April 3, 2012

Spiders in Borneo: Mulu wrap-up

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American

Our 17 days at Mulu have passed. Today, we took the day off from sampling to rest and pack up for the next stage of our expedition, a shorter stay of 8 days at Lambir Hills National Park.

Each day we have sampled and processed so intensely that we fall in bed exhausted. It was only today that I found the time to review what we've found at Mulu. As we go, I take photos of every species collected, and try to organize the photos to act as a growing "field guide" to the species at the site. We don't know the names of most of the species, but we can still recognize them by their appearances. After each day's collecting, I try to match each species collected to the current "field guide" to see if it's new for us and needs to be photographed. I had been getting behind at organizing the photos, but today I cleared up the backlog.

My preliminary estimate of the number of jumping spider species we found at Mulu: 116. This is a pretty impressive number for one family of spiders at one site. It's fewer than we found last year in our similar sampling at Yasuní, Ecuador, where we estimated 153 species of salticids. I'm sure there are many species we missed at both sites, but I also suspect this difference is real. In my experience, for jumping spiders there is no place like the Amazon basin.

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We are nonetheless thrilled to have such a solid sample from Mulu. The scientific literature reports only about 100 species from all of Borneo, and yet we've found almost 150 in our whole trip. This shows how poorly studied is the island: we can exceed the published reports of the last 200 years with only 3 weeks of collecting.

In honor of the species we found, some awards are deserved. Here they are. Remember, despite how different these look, they are all jumping spiders, recognizable by the classic pattern of eyes.

The commonest salticid on leaf litter, genus unknown (possibly a hasariine):

The commonest on foliage, Bathippus (female):

The commonest on tree trunks, Laufeia:

The most colorful, Siler:

Most like a tank, Porius:

Most convincing ant mimic, Myrmarachne:

Scariest legs, Harmochirus:

Longest legs, Viciria:

Best jumper, Bavia:

Cutest, Uroballus:

Previously in this series:

Spiders in Borneo: Introduction