Striated Pardalotes - juveniles

A juvenile Striated Pardalote - nominate Pardalotus striatus striatus

When we caught two young Striated Pardalotes Pardalotus striatus on the last trip to Charcoal Tank (see previous posts), I noticed that they were of different subspecies. The one above is of the nominate type striatus, which only breeds in Tasmania and spends autumn and winter on mainland Australia, where it overlaps the range of two subspecies, ornatus and substriatus. The nominate has yellow wing-spots, colouring on the tips of the greater primary coverts, while the subspecies have red wing-spots - see below.

The yellow wing-spot on the primary coverts of a  Pardalotus striatus striatus

The red wing-spot  on the primary coverts of a Pardalotus striatus substriatus
(The wide band of white on primaries differentiates this subspecies from the similar subspecies ornatus, which has narrow white edges to the primaries. See post of  17th September 2012)

A juvenile Pardalotus striatus substriatus

Then I noticed that the striatus juvenile's moult into adult type plumage was less advanced than that of the substriatus bird. In particular, its crown was still spotted rather than streaked like that of the substriatus (see below). This is only a sample of one from each subspecies, but I wonder whether the young Tasmanian striatus birds deliberately delay their moult until they have migrated across the Bass strait and settled in their winter range on the mainland. Meanwhile the resident subspecies of South-west New South wales, substriatus, begin their moult as soon as possible. Both birds were caught on the 15th March 2014. If the Tasmanian birds migrate from March-April (HANZAB), this bird would have been one of the earlier to leave. Would it have been one of the earlier to hatch too? If so the delay in its moult would be more likely a strategy to moult post migration. I would be grateful if anyone has more information on the plumages or migration strategy of juvenile Tasmanian Pardalotus striatus striatus.

Juvenile Pardalotus striatus striatus,
with a spotted crown

Juvenile Pardalotus striatus substriatus,
with a partially streaked crown

                               

Striated Pardalotes

                                                                             Striated Pardalote Pardalotus ornatus

Over the weekend I was out helping Mark Clayton banding birds with his long-term bird-banding project at Charcoal Tank Nature Reserve near West Wyalong. The study site is in western New South Wales, in a remnant of once extensive woodland growing on the western plains.

  Striated Pardalote Pardalotus striatus, with a yellow wing spot

It is still early Spring and many migrants are on their return flights home to their respective breeding grounds after spending winter elsewhere. And one of the birds we caught and banded was of a race of Striated Pardalote Pardalotus striatus, which only breeds in Tasmania, but overwinters within the range of two other races of Striated pardalote. On the same day in the same place, we also caught and banded pardalotes of the eastern race, P. ornatus, which only breeds in south-east Australia. The distinguishing feature between them is the colour of their wing spots - coloured tips to their greater primary coverts. In the Tasmanian race they are yellow, and in the Eastern race they are red.

                                                              Striated Pardalote Pardalotus ornatus, with a red wing spot

                                                      Striated Pardalote Pardalotus striatus, showing the yellow tips  to 
                                                      the primary coverts which merge when folded to form the wingspot,
                                                      and a single narrow white stripe on the seventh primary. 
                                                      (Pardalotes only have nine primaries).

The study site sits on the boundary between the range of the P. ornatus race and that of the very similar race P. substriatus, which breeds in west and central Australia. The two races described above have only a narrow white wingstripe on the outer web of one primary feather (p7), while the P. substriatus race has a wide stripe over several primary feathers (p3-7). See the report for September 20 2011 for comparison with these. Click on this link to go directly there. Pardalote substriatus