Guidebooks v the field: the case of female fairywrens

In the numerous guidebooks to Australian birds, I have always felt they are clear enough to allow quite easy identification of quite similar species after one reads carefully.

The classic case of this is the female Petroica species, which are identified largely by whether or not there is white in the tail or wing:

1. Petroica rodinogaster has no white in the wing or tail
2. Petroica rosea has white in the tail but not the wing
3. Petroica phoenica has white in both the tail and wing
4. Female Petroica boodang has a faintly scarlet patch on her breast, like the blue of female Malurus amabilis.
5. Female Petroica goodenovii has a distinct red patch above her bill

When I had a look at the other female Malurus from a total of four guidebooks to birds of Australia, it seems as if one can generally identify the superficially similar dull-brown female (“jenny”) fairywrens by looking closely:

1. Female Malurus melanocephalus and Malurus leucopterus are pale in colour,  yellowish-grey with no eye-ring. They can be distinguished because:
   • leucopterus has (a very pale) blue in the tail
   • melanocephalus has no blue in that tail
2. Female Malurus lamberti and Malurus elegans are a greyish-blue above and have a dark greyish-blue tail. They can be distinguished because:
   • lamberti has an orange-chestnut-coloured bill
   • elegans has a black bill like male fairywrens
3. Female Malurus pulcherrimus has duller greyish-blue upperparts, a bright blue tail and dark brown bill, lores and eye-ring of the same colour with no faintly white eye-ring.
4. Female Malurus coronatus has a grey-blue head with a black bill and a deep chestnut patch next to that bill
5. Female Malurus cyaneus and Malurus splendens are entirely brown with no bluish tinge, with a chestnut bill and lore. They can be distinguishedbecause:
   • cyaneus has a basically brown tail like Malurus melanocephalus
   • splendens has a blue tail, similar in colour to Malurus melanocephalus and Malurus leucopterus.

Female Purple-Crowned Fairywren (Malurus coronatus)

However, what these pictures show is that the recognition features that are show clearly in most guidebooks are of little field use in the heathlands where fairywrens are found. Most especially, the difference in colour between Malurus leucopterus and the other fairywren species found in Western Australia is not actually of that much value: if you look, the Malurus leucopterus appears equally grey vis-à-vis the other fairywrens. Also, the greyish-blue upperparts seen in Malurus elegans, pulcherrimus and lamberti from the guidebooks do not appear any different from the brown colour of splendens (which indeed is just as grey)! The easist to grasp from this is in fact female lamberti, because the bill and lores are so different in colour, though not to the same extent as in female Malurus coronatus, which is very distinctive with its faint purple cap, chestnut cheek and black bill.

The pictures shown for species found near Perth, and those at BirdLife (‘Fifty Shades of Brown’) are actually clearer in the field than guidebooks, or at least those guidebooks where fairywrens are not shown in real habitat. In fact, these pictures make one treat guidebooks with caution, though I have known to do this for some time despite their great value.