Friday, 30 June 2017

On Owls and Owling

Some years ago Birds Australia published research that appeared to show that Boobooks were threatened in Australia.  Knowing, from McComas Taylor's work on the Atlas of ACT birds that it is crucial to conduct surveys at night to count this species I enquired if the drop between the 1st and 2nd Atlasses could be due to there being less Owling (nocturnal activity by birders) rather than a decrease in owls.  To my total expectation I never got an answer to my question.

There is now a fair body of information around from eBird that is publicly available so I thought I would have a look at this to see what it could say about the less uncommon owls in the Canberra area.  It turned out to be a very interesting exercise in many ways.  There are quite a few graphs in what follows, but hopefully the text will be enough to keep the interest going for the cartophobic.

The three owls I am examining are Southern Boobook (hereafter Boobook), Powerful Owl (Powl) and Eastern Barn Owl (Barn Owl).  I will look at each of these in three ways in what follows and conclude with some commentary about eBird and the entertainments available from downloading it!

Which Month are they seen in?

It is thought that many of the records relate to hearing birds calling to attract mates so it could be expected that the number of reports will vary by month.  That is shown in the following chart: note that to enable easy comparison of the shape of the lines I have multiplied the number of Barn Owl records by 3.
According to HANZAB V4 Powl breeds in Winter,  Boobook in September - November and Barn Owl throughout the year (influenced by mouse plagues).  In view of those comments it is a little surprising that all three series show peaks in April-May and September - October.  My immediate thought is that those are the best months for birding- like Baby Bear's porridge, not too hot and not too cold!)  I shall return to this later.

What o'clock are they observed?

This next line of enquiry looks at the time of day when the birds are reported.
The pattern for Boobook and Barn Owl is very similar (with peaks in the evening and early-mid morning) while that for Powl is rather different with a peak late morning to afternoon.  They all agree that there are few records in the middle of the night, suggesting that birders, if they aren't Owl specialists, still need their beauty sleep.  This issue will be dealt with by using reporting rates in the third section of this report.

With regard to the Powerful Owl situation I suggest that this is because the birds are sufficiently rare to be of great interest to birders and when one is found roosting lotsa people will turn up to tick it at a time suitable to them.  By way of examples:
  • Of the 137 eBird records for Powl in the ACT 114 (83%) relate to a bird that roosted near the Turner Bowling Club for ~18 months.
  • The most frequently reported site for the species is "Mt Coot-tha Reserve--JC Slaughter Falls" from which a number of reports have been made by a friend from Brisbane.  He has advised that a pair nest here and  "Most of our eBird lists will be to specifically try and locate them."
I also looked at the combination of time of year and hour of the day for Boobooks.  The chart was very messy if plotted for months so I combined months into the 4 traditional seasons.
Winter obviously has a much lower number of records than the other three seasons.  The pattern for those other seasons is quite similar with a tendency for the peak calling times to be later in the morning and earlier in the afternoon according to day length.  (In other words the birds seem to be active around sunrise and sunset; this is consistent with comments in HANZAB.)

Reporting rates

I have referred in a couple of places above that the patterns of reports seem to be influenced more by the activities of the birders than the birds.  So I decided to create a measure that showed the proportion of records that included Boobooks.  On consulting eBird Central the only way of getting a count of overall numbers of checklists was to download records for all species and then calculate the number of checklists.  

The next three paragraphs - in blue - can be skipped by those not trying to calculate reporting rates for themselves

The core problem with this is the size of files that results.  I knew that an "all species - all years" file for Australia would be huge so thought I would work with a file of this nature for NSW.  This was about 80Mb which expanded to nearly 1Gb when unzipped.  None of my programs seemed keen on processing this (ACCESS had the best effort but kept refusing to handle the crucial date field)! 

So I tried a file for all NSW species restricting it to 2015 and 2016.  This was still 50Mb when zipped but I was eventually able to load it to EXCEL from where I deleted many of the variables not of interest to me in working out how many checklists were lodged each month and each hour.  There are about 770,000 records in this file! 

My next step was to extract Month from the Date variable and Hour from the Starting Time variable and use those as denominators in calculating reporting rates. There was also considerable entertainment in stripping checklist number out of a field  GLOBAL UNIQUE IDENTIFIER of the form: URN:CornellLabOfOrnithology:EBIRD:OBS220444969 where I think the checklist number is the element in bold red.  However it was done, giving me 31472 checklists (thus an average of 24.4 species per checklist) to work with.

