Treecreeper feeding on Xanthorrhoea nectar

Photo of White-throated Treecreeper on Xanthorrhoea flower spike
White-throated Treecreeper, Cormobates leucophaea. Click to enlarge.

Last weekend (6th August) I visited Booderee National Park, one of the most beautiful and unspoilt parts of the NSW south coast. Long straight flower spikes had shot up like spears from the grass-trees (Xanthorrhoea sp.) and tiny star-like flowers were opening to form a delicate white mantle on their surface. These flowers are highly attractive to nectar-feeding birds and insects; on this occasion it was mostly Yellow-faced Honeyeaters and Silvereyes converging on them.

Silvereye on grasstree
Silvereye on a Xanthorrhoea flower spike

I waited quietly near a particularly productive flower spike to try for photos of the nectar-feeding birds. To my surprise, it was a White-throated Treecreeper that landed next at the base of the flowering spike. Treecreepers normally work their way up the trunks and branches of trees to feed on insects (including ants) and spiders they find on and under the bark. This one worked its way up and around the spike as if it were a skinny tree, probing its bill into each little flower in turn. After climbing most of the way up, it did something I’ve never seen a treecreeper do: it reversed quickly down, backwards…to start again at the bottom.

White-throated Treecreeper on grasstree_2493

It’s hard to be sure whether a bird is feeding on nectar or tiny insects attracted to it, but the treecreeper’s behaviour suggested it was after the nectar. And none of the photos show any insects in the bird’s bill.

White-throated Treecreeper on grasstree_2507
Droplets of nectar glisten on the treecreeper’s bill

Nectar produced by flowers is an important food resource for many Australian birds — most notably honeyeaters, lorikeets and Swift Parrots. In addition, Silvereyes, woodswallows and chats have a brush-like tongue similar to honeyeaters and can also take nectar. But it’s surprising how many other birds take advantage of a rich nectar flow when they have the opportunity. For example, normally insectivorous Brown Thornbills will feed at banksia flowers when they’re full of nectar. I’ve seen a Rockwarbler do the same thing.

Rosellas and cockatoos don’t have a pointed bill or a brush-like tongue so they obtain nectar by chewing the flowers to pieces. Banksia wheels — those neat circular slices of flower-head scattered under a banksia — are a sign that cockies have been getting a sugar fix (as opposed to their more usual habit of demolishing the woody fruit to snack on the seeds).

Banksia wheels
Banksia wheels

I’ve also seen a cunning Pied Currawong watch a Red Wattlebird feeding at a banksia before attempting to copy its technique. The currawong’s heavier bill and shorter tongue would have ensured its efforts were less successful.

A treecreeper’s bill is remarkably similar to a honeyeater’s — longish and slightly down-curved, though its tongue isn’t brush-tipped like those of the more specialist nectar-feeders. Nevertheless, White-throated Treecreepers are known to occasionally feed on banksia nectar, for example see this post from 2006 on my old website.

On a related note, last summer I photographed a Brown Treecreeper (below) which seemed to be tasting the sap flowing from a eucalyptus trunk in the Capertee Valley. The only other birds I’ve seen feeding on eucalypt sap are honeyeaters — always when it’s freshly exuded and still flowing. (The sticky red sap or kino that oozes from damaged eucalypt trunks is the reason they’re commonly called ‘gum trees’. Within a few hours it hardens into an amber-like substance.)

Brown Treecreeper tasting sap

You could say that treecreepers feeding on nectar and sap ‘haven’t read the books’ to know what they’re supposed to be doing. Then again, it might just be ‘the books’ that are wrong.


For those who like to be formally introduced

Australian Treecreepers: family Climacteridae
White-throated Treecreeper: Cormobates leucophaea
Brown Treecreeper: Climacteris picumnus


 

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9 thoughts on “Treecreeper feeding on Xanthorrhoea nectar

  1. Sarah Maddox 14 August 2017 / 7:12 am

    Hallo Carol

    Lovely pictures! I’ve never knowingly seen a treecreeper in Australia (though I did see one, I think, in California). I’ll know what to keep a look out for now.Amazing feet the Aussie ones have – like huntsmen attached to their legs.

    Any book-reading treecreeper that’s felt it may have been letting the side down with its weird nectar feeding can now come to your blog for validation. 😉

    Cheers
    Sarah

    Liked by 1 person

    • Carol Probets 14 August 2017 / 10:55 am

      Hahaha, thanks Sarah! It’s interesting, American treecreepers belong to a completely different group to the Australian ones, but there are definite similarities in their behaviour and general appearance. A great example of convergent evolution. And yes, those feet on the Aussie ones…the hind claw seems way out of proportion to the rest too!

      Like

  2. John 14 August 2017 / 8:21 am

    Fab article & pics – as per usual Carol. Thanks heaps. Cheers. John

    Liked by 1 person

  3. bushboy 14 August 2017 / 8:56 am

    Great post Carol. I will have to sit in the gullies & see who comes to my Grass Trees 😀

    Liked by 1 person

  4. naturebackin 14 August 2017 / 4:18 pm

    Thanks for the interesting insights and pics, and what an amazing plant! Btw we have birds here in South Africa with similar eye rings to your Silvereye, but here they are more prosaically called White-eyes.

    Liked by 1 person

    • Carol Probets 14 August 2017 / 5:53 pm

      Yes! We have white-eyes in northern Australia. The Silvereye is part of that group 😍 And totally agree Xanthorrhoea is a wonderful plant…I regretted not having taken photos of the whole plant to illustrate the story better. But I have photos of other Xanthorrhoeas which I will post sometime. Thanks for your comment!

      Liked by 1 person

  5. naturebackin 14 August 2017 / 6:30 pm

    Thanks Carol. Interesting to know that the Silvereye is part of the broader White-eye group that occur elsewhere in Australia. I look forward to more photos of the Xanthorrhoeas.

    Liked by 1 person

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