Archive for the ‘40th Anniversary’ Category

Ode to six-legged wonder

September 8, 2017

If four legs are great, six legs are better. Right? For forty years now, the Portal Project has primarily focused on two-legged creatures trapping, studying, and sometimes cuddling small, furry four-legged creatures. But we haven’t ignored the six-legged inhabitants of our long-term research site, and I am going to tell you more about them now.

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Which one of these is least like the other?

I am the Ernest lab entomologist, who doesn’t consider herself an entomologist. I am interested in biodiversity, community, and macroecological patterns like those studied by generations of Portal rodent researchers. I just happen to study them using bees. There are over twenty thousand species of bees in the world, and about four thousand in North America. My research so far has focused on the community ecology of native bees in a global hotspot of bee diversity in California. But as fate or luck would have it, another documented haven for native bees lies just down the road from our long-term rodent site in Portal. Between 2000 and 2007, bee researcher Robert Minckley documented 383 different species and 69 genera of bees from the San Bernardino Valley of Arizona and Mexico. The Smithsonian’s Southwestern Research Station, which is nestled up in the hills only a few miles from our rodent site, also celebrates the insect diversity of this area with field courses focused on bees or ants that attract dozens of eager entomologists from all around the world every summer.

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Look familiar? This is the San Bernardino Valley on the border of Arizona and Mexico, just 50 miles south of our Portal research site. By BAlvarius – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=11806210

A few months ago, I set out to see what kind of six-legged creatures we have scurrying around at Portal. My adventurous and ever-curious lab mates were willing to help, and (I think) even had a bit of fun learning to collect, pin, and curate bugs. During the March and May 2017 rodent censuses, we used a variety of passive (let the insects come to the trap) and active (go get ’em!) methods of insect collection to sample the local diversity on six legs:

  • Pan traps are brightly colored bowls full of soapy water that (passively) attract flying insects like bees that visit the bowls, fall into the water, and can be strained out and examined later.
  • Aerial nets (or “butterfly nets”) can be used to actively snag insects flying by or foraging on flowers, or can be used to more methodically sweep the ground to sample insects hiding in the grass or shrubs.
  • Blacklights lit underneath a white sheet at night passively bring in moths, roaches, and other nocturnal creatures that are drawn to ultraviolet wavelengths, perhaps because they confuse them with the moonlight they use to navigate, and can be scooped into collecting vials from their perches on the sheet.
  • Pitfall traps are plastic containers that are buried in the ground with their top openings flush with the ground level and covered with a coarse mesh with a hole in the center. Insects walking along the ground cross the mesh, fall into the hole, and are preserved in a small amount of ethanol at the bottom of the container. Do you think this is active or passive insect collecting? (Hint: we leave them out all day and only come back at dusk to check what is there.)
  • The crowd favorite was probably the “beat sheet,” which is simply a white sheet placed on the ground underneath an intriguing shrub, which is then vigorously beat with a piece of PVC pipe, a shovel, a hockey stick — really any bludgeoning tool will work. Insects that fall onto the sheet are then sucked up into an aspirator device — like a tiny, scientific, human-powered vacuum — and transferred into a collecting vial. This method of collecting is pretty active!

The spoils of our collecting efforts were creepy, crawly, and diverse.  The field crew had fun learning to pin them using the cooler and truck tailgate as our insect lab. Then I mailed them back to the lab and have been working on labeling, curating, and identifying our new Portal insect collection.

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Then just last week I took them to campus for a photo glam session with the fancy microscope camera. Take a look:

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I’m certainly not the only one who has been interested in the insect fauna in and around the rodent plots at Portal. Ants were actually a big part of the original research design. Between 1977 and 2009, ant colonies were censused once a year at every stake on all the plots, and between 1988 and 2009 ants were also baited (with Pecan Sandies!) and counted at 25 stakes in the thirteen unmanipulated plots. Research papers using this data, which is available to the public on the Weecology GitHub PortalData repository, have been authored by Tom Valone, Mike Kaspari, and more. Other brilliant ecologists like Deborah Gordon and Nate Sanders have also studied ant diversity, behavior, and community composition in the valley around our research site. I was actually following some of these researchers’ work long ago when I was first looking for graduate advisers and nerding out over my giant book about ants. And now here I am, working with the rodent branch of the legendary Portal Project while focusing on bees for my own work. It’s a small world after all, full of small six-legged wonder.