OK so now I can calculate reporting rates as the percentage of NSW checklists that included Boobook and classify these for hours and months.  Here is the chart for hours.
As expected it shows that Boobook records become very important before 6am and after 9pm. 

Let us now have a look at reporting rates for NSW Boobooks by Months.
Interestingly this chart still shows a pronounced low in Winter.  The (relatively) few birders who go out in Winter seem to have more trouble than usual in locating Boobooks!  This possibly reflects what appears to be - from my reading of the species account in HANZAB - a low rate of vocalisation in Winter, building up to a noisier lifestyle prior to egg laying.


An interesting exercise in I think demonstrating the importance of nocturnal records in assessing the status of Boobooks.  There is also a suggestion that careful thought needs to be given to the impact of 'heard' records, and seasonality, in coming to such conclusions.  

For Powerful Owl any analysis of citizen science records needs to take particular note of the likelihood than a large increase in records reflects one bird recorded many times.  (In that regard I'd mention that despite the best efforts of eBird moderators to use standard names for sites at least 5 location names refer to the area around the Bowling Club and thus the same bird.)

The reporting rate analysis for Boobook was interesting to work on but took close to a day of very frustrating effort.  Obviously this would be less of a problem for a Serious User, with industrial computing power, decent internet access, and someone else paying for the downloads.   I'm not sure what the answer is but suggest that in view of the importance of the number of checklists in such exercises it would be useful for eBird to develop a standard "product" (pass the marketing jargon barf-box please) with checklist counts to sub-national level x month (while hour was needed in this exercise, as a generalisation I'd rate it as nice to know rather than essential).  

Tuesday, 27 June 2017

xxx Census results are out.

The 2016 Census results have been released today. 27 June 2017.  Not bad for timeliness, especially considering the chaos around collection day.

A note of caution:  I have subsequently discovered that the boundaries of State Suburbs have been substantially revised in this area since 2011.  The names haven't changed however so I only picked this up later when comparing population sizes and wondered why Hoskinstown and Primrose Valley had shrunk so much.  So be wary of material for State Suburb level.

Further, I found that in my earlier deliberations in making the comparison between Table Builder for 2011 and a Profile for 2016 I didn't pay enough attention to the fine print regarding what was included and what was excluded form the various tables.  Thus some of the analysis of dwellings was well wrong.  I have now corrected it

It also appears that the ABS has got its servers sorted out as when I tried to get data (about 90 minutes after the release) I was able to
  • download a General Profile for Carwoola 2016; and
  • get data for a table for Carwoola 2011 through Table Builder.
So my concerns - following the release of the TableBuilder shells - appear to have been allayed, at least as far as the capacity of ABS systems.

I haven't really got into the data yet but the age profile looks quite similar between the two censuses.
Considering the polynomial line it seems to have moved up an age class, which I'd expect with a pretty stable population having got 5 years older between the two counts.

Of some small concern is an apparent decline in population between the two censuses.  In 2011 there were 1433 people counted in Carwoola which had declined to 1418 by 2016.  There are two broad ways in which this could have occurred:
  1. a net drop in the number of occupied dwellings; or
  2. a decrease in the average number of people per dwelling.
My observation around the area is that there has been a reasonable increase in the number of letterboxes which I know in some cases has meant that new houses have been built.  I suspect there have also been some extra dwellings built in the development at the end of Wanna Wanna Rd.  Thus I am inclined to doubt reason 1.  Fortunately information is available from the Census on the number of dwellings.

I am not aware of any non-private dwellings in the area although it appears that there were a small number (it appears in the results as 3, but this may be an artifact of the confidentiality processes) found in both Censuses.  However I will ignore this and focus on the private dwellings
2016 2011
Occupied private dwellings 490 462
Unoccupied private dwellings 41 30
Total 531 492

So my expectations of an increased number of dwellings were met, once I was able to compare two datasets through Table Builder.  I have mentioned to ABS that it would be good if the apparently similar tables in Table Builder and the Profiles could be based on similar definitions rather than having to perform relatively complex adjustments to match them.  (As I am not sure that all the data required - eg on Household Type - was in the first data release this becomes very tricky.)

