Footmobile Orchids

 On 1 October the Mallacoota Footmobiles did a car crawl, with short walks, checking out flowering orchids.  This shows where we stopped.

Calochilus paludosis Red Beard Orchid

Thelymitra carnea Pink Sun Orchid

Thelymitra ixioides Spotted Sun Orchid

Prasophyllum elatum Tall Leek orchid

Diuris orientis Wallflower orchid

Glossodia major Large Waxlip Orchid

Caladenia tentaculata Eastern Mantis Orchid

As we got back towards the cars a pair of Jacky Lizards (Amphibolus muricatus) were taking some rays.

They let me get quite close!

September 2024 Weather report

 Overall a rather temperate month: somewhat like Baby Bear's porridge in avoiding extremes!

Rainfall

After a dry August (36% of median fall) the rainfall improved to 89% of median (64.2 mm) in September, which is well above last year.

 As a result we are now 330 mm above last year's fall to date and my prorata estimate of the annual fall for 2024 is now 1055 mm.  The development of the prorata estimate since March shows that it has been fairly flat over September (as one would expect with a close to median fall).

Temperatures

The overall value of the anomaly ended the month at -0.07C which I regard as effectively zero.  The development of the anomaly shows a hot start to the month with a steady cooling later.  (We lit the fire on a few evenings late in the month.)  The last third of the month was a value constantly just below 0C.

A time series of values of the anomaly shows it as beginning to head downwards although the trend of the moving average is still upwards.

A chart of the daily extremes shows the warm start to the month followed by some low temperatures and the end of the month quite close to average.  (Note that the averages are now limited to the period since 2019 and only show the values from my weather station.)  There were 3 warm days (both extremes significantly above the monthly average) but not consecutive so no heatwave and 2 cold days (both extremes significantly below the monthly average)

The fluctuations in the average series did cause me to explore the pattern of variability between months and to my surprise September temperatures overall were not as variable as those for July and August.

Minimum Temperatures

The average minimum temperature was 9.03C, with a range from 4.1C to 14.6C.  The lowest value was the 3rd lowest recorded in September at home while the highest was the 6th highest.    In total there were 4 days significantly of low minima and 4 with significantly high minima: not all of these coincided with high maxima.

The set of monthly minima since 2019 show this year to be in the middle of the bunch.

Maximum Temperatures

The average maximum temperature was 18.7C, with a range from 11.8C to 30.6C.  The lowest value, on the 14th, was the lowest maximum recorded in September at home (and the second lowest this year - 12.2C was the second lowest at home).  The value of 11.8 was still the lowest if the values from the BoM back to 1995 were included.  The highest was the 2nd highest at home, but only the 6th highest if the Airport values are included (the highest 2 values were both over 34C.

By coincidence, in total there were 4 days significantly of low maxima and 4 with significantly high maxima: not all of these coincided with high maxima.

The average maximum was above average but below 2023.

Looking at the time series for home 2024 is (again) in the middle of the range.

Humidity

The daily humidities at standard times present a strange picture.  

• The first unusual feature is the very low readings early in the month: these would have been low reading at the relatively inland site we used to live in near Canberra.
• Secondly the closeness of the morning and afternoon values; and
• Finally the high level of variation, especially in the morning series.

The morning series is a little below average but above 2023.

The afternoon series is a little above mean and a lot above 2023.

Wind

The daily wind run shows three periods in brisk winds.

The longest run, 228km on the 2nd was the 12th longest September run (of 180 I have recorded) so of interest but not exceptional.  The longest run in September at home was 519km on the 20th in 2019 (and the second longest, of 363 km, occurred on the next day).

Overall the breezes showed the expected pick up after a calm couple of months over Winter.  The average run was a little below 2023 and the 6 year September average.  

Following a tip on Orchids

 The Grand Final of the AFL was boring in the extreme so we went to check on a sighting of Beard Orchids reported by a friend.  That was at point 1 in the map.

We found beard orchids very quickly.  According to iNaturalist these tow images are Calochilus paludosus.

This one seemed 'different'.  Possibly just aged but I have called it C. campestris, Copper Beard Orchid.

We then explored the track into the Water Treatment Plant (WTP).  Area 2 on the map. Few Beard Orchids but many buds of Thelymitra sp. (Sun Orchids).  The weather was not propitious for the flowers to open, being about 15C and very windy.

One small Onion Orchid (Microtis sp.)

We moved up to the track under the power lines (3 on the map).  

Despite the weather referred to above this one has a bud open.  I feel safe calling it Thelymitra ixioides - the default Sun Orchid in this District.

On the verge of the main road, heading towards point 2,there were many Glossodia major (or whatever the DNA freaks are calling Waxlip Orchids this week).

A few other images.  I think this (from area 1) is Thelionema caespitosum in a white, rather than blue, form.

Mitrasacme polyforma from Area 3.

When we got home Channel 7 was still showing proceedings from the G.  I hesitate to call it football as the Lions were around 80 points in front.  The Swans had given up and the Lions were playing a style of football I remember from playing in Torrens St, Mitcham with my mates: dobbing the ball from end to end with no real purpose.  Glad we went out for a nice walk!

