Tuesday, 31 August 2021

Signs of the season: Avian aspects

 Today (31 August) is the last day of Winter.  Birds seem to be getting ready for Spring!

Not quite the first cuckoo of the year but it is notable that today's "Rare Bird Alert" from eBird includes 5 reports of Channel-billed Cuckoo from Sydney.  So they are on the move South!  Keep eyes and ears open, especially near fig trees!

It is hardly news to mention breeding by Masked Lapwings.  However there has been an interesting - and welcome - development with "our" Masked Lapwings.  Although the chicks are only 5 days old the whole family disappeared from the fenced garden next door.  To our surprise we couldn't see them in the horse paddock down hill.  I then spotted them on the far side of Angophora Drive: both adults and all three chicks had made the trek.

That is at least  metres from the nest site, which seems like a long walk for such tiny birds,

If wondering why I describe this as a welcome you have obviously never been swooped by a pair of upset Lapwings.  They had what the Couldabeens would call a Red Hot Go at me yesterday and we were thinking we might have to abandon our back yard for the next few weeks.  Fake News!!

The second sign is that I have had reports of Azure Kingfisher behaviour suggestive of breeding (mud on bill perhaps indicating excavating nest burrow at the mouth of Mullet Creek, and a pair in close contact at the part of Coulls Inlet close to Shady Gully).  In addition I have seen this species around the Broome St Lagoon a few times in the past 2 weeks.  

I have in the past guestimated (based on where I have seen birds at very close times) that the species might hold a territory of 1 kilometre which would be equivalent to a circle of 1 kilometre diameter.  The following image shows circles of 500m radius around the three sites listed above.

My take on this is that there are at least three pairs of Kingfishers currently along the Inlet from Mullet Creek to Shady Gully.


Betka loop flowers

 This is a collection of floral photos (or phloral fotos) from a walk along the Betka River and return along the clifftops.  The map shows the River segment.

My reason for this route was really to check out the flowering of the Kennedia rubicunda.  While they are flowering this year (unlike last) I had expected the woodland to be completely red - sort of like a Coral Tree or a display of Sturt's Desert Pea.  But it was a bit understated due to the mass of foliage.

This is a three-in-one shot with Hardenbergia violacea, Kennedia rubicunda and Glycine clandestina all evident (or at least visible if you peer closely).
A secondary hope was to spot some orchids.  The first seen (at point 1 in the map) was Pterostylis pedunculata (Maroonhood)
A few P. nutans were in the same genera area.
As we got to the end of this part of the walk another walker suggested we looked at the short track to the River under the powerlines.  That is point 2 on the map.  There were Prasophyllum sp. there, and I suspect these big dark ones were P. elatum.  
Also some shorter, greener specimens, possibly of a different species.
Kennedia protrata was all through the area when not covered by other vegetation.
Leucopogon virgatus
Hovea heterophylla
The next 4 images are of Pomaderris sp.  I think there are 2 species shown here and have sought advice from iNaturalist as to the further identification.  While very boring for most of the year, they do have pretty flowers.



A white version of Solanum aviculare.
Viola hederacea was common through the area.
At the end of Betka beach the Kelp was piling up.
The foam floating out on the River initially looked like floating gulls!


Sunday, 29 August 2021

Overall grotty episode

There seems to be a decent break in the rain and wind ( I have even, briefly, seen a strange yellow object in the sky this morning - giving a nod to the Billy Cotton Band Show, BBC circa 1965).  Thus I calling this event done and dusted.  Total rainfall at my WS for the 6 days was 125.6 mm.

The total rainfall by hour is shown in the following chart.  I hope the axes in this, and some other charts can be understood as it involves some ad-hoc text boxes overlaid on the axis values by EXCEL.

While the 25th-26th was the most miserable with constant light rain for 2 days the peak rain episode was overnight 27th to 28th.  This was explained by a friend (a retired meteorologist) in a weather forum:
"This is a cold occlusion with three airmasses involved: the coldest air is moving in from the SE undercutting warmer cold air, which is the residual airmass over NE Bass Strait and the far South Coast, both of which undercut the subtropical moist air that brought our heavy rain earlier in the week. The subtropical airmass is still hanging around, but is now entirely above the surface. Heavy rain, storms and even funnel clouds can develop at the point above the surface where the warm air wedge is at its lowest, known as the trowal, short for TROugh of Warm air ALoft.

