I don't know about the Darter other than saying why not?
As for the Raven question: This extract from The GBS Report: Note my third &
fourth sentences!
Philip
Australian Raven Corvus coronoides
This species is a scavenger and is common in urban shopping centres, parks,
open areas, school yards, etc. It appears to have adapted well to the
Canberra environment. Its monthly pattern is very smooth and stable with
minimum amplitude through the year. From a low in October it rises to a peak
in March then declines. The peak from late summer probably reflects presence
of new juvenile birds in the population. Numbers are stable during winter.
Numbers showed strong smooth decline in Years 1 to 5 then strong fairly
smooth increase from Years 8 to 21. The number of breeding records has also
risen over those years. Less than 5% of records of the species for the first
6 years had breeding whereas this increased to about 15% for last 6 years.
This species is usually solitary or in pairs or families. The average group
size 2.04 is indicative of their social behaviour. At Site 169, which is
close to the Mugga Lane tip, there were sometimes counts of 20 to 40
individuals of this species. There are seven other observations of large
groups of birds (from 20 to 25 from other sites). Some of these may be
misidentifications of Little Ravens, flying over sites where the Australian
Raven regularly occurs and the observer has not appreciated the difference.
The Little Raven, unlike this species, typically occurs in flocks. Such
observations should be made with care and confirmed by the call. The small
number of such observations is too few to have much impact on the averages
for this species. The species has a long breeding time and single events
that were well documented took up to 31 weeks, though most appear to be
between 20 & 30 weeks. This is almost twice the duration of magpies and
currawongs. Nest building has been noted to commence in April, leading to
young becoming independent by late September. However, the usual pattern is
nest building from July and most dependent young observations finished by
late January. Pairs will nest a second time in a breeding season.
Graphs on page: 103, Rank: 14, Breeding Rank: 17, Breeding graph on page:
107, A = 0.96409, F = 93.30%, W = 52.0, R = 47.329%, G = 2.04.
-----Original Message-----
From: Rosemary Blemings
Sent: Monday, 21 March 2016 8:36 AM
To: canberra birds
Subject: Darter query
Yesterday at 14.00hrs there was a Darter busily diving upstream of the
stepping stones on Sullivans' Creek, ANU.
A delightful encounter to the east of ANU's Sports complex. Is it usual to
be seeing the species within the ANU campus?
Are the territory's suburbs usually inundated with Ravens at this time of
the year?
Around Flynn, the ANBG (on Saturday) and elsewhere they are making more
noise than Currawongs prior to rain &/o air-pressure changes.
Rosemary
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