Testing the Kayak (again)

 For a range of reasons, but mainly poor weather and/or bogans in power boats, we have not used our kayaks for about a year.  I decided that this was the only way to get some snaps of the waders on the sand bars in front of Captain Stevenson's Point.  So I took one of the kayaks off the trailer and headed for the wharf to check things out.  I had three objectives for this exercise:

1. Prove to myself that I could launch etc the kayaks on my own.  A specific sub-objective here was not to fall in the water while launching or landing the kayak;
2. Get to check out the birds on the sandbar;
3. Not cause too much disturbance to the birds.

All 3 objectives - and the sub-objective - were met.  

The route was intended to avoid the sandbars along the way, thinking the channel serving the Campground moorings was a  pretty good idea.  So it was: trying to shortcut ran out of draught rather quickly but no biggy.  The last few metres (yellow arrow) were shallow, so pedals out and paddle in.  From a combination of Google Earth and eBird tracking I think the distance from launch to landing was about 600m, so not really worthy of a Viking saga.

Here is my track on the sand bar as recorded by eBird.  There was less exposed sand outside where I walked: the image was taken on March 30, I suspect at low tide (and there had been little rain for about 10 weeks).

Photos of birds,  These are not unduly high quality as I took my old Panasonic camera in case the sub-objective was not met!

Caspian Terns and Red-necked Stints.

Stints and Red Knots.

Stints.

WRT to objective 3 the birds seemed unfussed by my presence - I did TRY to maintain an ethical distance - apart from where a couple of Silver Gulls, not part of the main flock, went postal and the whole lot (my guess was ~500 Crested Terns) took wing.  They just did one circle and landed again.

There were about 40 Bar-tailed Godwits in 3 groups.

One Eastern Curlew - I think a male from bill length: IMO the female would be about 30% longer.

Altogether a pretty successful outing.  It seemed that the numbers and diversity of waders were somewhat less tan some recent visits.  No Grey Plover, Greenshank or Turnstone which being on migration have probably just moved on.  Only a single Red-capped Plover and no Double-banded Plovers (the latter having possibly gone to their breeding grounds in New Zealand).

Variation in temperatures

 I have recently changed my calculation of the long term averages in my assessment of the temperature anomaly from a series starting in January 1993 which included data from (or based on) BoM data at the Airport site and my Weather Station (WS), to a series starting in January 2019 solely from my WS.  This was done to avoid differences due to the change in site,

I knew there were differences in maximum temperatures due to the cooling effects of sea breezes on the BoM data and had made adjustments sing regression models to compensate for that.  However recently I had decided that there might also be less significant, but still regular differences in the minimum series.  Rather than fiddle around trying to adjust the minima as well - giving a rather artificial set of data from 1993 - 2018 - I decided that a 6 year series would give a "good enough" basis for noting if a month was generally warmer/colder than normal (which is my aim in calculating the anomaly).

In working on the September data I noticed that the average temperatures were all over the place, as shown by the dashed lines in this chart.

This made me wonder if:

• September was an unusually variable month; and/or
• If the variability was higher in the WS series than in the previous longer series.

So I calculated the average daily maximum and minimum temperatures for each month and the Standard Error (SE) of those averages.  I then calculated the Relative Standard Error by expressing the SE as a % of the average.  That gave the following chart.

There are several interesting points in the chart.

1. Minima are subject to much greater variation than maxima;
2. September is variable but not as variable as July/August;
3. The WS series for minima is less variable that the hybrid series (possibly to be expected as it is much shorter so less chance of outliers);
4. The two maximum series are very similar (suggesting that my adjustments were satisfactory); and
5. Overall, the differences in the maximum series suggest the recent years are warmer than the earlier years (but there isn't a long enough WS series to make much of this).

I don't see any need for change as a result of this investigation.  I will keep the original (longer) series but use the WS-only series for calculating the anomaly.  If I find a rainy period I might investigate adjusting the old minimum series as I did the maxima but it is a fair bit of effort.

Some recent bird sightings

 I have seen an image of a Black-shouldered Kite flying around with a twig in it's beak.  I am happy to record this as a breeding record.  Also the Silver Gulls have assumed the position on Seagull Island. 

The Masked Lapwings running a reign of terror on our neighbours' lawn have hatched the first chick. 

Three more to go!

That was then, this is now (about 0900 on 19 September)

By the early morning of 20 September the chicks were moving about.

This image shows that they are several metres from the nest, on which the other parent is sitting with ? underneath her!  On checking a little later it was a chick in the nest: all 4 eggs have hatched.

A pair of Whistling Kites have been hanging about in the big Angophoras near by for some time.  I haven't seen them adding to the nest yet, but they perch near it.

I also took a couple of snaps of Common Bronzewings because why not ?

I went for a drive round the airport at lunchtime.  Although the last 2 months have been average or less in rain some areas are still boggy so I cut my route a bit short.  Sill got some interesting birds.

A Fan-tailed Cuckoo on the fence.

2 - I am tempted to say a pair - of Black-shouldered Kites, a little further down the fence.  I am uncertain whether these are likely to be the same 2 birds seen by another observer in Martin St.

A close up of the nearer bird!

Coming home via Betka I found 2 Hooded Plovers on a shingle bank in front of the car loop.