The first day I saw the Pink Robin at ANBG this year I thought it was an immature bird. I have only limited experience with this species but the amount of pale colour in the lower mandible made me feel it was an immature (first year) bird.
The other observations I made at the time were the richness of the wing bars and the colour of its soles (yellow) but at the time I did not know if sole colour was significant.
I have now done some research and looked at my videos in more detail.
Bird in the Hand v2 contains the following table to distinguish the immature birds from the adult females.
Adult females separated from immatures as follows:
Adult Female (2+) Immature (1) or (2-)
Wing bars: buff; rufous-orange;
Soles: dark orange; light yellow;
Lores: light grey-brown; greyish;
Back: dark brown; olive-brown;
Vent & undertail coverts: off-white with cream wash; grey;
Alula: dark brown; dark grey-brown;
Bird in the Hand v2 also describes immatures as:
Immatures retain juvenile alula, greater primary coverts, remiges (giving two very distinctive
orange-rufous wing bars) and rectrices. Most immature males have a pink wash on the breast;
HANZAB (older than Bird in the Hand v2) provides some slightly different information which I will summarise with some extracts. Immatures have buff tips to varying number of retained greater secondary coverts (HANZAB says this is the best
diagnostic to determine immatures from adult females), the bill is like the adult female but with a larger orange or dull orange-brown base, retained primary coverts have warm brownish suffusion to edge of outer webs (not obvious when feathers worn), soles
orange-buff (same as adult female) or light yellow.
The attached picture shows that the ANBG bird has buff tips to the greater secondary coverts, the alula has a distinct grey tinge and is not the same colour as the back and the soles are yellow (hard to photograph but insert shows the colour,
if blurred). The primary coverts also have what could be considered a warm brownish suffusion to the edge of the outer webs. The lores also appear greyish. There is also a significant pale area on the lower mandible. The lack of a pink wash on the beast does
point to a female but both sources do suggest that some immature males do not have the pink wash.
Although the descriptions in the two sources are slightly different and not all characteristics are obvious in attached picture, I still concluded that the bird recently reported at ANBG is an immature bird.
I am happy to hear from anyone with more experience with the species who can either confirm or refute my reasoning. Unless there is evidence to the contrary, I will be changing the description in my videos loaded to IBC (links sent in a
previous message) to an immature bird.
The dispersal of first year birds is described in HANZAB and seems to support the idea that most reports in the ACT of female like birds would be immature birds. It is highly likely that previous Pink Robin sightings at ANBG were also first
year birds but I do not have video good enough to check this. Others may have photographs that could be used to check.
Steve
