Saturday, 30 November 2013

Window 1 Fan-tailed cuckoo ? Dog 0

The question mark in the above scorecard is to show that the final score by the Cuckoo is not yet known, but is not 0.

This morning I was aware that a pair of Fan-tailed Cuckoos (Cacomantis flabelliformis - see below) were doing a call and response routine in the grdean so took myself off to see if I could score a photo or two - possibly an X-rated action shot.  The first bird located was a male, perched in the base of a crab-apple tree.
Then a female joined it and perched in a Pistachio tree.
After a short while the female took flight and for reasons known (briefly) to itself decided to short cut through my study.  Which does have a window, but not with a straight-through view.  In the words of Comics: thud!!!  and also splat!!!!
The bird soon got its head up - and seemed to be looking for some analgesics.  The small dog  - in my study - was very interested in this appearance on the deck.
She stayed indoors.  I doubt if she would play well with others (unlike this Jack Russell).

I then shifted the cuckoo out of canine sight and left it to recover.  I did take the opportunity to photograph the diagnostic yellow eye-ring!
After about 40 minutes it was still in the same posture.  I came up with two possible explanations of this behaviour.
  1. It was studying art-history and planning a dissertation on "Mark Rothko: the blue period in rural Australia"; or
  2. It had somehow become mesmerised by the boring phenomenon into which it had been thrust (not necessarily ruling out option 1).
Assuming option 2 was the go I shifted it to the edge of the deck.
The bird seemed quite pleased to have been removed from its dreadful predicament (again, both options still seem viable) and after about 5 minutes it took off and flew 10m or so to our Cypress hedge.

About an hour later I became aware that a bunch of assorted thornbills were making a ruckus in the Cypress so went down to see what was going on.  I wondered if I might be getting an additional image of a reptile.  No. it was just the thornbills demonstrating their view on evil prophets (see discussion of genus name below).
I thought the words of Ian Fraser and Jeannie Gray on this species were worthy of wider dissemination.
  1. The genus name combines Greek 'kakos" = evil and "mantis" = prophet.  Personally, I reckon hearing one of these birds in the area is bad news for fairy-wrens and thornbills who are hoping for a happy family life and no further explanation of that name is needed.  .
  2. The specific component comes from Latin, with "flabellum" = a small fan or fly whisk and "forma" = shape.  I take heart from that, in so far as being able to assume that any references to my being 'flabby' mean I look like a fly whisk rather than being a porker (which is, unfortunately more truthful). 
Overall, I think I would now change the scoreline to "Window  0 Fan-tailed cuckoo 0 Dog 0".

Friday, 29 November 2013

Reptiles with legs!

The weather has decided to warm up eventually.  Normally this means that after a few days people start grizzling about "When is it going to cool down?".  I will avoid the rush and complain today!

Among those not complaining about the warmth are the local lizards.  The first seen was a Nobbi dragon (Amphibolrus nobbi) which was investigating a window sill for insects.
 I am impressed by the length of the tail relative to the body!
I still had my camera when I went in to Frances' potting shed where an Eastern Three-lined Skink was skulking.
This one has obviously had a close call, going bythe abrupt end to its tail!

Thursday, 28 November 2013

ANPS visits Piccadilly Circus

On 26 November I was in the vicinity of Urriara with an English friend noted the words "Piccadilly Circus" on a road sign.  Being quite familiar with Central London he expressed surprise that it was only about 20km from the lower Brindabellas.  I explained that it was a different major intersection.

This image appears to suggest that there was another similarity between the two locations.
There was no evidence of the Shaftesbury Memorial Fountain, but a spectral form of the statue of Eros seems to have been captured.  As will be evident below this appears to have affected at least some of the local beetles.

We started off walking under a power line with few trees (until they re-grow after pruning) but quite a good array of shrubs,
Off to the side the forest was well endowed with Eucalypts (mainly E pauciflora and a few E delegatensis) and a very thick understorey of Daviesia mimosoides - aka fireweed.

Theer were a number of 'daisies' seen through the day with the first being Olearia erubescens.
Pimelea glauca
Monistria corcinna is also known as Spotted Mountain Grasshoper and met all three parts of its name
I checked the leaves of a patch of Acacia melanoxylon and found quite a lot of insects.  The passions of these two beetles had obviously been inflamed by the presence of the statue.
One of the horde of flies found the shrub a convenient place to pose for a portrait.
Both local violets were present.  Viola hederacea was common amongst the grasses ...
.. while the more solid coloured V. betonicifolia was also found in a few places with the more 'spearhead' shaped leaves being diagnostic.
A bee was busy on Oxylobium ellipticum.
I was confused (situation normal?) by the pinkish colour of this specimen of Poranthera microphylla.
The hollow centre of this Eucalyptus delegatensis  probably explains why it had adopted a horizontal form.  A patch of paint fungus is visible at the head of the hollow.
Clematis aristata was inflower at many locations.
A very tall Stegostyla moschata showing the entire side lobes of the labellum as well as the purple callidown the centre.  The first two images are detal of a plant with several flowers on one stem.

