|
Hi Bronwyn,
Good of you to be able to pick adults and young
with both species and be able to show them off to others. You ask: Are mixed flocks common and are they normally here
in summer? Well yes, but it sort of depends on what is meant by
"common". What you describe is in part consistent and in part not really
consistent with the typical pattern for summer. However this trend is based on
results over a long time and as there are lots of them around, there will be
occasional concentrations of these birds at times that are not typical.
The relevant text from my report: "Canberra
Birds: A Report on the first 21 years of the Garden Bird Survey" (i.e. the
21 Year GBS Report), may be of interest, it is as follows:
This family (Pardalotidae)
are small birds which among them, inhabit the full range of vegetation levels
from ground level to canopy. They are generally insectivorous. Warbler is an
unsatisfactory group name, as they are separate from the later group also called
warblers, of the family Sylviidae. Some can be difficult to identify. Most are
vocal and for some, calls provide the best identification cues. .... The
pardalotes are two small colourful birds that feed on lerp and scale in the
eucalypt canopy. Their breeding requirements differ. The Spotted Pardalote
breeds in tunnels that it excavates in sand banks, garden beds or even in plant
pots quite close to houses. The Striated Pardalote uses small tree
hollows. ....... The average monthly patterns of the two pardalotes are
different yet the long-term pattern is similar. The Striated Pardalote?s
abundance peak occurs four months later than the Spotted?s, so that may be why
the Striated Pardalote?s long-term abundance pattern appears to follow the
Spotted?s. This is a robust result. Although the Striated Pardalote is far more
likely to be recorded in larger groups, the average number of birds per
observation (G) is similar for the two species. Pardalote nests are easy to find
but they have few dependent young records, probably because once the young
fledge, these tiny birds join their parents in the tree tops where they are hard
to identify as young.
Spotted Pardalote Pardalotus punctatus
The monthly pattern of this species is regular. From a peak in numbers in
April, declines to the low in November before rising smoothly back to the April
peak. April is the month of peak honeyeater migration and some pardalotes
accompany that. However the pattern for this species is different to that of the
honeyeaters and the April peak may be just a coincidence. The long-term
abundance pattern has shown random variations, although it is suggestive of a
decline.
Breeding commences early with the first inspecting hollows and nest building
during early July with active nests peaking in October and extending until
January. Dependent young mostly from late October until February. Only 19 of the
151 breeding observations related to post nesting stages. This species nests in
low tunnels that can easily be found. Many records go for seven to ten weeks
with nesting data, the longest was 20 weeks with what may have been two broods,
in Year 14 at Site 251.
Graphs on page: 97, Rank: 21, Breeding Rank: 20,
A = 0.61774, F = 77.70%, W = 52.0,
R = 28.459%, G = 2.17.
Striated Pardalote Pardalotus striatus
This species has a less regular and different monthly pattern to that of the
Spotted Pardalote. It has two rather than one annual peak. From an August peak,
declines to a December low then increases to a smaller March peak then declines
again to a winter low. Exceptionally high numbers (up to 200 for one
observation) occurred in August and September of Year 12. A suggestion of a
slight decline in long-term abundance.
Breeding appears to commence early as there was one bird on a nest in early
July and one dependent young in late August. However most breeding records are
of birds at nests after early September, peaking in October and November,
through to late records in early March. Dependent young mostly from late October
to late January. Only 33 of the 143 breeding observations related to post
nesting stages.
Graphs on page: 97, Rank: 22, Breeding Rank: 21,
A = 0.62086, F = 75.18%, W = 52.0,
R = 28.064%, G = 2.21.
|
