Thanks to a sharp-eyed group of devoted citizen scientists, three more species of disco-dancing peacock spiders have been discovered in southwestern Australia
Are you afraid of spiders? Most people are, but you might change your mind after learning about three newly-described peacock spiders, Maratus species, discovered in southwestern Australia. In fact, these tiny spiders are so adorable that an entire community of people from all walks of life have come together to devote time and resources to better understand them, making this a labor of love.
“I work on these spiders in my spare time after work hours,” said the author of the study, biologist Joseph Schubert, who pays his bills by researching a group of invertebrates known as Collembola (these are six-legged relatives of insects), at Monash University.
These new species were discovered by the citizen science group, Project Maratus
“These spiders were found by a group of keen-eyed individuals called ‘Project Maratus’, who actively head out into the wilderness and seek out new species of Maratus,” Mr. Schubert said in email. “They sent the specimens they found to me to formally classify in the lab.”
Project Maratus is a not-for-profit self-funded group of citizen scientists that undertakes field work and promotes peacock spider research. According to their Facebook page, Project Maratus is a “mammoth commitment”, often involving many thousands of kilometers of driving from habitat to habitat throughout Australia and weeks spent away from home.
“Our dedication and passion for the natural world is what drives us,” writes Project Maratus on their Facebook page.
The devotion of Project Maratus’s volunteers is invaluable. Currently, little is known about these spiders’ status in Australia, so Project Maratus’s findings are essential for expanding our meager understanding of peacock spider evolution and ecology. This dedicated community of spider hunters and macro photographers and videographers is the first coordinated effort to locate and identify these overlooked spiders’ distributions and preferred habitats throughout Australia.
Peacock spiders are Australia’s most charismatic minibeasts
“Surprisingly, I grew up an arachnophobe,” Mr. Schubert said in email. “In an attempt to cure my fear, I began keeping spiders as pets in high school. My fear slowly developed into fascination, and over time I have learned to love them!”
Their brilliant color patterns and fascinating behaviors make it easy for most people to enjoy peacock spiders.
“I find peacock spiders to be the most charismatic spiders Australia has to offer, and an incredibly fun group to study,” Mr. Schubert explained in email. “They’re a great group to expose arachnophobes to, as they’re quite cute compared to the scary, hairy spiders we’re used to seeing.”
Peacock spiders are members of the jumping spider family, Salticidae, which is the most diverse group of spiders. Originally classified into just one genus, Maratus, a new grassland peacock spider discovered in 2013 was different enough to be classified into a second, new, genus, Saratus (PDF). There are likely more members of this genus awaiting discovery.
“Their tiny size is quite amazing,” Mr. Schubert pointed out in email. “Most species are only 4-5mm long (roughly the length of a grain of rice).”
Their size is the reason “most peacock spider species had been overlooked by scientists until quite recently, which is why at least 60 species have been discovered in the last 10 years,” Mr. Schubert said in email, adding that “social media has played a significant role in popularizing this awesome group of creatures and getting people outdoors looking for new species.”
Peacock spiders occur across much of Australia but the greatest number and diversity of species are being discovered in the temperate bushlands on the southwestern corner of the continent (Figure 1).
This special region is recognized as one of the planet’s major biodiversity hotspots (ref) as well as a hotspot for peacock spider diversity (ref). Of the 74 species of peacock spiders currently known, at least 35 are known to occur in this region; 29 of them exclusively. All three newly-described Maratus species are found in the southwestern corner of Australia.
Eagle peacock spider
The eagle peacock spider, Maratus aquilus, gets its name from markings on the male’s upper abdomen, which resemble an eagle’s face when seen from the front. This species, which occurs near Mount Romance, Western Australia (triangle; Figure 1), is similar to specimens collected by Jürgen “peacock spiderman” Otto at another location near Mount Romance in 2018, and thus, may be a variant of the same species.
Burnt-orange peacock spider
This peacock spider’s scientific name, Maratus combustus, refers to the medium-dark burnt-orange color of the male’s abdomen. This species was collected near Mount Romance, Western Australia (circle; Figure 1). Although this species was discovered very close where the eagle peacock spider was first found, their ranges do not overlap.
Kitty-cat peacock spider
“Surprisingly, Maratus felinus was discovered by accident,” Mr. Schubert said in email. “The team thought it was a known species at first glance, but decided to collect a few individuals just to photograph. Upon photographing it, they realised it was a brand new species and quite a significant find!”
This species is only found near Lake Jasper, Western Australia (star; Figure 1).
“The abdomen of this species looks like a cat’s face, hence me naming it ‘felinus’.”
Each peacock spider species dances to the beat of its own special drum
Jumping spiders, as a taxonomic family, are highly visual animals, yet the peacock spiders maintain a high level of sexual dimorphism, a trait where males and females have recognizably different appearances.
“The males are brilliantly coloured, whereas the females are drab and brown,” Mr. Schubert said in email.
The males can be easily identified by brilliant color patterns, which are often iridescent, on the upper side of their abdomens. Many species have flaps on the sides of their abdomens that can be opened and fluttered rapidly during courtship, thereby increasing visibility. The males’ third pair of legs, which they wave around during their courtship displays, are often fuzzy and distinctively marked, too.
But the females are cryptically colored and difficult to distinguish, even by human experts, so how do male peacock spiders correctly identify a potential mate?
“The males don’t seem to be the ones who are identifying the females,” Mr. Schubert said in email.
“Male peacock spiders have been observed displaying to females of the wrong species before, meaning that they are likely only aware that they are displaying to a congener. Since females are the ones who select the males based on their courtship and colouration, it’s much more likely that the females are the ones identifying conspecific males.”
After thousands of years of female choice, each of these species have been made into “Australia’s mini birds of paradise” with brilliant color patterns and intricate courtship rituals.
What are females looking for in a male’s dance? Because males don’t provide parental care, is the combination of coloration and courtship dance strictly for the purpose of identifying the correct species? Or might these visual signals also provide clues to a female about a male’s genetic quality? This seems likely because males with atypical dances or color patterns are generally eaten by their intended sweethearts.
What other sorts of information might the females be detecting about the males?
“Perhaps they also pick up on pheromone cues as well as visual cues,” Mr. Schubert speculated in email. “[H]owever, no studies have been undertaken to test this.”
Peacock spiders’ interesting courtship behaviors are unique and studies probably will provide clues to the mysteries of visual signalling and communication within these species.
“I think this story shows how easily these creatures can be overlooked, even when seeking them out,” Mr. Schubert said in email. “It leads me to believe that there may be more unnamed species out there, yet to be found.”
Joseph Schubert (2019). Three new peacock spiders from Southwestern Australia (Araneae: Salticidae: Euophryini: Maratus Karsch, 1878), Zootaxa, 4564(1):81-100 | doi:10.11646/zootaxa.4564.1.3