On the Trail of the Giant Joro Spider

Rutgers ecologist monitors ecosystem changes as effects of climate change

For the past decade, José Ramírez-Garofalo, a doctoral candidate in the Department of Ecology, Evolution and Natural Resources in the Rutgers School of Environmental and Biological Sciences, has tramped through swamps and meadows in the tri-state metropolitan area looking for signs of environmental change, including signs of new species, insect and otherwise.

When he is not in the field, he is glued to his computer in the lab of his mentor, Professor Julie Lockwood, an ecologist and director of the Rutgers Climate and Energy Institute. At the Lockwood lab, Ramírez-Garofalo employs Artificial Intelligence to understand how climate change affects and potentially alters a species' geographical distribution.

He discussed the movement of the Joro spider, a palm-sized arachnid native to Japan that he is tracking as it moves up the U.S. East Coast, along with other aspects of his research.

José Ramírez-Garofalo, a doctoral candidate, is on the lookout for signs of environmental change, including signs of new species.

What's the latest news about the Joro spider? Where was it last sighted in proximity to New Jersey? Are those sightings credible?

The closest to New Jersey that Joro spiders have been found is in Bucks County, Pennsylvania, about 30 minutes from the border of New Jersey. The population has been well-documented, so very credible.

When can New Jerseyans expect landfall of the Joro spider?

Joro spiders could show up in New Jersey at any time, if they aren't already here in small numbers. Given how close they are currently being found to the state border, I wouldn't be surprised if the first sighting happens soon. However, I should also note that if you think you found a Joro spider, it's still more likely that you have found one of our native orb weaver spiders which are very common and widespread in New Jersey. The differences between Joro spiders and our native orb weavers may not be immediately apparent to the untrained eye. So, you should not try to kill any spiders that you see-even if you think it is a Joro. Adding to this is the fact that, while all spiders are technically venomous, this species isn't dangerous to humans.

As an ecologist, what to you is the most interesting aspect of the Joro spider?

For me, the most interesting aspect with Joro spiders is how far and how quickly they are moving, particularly their method of dispersal - that they can move large distances by using their webs to drift with the wind. Although they are probably moving so far because they can hitch rides on cars, the "ballooning" dispersal method that they employ is a great area to further study.

The non-native Joro spider, though frightening to behold, is not considered dangerous to humans.

How does the movement of the Joro spider speak to the phenomenon of climate change?

The physical movement of Joro spiders is happening independently of climate change. But the potential for Joro spiders to persist in each location is definitely aided by warming temperatures. As it stands, the native range of Joro spiders is already climatically like the mid-Atlantic and northeastern United States, so they are already well suited to be here.

Can you describe how you conduct your research?

My research takes two forms: data collection and analysis. I start by going into the field, making observations and selectively capturing animals to conduct marking and tracking studies. For analysis, I combine large and often messy datasets with what we call supervised learning algorithms - powerful tools that allow us to find patterns we wouldn't normally detect. I also work with a network of collaborators at Rutgers, the Cornell Lab of Ornithology, and other institutions that are also spearheading these methods.

I'm also the director of the Freshkills Biological Stationin New York City. My colleagues - many of whom I have worked with since the mid-2010s - and I work on problems related to conservation in the face of global change brought about by human activity. We focus on temperate grasslands, among the most critically imperiled habitats in the world. In the metropolitan tri-state area, we have several former landfills that now act as grassland habitats, such as ones located in the New Jersey Meadowlands and at Freshkills Park in Staten Island. Over the last decade, we have documented the changing ecological communities across a few grasslands on former landfill sites, which are now home to a few species that specifically need this grassland habitat to breed, such as grasshopper sparrows and sedge wrens.

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