Australian Magpie building nest - an early season?

["Philip Veerman" <>]

Hello Con,

 

You asked what might constitute an early season. This and any other similar types of questions, are already answered in my "Canberra Birds: A Report on the first 21 years of the Garden Bird Survey". The data were collected, analysed, written and published for a reason - to be used. Yes this is an early breeding start for Magpies but it is entirely normal for Yellow-rumped Thornbills. The breeding graphs in the 21 years report (not in the 18 year report) are invaluable instant representations of these data. But without them the relevant texts (just the bits about breeding) are:

 

Australian Magpie Gymnorhina tibicen

.........

Nest building commences and peaks in July and is finished by October. Nests with eggs or young commence in July, peaks in September and is finished by January. First dependent young in September, peaking in November and last in May. There are many records that appear to show a complete breeding event and the duration is generally close to 15 weeks. The frequency of breeding has been quite stable over the years (was very low in Year 2).
Graphs on page: 103, Rank: 1, Breeding Rank: 1, Breeding graph on page: 107, A = 2.71793, F = 99.47%, W = 52.0, R = 84.861%, G = 3.20.

Yellow-rumped Thornbill Acanthiza chrysorrhoa

.....

This is one of only two species of very small native birds that have many breeding records. Their relatively large and conspicuous nest is generally in low open foliage and the dependent young are constantly vocal although their buzzing is not a loud sound. Breeding starts early, nest building can start in early July or even mid June (two observations of this) but most start in August or September. The last activities at nest are in mid January. Dependent young are observed from late August till late March but most from October to January. Most of the breeding records involve repeat observations of the same birds over a period of many weeks. It looks as if a full breeding event takes from 10 to 12 weeks and there is evidence from some records of repeat nesting by pairs in the one breeding season.
Graphs on page: 98, Rank: 17, Breeding Rank: 11, Breeding graph on page: 106, A = 1.52016, F = 87.94%, W = 52.0, R = 37.113%, G = 4.10.

Philip