Great Southern Bioblitz Region Report: South America

South America contributed a substantial and highly diverse set of records to the Great Southern BioBlitz 2025, with 43,814 observations, 10,997 unique taxa, and 2,153 observers, yielding 5.11 taxa per observer. This taxa-per-observer value is notably high relative to regions with larger participation bases, suggesting that South America’s contribution was driven by a strong proportion of highly engaged participants recording broadly across taxa.

Table 1 Overall summary of South America (GSB 2025)

Observations	Unique taxa	Observers	Taxa per observer
43814	10997	2153	5.11

Seasonal Trends Across All Years

Across the full GSB time series, South America has maintained consistently strong biodiversity yield. Observations increased from 29,124 (2020) to a peak of 51,380 (2021), before stabilising in the ~38,000–44,000 range through 2025. In contrast, unique taxa increased steadily every year, rising from 6,862 (2020) to 10,997 (2025)—the highest taxonomic richness recorded for the region to date. Taxa per observer also remained consistently strong (generally ~5–6), peaking in 2023 (5.81), indicating sustained depth of contribution even as participation expanded.

Table 2 Seasonal summary of the GSB in South America across all years

Year	Observations	Unique taxa	Observers	Taxa per observer
2020	29124	6862	1471	4.66
2021	51380	9670	1776	5.44
2022	38486	8962	1669	5.37
2023	38756	9497	1636	5.81
2024	44396	9895	1885	5.25
2025	43814	10997	2153	5.11

Figure 1

 Number of observers contributing to the GSB in South America each year 2020-2025

Observer Contributions

South America’s 2025 totals reflect both committed high-volume observers and dedicated “species chasers.” jonathan_janse led observation volume (950 observations), followed by contributors including geanella_lisseth, ariana_silva, and carlosjustinianoparada. Taxonomic breadth was led by ariana_silva (434 unique taxa), closely followed by carlosjustinianoparada (423) and jonathan_janse (414), demonstrating the critical role of high-diversity recorders in expanding regional taxonomic coverage.

Table 3 Top 10 observers from South America (GSB 2025)

Username	Observations
jonathan_janse	950
geanella_lisseth	640
ariana_silva	601
carlosjustinianoparada	591
dgalarza	513
ateleginski	464
fertam	462
joelmiserendinocuellar	455
dolma33	418
josev_ge	413
misshaelantony	413

Table 4 Top 10 species chasers from South America (GSB 2025)

Username	Unique taxa
ariana_silva	434
carlosjustinianoparada	423
jonathan_janse	414
fertam	376
joelmiserendinocuellar	325
geanella_lisseth	287
josev_ge	278
vitorcdg	265
blanquita2	262
paularomano	254

Kingdom-Level Patterns

South America’s records were dominated by Plantae and Animalia, with Plantae contributing 21,346 observations (4,794 unique taxa) and Animalia contributing 20,135 observations (5,639 unique taxa). This near-balance highlights strong engagement with both flora and fauna and suggests that participants captured biodiversity across a wide range of habitats and observation styles. Fungi were also comparatively well represented (2,254 observations; 549 unique taxa), while Chromista, Bacteria, and Protozoa were recorded only rarely—consistent with the specialist identification requirements and microscopic nature of many taxa in these groups.

Table 5 Kingdom statistics of South America (GSB 2025)

Kingdom	Observations	Unique taxa	Observers	Taxa per observer
Animalia	20135	5639	1652	3.41
Bacteria	2	2	2	1.00
Chromista	5	4	3	1.33
Fungi	2254	549	496	1.11
Plantae	21346	4794	1298	3.69
Protozoa	15	8	13	0.62

Vertebrates (Chordata)

Among vertebrates, Aves dominated, with 4,952 observations and 910 unique taxa, supported by 676 observers, indicating both strong participation and high bird diversity. Reptilia (596 observations; 170 taxa) and Amphibia (480 observations; 123 taxa) contributed meaningful richness relative to observation volume, consistent with South America’s strong herpetofaunal diversity and the value of targeted observation effort. Mammalia recorded fewer observations (361) but maintained solid taxonomic breadth (130 taxa), while aquatic vertebrates (Actinopterygii and Chondrichthyes) were represented at lower levels but showed high taxa-per-observer ratios, suggesting contributions from more specialised observers.

Table 6 Vertebrates (Chordata) from South America

Class	Observations	Unique taxa	Observers	Taxa per observer
Actinopterygii	134	91	45	2.02
Amphibia	480	123	186	0.66
Aves	4952	910	676	1.35
Chondrichthyes	9	9	6	1.50
Mammalia	361	130	203	0.64
Reptilia	596	170	267	0.64

Invertebrates (Arthropoda)

Invertebrates made up a major component of South America’s biodiversity signal, led overwhelmingly by Insecta, which accounted for 11,185 observations and 3,515 unique taxa, with a notably high 3.00 taxa per observer, one of the strongest values among the major arthropod classes. Arachnida also contributed substantially (1,570 observations; 437 taxa), while other groups such as Diplopoda, Chilopoda, and aquatic crustacean classes were recorded at lower levels, adding ecological breadth but reflecting lower detectability and/or less observer focus.

