Wednesday, 18 January 2017

Clouds after a bloody hot two days

As I was driving home from a run today the thermometer in the car showed 39.5oC.  However a hopeful sign was that clouds were building up, getting close to lenticular formation. This article offers a fair - if somewhat US-oriented - explanation of their genesis.



 This was more like a wave cloud, but I think formed through much the same process.
At home much pf the sky was covered with general stratus cloud, with some high level cirrus visible through the gaps.
 An unusual shape.



Monday, 16 January 2017

Bird-A-Day Update(s)

As well as the formal Bird-a-Day competition/game/challenge/whatever I started a personal effort on July 1 last year.  That was done with slight malice aforethought knowing that we were heading off on a 6 week trip to Atherton on July 2.  Largely as a result of that trip I made it through the rest of 2016 and into 2017.

As a commentary on the difficulty of doing BaD from Carwoola it is interesting to compare my house-block list from Carwoola with that of another birder from the Atherton area.  My home list (after 10 years) is 109 species.  The Atherton list (after a few more years, but ...) is 200.

I did run a top-up version of the formal effort adding new birds as I saw them, but missing out days between.  This got me up to 245 birds (dropping out of competition on 23 June with 175 species).  The January effort is covered here and other than some brief mentions for comparative purposes won't be further covered in this.

So, as from January 1 2017 I was running two database tables: my personal one for the second half of 2016 and the formal one for 2017.  I ran out of luck today for the former so here is the situation for both efforts.

2016 July-Start

The geographic extent of my birding was not too bad for someone who didn't get out of the country, and only got on a plane once, during the year.
The extremes were North - Daintree; East - Sydney; South - Mallacoota; and West - Adelaide.  Most of my birding however,was  around the site marked "Home".  According to the checklists on eBird, during the second half of 2016 I compiled 161 (43%) of my 377 checklists within about 50kms from home.  By State:

ACT  41
NSW close  121
NSW other 12
QLD 122
SA 4
VIC 77
I will confess surprise at how few sheets were from "NSW other".  Then I refocussed on the time period, realising most of our trips away have been to Victoria.

Overall I managed 196 species for the July start.  Allowing for the 28 days we stayed in Atherton this suggests that had we stayed home (or at least only taken short trips) I would probably have done slightly less well than in the Jan effort.

Disregarding claptrap such as "all birds are equally good" the best bird was the Tawny Grassbird seen at Jerrabomberra Wetlands on 11 Jnauary 2017!  Only my second sighting ever and a new bird for the area.  My best flock is still the 700+ Brolgas near Mazeppa NP QLD in July.

As usual I scored each bird according to a somewhat subjective BaD rarity rating for the location and season, and a rather more objective index derived (by methods for which I can't remember the detail) from eBird.  The lack of detail doesn't matter: this analysis isn't going to crash the Dow Jones, start a war, stop climate change or cause the Trumpeter to become rational.  The first chart compares these two measures for this period.

This is more or less the normal pattern as I am "forced" to use the common yard birds at the end.

Comparing my performance in the first and second halves of the year (OK, the latter includes a few days from 2017) is interesting.  Beginning with the BaD rarity score (bigger is better):
I think what it means is that when I am at home, in the first few days (as in the Jan 2016 case) I am able to chase unusual birds for the area but when travelling I don't know the territory well enough to twitch, but all the birds are eligible for ticking.  I used field guides to assess the BaD ratings while in Queensland.

Moving to the Index scores.
The start for the January exercise was given a major boost with Paradise Shelduck (Index score 0, as it was an Australian first - found by someone else) but once things settled down the two series were pretty similar until the final stages.  The last few birds for the January start were all very common birds in the area whereas for the July start there were some very 'good' birds found right up to the end and the very high scoring species were spaced out.

