More invertebrates (and a bird)

 On 27 January we found a few interesting invertebrates.  This began in our garden finding this colourful jobbie crawling around behind the shed,

iNaturalist.org identified this as a Blue Ant (Diamma bicolor) which has been confirmed by some fleshware associated with that facility.  It's more of an ain't than an ant, as it is actually a wingless flower wasp.  The females hunt mole crickets in which they lay their eggs,

We then we to Bastion Point, following up a further sighting of Southern Emuwrens in that area.  We were unlucky with the wrens but there was plenty of insect activity on the Sea Rocket Calkile maritma.   This first butterfly in an Australian Painted Lady Vanessa kershawi.

The Cabbage Whites Pieris rapae were in swarms, as they seem to be everywhere this year.

While I continued the fruitless search for Emuwrens Frances went to rocks exposed by a low tide  and found this beastie.  It is a Calloused Keyhole Limpet Amblychilepas nigrita and referring to our book on Coffin Bay (in SA but it is a mine of information on our marine life) says that it's body is far too big to fit under the shell.

Here are its antennae.

This looks like a mini-lobster but iNaturalist has been consulted.  It was not well.

An Eastern Reef Heron was also exploring the reef.  No idea why it had its beak open.

When we got home I had more information about another site for Emuwrens: the marsh opposite our street.  I managed to spot a male!  But be warned: wear wellies not shorts and don't think about Tiger Snakes.

Weather 25-26 January

The 25th January 2021 was forecast to be stinking hot.  And so it was.  I cowered indoors for most of the day.  

The maximum temperature recorded on my Weather Station was 42.1C, the highest temperature I have recorded here in the 2 years my station has been operating.  (The previous high was on 30 December 2019, the day before the fire hit.)  For the Bureau of Meteorology site at the Airport the maximum was 39.6C while the hottest (fair) temperature recorded there was 42.0C on 18 January 2013.    (I have qualified as 'fair' since the station did record 60C on 31 Decemeber 2019, as the fire front passed through.  That observation has been removed by BoM.)

Here is a chart showing the hourly temperatures at both sites.

The relative humidity reading were also interesting because of the low values recorded.  My weather station got to 22% at 1400hrs while the BoM recorded an arid 18% at noon.

Both stations recorded simultaneous turning points for both series at the same time (noon for BoM, 1400 hrs for my WS).  In the case of the BoM this reflected a change in wind direction from NNW (ie overland) to NE (more of a sea breeze).  My WS doesn't show such a change, but is more sheltered in the ESE to NE quadrant.

After a few 'spits' for most of the afternoon - not enough to register - a squall (26mm/hr) arrived about 1915 and gave us 0.4mm.

Hawk Moth and a goanna

 A recent comment on the MCN Facebook oage drew attention to hawk moths visiting flowers in the area.  This morning walking down Angophora Drive Frances spotted this very large specimen in the road.   Also well camouflaged.

We shifted it on to the the grass where it spread its wings.  I don't think it was well!

I shall consult iNaturalist.org for an expert identification.

Later in the day I was riding my bike up Angophora and heard small birds generating a ruckus in  a friends garden.  My first hope was a roosting owl.  Second prize, which eventuated, was a visiting reptile.  A Lace Monitor (aka Goanna) about 1.8m long.

I walked back with Frances a little later and it was still visible perhaps 5 m further up the tree.

Low tide wanderings

This week has the last spell of really low tides (well below 0.1m) so we have been visiting the local rocky areas and pools exposed thereby.  In essence the low diversity of recent visits has continued.  No Abalone, no Elephant Snails, few Sea Anemones or Sea Stars.  On these visits even the hordes of Sea Hares have vanished (although a few tide-washed egg masses were seen at Bastion Point.  

One largeish crab was seen .  This appears to be a Purple Rock Crab (iNaturalist) or Swift-footed Shore Crab (Museum of Victoria), both agreeing on Leptograpsus variegatus.

On the steps at the end of the breakwater some Alyxia buxifolia was in bloom ...

.. or fruit.

AS we left an immature White-bellied Sea-Eagle passed by.

On 13 January I rode past the wharf where a large (my estimate was about 1 m across the wings) stingray was scarfing up the fish remnants dropped from the cleaning table. This is an Eagle Ray (Myliobatis australis) indicated by the shape of the head.  

In the afternoon we did the 3 Beaches walk starting at Betka.  A very pleasant stroll, but again very little wildlife.  Many dead beetles washed up on Betka Beach (ie Beach #1): as there were none on the other 2 beaches I wondered if they had been washed down the River.

On the second beach these rock bubbled reminded Frances (and me, once she had made the suggestion) of the lower regions of Skywhale.

