Breeding Birds

As we are approaching the time when birds start to think about continuing their species I thought I would take a look at what the existing records tell  us about the timing of breeding in Carwoola.

I have got 428 Breeding records (widely defined: see below) of which 349 have been coded to month and type of event.  I have compacted the type of event into 3 categories

1. Pre-nesting: display, copulation, inspecting hollow and nest building (59 records)
2. Nesting: Nest with eggs; nest with young, on nest, carrying food (116 records)
3. Dependent young. (174 records).

The distribution of these broad groups through the year is illustrated below.

This does to a large extent follow common sense: pre-nesting activities peak first (August- September), then the nesting phase (October - November) and then dependent young in December January.  The dependent young recorded after February may be second broods (or more likely what I refer to as indolent young: capable of looking after themselves but prefer to bludge off the olds - this term is not recognised by the birding hierarchy).

Its migrant time!

I have posted a few warbles about migrants in the past.  The most important (OK, less trivial) of these was a consideration of which species were "practical" Summer migrants to the Carwoola area.  I have used that term to exclude species listed by COG as migrants but which

• Migrate to Carwoola in Winter; or
• Regularly occur in this area year round; or
• Occur very rarely in this area.

There are 20 of these practical migrant species, and given that I have record for 7 years (months February to July) or 6 years (August to January - we moved her in February 2007) the maximum number of species-years per month is 140 or 120.  In practise the maximum score is only 97 (in November) as some species are somewhat unusual.

The species with the lowest number of records are:

• Rufous Songlark (12 records) arrives late and is only reported for three months.  This possibly reflects it only being 'noticed' when the males do a display flight.
• Dollarbird (13 records) A rather more noticeable species, but it seems absent away from the Hoskinstown area.
• White-winged triller: (13 records)  This species almost disappeared from the Canberra area during the wet years.  In drier periods could be expected for about 6 months.
• White-throated Needletail:  (15 records) Only likely in 3 months (Jan to March) although we have had 2 December records.
• Brush Cuckoo: later arriving, and earlier leaving that the other common local cuckoos.  That is interesting as I have found it quite regualarly in the Tinderries up to 1200m.

This next image shows the number of years in which each of the species were seen each month (click on the image to make it legible).

The species likely to return in August are Horsefields Bronze-Cuckoo, Pallid Cuckoo (already heard, 20/8), Fan-tailed Cuckoo, Olive-backed Oriole, Dusky Woodswallow, and Tree Martin.