ‘Phenological events are excellent vehicles through which to demonstrate a changing climate to the general public.’ Most of the phenological studies published so far are limited to results for the northern hemisphere. Within Australia there has not been a coordinated approach to phenological records and the extent and availability of such records is largely unknown (Keatley et al. 2002; Hughes 2003). Long-term datasets, of greater than 20 years, with relatively consistent collection and recording methods, are rare. One such dataset is that collected on breeding in the Little Penguin on Phillip Island, in Victoria, to which this paper is dedicated. Aust. Met. Mag. 53 (2004) 13-19