Thanks Philip.
My question was perhaps a little ambiguous- I was referring specifically to the time involved in constructing a single nest (or in the case of the Campbell St. pair, two abandoned, half-constructed. nests and starting on a third).
More than 4 weeks working every day constructing a single nest seemed to me like a major time investment?.
Robin
From: Philip Veerman
Sent: Friday, 8 November 2019 1:34 PM
To: Robin Hide; 'Canberra Birds'
Subject: RE: [canberrabirds] Magpie-larks nest-building delays...
Hello Robin,
From The GBS Report:
Magpie-lark
Grallina cyanoleuca
This bold and confiding bird is well adapted to the suburban and even urban environments. Some will accept
hand feeding. Some individuals will attack people when nesting but they are not as bad as Australian
Magpies. They often display aggression towards Australian Magpies (which ignore them). Adult males, adult
females and the juveniles are each easily distinguished by the pied pattern of the head. They are among our
most regular species, present all year and with a consistent small amplitude monthly pattern. This is probably
because the species maintains permanent evenly spaced territories. From a minimum in October they rise
smoothly to a maximum in March, then decline smoothly again. This is only minor variation and is due to two
factors. The spring drop reflects some birds moving away from garden areas for breeding or lowered counts
if birds are undetected when on nests. The autumn rise reflects new young birds in the population becoming
independent and the birds forming flocks and being counted in larger aggregations (though at fewer sites).
Single observations of over 20 birds (sometimes up to 100) are mostly during autumn and early winter. Long term
numbers have had a smooth to undulating increase. Being a widespread species, this trend is across
the board. It has clearly been contributed to by Site 230 that has habitat to support large groups.
Breeding records have fluctuated but there is a strong increasing trend. The breeding period is long, there are
many records that suggest double brooding. A full breeding event appears to take up 19 weeks. One record
contained breeding data for two events continuously for 23 weeks. Some nest building starts in early August
but mostly they start in September, mostly activities at nest have finished by end of January. Dependent
young from late November, peaks in January, finishes in late March.
Graphs on page: 101, Rank: 5, Breeding Rank: 4,
Breeding graph on page: 106, A = 2.02629, F = 98.28%,
W = 52.0, R = 73.612%, G = 2.75.
Note that the breeding graph (page 106) answers your question. So in quick answer to:
Is this unusually protracted?
No.
Philip
Is the nest-building of
Magpie-larks usually a long-drawn out affair?
I’ve been watching off and on since early October the activities of two pairs of Magpie-larks in neighbouring Ainslie streets - Paterson and Campbell Streets.
The Paterson St nest- in a
Celtis australis street tree- was well under way on the 7th of October.- with both birds ferrying wet mud from the gutter on a shed next door to us and flying constantly across our garden.
The half built nest looked like this on Oct 7:
They have continued working on it since - and were hard at work still this morning (8 Nov., 4 weeks later) with the nest wall a few cms taller now.
Over the same period, the Campbell Street pair (a bare 200 m away) have started and abandoned two nests (far left and far right in ths photo below) , and
are now working on a third one -all on the same branch of a Quercus lusitanica street tree.
Is this unusually protracted?
Robin Hide