What I did observe after the Census was a high proportion (~20% from memory) of the letterboxes to which I deliver the Stoney Creek Gazette contained copies of the Census Form labelled "Final Reminder".  Since it seemed that the Census Collector for that area didn't visit houses but just dropped the forms and other correspondence in the letterbox I strongly suspect that:
  • he (I met the person at one point so can attest to his sex) will have missed any dwellings that didn't have a letterbox (including ours since I had removed the box as we were travelling away for a period around the Census - we completed the form in a caravan park near Rockhampton); and
  • If the form wasn't removed from the letterbox when the Collector came back the property was regarded as either not having a dwelling or at best an unoccupied dwelling.  
All in all I am not very happy about this situation!  However, down the track it appears that only 6% of identified dwellings didn't respond - but how many were not identified?

I also note
  1. an article by Bill McLennan, former Australian Statistician, expressing some doubts about whether the quality of the data can actually be established; and
  2. the report of the Census Independent Assurance Panel which appears to give the count an rating of OK.  They do however qualify their findings:
"Given the limited time and data availability, the Panel made this assessment at the national and state and/or territory levels for selected variables. Specifically, it was not possible to assess the accuracy of statistics for small geographic areas." (emphasis added).

Monday, 26 June 2017

Some random images

The weather has been cold so much of nature has been rather quiet.

Although we have had little rain since March Whiskers Creek has continued to run.  So has the Queanbeyan River, so Googong Dam must be full or close thereto.
On the matter of hydrology, judging by the size of the pipes QPRC are about to install under Captains Flat Rd they are obviously expecting a deluge of biblical proportions.  Either that or they have a contract to train folk for Snowy 2 and are use full scale kit rather than models.

 On the 25th an Eastern Yellow Robin flew into a window and stunned itself.    It eventually flew off (or at least disappeared).
The water jet in Lake Burley Griffin is achieving good height ...
 .. and with the sun in the right place a nice rainbow,
 A bit of wind causing the array of flags to make pleasing snaps.

Saturday, 24 June 2017

More indignation about Taxonomy!

Warning: this is probably of "special interest"only.  Lots of semantics and pedantry ahead!

I quite often post in a light-hearted and unbiased way about the efforts of taxonomists to add to our understanding of relationships between members of the carbon-based world.  Actually that is not true: I really disagree with quite a bit of what taxonomists do which seems to be more about advancing their careers by boosting their publication count than actually adding to knowledge.  The archetypal model is:
  • Researcher A publishes a paper combining 6 taxa into 3; 
  • Researcher B then comes along and splits the 3 new taxa into 6 (possibly a completely different set to those existing before A weaved their magic);
  • .Researcher C then reviews the whole lot and changes everything back to the way it was originally.  Neither A nor B accept this so all other researchers select which model suits them and war breaks out!
The catalyst for this rant is receiving a table from my friend Ian showing the percentage of each family of birds which he has observed.  He did so knowing this would incite me to attempt to replicate his table for my own, far shorter life list.  How could I  resist?

The initial problem was that of the volume of typing.  Even with only close to 2,000 species typing an entry such as "Machaerirhynchidae" would be very prone to error (and also a cramp)!   The obvious solution was to:
  1. find an on-line list of species which also showed the family to which they belonged and 
  2. automatically match this to my life list. 
Ian assisted by saying he used the IOC list for this purpose.  Once I had persuaded Google that I was totally uninterested in the International Olympic Committee (a general statement, unrelated to this exercise) I was able to download a spreadsheet with 33,500 rows and 14 columns which looked like this:

The first issue is why there are 33,500 rows when there are only ~11,000 species of birds?  The main response to this is that the IOC list includes subspecies which are of no interest to me (I have enough difficulty identifying to species)!  Some creative editing should fix that , but how?

As an aside I'm really only interested in two columns containing Family name and Species name but can see that the others are useful to other people.  That is why the EXCEL delete column function exists.

Some points arose indicated by the lurid symbols in this image:
As shown by the green arrow the family name only appears for the first row of the family.  OK, a bit of "Copy Down by dragging" will fix that.  Of more difficulty was the fact, illustrated by the red arrows, that the species name was a row below the genus name.  Why on earth this is the case I have no idea: my assumption is that someone in the IOC IT department hasn't been taking their tablets to the required dosage.  It looked like a complete bugger to overcome this until I spotted the column headed "Species English" and highlighted by a purple ring: again vernacular names become more useful than the Scientific/binomial names.

I added a record number field (so that I could if needed cross refer back to the downloaded information) and then reduced the number of records by deleting all the subspecies records, and the number of columns to the English name and the family name.  Then uploaded this to an ACCESS DB.  I also uploaded my life list, and ran a mismatch query, which gave me 284 mismatches.