The trowal came closest to shore in the middle of last night near the VIC/NSW border, giving Gabo Island 41mm between 21:00 and 03:00 for a 24 hour total of 75.4mm and Mallacoota 40mm from 21:00 and 03:00 to give 60.0mm to 09:00. There's a straightforward description with diagrams of the different types of occlusion and associated weather in Wikipedia, and I find the diagrams are essential to getting my head around the mechanism.
My weather station also records peak rain rate in each hour.  The next chart shows the rate with the total amounts also shown in the background.
It was basically mild (in terms of minimum temperatures) to cool (in terms of maximum temperatures.  The drop in temperature on 23 August is quite evident but during the rest of the event a blanket of cloud kept temperatures quite steady.
For most of the event it was quite windy.
Rather unusually the wind was worse to North of Mallacoota than to the South.  The strength of winds to the north is shown in Australian Weather News by it setting a gust record for the month at Montague Island and all time gust record at Point Perpendicular

In another post I tried to bring the three unpleasantnesses (wet, cold and windy) together by counting the number of hours per day where the temperature was <10C; and the wind above 20kph; and >1 mm  of rain in an hour.  The 25 August set a new record with 9 hours meeting those criteria of crappiness.  A further 2 faecal hours were recorded on the 27th and i more on the 28th.  A scatterplot shows the incidence of these 'orrible days since I began recording in February 2019.


Friday, 27 August 2021

Once (or twice) more on to the beach ...

 Warning: this post includes a picture of a dead bird.  Apparently that upsets some people: if you are such a person I suggest stop reading now.

By mid-morning on 26 August cabin fever was fairly evident so we put on our wet weather gear and took ourselves off to Bastion Point.  There was a lot of seaweed washed up on the beach and in some places (eg the track to the Campground) this showed the wash had evidently gone over the top and through the dunes.

The sea was still very rough!

A reasonable crop of small waders (about 12 Red-capped Plovers, 2 Double-banded Plovers and 1 Red-necked Stint were running along the beach, dodging out of the incoming waves.  The Inlet was quite full of water, as it was getting a double whammy: a strong Southerly blowing water in from the ocean and sustained rainfall flowing down the rivers. As a result there were limited sandbars available for birds to occupy.

Unfortunately as we got to this interesting group a squall came through, with strong wind and rain.  So I basically noted a few birds and headed for home.  

Here is the route.
Point 1 is where I took the photo of the flock, 2 is the track lined with seaweed, indicating over-topping  and 3 is where Frances decided the water level was too high, and headed back to the beach.

This is the initial photograph of the flock.

Hear the words of Milburn! "Look at every bird!"  Silver gull (blue arrow) - obvious.  Bar-tailed Godwit green, Red-capped Plover orange and Crested Tern pink.  All normal and expected  However, I then noticed an outlying Tern -  Red arrow.  On the principle of better late than never I peered closely and it was a White-fronted Tern.  Add one species to the list!
When I got home I found a friend had sent a message with a photo of a dead bird found on the beach between Davis Creek and Betka Beach.  She asked for help with ID suggesting Albatross.  A Labrador was included for sizing!
Certainly a large pelagic bird.  The bill was clearly wrong for Gannet so I felt it was indeed an Albatross, and the colouring of the bill in particular suggested juvenile Shy Albatross to me.  I put the image on Australian Bird IDentification Facebook group where an expert suggested Shy Albatross, possible a NZ bird.  I went back to try to find the body, even though my friend suggested it had probably been washed out again.  She was correct.

My friend revisited the beach on 27 August and could not relocate the corpse.  She reported that the Sperm Whale jawbone, which has been on the beach for a few months, has also gone away.

On the 28th we went back to Bastion to see what was around.  The first thing noted was what was not around, being about 50 cm of sand at the foot of the steps!
Taken together with the presence of some kelp at the foot of the higher set of steps in that image, this confirms that there has been some very rough weather.

Out past the dunes a fair number (my count was 47) of Bar-tailed Godwits were present.  I tried hard to turn one into a Black-tailed Godwit but no ....
It is not unusual to see a Caspian Tern around the area but today 3 were chasing around.  Here are two of them.
There were some interesting patterns in the sand.
We didn't spend much time out on the sand as it seemed to be very soft: not quite quicksand, and not even the boggy mud of the Essex marshes, but still rather disconcerting to walk on.  As we turned we were surprised to find the waves washing over the rea we needed to walk over, which had been dry when we walked out 15 minutes earlier.   No biggie, as it was at most 5 cm deep, but a salutary lesson to pay attention to what is going on around oneself when the sea is involved.