2017 effort (early)

The start of 2017 has been a good one with the Tawny Grassbird also featuring as BaD code 7 and several of the unusual birds from the the Hoskinstown Plain marsh keeping BaD scores up and the Index down.  The most frustrating day so far included:
  • Whiskered Tern (code 6) - selected
  • Spotted Harrier (code 5)
  • Brown Songlark (code 5)
  • Baillons Crake (code 6)
 Here is a chart comparing the first 16 days of the last three efforts.
This shows that the current essay is very similar to last years January effort and somewhat better than thé first few days of July 2016.

Sunday, 15 January 2017

But wait ... there are more invertebrates

... and some steak knives!!!
Possibly due to the warm weather there continue to be a diverse lot of insects around.  Interestingly, so far there have been very few Plague Soldier Beetles (Chauliognathus lugubris).

I will begin with butterflies, of which there have been both high numbers and  - by my standards - wide diversity.

The first is a Common Grass Blue enjoying a daisy rather than the grass ...
 .. and a Meadow Argus (ditto).
This rather tatty specimen is a Yellow Admiral - they are not frequent visitors to our garden..
Possibly part of the reason it is tatty is that it was getting attacked by a male Common Brown butterfly.  (The Admiral is on the bottom in this very poor quality snap).
Staying with the moth family (of which butterflies are a subset) a woolly bear was encountered on Widgiewa Rd one morning.
Using the 'road' as a link we also found a Botany Bay Weevil on Whiskers Creek Rd.
I didn't want to leave it to get squashed but found it to have a rather firm grasp on the road chips.

Having got into Coleoptera (ie Beetles) here are some more.  This first one is a monster - about 50mm in length.  Surprisingly I couldn't definitely identify it, but one image from the Museum of Victoria suggested Temognatha variabilis (note species name) and brisbaneinsects commented that this species was the largest beetle they had seen.  So that is my working ID.


In another part of the same clump of Bursaria was a more colourful than usual Pintail Beetle.  I suspect it is Mordella leucostista.
The remaining photos are a miscellany, mainly showing the diverse shapes of insects.

Firstly a true bug Stilostethus pacificus.
That oversubscribed taxon "Unidentified".  In this case I am not game to guess beyond Class level, but I am sure its an insect of some sort.
 I am sure this is a dipterid (only two wings), and possibly a Bee-fly.
Another fly, but from the Order Mecoptera in this case a Hanging Fly - possibly Harpobittacus  sp.
A damselfly - rather unlurid for this family, but it has its wings folded along its back.
Just to keep the arachnophobes on their toes here is a colourful member of the Areneidae (Orb-weavers).

Thursday, 12 January 2017

Tawny Grassbirds visit Canberra.

On 29 December 2016 a Canberra birder, Kim Larmour, reported a Tawny Grassbird from Jerrabomberra Wetlands NR.  This was thought to be a first for the ACT and the twitching hordes have duly descended to confirm Kim's observation.

Another birder has subsequently discovered 5 earlier reports of this species in the Atlas of Living Australia.  They were supplied through 2 other - reputable - organisations.  However on following up with those organisations 4 records have been found to be erroneous and the 5th an historic record, of eggs, seen as likely to be very dubious at best.  So Kim Larmour's 'first' stands.

I made a couple of unsuccessful visits to the general area, misunderstanding where she had seen the bird.  One of the subsequent observers made reference to one of the established hides ("blinds" in North American parlance) from which the bird was visible with a spotting scope.  So on a third visit I took myself off to that hide.  There I met another pair of birders who had seen the bird that morning and explained exactly where it was seen.

It was a bit off the beaten track but on heading back in that direction a somewhat unusual call was heard while I was on said beaten track.  (Kim Larmour is familiar with the species from elsewhere and had recognised the call, leading her to the bird.)  Sure enough there was the bird.
In fact there were clearly two of them.  One seemed to be out in the open most of the time while the other was lurking, and calling, from within the vegetation.  This led me to speculate in my report to ebird about the possibility that the birds were breeding.  Subsequently:
  • one member of the COG chatline has hypothesised that the call (recorded by another birder while I was there) sounded like "a scolding call"; and
  • another member of the chatline reported seeing one bird fly into the reeds with what might have been a white caterpillar in its beak.
  • some members reviewing the video shot yesterday suspect a brood patch is evident.
...  all of which might indicate a breeding event.  I have now updated my eBird to report to include their breeding code "Probable: Pair in suitable habitat."

