With the Great Southern BioBlitz 2021 approaching, I thought I’d review my City Nature Challenge and Great Southern BioBlitz history, and see if I can break some personal records during the GSB2021.

I’ve previously taken part in the City Nature Challenge 2020 with 1172 observations of 372 species, the Great Southern BioBlitz 2020 with 1440 observations of 461 species, and the City Nature Challenge 2021 with 1403 observations of 426 species.

City Nature Challenge 2020
My first attempt at a 4-day BioBlitz was the CNC2020. Taking place in our Autumn, this wasn’t an ideal time of year to discover as many species as possible. The weather can put a damper on most activity and the short daylight hours can be limiting. Many seasonal plant species aren’t present, Insects are hidden away in egg or larval stages, and identifying plants without flowers can present difficulties. Nevertheless, over the four days I visited 17 locations recording 1172 observations covering 373 species (using the ‘leaf count’ method), with 325 of those identified all the way to species.

Given the season and ease of observation, Plants featured heavily with the top 24 most recorded species being Plants. Most recorded was the Myrtle Wattle (Acacia myrtifolia) with 24 records across 8 different locations. The most recorded Bird was the Superb Fairywren (Malurus cyaneus), with 7 records across 7 different locations. The first Insect, the Meadow Argus (Junonia villida) appeared in 25th place with 6 records.

Observations from my property over the 4 days totalled 155 records covering 78 species. Many of these were Lepidoptera attracted to a UV light, however the species total also included 6 Flies, 6 Beetles, 5 Arachnids, 5 Plants (naturally occurring), 3 Molluscs and 3 Ants.

CNC2020 Highlights:

• First sighting of a Variable Peacock Spider (Maratus chrysomelas) found in leaf litter at Manning Flora & Fauna Reserve. This particular observation made its way into the Interesting Finds section of the City Nature Challenge Results infographic.
• On my property I found my first Carrion Beetle (Ptomaphila lacrymosa)
• A Tau Emerald (Hemicordulia tau) caught mid-flight near a wetland.
• A short video clip of Dolichoderus scabridus Ants at their nest entrance.
• An unexpected sighting of a Rufous Night-Heron (Nycticorax caledonicus) at Hart Road Wetlands. Still the only record at this wetland on iNat.

Great Southern BioBlitz 2020
This is a BioBlitz much more suitable for tracking down those Spring flowers and Insects. The first Great Southern BioBlitz offered warm days with longer daylight hours. But the weather doesn’t always play nice as I found myself in the middle of Ferries-McDonald CP fending off a hailstorm.

Over the four days I visited 17 locations recording 1440 observations covering 461 species (using the ‘leaf count’ method), with 403 of those identified all the way to species. That’s +268 observations and +89 species beyond the CNC2020 totals.

The higher species count came from both records of seasonal plants and the inclusion of two beach locations in the mix which brought in additional marine species. While Plants feature heavily in the most observed list, 4 of the top 5 observed species were seasonal Orchids, with the Waxlip Orchid (Glossodia major) taking out the top spot having 23 observations across 3 different locations. The most observed Bird was the Australian Pelican (Pelecanus conspicillatus) coming in 9th place with 11 records across 4 different locations. The first Insect was again a Butterfly, with the Australian Painted Lady (Vanessa kershawi) coming in 52nd place with 5 records across 2 different locations.

Observations from my property over the 4 days totalled only 61 records covering 33 species. The lower numbers than in the CNC2020 were due to poor weather limiting the use of the UV light and time to search in the yard.

GSB2020 Highlights:

• A collection of Birds resting in the shallows down past the Goolwa Barrage shortly after sunrise.
• A Thick-lipped Spider-Orchid (Caladenia cardiochila) from Monarto CP. Not uncommon, but a first record for me.
• Several Southern Meat Ants (Iridomyrmex purpureus) waiting patiently at the nest entrance until its warm enough for them to forage.
• Multiple European Starlings (Sturnus vulgaris) occupying nesting boxes.
• Castiarina xanthopilosa. One of several Castiarina species found on a large patch of Heath Teatrees (Leptospermum myrsinoides).
• My first record of a Calomela ioptera.
• Possibly the first photo of a living Heteroptolis leucosta.
• A Tasmanian Ladybird (Cleobora mellyi), rarely sighted in SA.

City Nature Challenge 2021
My second run at the City Nature Challenge followed much the same pattern as the first, with Plants featuring heavily, followed by Birds, and few Invertebrates.

Over the four days I visited 14 locations recording 1403 observations covering 426 species (using the ‘leaf count’ method), with 364 of those identified all the way to species. This was less than during the Spring GSB2020, as expected, but compared to the previous Autumn CNC2020 it was +231 observations and +54 species.

I had expected that across both years the species seen would have been fairly similar. The locations visited were different, but generally within the same region. However comparing both species lists (using the iNat compare tool) showed that of the 426 species seen in the CNC2021, 225 of them were NOT seen in the CNC2020. And of the 372 species seen in the CNC2020, 177 were NOT seen in the CNC2021. This strongly suggests that the key to recording as many species as possible during the BioBlitz is to visit as many, and varied, locations as possible. As opposed to longer visits to fewer locations.

The most observed species was the Golden Wattle (Acacia pycnantha), with 31 records across 5 different locations. Some species featured heavily this year due to choice of location, such as the Mount Lofty Ground-Berry (Acrotriche fasciculiflora) which placed 6th with 16 observations across only 2 locations in the Adelaide Hills.

Observations from my property over the 4 days totalled only 191 records covering 79 species. Lepidoptera featured heavily (143 observations) thanks to some warm weather. Interestingly, even though these observations were recorded at the same location and the same time of year, there was limited crossover. In the CNC2021 there were 50 species not recorded in CNC2020, and in the CNC2020 there were 52 species not recorded in the CNC2021. This suggests with a little effort the number of species recorded on my property over the 4 days could be doubled.

CNC2021 Highlights:

• A Two-pronged Bristletail found in my own yard. An entire Order I know almost nothing about.
• A couple of very active Australasian Swamphens (Porphyrio melanotus).
• Just a pair of common Grey Teals (Anas gracilis) that happen to be resting in an ideal location for a photo, at Laratinga Wetland, Mount Barker.
• A fascinating Psylloid found on a Eucalyptus incrassata in Ferries McDonald CP.
• A Peregrine Falcon (Falco peregrinus) in Aldinga Scrub CP, found on the last hike of the last day.

Great Southern BioBlitz 2021
This all brings us to the Great Southern BioBlitz 2021. This year I’ll be looking at visiting new locations and recording new species. Having learnt a few lessons from the previous BioBlitz events, I’ll be aiming to:

• Add 50 new species to my life list.
• Record at least 1,500 observations.
• Record at least 500 species.

It’ll take a bit of effort to achieve all three. I’ll be visiting some semi-arid locations to track down some new species, however such areas tend to have lower species diversity, so I may be hard pressed to reach 500 species for the 4 days. It’ll also very much depend on the weather.

Good luck to anyone participating in this years Great Southern BioBlitz. Whether you’re heading out on all 4 days or just spending some time discovering the species in your own backyard, all will contribute important biodiversity records to the Atlas of Living Australia.