Seasonally Adjusted – A “Down Under” Perspective by John Tiddy, Victoria, Australia2
“Seasonally adjusted” is one of those expressions much loved by politicians when they are trying to make a set of figures look better than they really are. In nature however I tend to think of it as having a different connotation. The calendar marks autumn as the months of March, April and May (those of you in the northern hemisphere can make your own adjustment) but regardless of the calendar, nature is not as clear cut. Is autumn simply a date or the appearance of the Small Citrus Butterfly larvae or is it the appearance of Swamp harriers migrating across Bass Strait from Tasmania? Even from such a local viewpoint as this there is plenty of variation. The Koori people of Victoria, Australia, recognise six seasons all based on changes in nature. Indicators such as the movement of eels to or from the ocean, the appearance of Cup Moth larvae, birds breeding all contributed to an understanding that a new season had begun. Currently it is the season known as Kooyang – the eel season – and covers late summer to early autumn.
One of the fascinating aspects of the global approach of the MYN project to me is seeing how in different countries and in different hemispheres the harbingers of a new season vary. Last year in February I saw a post from Clay Bolt that the Spring Peepers (a small frog) were about, thus announcing the end of winter in South Carolina. David Hunter posted a picture of the Snow Flower, Sarcodes sanguinea that appears at the change of season in California. Just last month Clay Bolt had a picture of the Eastern Skunk Cabbage, Symplocarpus foetidus that is an early season flowerer from North Carolina. Presumably one you photograph while holding your breath.
In the land down under we are officially ten days into autumn and yesterday I photographed the larvae of the Small Citrus Butterfly Papilio anactus (this butterfly has the misfortune to be also known as the Dingy Swallowtail). I looked at my records and found that I had photographed the same species of caterpillar last year towards the end of April. The big seasonal variation between this year and last year is that last summer was very wet with major flooding. One of the implications of this was a marvellous insect season (try telling that to everyone who was munched by mosquitoes). Was the flooding with the ensuing prolific growth and dampness, sufficient reason for the caterpillars to be so much later or was it good enough for a second hatching? I find the questions raised by these local seasonal variations interesting enough, but the posts on the MYN Facebook site take me beyond the wow factor of the posted images to a view of seasons in reverse!