Great Southern Bioblitz

The inaugural Great Southern Bioblitz (GSB) was in 2020.  The Castlemaine Field Naturalists Club joined in 2021 and has taken part every year since. Each Bioblitz is held over 4 days in spring (September to November) with an iNaturalist project established to collect the observations.  Observations, photos and/or recordings within the Mt. Alexander Shire and the eastern half of Hepburn Shire are uploaded to iNaturalist where they are included in our project. 

The Journey So Far

This article is the first interrogation of the accumulated data.  The analysis is not exhaustive but will perhaps offer suggestions for more detailed analysis and how to prepare for future Bioblitz. There are many factors which can influence the bias of the data including seasonal factors, mismatched timing of the bioblitz across years, and the many human factors such as rare or conspicuous species being over-represented.

Spring 2021: 22nd to 25th October
This was the first year that we took part in the GSB. See the summary (below) of what we found in 2021 and take a closer look at our project and the Umbrella site for the year which shows all groups.

See notes below for an explanation of the categories.	Total	Plants	Birds	Insects	Amphibians	Animals	Arachnids	Fungi	Mammals	Molluscs	Reptiles
All observations Verifiable	1828	1221	168	292	4	20	47	54	7	1	14
All observations Research Grade	1266	938	166	103	4	13	15	6	6	1	14
All species Verifiable	575	322	63	119	2	8	21	24	4	1	11
All species Research Grade	430	277	63	53	2	4	11	5	3	1	11
Threatened	16	15	1

Spring 2022: 28th to 31st October.
See the summary (below) of what we found in 2022 and take a closer look at our project and the Umbrella site for the year which shows all groups.

See notes below for an explanation of the categories.	Total	Plants	Birds	Insects	Amphibians	Animals	Arachnids	Fungi	Mammals	Molluscs	Reptiles
All observations Verifiable	2173	1384	195	274	16	28	26	207	30	5	8
All observations Research Grade	1439	1020	194	108	13	18	7	41	27	4	7
All species Verifiable	622	347	63	112	4	14
All species Research Grade	452	273	63	66	4	3	6	16	8	2	7
Threatened	14	11	3

Spring 2023: 24th to 27th November
See the summary (below) of what we found in 2023 and take a closer look at our project and the Umbrella site for the year which shows all groups.

See notes below for an explanation of the categories.	Total	Plants	Birds	Insects	Amphibians	Animals	Arachnids	Fungi	Mammals	Molluscs	Reptiles
All observations Verifiable	2474	1130	375	735	18	30	65	65	34	4	18
All Observations Research Grade	1579	796	372	293	15	20	25	4	33	4	17
All species Verifiable	721	293	85	253	5	629	29	15	1	5	6
All species Research Grade	456	212	85	117	5	3	9	4	15	1	5
Threatened	16	12	3						1

Notes

‘Verifiable Observation’

This status is applied to any observation that is uploaded that contains a valid date, a location, has photo or sound, and isn’t of a captive/cultivated organism. Without any one of these vital pieces of information, an observation cannot reach Research Grade and is not shared with the Atlas of Living Australia (ALA). Reseach Grade observations are a sub-set of Verifiable observations.

‘Research Grade’

This status is achieved when a ‘Verifiable Observation’ has been reviewed and the community is in agreement on the ID. The observation will now be shared with the ALA and other iNaturalist partners.

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In the graphs below, the category ‘All other categories’ is the sum of ‘Amphibians, Arachnids, Fungi, Mammals, Molluscs, Other Animals & Reptiles’. In these groups there were insufficient observations for meaningful comparisons.

The first point to note is that the number of observations increased each year (Charts 1 & 2).  This is expected as the number of participants increased from 28 in 2021 to 38 in 2022 but 37 in 2023.  Although there is a core group of observers who have participated in all 3 Bioblitz, there are others who have participated in only one of the three Bioblitz.  The increase in total observations from 2022 to 2023, 38 and 37 observers respectively, could be due to the increased experience of each of the observers in 2023.

Bioblitz 2022 shows a significant increase in plant observations.  The timing was shortly after the heavy rainfall.  The data were not examined to identify how many invasive weeds were included.  However, in late November 2023, many native plants had already finished flowering and they may have been overlooked. 

In 2023, the moth night, held on November 25^th was the first time for this dedicated activity.  Together with the later time of the year and the milder weather, these factors may account for the higher number of insect and bird observations in 2023.

Also noteworthy is the increase of Fungi observations in 2022.  Again this may be attributable to the high rainfall in late winter and spring.