This was found later with only a single quite large flower but I think the shape of the labellum tags it as S. moschata again
We finally found a 'bird orchid'.  THE book calls this Simpliglottis valida: I have no idea what the taxonomists are calling it this week.
Going out on a limb I will call this a beard orchid.  The limited amount of red streaking on the sepal and my not being able to see a ridge between the 'eyes' leads me to call it Calochilus montanus.  The elevation of the site is certainly appropriate.
Getting back to the open country under the powerlines a solitary specimen of Diuris monticola was discovered.
The same area had:

  • some specimens of Stackhousia viminea (most of the specimens were more straggly than this); and 


  • Epacris breviflora.

After lunch at Bulls Head we set off on a car crawl down Bendora Dam Rd, stopping when the leader saw an interesting looking specimen.  The first such plant was Euphrasia collina.
A roadside bank was well supplied with Tetratheca bauerifolia and in this case growing with Daviesia ulicifolia.
An unusual specimen of a Billardiera.  The internal colour of the 'tube' was unusual  and led to this being considered to be something other than B. scandens
Which duly turned up a little later.
Leptospermum brevipes ...
.. with a bonus pintail beetle.  There are apparently 136 species of these so I am not going to offer anything further than the family Mordellidae.
Prostanthera lasianthos.
Veronica perfoliata and
V. derwentiana.
Near the base of Bendora Rd a Callistemon pallidus was found and photographed.  Apparently the forces of evil have found time in their sorry lives to reclassify Callistemon to Melaleuca - but I don't care - I am sticking with the name that appears to have lasted for 185 years!
This tasteful collection of bottles were alongside the charcoal from a small camp fire under the powerlines.  I wonder to what extent a bottle deposit scheme would prevent such stuff - it certainly wouldn't increase littering (but might make life a little more complicated for pubs and liquor stores so won't happen anytime soon)!

Monday, 25 November 2013

Breeding of White-browed Woodswallows in the Canberra area

The current sightings of breeding White-browed Woodswallows (WBWS - Artamus superciliosus

stimulated Steve Wallace to summarise the official records for Woodswallows in the ACT and circulate his summary to the COG Chatline.   I was interested to compare the 20% of records for WBWS having a breeding element with the 2% of COG Garden Bird Survey (GBS) records (for all species) showing breeding.   (As a general point for about 65% of the year there will be few if any breeding records whereas the WBWS tend to be recorded only in the breeding season.  However, the % of breeding records for WBWS still looked impressive.)

I was taken with Jack Holland's suggestion that when the WBWS hang around a bit they tend to exhibit breeding behaviour  Steve provided me with an extract from a dataset he maintains which includes both General Records and GBS data.  (For the purposes of this analysis the differences in methodology are felt to be not significant.)

As this gets a bit long and involved I can summarise my thoughts as two points.
  • When there are a higher number of sightings of WBWS prior to November it is likely that breeding will be reported that year; and
  • Larger flocks are more frequently reported in October than other months suggesting movement from over Wintering areas searching for food.
A first issue was that trying to analyse anything by calendar year was hopeless.  Being migrants WBWS start appearing (typically) around September and quite often hang around into the New Year. Of the 501 records 95 occur in the first half of a calendar year and are clearly part of a financial year based season (not that I am suggesting their behaviour is influenced by taxation considerations).  There is one “odd-ball” record for June which could be either very early or very late but it’s importance is I think low.  (The single record for August is almost certainly early.)  

So, with a bit of fiddling around I added a financial year code to the subset of data.  I also entered null records for the 4 financial years in which no WBWS were recorded in any surveys.
My next steps were to calculate 
  • the number of days between first and last sighting for the calendar year; and
  • the total number of Breeding records for each year
I then got Excel to give me a measure of correlation between the series “Duration of visit “ and “# breeding records”.  This was not great, at .0.46, especially since both series are 0 when no WBWS were sighted in a year (and a year with breeding records must have at least 1 observation record).   Here is a scatterplot of the two series.
I regard it as important to focus on the word "scatter" in interpreting this chart.  Not quite a randomplot but heading in that direction.

Another possible correlate was the number of reports in a year.  So I simply counted (OK got ACCESS to count) the number of reports in a year and Excel delivered a correlation coefficient between that variable and the number of breeding records previously acquired. 