My basic approach was to go through the list of mismatches and then identify the relevant name in the IOC list.

  1. In a fair proportion of cases it was possible to do this by picking a key word in the eBird name and searching for that (or, if a hyphen was involved, searching for the name omitting the hyphen).  
  2. If that didn't work I would refer to Avibase, which has a great list of synonyms, and try them.
  3. If nothing looked promising in the English synonyms I would search the IOC spreadsheet using the binomial words.
  4. In one case - so far - I had to go back to eBird to find the binomial they have adopted and search on that.
I can't change the eBird taxonomy (and all I really want to do is get a matching name so as to be able to capture the Family name) so always change the IOC name.  Then rerun the mismatch query to check that the match occurs.

Here are some samples of the mismatches.
  • Crested Caracara - IOC has split into Northern and Southern. I recorded mine in Mexico, so Northern.  OK: accept split with difficulty.   Delete the word "Northern" from IOC table.
  • Crested Serpent-Eagle IOC doesn't have the hyphen.  Does now.
  • Crested Tit: IOC has European Crested Tit. They also have Grey Crested Tit.  Looking at Avibase their listing for "Crested Tit" offers birds in three genera so it would seem that the eBird listing could benefit from the qualifier but I can't change that.
  • Crested Shrike-tit IOC has Crested Shriketit  As neither 'Shrike' nor 'tit' possibly fair enough.
  • Crested Tern  IOC Greater Crested Tern.  Both have Lesser Crested Tern.  Seems sensible to have qualifier in both, but ......
  • Dark Chanting-Goshawk IOC Dark Chanting Goshawk  Would seem reasonable to have the hyphen if there was some other Goshawks called Dark, Pale or Eastern.  However they seem to be a closely related group so having them as hyphenated also fair enough.
  • Dark-brown Honeyeater IOC has Grey-eared Honeyeater.  OK Not a trivial difference.
  • Unusually eBird has Eastern Mountain-Greenbul but IOC only has Mountain Greenbul
  • EBird has Gould's Sunbird while IOC has Mrs Gould's Sunbird.  Looking at "Whose bird" didn't help resolve which of these is correct!  Both versions are sourced as Vigors 1831.  Of course, go with the sexist eBird
  • The trickiest one thus far has been the eBird species "Greyish Flycatcher".  This isn't listed in Avibase nor in "Birds of East Africa".  Referring back to eBird the binomial is Bradornis microrhyncha  and I was able to find that in the IOC spreadsheet (although the genus has been lumped into Melaenornis.  Why do I hate taxonomists?  The name I am after (to change) is African Grey Flycatcher!
  • As far as I can recall Initially I recalled that there was only one case in which eBird had a species that was rated a subspecies by the IOC.  This was the Red-billed Gull of New Zealand, which the IOC rate as a subspecies of the Silver Gull. I have subsequently found that eBird has splut Black-shouldered Kite and Back-winged Stilt into Eurasian and Australian Species and recognises both African Swift and Black Swift (while IOC only recognises African Black Swift..
I didn't keep a score of the causes of the differences between the 2 taxonomies. It was sufficiently difficult to keep focused on the job of resolving the mismatches.

My overall impressions were that there were only a few cases in which species had been split by IOC.  Of these several appeared to be latitudinal splits (eg a single species now had two species labelled 'Northern' and 'Southern').  A further situation is adding a continental modifier (eg African XXXX): this seems unavoidable where colonial powers use similar names for different species in the various parts of their hegemony.

The situation reported above for Dark-brown Honeyeater seemed reasonably common: how realistic this renaming was is beyond my ability to say in the absence of the papers supporting the change.

The use of hyphens certainly explained a fair number of the mismatches.  This was generally in the "group name" part of the vernacular name (eg Hanging-Parrot vs Hanging Parrot; Sea-Eagle vs Sea-eagle).  I can't recall any in which the "descriptive" part of the name changed hyphenation (eg White-bellied would never become "White bellied").  To my mind the use of hyphens is sensible where a subset of a wider group are all similar: thus "Whistling-Ducks" are a pretty similar subset of "Ducks".

A couple of groups seemed to be very variable in which one of a pair of alternative names were used.  An example here is eBird making much greater use of Francolin while the IOC preferred Spurfowl.  Again I have no idea which is better, but it is a pain in the backside that the "authorities" can't agree which is what.

