Saturday, 1 February 2014

Bird of the day: January update

I blogged early in the month about my endeavours to add a bird to my year list every day this year.  This post reports on what has gone on through the month.

My best bird of the month is the Red-capped Robin, seen in my garden at Carwoola.
They are far from common in the COG area and only seen twice before in the Carwoola area.  This gives them an index value (see below) of 0.0009.  However what gets them the monthly award is that the males are really beautiful birds.  In one of Bill Oddie's books he comments that some birds are drab and uninteresting (eg Fuscous Honeyeater) so that even though they are uncommon adding them to a list is ho-hum.  Others - and I think he mentioned a Hummingbird - are what he describes as cosmic mind f***ers (I hope I have the asterisks correct there) due to their beauty.

As others have commented participating in this 'game' provides much scope for improving aspects of one's birding.  This applies both to enhancing one's skills at identifying birds and managing time and other resources to maximise the chances of adding a bird within a limited time frame and budget.

To deal with the first issue, I find that I am now looking at every bird I see, rather than just passing over some as "just a bird".   Clearly a good step towards getting a good list.

I have a blog in which I report on the birds seen in my local patch by myself and a number of other locals in an area roughtly 20km radius from our house.  This project has reported 183 species over the 7 years I have been working it and recording details in an ACCESS database.  Obviously I need to bring in a wider area to stand any chance of getting to the end of the year.  The Canberra Ornithologists Group (COG) has a database in which somewhat over 300 species are included, and I have an old back up copy of that.

By combining proportions from those two sources I have been able to generate an index of the likelihood of seeing a species.  Index values range from 3.385 (Australian Magpie) and another 25 species with a value >1, to over 100 species with a value  less than 0.00001.

Obviously the very common species should be saved until nothing else can be found on that day, or it is after Christmas and one can squander the remaining resources.  (Following on from a question on the BirdaDay message board it would be wise to keep ubiquitous species such as Rock Dove, Common Starling and House Sparrow for emergencies when travelling all day by plane.  Also, watch the grass while taxi-ing!) I have taken that process a step further by recording all species seen each day and ranking them according to the index value.   My default position is to treat the species with the lowest default value as my "Bird of the Day".
  1. A first example of how this works is offered by a day in which I had noted about 25 species and was expecting Australian Pipit (index 0.499) to be my BaD.  However I also spotted a Hardhead (referred to in the Bird a Day Australian list under the very out of date name "White-eyed Duck") with a surprisingly low index value of 0.080: see image above.
  2. My second example was on a trip to Young where I saw a Little Friarbird (index value 0.0000021, derived from 117 COG sightings - exciting plus).  However I then saw a Blue-faced Honeyeater (0.0000001 as a result of 5 observations of a single bird) and that went in as BaD (see image below).  A week later I was questioning the system as every tree in Wagga contained a Blue-faced Honeyeater and I didn't find a Little Friarbird.  
The second example posed an ethical issue.  Should I go back and change the Young entry to the Friarbird, thus using the Blue-faced in Wagga and freeing up Dollarbird for later?   Nope: rools is rools!

An interesting situation arose on a day in which I recorded Silver Gull and Fairy Martin.  Silver Gull had the lower index value and was thus the default selection.  However the low value of the Gull is because they are very unusual in my local patch: they are bog common in Lake Burley Griffin about 40km away.  On the other hand the Martin is only reliably found in one location and they leave that in February-March.  Thus, if stuck in April, the Gull could be acquired with a short trip, but the Martin will be absent.  So the Martin was elected.

Another nice choice arose on the 27th.  I went to a small wetland at the Namadgi Visitors Centre hoping to twitch a Lewin's Rail reported there.  I dipped on that but did record an Australian (Spotted) Crake with an index value of 0.0002232.  Later in the day I found a pair of Brown Treecreepers, unusual in the area, but their index value of 0.0071546 didn't cut the mustard.

It does appear that this month is a good time to start the game with many birds being driven out of the Inland by appalling weather.  Very hot and very little rain for the past 10 months.  This has accounted for me scoring several birds in categories 6 and 7.

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