Before Steve sent me the data he had identified 2002-03 as an outlier year as when plotting the number of obs records against the number of breeding records that year was well off the trend line.  Deleting that year from the series improved the correlation coefficient significantly. 

I was interested to identify why the year was unusual – it seemed that there were considerably fewer than expected breeding records for the number of observation records.  On looking at the data it was apparent that an influx of WBWS coincided with a Woodland Survey (WOO) weekend.  This is a time of high observer activity and 15 records were from that source in that year.  No other year recorded WBWS in WOO.  Thus for my purposes I have deleted the WOO records from my data set.

The result was quite astonishing, given the poor outcome from ‘length of observation period”  The coefficient was 0.91 which will certainly do me for significant!  (Of course there are a few variable independence issues since there must be >0 observations for there to be a breeding record. Here is a scatterplot.

The linear trend fits quite well (R2 0.83) but the 4th order polynomial (I use that style of poly as it seems to be a fair compromise between fitting to a non-linear series and not chewing up too many degrees of freedom) has a very good fit at R2 = 0.94. 

How I interpret this is that simply having a small number of birds “book-ending” a long season is not enough to generate a lot of breeding records.  It is a matter of there being enough birds around to be widely seen that indicates they are likely to start breeding.  This may then mean that the birds will be around for a fair while to allow the young to fledge and develop.

My next thought on this matter was to look at the timing of various breeding indicators.  There are about 12 of these in the COG data set (8 of which have been reported for WBWS) and I summarise them into three groups:
  1. Pre-nesting (Display; Copulation, and Nest Building);
  2. Active Nest (Nest with Eggs; Nest with Young, On Nest, Carrying Food);
  3. Post nesting (Dependent Young) 

Plotting the number of occurrences by month gives the following.

This suggested that if the birds aren’t around by October/November they will be too late to start breeding activities.  Looking at the data there seemed to be a pattern of a (relatively) large number of observations before November correlating with breeding being reported in that season.  This is summarised by the following table.
Breeding observed
4+ flocks before nov
Yes
No
Total
Yes
10
3
13
No
2
18
20
Total
12
21
33

This seems to confirm an hypothesis that if there are a large number of observations made before November in a year it is likely that the birds will “settle down” and breed.  In one of the cases where breeding was observed with few reports before November, there were 5 reports in November and 19 in December (so things were just a little late).  In the three cases where there were >4 reports prior to November and no breeding the number of reports was 5 or 6 in October and 2 or less reports in the rest of the year (ie overall a fairly weak WBWS turnout).

As part of an off-line discussion of the phenomenon Geoffrey Dabb raised some issues relating to flock size, likelihood of breeding; and whether the big flocks are just “passing through”.  The following table shows the number of flocks by size class of flock and month.  (Note: there are less flocks shown here than the 501 referred to above as some of the reports have been of presence/absence rather than giving a number of birds in the flock.)
Month
Flock size class
1-10
11-20
21-40
41+
Total
Aug
1



1
Sep
7
3
6
7
23
Oct
60
21
16
29
126
Nov
66
19
15
9
109
Dec
70
19
11
8
108
Jan
43
11
6

60
Feb
8
3


11
Mar
5
1
1

7
Apr
9



9
May




0
Jun
1



1
Total
270
77
55
53
455

This shows the over-representation of October as a time for 'big flocks'.  Possibly this can be interpreted as the birds leaving their Wintering grounds in a big flock searching for food resources and when they find one they settle down and breed.  When conditions are not favourable - ie there is little food around - in this area they may be seen a small number of times but move on.

I may try to explore this area a little more, but at the moment can't quite see how to massage the data to do this (and I have taken up enough of your download limit anyway).

Saturday, 23 November 2013

A few native flowers in Carwoola

Although most of the native flowers on our block have finished flowering a few are just starting up.  The first of those to be featured is Acacia falciformis.
We are particularly pleased to see this as we have two quite large specimens, from the Greening Australia tubestock, and they have not flowered before this year.

On our morning walk yesterday Frances spotted the first example - this year - of Twining Fringe-lily, Thysanotus patersonii.
On the 23rd I went for a walk round the block looking for Arthropodium sp. (Chocolate lilies) following a story in the Canberra Times about them flowering in the City.  I didn't find any, but there were lots of other pretty things.

Pultenaea procumbens
 Wahlenbergia spp.  There were many of these of a range of sizes around the block.  I'll try to sort out the species shortly.


 Craspedia sp.  In one area there was quite a meadow of these.

A clump of Xerochrysum viscosum.

My best photograph: of Dianella revoluta.