I have extracted part of the species map from eBird.
Prior to researching this post I had assumed that the limit of the distribution of the species was the area just South of Wollongong (some 150kms NE of Canberra as a sensible bird flies).  However the map from eBird also shows the following sightings which have been endorsed by eBird moderators. In chronological order these are:

  • 2010 August: point 2, McLeod Morass
  • 2013 December:  point 1 Lake Cargelligo WTP
  • 2014 March- April: point 3 - Seaford Wetlands
  • 2014 May: point 3 - Braeside
  • 2014 October - December: point 3 - Liverpool Rd Retarding Basin
The species account in HANZAB indicates the species has been reported infrequently from scattered locations away from the coast in NSW (eg Maquarie Marshes).  Unconfirmed reports from near Canberra and Albury are mentioned.  One vagrant record is cited for Tasmania.  The accounts simply states " Vic: No records." 

I take two points from this:
  1. the species reaches places outside the 'normal range from time to time; and
  2. the bird (all the Vic checklists have been of a single bird) in these other outlier reports has not stuck around for more than a few months.  The Seaford Wetlands (126 eBird checklists) and Lake Cargelligo WTP (199 lists) are intensively well covered by eBird so if such a vocal species was lurking there it would have been reported.

Early thoughts on January weather

It has been hot and dry pretty much since Christmas.  However, the morning of 10 January started out quite foggy out in Carwoola.  This made the spider webs look very spiffy.

 At the top of the hill in Widgiewa Rd it was very foggy but as we got down towards Captains Flat Rd the sky cleared and there was just a little cloud over the Taliesin Hills.
Back up at the high point there was now a view available to the East although the moisture was still going up.
All of this has caused me to look at some day x day weather information for January in previous years.  Since 2013 most of this comes from my records but before that it's information collected by others for the Stoney Creek Gazette.  Since I know some readers are not too fascinated by graphs and stats-babble here are the highlights:

  • 75% of days in past Januarys past have had 0mm rainfall. More than 20mm in a day is unusual, but thunderstorms can dump a lot in a little while.
  • Maximum temperatures over 30oC are normal and for several years comprised the majority of observations.  The usual range of maxima seems to be between 20oC and 40oC.
  • Minimum temperatures show a much tighter range with the majority falling between 10oC and 15oC .  A minimum below 5oC or above 20oC would be very unusual.

On with the detail!

My first chart shows the number of days with a range of amounts of rain.
Clearly there are normally a lot of dry days in January.

The incidence of rain x day is largely a random event.  The average rain per day of the month is 2mm with a range from 0.63 to 6.2mm.  The high value is entirely due to a fall of 80mm in a day in one year.  I thought it interesting to plot the average fall x day of the month across the years.
That is the blue line which bumps around near zero!  I added +/- 1.96 Standard deviations to give a 95% confidence interval (CI).  It is obviously logically impossible to get a negative amount of rainfall - and I hope no one is thinking about evaporation - but it does show that 0mm rainfall is well within the possible values on any day!  Of course, with 75% of rainfall readings actually being 0mm the distribution of values is nothing like the normal distribution which is usually the basis for analysis of standard deviations.

Moving to temperatures here is a chart showing the % of days in each January with a maximum in the specified ranges.
There seem to have been several hot years during the drought in the early-mid noughties, with temperatures above 35oC.occurring on up to 40% of days.  I'm glad we were overseas for most of that time - which probably explains why we don't remember it.

My next step was to compile a graph of average maximum temperatures and related statistics.  In this case the standard deviations give a more logical result and don't include zero in the 95% confidence interval.
Note that in this case very few of the extremes are outside the CI.  It would probably be reasonable to say temperatures outside a range from 20oC to 40oC would be quite unusual.