On 14 January we went to Pebbly Beach to see what the low tide revealed there.  This is the approximate path we followed (I didn't start eBird until we were on the beach).

The first issue we noticed was that the rocks were very slippery.  Possibly this was due to some exudate from the kelp - visible on these rocks - being washed in.

A general view of the rock.  I scanned carefully for Tattlers (of either species) but none were present.  We did see two Eastern Reef Egrets fly past which was good.

A long-legged crab.  ID to come from iNaturalist - I hope.

A smaller, and definitely hyperactive crab. Again iNaturalist to be consulted.

Plants on the tracks

 On New Years Eve we were given a recommendation that "Native Trees and Shrubs of South- Eastern Australia" by Leon Costermans was a good reference to identifying the vegetation (especially the trees) in this area.  Somewhat to our surprise we found we had a copy thereof!  Indeed it seems to be very useful, especially as we have now pulled it out of the bookshelves.  This has led to a thought that we should use this book, together with "Wildflowers of the Wilderness Coast" by Joy Grieg to document the plants along the various tracks on which we walk. Note that not all the plants have read Joy's book and thus my be shown under different habitats.

In difficult cases I have also referred to Flora of Victoria, but that is usually only helpful if you know more or less what you are interested in and are seeking confirmation (or more detail). 

So we started this project, beginning at the beach end of the Chip track.  This map, captured by eBird, shows our route, with the ends of the track marked by the arrows.

We made life difficult by starting this project in mid-Summer when few plants have flowers, but in most cases the leaves are quite distinctive.  The images are in the order they were taken.

This was right on the beach.  I think it is Cakile maritima subsp. maritima, a species introduced from Europe known as Sea Rocket.

Olearia axillaris: only leaves visible on this track.

The next day at Bastion Point we found a specimen in good flower.

The commonest wattle of the dune region Acacia longifolia.

This is a Tea-tree probably Leptosperumum laevigatum.

Somewhere along the way I seem to have managed to delete a photo of Leucopogon parviflorus which I know occurs throughout the path.  I will try to add one later.

This next was, I thought, easy to identify as Pigface.  Not so!  That word isn't in Joy's book and the only Pigface in Flora of Victoria is an introduced species Carpobrotus aequilaterus (Angled Pigface), which didn't seem to fit.  Getting desperate I referred to Plantnet which listed a few more species in the genus Caropbrotus.  Back to FoV and I came up with Carpobrotus rossii which gets a mention in Joj's book (and FoV) with the vernacular name "Karkalla".   That is certainly not a common name in most of society!

Joy also mentions, but no image, another species Disphyma crassifolium of similar appearnace but with round-section leaves.  Some close perring will be needed as I am quite sure I have seem such a plant in the area.

Many of the Banksias in the area were burnt but many are recovering.  The most common species is B. integrifolia (Coast Banksia) with entire leaf margins.  Some of the leaves along this track looked quite 'toothed' but I cannot think of another species to attach to those trees.

 The trees did flower in Spring but all the cones are now spent.

Both the creeper and the laminar plants in this image are in need of identification.

Senecio pinnatifolius was widespread all along the track.  Some plants were still in flower ...

... while others had seedheads.

From the mid-way point of the track onwards we have found a good range of Spring orchids.  The have obviously vanished by mid-January but to make this post more comprehensive I shall give some thought to gathering together the species found and their approximate location.

Although listed against "Heathland" rather than "Coastal Dunes" I believe this is Amperea xiphoclada (Broom Spurge) a member of the Euphorbia family.

I have no idea of this blue job.

Pelargonium australe

A sedge. 

A little off the topic of this post but this image of a family of Hooded Plovers is interesting as it shows how the Plovers appear totally relaxed within about 30 metres of a horde of beachgoers.  The situation might be different if unleashed dogs were present but as it was there is good news for the Hoodies.  One expert who has seen this image commented that possibly the humans deterred other predators, such as the Magpie, exploring a pile of kelp 100m up the beach.

A new reptile

 Frances called me to hurry to the garage but didn't sound in pain.  When I arrived having sprinted down the hall there was a new reptile.  So I sprinted back and grabbed a camera.

By the time of my second appearance the animal had snuck out through a small gap at the edge of the door but it did then pose nicely for some photos.  The first image was the last I took, but it does show most of the beast.

The pointy tail reminded me of a Cunningham's Skink (but at about 1/3rd scale).

Referring to the excellent  "Reptiles of Victoria" says this is Black Rock Skink (Egernia saxatilis).  It is described as uncommon but widespread/

Annual Weather Report 2020

This is intended to be a summary report on the overall metrics of the weather in 2020.  It is made more difficult by the BoM site being off air for several days (especially January 2020 due to bushfire related issues).  I will endeavour to avoid too many graphs.  