Wednesday, 25 August 2021

Call this bad weather?

 Our walk this morning was not pleasant. We rugged up and put on rain pants but decided to turn half-way along the Lagoon Boardwalk when a gust just about blew us over. That led to some conversation about whether this was the worst period of weather we have had since coming to Mallacoota: what seems like several days of cold, wet and windy.

So on returning I decided to interrogate my database of records for my weather station. My target observations were

  • maximum hourly temperature <10C; and
  • Maximum wind gust >20 kph; and
  • Rain >1 mm.

Those conditions were met for at least 1 hour on 19 days since the WS was installed on 13 February 2019. Tallying the number of bad-weather hours by day gives the following scatterplot to 0600 on 25 August 2021.


The worst single day was 23 August 2020 when 7 hours met all the criteria. Where the dots are almost vertically above one another indicates that there was a multiday period in which the conditions were met on consecutive (or nearly consecutive) days. For example 20 July had 2 bad hours and another occurred on the 21st, and 27 May 2019 had a bad hour followed by 3 bad hours on 30 May 2019.

To my surprise there are no observations matching all three criteria in the period starting 0100 hrs on 23 August 2021 to 0600 on 25 August 2021. Were we just wimps? Fortunately extending the period to 0900 shows the maximum temperature in the hour as 9.9C ; Maximum wind gust 25.7 kph and 1.2 mm of rain . The hour to 1000 also got three ticks, (so that is 2 hours for the day) but by 1100 the maximum had risen above 10C to a toasty (?) 10.2C! So I conclude:

  1. the weather was crap while we were walking; and
  2. the criteria I used for defining bad weather were reasonable; but
  3. in comparison to some other periods in the last 30 months it wasn't that bad!


Tuesday, 24 August 2021

Jeepers creepers

 Several of the photos in this will involve flowering vines!  But I will start with a Melaleuca armillaris which we noticed as being in flower for the first time on 23 August.

The first vine noticed was Pandora pandorana (Wonga-vine)
Taking white flowers against an overcast sky is a dodgy prospect, but hopefully you can see the Clematis aristata
The Kennedia rubicunda along Lakeside Drive is beginning to hit its straps.  The mountains of this species in the Betka area will be spectacular.
A Masked Lapwing was sitting in the lawn at the end of Coulls  Inlet.  Frances thought it might be sitting on a nest but I thought it wasn't low enough.  Then the bird stood up and 3 chicks ran out.
At some point in our walk a flock of about 50 Little Corellas flew over.  I missed the photo then, but later in the day got this one: a similar number of birds are out of shot.
For several days I have been trying to spot a pardalote's nest tunnel in a bank along Lakeside, and today I managed to see it.  The red arrow shows the crack in which the tunnel is being dug and the green arrow points to the excavated dirt,

Friday, 20 August 2021

Casuarina walk

 It has been a while since I did the Casuarina Walk and thought there might be some interesting wattle s along there.  That wasn't the case but it was a pleasant stroll.  I only did half the walk as it was the gullies I was mainly interested in

Here is an Allocasuarina verticillata, regrowing from a lignotuber.  It is going to be a long while before they are providing food for Glossy Black-Cockatoos.
Throughout the area covered by my walk the vegetation has regrown dramatically.  Most of it is Acacia, mainly A. longifolia or A. terminalis, with a wise range of species in the understorey.
The next few photos cover members of the family Fabaceae.  Quite a few specimens of Indigofera australis along the track.
Glycine clandestina is not really clandestine, but quite obvious climbing over other foliage!
The most obvious of the family is Hardenbergia violacea climbing over everything with very showy flowers
The other obvious climber in some areas is Kennedia rubicunda.  Aound the Betka area it if the dominant foliage climbing several metres up tree trunks.  It has grown dramatically as years of seeds in the ground were stimulated by the 2019-20 fire to germinate.  Last year it didn't flower greatly but the signs are that it will do so this year. 
I found a few open flowers: they are much larger than those of Kennedia prostrata a ground-hugging species.
There was a fair amount of bird call and a few were bold enough to be seen.  Golden Whistler male is shown: he was attracting a female but she didn't hang around for a photo.
Several White-throated Treecreepers were heard and one actually stayed the right side of the tree trunk to be snapped.