While the total number of observations is fixed for the time of each GSB project, species identification values may change as experts and knowledgeable people make further confirmations upgrading ‘verifiable’ to ‘research grade’ status (Charts 3 and 4).  In some instances this could take a year or more.  The quality of the photos which include clear identification features may also influence the level of species identification as will the number of people with sufficient knowledge to accurately identify some species.

Personal preferences, locations (grasslands, forests creeks or higher altitude), time of day/night, the season and weather (rain, sun, wind) will always influence which observations are made. 

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Threatened Species

The ‘Threatened’ classification is a grey area.  It may be influenced by data sources such as:
(1) The International Union for Conservation of Nature’s Red List of Threatened Species (IUCN Red List); In the table below the IUCN threat status may only be relevant to some named sub-species.
(2) The Federal Government’s Environment Protection and Biodiversity Conservation Act 1999 (EPBC);
(3) The Victorian Government’s Flora and Fauna Guarantee Act 1988;
(4) Other regional and local data sources such as – Threatened Species Scientific Committee, Indigenous Advisory Committee and the CSIRO among others.

For example, The IUCN and iNaturalist list the European Rabbit Oryctolagus cuniculus as ‘Threatened’ within its natural range in areas of Europe and north Africa!!  iNaturalist lists the Fryerstown Grevillea, Grevillea obtecta as ‘Threatened’ but the FFG lists it as ‘Endangered’ while it is not listed at all on the IUCN.  FFG lists the Small-flower Grevillea Grevillea micrantha as Critically endangered.

During the GSB Castlemaine 2021 and 2023, the European Rabbit was observed and uploaded into the respective projects.  They are valid observations and have been identified at research grade but the European Rabbit, has not been included in this survey as a ‘threatened’ mammal’ in the Mt. Alexander / Hepburn Shires. Red-flowering Gum, Corymbia ficifolia, and Pincushion Hakea, Hakea laurina, both native to WA and introduced to our region were likewise, not included in the analysis.

Nearly all threats to the global flora and fauna can be attributed to humans – the conflict between human activities and the conservation of our environment.  Some of the major threats include global warming, habitat loss due to exploitation of natural resources or changed land use, the over-exploitation of wildlife and plants for commercial purposes including trade of rare or charismatic species, novel diseases and competition from the introduction of invasive non-native species.  While many species may be threatened locally due to human or environmental factors this local status has not been picked up by this analysis. 

Threatened Species Native to our Region found during the GSBs

Common Name	Scientific Name	Threat Category	2021	2022	2023
Hardhead Duck	Aythya australis	Vulnerable (FFG)			X
Musk Duck	Biziura lobata	Vulnerable (FFG)	X	X
Gang-gang Cockatoo	Callocephalon fimbriatum	Endangered (EPBC)		X	X
Powerful Owl	Ninox strenua	Vulnerable (FFG)			X
Diamond Firetail	Stagonopleura guttata	Vulnerable (FFG)		X
Koala	Phascolarctos cinereus	Endangered (EPBC)			X
Late-Flowered Flax-lily	Dianella tarda	Critically Endangered (FFG)	X		X
Ornate Pink Fingers	Caladenia ornata	Endangered (FFG)	X	X
Golden Cowslips	Diuris behrii	Endangered (FFG)	X	X
Cassinia diminuta	Cassinia diminuta	Endangered (FFG)			X
River Red Gum	Eucalyptus camaldulensis	Near Threatend (IUCN)	X		X
Wiry bossiaea	Bossiaea cordigera	Endangered (FFG)			X
Long-leaved Box	Eucalyptus goniocalyx	Vulnerable (IUCN)	X		X
Yellow Gum	Eucalyptus leucoxylon	Vulnerable (IUCN)		X	X
Yellow Box	Eucalyptus melliodora	Vulnerable (IUCN)	X		X
Grey Box	Eucalyptus microcarpa	Endangered (IUCN)	X	X
Red Box (Silver Dollar Gum)	Eucalyptus polyanthemos	Some sub-species	X		X
Manna Gum	Eucalyptus viminalis	Near Threatend (IUCN)	X
Goldfields Grevillea	Grevillea dryophylla	Endangered (FFG)		X	X
Small-flower Grevillea	Grevillea micrantha	Critically Endangered (FFG)		X	X
Fryerstown Grevillea	Grevillea obtecta	Endangered (FFG)	X	X	X
Creeping Grevillea	Grevillea repens	Endangered (FFG)	X
Hairy Geebung	Persoonia rigida	Vulnerable (IUCN)		X
Dense Mint Bush	Prostanthera decussata	Endangered (FFG)	X	X
Scented Bush-pea	Pultenaea graveolens	Endangered (FFG)	X	X	X