The haemorhoidal reference in the preceding paragraph is really the source of much of my annoyance: it is fair enough that change occurs where real knowledge increases.  (I am not sure how much of the DNA stuff is real knowledge: the practitioners of that dark art are not good at revealing confidence intervals.)  However where people seem to base their ideas purely on their preferences rather than any evidence I get very annoyed.

Over all I have members of 179 of the 123 families.  There are:
  • 17 families in which I have seen all the species (mainly families with only one member);
  • 31 families in which I have more than half (but not all) the species;
  • 131 families in which I have seen at least 1 species but less than half of those available, and 
  • 59 families for which I have seen none.
A further nuance is that IOC include several extinct species (including all 5 in the Hawaiian Family Mohoidae).  So in a few cases getting to 100% of the species listed by IOC is impossible.  Thanks to Ian  for pointing that out.

Wednesday, 21 June 2017

Callum Brae imitates Brigadoon

A cold and very foggy scene, quite suitable for hiding a small Scots town. greeted the 20 members who gathered on Narrabundah Lane at 9am.

Dimly visible through the vapour were large flocks of Sulphur Crested Cockatoos and Little Corellas, roosting in trees just inside the Reserve. 
The birds were gradually departing in flocks of about 50 birds (and 100+ decibels) heading for their feeding grounds on the lawns and Nature strips of the urban area. It was conservatively estimated there were about 200 Cockatoos and 150 Corellas.
The last group of birders (from U3A) to visit the Reserve had a near miss from a falling tree.  Some debris was still on the ground.
 Other debris, a little up the track, was cockie left-overs!
As we moved up through the Reserve we saw a few Kangaroos around.
This was a little surprising in view of the various control activities being undertaken in the Reserve (the most lethal not being during daylight).
It was somewhat surprising in view of the temperature to find some Olive-backed Oriole, Black-faced Cuckoo-shrike and (female) Rufous Whistler. These are all usually regarded as Summer migrants. Of the few species which come to the ACT for Winter the only sighting was a (male) Golden Whistler. To the surprise of those attending we saw no Flame Robins.
The first mixed flock encountered (near the Quarry fence line, as the fog lifted, 
...  included 2 Speckled Warblers. 4 Superb Fairy-wrens, 10 Yellow-rumped Thornbills and the first pair of Scarlet Robins. We met at least 4 pairs of Scarlet Robins in total during the walk.
Some eucalypt blossom was encountered (in this case E. macrorhynca).
The final large flock was approximately 50 Welcome Swallows near the entrance to Callum Brae homestead. Two further flocks of approximately 20 birds each were seen in the latter stages of the walk.
Artistic spider webs were available throughout the walk.
We totalled 35 species and a full list can be found on eBird.  To my great pleasure none of the members on the walk were gassed, poisoned or shot!

Monday, 19 June 2017

A couple more outings

The first was on 17 June, to Bungendore to go to the Waste Transfer Station (still referred to, by traditionalists, as the tip).  On the way home I checked out the main dam on Trucking Yard Lane.  The main reason for stopping there was to check the ducks.
Especially the Plumed Whistling Ducks (or, as the property owner said recently to another birder, Darwin Ducks).  There were 21 present on this day: the flock has been around 20 -30 birds for the last while.
 A huge number of Galahs were present.  They were in several flocks.  This is part of a mob on some power lines.
Here is a cropped image of the one flying in because it shows the feather positions as it manoevures for a landing
There were a couple of other flocks on other power lines and four trees with this density of birds.  All up I estimated about 500 Galahs.  Smaller numbers of Sulphur-crested Cockatoos and Little Corellas were also present.
 On the Sunday Frances and I did a lap of the Central Basin of Lake Burley Griffiin. We parked at NGA (as a return visit to the Triennial exhibition was planned) and started by going through the underpass.  It is a very attractive bit of civil engineering, as it should be given the generations of members of the CFMEU who founded dynasties through its construction.
 A couple of Black Swans were tried to bum food from passers-by.
 A darter was more concerned about drying its wings than feeding.
There were quite a mob of folk enjoying the walk around the basin.  A fair proportion had dogs with them, on leads and causing no grief to anyone.Certainly the birdswere not fussed.
The sky was completely clear, which made a nice change from recent cloudy/murky/English-Summer days.
 On the final leg a series of plaques have been erected to celebrate Australians of the Year.  The plural is necessary as simply having an Australian of the year is way discriminatory so there are now Senior Australian of the Year, Young Australian of the Year and "Local Hero"of the Year.  There must soon be a category which I can win.  Whatever: I reckon 1990 was a classic year with these two winners.  
 As the basin is the haunt of both the Territory Government in the form of TAMS (boo, hiss) and the Commonwealth through NCA (BOO, BOO, I say, hissss) official dom is evident with various signs controlling the rabble. This lot appeared to be around a few m2 of repaired concrete.
 As the temperature was about 15oC no ice was evident but having the sign out from about April to October saves money and thought.
Despite my last bit of snark it was a very pleasnt walk on a nice Winters day.