The process was repeated for Minimum temperatures, giving the following charts.
Although the mid-range only covers 5oC it contains the majority of days.  It would seem fair to say that we can usually expect an overnight minimum between 10oC and 15oC which is quite comfortable.
The above finding is also reflected in the line chart.  It also suggests that nearly all minima fall between 5oC and 20oC which pretty much covers the confidence interval.

This has taken quite a bit of work to create and I am not sure I want to do it every month.  However I have now got some infrastructure in an ACCESS table and an EXCEL spreadsheet (with lotsa formulae) so I will use the broad idea for some analysis if it looks useful.



Wednesday, 11 January 2017

Some book and DVD reviews

Books

Bill Bailey's Remarkable Guide to British Birds: An excellent volume in which Bill discusses a number of British Birds.  The presentation of the book is 'different' as it's set up to look like a tatty used version (coffee rings on one page, text appears to be typed, photos reveal the durex holding them in place).  It is very amusing and while humour is the thrust does have a lot on interesting information.  Recommended 

Blake Charlton Spellwright etc.  The etc refers to this book being the first in a trilogy of fantasy books.  I read the 3rd volume first and it was comprehensible but would have been a lot easier if I had read them in the order written!  In part this is because the story is about casting of spells and knowing how they are created etc is rather useful.  To some extent the process reflects the authors life where he had severe dyslexia, but has overcome it such that he is currently a cardiology Fellow at UC San Francisco. Recommended 


Lionel Shriver "The Mandibles"  I was attracted to this author after hearing her talk about cultural appropriation.  I agreed with her and not the shrill squawkers who attacked her.  Unfortunately I found the book annoying rather than amusing.  Somehow it reminded me of many modern US books described as 'a novel' which are full of cleverness and preciseness but bore me witless (shades of the Brontes and Jane Austen)..

DVDs

Frances read a book by Clive James in which he burbled about really great TV series, most of which we hadn't seen because they were carried by commercial stations in Australia.  However the ACT Library service can lend DVDs so we have done some catch-up.

Game of thrones: Had some redeeming qualities (eg cast were mainly good looking). Unfortunately the plot seemed to be basically there to string together nudity and/or violence so we lost interest after a couple of episodes.

The West Wing: largely brilliant.  Very well acted and with a plot that moves right along.  My only reservation is that on a few occasions people overachieve when playing a role - typically Senator or Representative - that requires stupidity (but that is probably simply reality).  We have got to the end of the first season and can't wait to get into season 2. Recommended 

Sopranos  Well, we nearly made it through an episode.  In contrast to the West Wing where we like all the on-going characters, in this offering they were all either hateful or stupid (or both).  Pass (in the sense of we passed on the opportunity to watch more, not that this pot-boiler achieve a grade higher than F.
.
Twin Peaks I'm not sure if this made it into Mr James' tome.  However it was certainly well chattered about so got on to the list.  I found the set-up of the discs hard to navigate which was annoying but could live with that.  To begin with I like the look of the photography and was waiting for the weirdness to start.  After the pilot (90 minutes) and  episode 1 (45 minutes) we decided it was rather like a soap opera but all the characters were unpleasant and/or nuts.  Life is too short for this - I'll read a synopsis on Wikipedia..

Tuesday, 10 January 2017

Birdbath photos

As it has been stinky hot the bird bath has been seen a fair bit of action.  Some of the images which follow are pretty naff, but fill a role of populating a list of birds using the bath in January.

New Holland Honeyeaters are unusual at our place, and when they are here mainly hang around another part of the garden snuffling the Red Hot Pokers.  However on 9 January one turned up to share the bath with  a Superb Fairy-wren ...
 .. and subsequently a Brown Thornbill.
 Then it dived in and had a good thrash itself.
 It left enough water for an immature White-browed Scrubwren to also use the facilities.
A couple of days later a Striated Thornbill made a visit.
A Red-browed Finch had a sip.

 This is the best feature of a Grey Shrike-thrush!
 A very soggy Eastern Yellow Robin kept moving after its bath!
Its big-bird time.  A Crimson Rosella!