A comparison of Marchs

The number of species observed/reported in March 2016 was 10 below the number reported in March 2015 and 4 below the average.  That was quite a break from recent experience where we have beaten the previous year and the average quite severely.  So I thought I'd have a look at the two Marchs and see whether I could spot a reason or reasons.

On the basis of truth in advertising, I was expecting something to do with migrants leaving early to be a big factor.

Here is the big picture:

It is an interesting coincidence that the number of species recorded in both year is equal to the number seen in neither of the months of March.  But it is still, IMHO, a coincidence.  The interest possibly lies in the 25 species only recorded in one of the two years.

Of those seen in 2015 but not 2016:

• 11 species are relatively uncommon so their absence is not that surprising.  Two of them- White-throated Needletail and Australian Koel - are also migrants.
• 3 species - Sacred Kingfisher, Leaden Flycatcher and Fan-tailed Cuckoo - are migrants which may have left early.
• 1 species - Straw-necked Ibis - I had thought this species as quite common in the area.  However that has really only applied in a few years.  Also it is most common in Spring, rather then Autumn.
• 3 Species - Mistletoebird, Skylark, and Brown Goshawk - are resident in the area and just haven't been spotted

Of those seen in 2016 which we dipped on in 2015:

• 3 species - Rainbow Bee-eater; Western Gerygone and Fairy Martin - are Summer migrants which seem to have stayed on for a while longer;
• 1 species  - Golden Whistler - is a Winter migrant which has appeared a bit earlier.
• The other 3 are a mixture : Little Corella and Common Myna are just beginning to appear in the area.  Black-shouldered Kite became very scarce in the last couple of years but may now be returning.

As is so often the case, the facts seem to have disposed of my expectations.  Early out-migration accounts for 3 - 5 species but that is balanced by late out-migration of three species and the early in-migration of a 4th.

The main issue leading to the drop  seems to have been the non-observance of about 10 less common, and 3 more common, species.  Possibly this reflects some observers travelling more this year than last?