Saturday, 17 June 2017

Stoney Creek and Australia in the Census

In a recent post I covered a few aspects of the 2011 Census for Carwoola and a couple of other local areas.  After posting about that on the Carwoola Community Facebook page I got a couple of suggestions that I should compare the local areas with Australia and should show information about the locality of Primrose Valley.

To deal with the second issue first, Primrose Valley with Carwoola and Hoskinstown makes up the catchment area of the Stoney Creek Gazette and I have in past posted some analysis which does show the Valley.  For my more recent effort I didn't do that as I was experiencing difficulties with Table Builder.

However I haven't done a direct comparison of Stoney Creek with Australia.  So here are a few charts comparing Stoney Creek (including Primrose Valley) compared with Australia.  For the age profiles it would get too messy to show the components of Stoney Creek separately.

The first chart shows the Age profiles, for 10 year groups for females in Stoney Creek and Australia.  I have added a trend line to smooth out the pattern.
 This shows both by the bars and the trend  line that a much higher proportion of the Stoney Creek female population are in the 40 -59 year age groups and much lower proportions in the 20 -39 and 70+ groups.  The situation of the 10 -19 females in interesting since the very low proportion of 20-29 year old females drags the trend line around to not reflect the relatively high proportion of 10 - 19 year old females.

The pattern is approximately the same for males.
 The 40-49 age group is not so much over-represented for males in Stony Creek but the 60-69 group is a little higher.  Also, the 20-29 age group does not show such a large reduction.

For sex ratios (ie males per hundred females) Stoney Creek as a whole is higher than Australia.
In this case I have shown the three components of StoneyCreek which reveals the interesting situation that Carwoola is very above Australia, while the other two areas are only slightly above the Australian value.

Again comments on why this is so are welcome.

Friday, 16 June 2017

A run with my friends in Queanbeyan

Some years ago The Committee decided that defining a run by yourself as a run with your friends was an official Joke.  I think that made the total number of official Jokes about 2.  The first one was established before I became a member of caucus, let alone The Committee, and was something to do with graders near Half-way Hill on Pipe Flat Rd.  The third official Joke was to do with Roast Lamb (rated as the only thing better than a 32km rain at 4oC with light rain and a 30kph Southerly.).

So today a quorum was 1 as I took myself off for a waddle along the mighty Queanbeyan.  For such events I take my phone and record bird sightings as I go: this tends to slow the run down a bit, but I have 90 minutes before Frances has finished her Pilates Class so that's alright.  I also take a few snaps with the phone, but they aren't great art when the light is scungy as it was today.

Birds were relatively thin on the ground until the last part of the outward leg when I came across 39 Australian Wood Ducks, 24 feral pigeons ...
(with 2 Eastern Rosellas  if you look closely) and 34 Galahs.
 On my way the Ducks were a bit agitated due to a white cat running around.  It jumped back into a yard before I could find something to heave in its general direction (such as a rock).  Further along I noticed for the first time - in about 70 runs on this course that the small park with the two-stall sacred site is called Glebe Park That is currently the site of a flowering gum tree, which I think is possibly Eucalyptus leucoxylon.  Its very pretty and very popular with Red Wattlebirds.

 About 300m further on the traditional diverges from a pure out and back to cross to the opposite side of the River.  This utilises the Suspension Bridge, originally built to allow nuns to cross the River when it was in flood.  Here is the Mighty Queanbeyan in somnolent mood and also showing the crappy weather.
 The main reason for this snap was not to show the infrastructure of the bridge but the ridge in the distances up which yesterday's stroll went (its about 250 vertical metres).
 Nearing the end I encountered a flock of 66 Little Corellas giving some beak to sundry roots in the lawn.
 Then a little further I logged the only Red-rumped Parrots of the outing.
All up I recorded 27 good species of birds and a domestic Mallard.