In summary:

• Rainfall: Above both mean and median.
• Temperatures
• Average: slightly above the long term mean;
• Maximum: close to long term mean
• Minimum: above long term mean
• Humidity: Difficult - see below - but probably balances out to slightly more humid in 2020 than 2019.
• Wind: Again difficult, but my data suggests slightly windier in 2019 than 2020.

Rain

At my Weather Station (WS) the year totaled 1007 mm effectively the same as the BoM station at the airport. This is 108% of the mean annual fall and 116% of tht median fall.  In summary a nicely damp year!

There is no significant trend in the annual data series with the first several years being highly variable, followed by a more stable 20 years and more recently further variability.

I also estimate, on a daily basis the possible annual fall by pro-rata expansion of the cumulative rainfall to date.  The next chart shows the daily estimates for 2020.  This can be interpreted as:

• low falls until mid-February (except a downpour in late January);
• below average falls until July (except a dump in early June);
• a gradual increase through July and August;
• about average falls for the rest of the year, with the annual estimate bobbling around 1000 mm.

In 2020 more than 0.2 mm of rain was recorded on 134 days.  This compares to 110 days in 2019 and an average (for years with complete data) since 1975 of 120 days.

Temperatures

Average Temperatures

There are two ways of calculating average temperatures.  

• The more precise is to take the mean of temperatures taken at points in time through a period.  I can do this with readings from my WS which gives an annual average temperature for 2020 of 15.76C.  
• As I don't have readings for the first 6 weeks of 2019 a comparable value is not possible.)  
• I cannot do this with BoM data since the series available though Climate Data on Line only include at the most detailed daily minima and maxima.
• A second method is to take the average of the maximum and minimum temperatures though a period.  This can be done on a daily, monthly or annual basis.  The result is usually very similar to the more precise value.  Applying the method to BoM data for 2020 gives a result of 15.81C and to the extremes from my WS 15.75C.  These are effectively identical to WS value given above.
• Note that for the BoM series I used my WS values for the 9 days in January 2020 when the BoM site was hors de feu but I don't believe this had any impact of outcome.

 

Another overall measure is the average extremes  - sort of a contradiction in in terms, but I mean the annual average maximum and minimum temperatures. 

The average minimum temperature for 2020 at my WS was 11.9C: the BoM does not offer an annual mean minimum, possibly due to missing 9 days in January (but the equivalent data is not available for other sites) well above the series average of 10.9C.

The average maximum temperature for the year, at my WS was 20.7C.  While the BoM has again not offered an annual maximum I have kept records through the year giving an approximate annual average value of 19.62 C.  This is within 0.01C of the mean annual average maximum!  (It is normal for the BoM station to have lower maxima than my station as the BoM site is far more exposed to cooling sea breezes.)

In both series the trend is upwards although the level of significance is not great.

Humidity

It is difficult to add much to that shown in my report for December, as BoM offers very scant historical information.  A chart of average rH at my WS through the year shows slightly higher values for 2020 than 2019.

A caveat should be issued that my WS did not become operational until mid February in 2019 and thus the data is not absolutely comparably.  However a comparison of my data for January 2020 with the rest of that year shows only slight differences (overall average -0.5%rH).  Looking at BoM data for monthly averages suggests a relatively high reading for 0900 hrs in January 2019 and a relatively low reading for 1500 hrs.

Overall I conclude that 2020 was slightly more humid than 2019.  This is hardly surprising given that rainfall in 2020 was close to double that of 2019.

Wind

This is a risky topic as (a) BoM present surprisingly little wind data beyond daily readings and (b) my WS is not situated ideally for measuring wind with various obstructions from NE to SW - going clockwise.  However I have found that the daily observations for direction are generally close to those from the airport and the measures of speed correlate well, so I conclude that while not absolutely reliable the data is fit for generalised statements.

Wind speed

Of the measures available from my WS I prefer using windrun and hourly gust.  Rather than showing the monthly data covered in earlier reports I have charted the average run and peak gust through the day for the two years for which I have data.  (The lack of data from the first 6 weeks of 2019 appears unlikely to significantly alter the comparison.)

I am not a meteorologist but assume the peak winds in the middle of the day is something to do with land heating up!   The pattern is similar, with 2019 slightly windier.

Wind direction

The pattern is again quite similar between the years.  The higher number of observations from ESE in 2020 may reflect the passage of several East Coast Lows in that year.

Contrasting the direction of the wind at the hourly point in time with the direction of the strongest gust  is somewhat interesting with the gusts being recorded from all directions but with less records from the N and ESE.