 

Learn more by checking out some of the published science on the ecological entomology around Portal:

Gordon, Deborah M. 1999. Ants at work: how an insect society is organized. Simon and Schuster.

Kaspari, M., & Valone, T. J. 2002. On ectotherm abundance in a seasonal environment—studies of a desert ant assemblage. Ecology, 83(11), 2991-2996.

Minckley, R. 2008. Faunal composition and species richness differences of bees (Hymenoptera: Apiformes) from two north American regions. Apidologie. 39: 176–188.

Sanders, Nathan J., and Deborah M. Gordon. 2003. Resource‐dependent interactions and the organization of desert ant communities.” Ecology 84.4: 1024-1031.
Sanders, N. J., & Gordon, D. M. 2000. The effects of interspecific interactions on resource use and behavior in a desert ant. Oecologia, 125(3), 436-443.
Valone, T. J., & Kaspari, M. 2005. Interactions between granivorous and omnivorous ants in a desert grassland: results from a long‐term experiment. Ecological Entomology, 30(1), 116-121.

 

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This four-legged creature thinks Portal is just the best place she’s ever been.

 

 

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Portal Phenocam

August 25, 2017

You may have noticed the super-cool daily images featured in last week’s post. They’re from our new network camera.

For starters, it allows us to do things like watch our desert field site turn from brown to green in no time flat (and back to brown again this winter).

 

 

 

 

But even cooler, our camera is part of the PhenoCam Network. They’re organizing a network of near-surface remote sensing images from sites all over the world. This creates a time series of images, in RGB and infrared, that can be used for phenology monitoring by the PhenoCam folks, us, or anyone who’s interested.

 

 

 

 

The PhenoCam folks make all the imagery freely available to download. From installation and configuration to image analysis, they provide awesome support. And their R package phenopix provides a quickstart to using phenocam imagery.

Pregnancy in Kangaroo rats

August 9, 2017

~While everyone’s busy at ESA this week, we’d like to keep the 40th anniversary ball rolling with a guest post from a visiting researcher at Portal. Jess Dudley has been using the Portal area to compare pregnancy in kangaroo rats and Australian marsupials. We’ll be featuring other guest posts through the rest of the year. (If you’d like to do something similar, please send us your info!)~

 

In July 2015 I travelled the 24+ hours from Sydney, Australia to the beautiful town of Portal to research pregnancy in Kangaroo rats. To everyone’s astonishment we do not have Kangaroo rats in Australia! I am sure I don’t need to explain my fascination with Kangaroo rats with this audience but in terms of pregnancy they have some unique features which differ from most rodents. This finding by King and Tibbitts in the 1960’s led me to wonder how the placenta forms during pregnancy in these resilient animals. To answer these questions I was lucky enough to visit Portal twice in the summers of 2015 and 2017 to trap Kangaroo rats and collect tissue from the females. I have completed Transmission and Scanning Electron Microscopy as well as Western blotting and Immunofluorescence microscopy on the uterine samples from pregnant Merrriam’s kangaroo rats to determine what structural and molecular changes are needed for implantation of the early embryo and ultimately a successful pregnancy.

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Fat tailed dunnart (Sminthopsis crassicaudata) (https://museumvictoria.com.au)

 

My initial research into the molecular mechanisms of implantation and pregnancy began in an Australian marsupial species the Fat tailed dunnart (Sminthopsis crassicaudata) which has the same partly invasive placenta as the Kangaroo rat.

Fat tailed dunnart (Sminthopsis crassicaudata) (https://museumvictoria.com.au) range. IUCN (International Union for Conservation of Nature) 2016.

 

Through these comparative studies we have found that the molecular mechanisms allowing for successful pregnancy are conserved among eutherian and marsupial mammals during the early stages of pregnancy regardless of how invasive their placenta becomes.