Table 7 Invertebrates (Arthropoda) from South America

Class	Observations	Unique taxa	Observers	Taxa per observer
Arachnida	1570	437	495	0.88
Chilopoda	24	15	21	0.71
Diplopoda	154	28	92	0.3
Entognatha	1	1	1	1
Hexanauplia	3	2	3	0.67
Insecta	11185	3515	1170	3
Malacostraca	128	42	71	0.59

Insects (Insecta) from South America

Within insects, Lepidoptera were the clear standout group, contributing 3,838 observations and 1,311 unique taxa with a very strong 2.05 taxa per observer, highlighting both high diversity and effective observer attention to moths and butterflies. Coleoptera, Hymenoptera, Hemiptera, and Diptera also contributed strongly, each recording high taxonomic richness relative to observation totals, indicating broad sampling across major insect lineages. Other orders (e.g., Orthoptera and Odonata) added additional habitat coverage, while low-frequency groups (e.g., Plecoptera, Megaloptera, and Zygentoma) were recorded infrequently but strengthened overall taxonomic completeness.

Table 8 Insects (Insecta) from South America

Order	Observations	Unique taxa	Observers	Taxa per observer
Archaeognatha	4	2	3	0.67
Blattodea	158	43	92	0.47
Coleoptera	1953	647	534	1.21
Dermaptera	32	16	23	0.7
Diptera	1136	337	327	1.03
Ephemeroptera	4	2	4	0.5
Hemiptera	1310	445	401	1.11
Hymenoptera	1556	359	470	0.76
Lepidoptera	3838	1311	641	2.05
Mantodea	62	29	47	0.62
Megaloptera	7	7	7	1
Neuroptera	41	19	34	0.56
Odonata	192	74	113	0.65
Orthoptera	678	186	278	0.67
Phasmida	34	17	26	0.65
Plecoptera	1	1	1	1
Psocodea	20	9	14	0.64
Thysanoptera	3	3	2	1.5
Trichoptera	11	5	11	0.45
Zygentoma	1	1	1	1

Flowering Plants (Magnoliopsida)

Flowering plant records were diverse across many orders, with Asterales contributing the highest totals (2,286 observations; 528 taxa; 553 observers). Lamiales and Solanales also stood out for both observation volume and taxonomic richness, reflecting their prominence across South American floras. Caryophyllales, Fabales, and Myrtales further contributed substantial diversity, while orders such as Malpighiales, Rosales, and Sapindales added breadth across ecosystems. Several orders were represented by very few observations (e.g., Buxales, Garryales, Chloranthales), but their inclusion adds valuable phylogenetic and biogeographic depth to the dataset.

Table 9 Flowering plants (Magnoliopsida) from South America

Order	Observations	Unique taxa	Observers	Taxa per observer
Apiales	173	61	109	0.56
Aquifoliales	12	6	10	0.60
Asterales	2286	528	553	0.95
Berberidopsidales	2	2	2	1.00
Boraginales	224	46	125	0.37
Brassicales	356	80	188	0.43
Buxales	1	1	1	1.00
Canellales	19	4	10	0.40
Caryophyllales	1481	343	400	0.86
Celastrales	30	6	15	0.40
Chloranthales	5	1	5	0.20
Cornales	64	19	48	0.40
Cucurbitales	160	56	97	0.58
Dilleniales	4	3	4	0.75
Dipsacales	79	20	58	0.34
Ericales	392	100	163	0.61
Escalloniales	12	8	11	0.73
Fabales	1422	338	476	0.71
Fagales	58	15	46	0.33
Garryales	1	1	1	1.00
Gentianales	536	181	246	0.74
Geraniales	62	18	47	0.38
Gunnerales	5	2	5	0.40
Lamiales	1612	417	513	0.81
Laurales	70	26	49	0.53
Magnoliales	28	11	26	0.42
Malpighiales	785	229	297	0.77
Malvales	576	130	242	0.54
Myrtales	927	197	336	0.59
Nymphaeales	12	5	11	0.45
Oxalidales	228	41	117	0.35
Piperales	216	40	96	0.42
Proteales	22	8	19	0.42
Ranunculales	84	34	63	0.54
Rosales	579	142	265	0.54
Santalales	58	24	48	0.50
Sapindales	353	107	175	0.61
Saxifragales	86	32	65	0.49
Solanales	1082	211	410	0.51
Vitales	28	10	20	0.50
Zygophyllales	35	13	25	0.52

Summary

Overall, South America’s GSB 2025 contribution is characterised by high taxonomic richness, strong taxa-per-observer performance, and a balanced emphasis on plants and animals, alongside meaningful fungal representation. The region’s results highlight the outsized impact of highly engaged participants and suggest that continued growth in participation, combined with targeted effort toward under-recorded groups, could further expand both the breadth and completeness of South America’s biodiversity documentation in future BioBlitz events.