Fantail phases
The all-black fantails of southern New Zealand get replaced by all pied birds as you head north. This pattern is repeated in some other NZ birds, like the variable oystercatcher. As things get warmer, there are fewer advantages to being black.
Below is a graph of our results so far (as of 21 November 2014). (The spike at 42 degrees south just means we need more observations to get a more accurate estimate of the proportion of black to pied birds at that latitude.)
We're interested in getting heaps of observations of fantails including whether they were pied or black phase. This will allows us to better understand how the ratio of black to pied changes throughout New Zealand and how it shifts in landscapes with less forest and over time as New Zealand's climate continues to warm.
Feel free to add a comment here if you've got something to say about this project.
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So what's the mechanism that determines the plumage? Is it a straight genotype = phenotype thing with natural selection picking winners? Or are the birds responding to their environment somehow?
That's a good question. I have it in my head that it's a straight genotype = phenotype thing, but I don't remember the source of that information. I'll look it up.
I've seen a pair of black and pied birds in Christchurch with black and pied babies. It's a one or the other switch.
Why does this project use "phase" instead of "morph" like just about everywhere else? http://nzbirdsonline.org.nz/species/new-zealand-fantail
"Phase" makes it seem like it is a life-cycle change or a breeding plumage, which it is not...
Field Guide to the Birds of NZ uses phase http://nzbirdsonline.org.nz/sites/all/files/RHIFUL_FG.pdf
: / Pretty authoritative book. Guess both are accepted.
Morph: Term denoting the co-existence in a single interbreeding population of two (dimorphism) or more readily distinguishable and genetically determined forms - called 'morphs' ('phases in older terminology) - all in numbers too great to be due merely to recurrent mutation. Familiar avian examples are the egg polymorphism of the various cuckoos (Cuculidae), the white and blue plumage dimorphism of the Reef Heron, and the numerous cases described as 'mutations' by Stresemann. - Thomson, Landsborough, Sir (ed). (1964). A New Dictionary of Birds. Copyright The British Ornithologists' Union. Nelson.
Yep. So morph woulda worked too! :)
Yes, I got "phase" from Heather and Robertson's (1987) Field guide to the birds of New Zealand. I hadn't noticed that NZ Birds Online now uses "morph". That is a better word. "Phase" these days suggests that individual birds can moult from one phase to another, which fantails cannot.
I could change it throughout the project, but changing the project title will have the unfortunate effect of changing the project URL, which would break any links on external websites. I'll leave things as is for now but add "morph" to the project description.
Well, that explains why the project is using phase, which was what the question was! Changing the project to use morph is a whole different ball-game...
Cheers!
I just did an update on the graph.
We'll need a lot more observations to do any gee-whiz things with stats and GIS, but it's a good start. Except in the top of the South Island. We need a lot more observations from up there. And my hat's off to Tony Wills in Wellington for most of the 126 observations from the lower North Island.
Can we have the "NZ Zone" place added to the project rules so that offshore observations can be added? (the project can have more than one place rule)
Thanks Tony. I missed your message the first time through. I've just done that. I've also started to work through NatureWatch NZ from south heading north looking for fantail observations with photos that are not currently in the project. There's 173 obs left at the moment.
Without any actual data to back me up, I'd've said that about 1:6 to 1:8 fantails are black in and around Westport. It'll be fun to know your 'final' stats. So for this project counts without photos would still be useful?
Thanks @bylsand Yes, counts without photos would be very helpful.
I've been working through the obs not assigned to the project so I can update the graph.
Note that I added the field "I note the colour phase of every fantail I see" to the project which I set up to apply to the year of the observations. In hindsight, year was a bit ambitious. I'm tempted to change that to apply to the month of the observation instead, so people can choose to keep an eye out for fantails for a month at a time.
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