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An Immunofluorescence image showing localization of adhesion molecules in green and cell nuclei in blue from a non-pregnant Merriams’ Kangaroo rat. Uterine Epithelial Cells = UEC. Lumen = L.

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Transmission Electron Microscopy image of uterine epithelial cells from a Merriams’ Kangaroo rat in the
early stages of pregnancy.

It has been an amazing experience to work in the Chihuahuan Desert. I was introduced to animals that I had never heard of and witnessed countless stunning sunrises and sunsets as well as beautiful starry night skies. It was an experience I will never forget. I would like to thank Glenda Yenni, Leigh Nicholson and all of the wonderful people at the Southwestern Research Station for their assistance and advice during the completion of this project.

nullA male K-rat hiding behind a SWRS intern (©Leigh Nicholson)

 

Jessica S. Dudley | PhD candidate
The University of Sydney

The Portal Project 40th Anniversary

July 26, 2017

Funded by the National Science Foundation to study the importance of competition and granivory in desert ecosystems, the Portal Project first started collecting data in the summer of 1977. The initial grant was just for 5 years, yet 40 years later the site is still collecting data on plants, rodents, and weather.

To our friends who study paleoecology, 40 years is an eyeblink but in the span of a human life, 40 years is a long time. As you might expect, much has changed on the project. For one thing, after 40 years, the team running the site has changed. The original team of scientists, Jim Brown, Dinah Davidson, and Jim Reichman have all retired from the daily challenges of training students and writing grants, though some are still doing science. In their place, Tom Valone and I do our best to keep things running, studying the mysteries of the desert, and training the next generation of scientists who will hopefully take our place.

But more than just the people have changed. The site has changed too. It was easier to gaze across the site back then, before the Acacia went wild and started to take over.

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Left: Jim Brown in the late 1970s at the site (unknown photographer) Right: View from the ramada towards plot 1 (photo by Erica Christensen). Not a paired photo, but you get the idea.

The invasive plant, Erodium cicutarium, was a lot rarer back then

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You can call Erodium cicutarium, redstem filaree, redstem stork’s bill, or common stork’s bill, but our rodents call it yummy.  Photo by Sarah Supp.

And Banner-tailed kangaroo rats (and their distinctive mounds) were abundant.

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The distinctive cleared off mound of a Banner-tailed Kangaroo rat. Typically only one individual lives in a mound (unless the kids are still living in mom’s basement). Photo by Sarah Supp.

Our weather data is now recorded by an automated weather station that sends us the data via cellular signals, as opposed to laboriously transcribed from a contraption that would boggle the minds of younger ecologists!

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Left: We don’t have any images of the original weather station, but we do have what it produced: large round sheets of paper with squiggles. Right: the new hotness in weather stations. A post about this bad boy will be coming in the future. The previous automated weather station, which is still running as we trouble shoot the new one, is to the left in the image.

But for all the things that have changed, there are many things that remain the same. We still collect data at the same plots at the same stakes using the same methods.

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We still use quadrats to count the plants – though quadrat size was decreased to its current state back in the 1980s. Photo by Erica Christensen

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The only change to the rodent processing has been the addition of PIT tags and we now process rodents at a central location on their plot. In the early years the number of rodents was lower and processing while picking up traps was common, but this is slow when numbers are high. Photo by Ryan O’Donnell

The site is still intellectually powered by motivated and creative young scientists who are inspired by the place and the data it generates

 

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We still collect data with paper and pencil (though we are debating moving to digital technologies there as well)

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The mountains are still stunning

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Photo by Glenda Yenni

And, most importantly, the Ramada is still where we gather to share stories, plan the day’s fieldwork, and commiserate over the inevitable challenges of doing fieldwork in a remote, challenging, but amazing location.

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To celebrate Portal’s 40th Anniversary, we plan on having a blog a week for the next year (that’s our goal anyway!). These blog posts will focus on the science, the natural history, and the people who have helped make this one of the world’s longest running community ecology experiments.

We have reached out to many of the graduate students and postdocs who have worked at the site over the years asking for memories and stories, but we have not been able to find all of you. If you have a story about Portal or pictures from the site (especially from the early years!) that you’d like to share, let us know in the comments! We have 51 more weeks to fill!