Morgan’s Favorite Portal Species

November 1, 2017 by

As part of our Portal 40th anniversary celebration, some of us will contribute our thoughts on our favorite species at Portal. We’ve already had several posts on the Banner-tailed Kangaroo Rat (a universally beloved species at the site). But, I have a confession, while I love Banner-tails, they are not my favorite species at Portal (cue collective gasp). No, my favorite species is the grasshopper mouse. We have two species of grasshopper mice at Portal, the Northern and the Southern Grasshopper Mouse (Onychomys leucogaster and Onychomys torridus).

They are similar in their biology and morphology. Both are small (usually less than 6 inches or 120-163 mm in length including the tail) and weigh less than 40 grams (or 0.088 lbs). Given their similarities, I like them equally well, so will simply refer to grasshopper mice generically for our purposes today.

Anyone who has interacted with a grasshopper mouse probably remembers the encounter. Grasshopper mice have sharp little teeth and love to use them. Keeping an eye on the front end wouldn’t be that hard if you didn’t also have to also keep a sharp eye on the back end. The teeth are just a distraction from the fact they are trying to coat you  with liquidy, yellowish diarrhea. Oh, and did I mention that grasshopper mice REEK. Yes, I do mean reek. Their oily, acrid scent curdles the nose hairs and lingers after the little rodent is gone (probably because they managed to smear some poo on you in retribution before they headed off).

So right about know, you’re probably wondering why this reeking, vicious little rodent is my favorite species at Portal (or you’re wondering what this says about my personality).  With so many amazing rodents to choose from at Portal, what makes the grasshopper mouse so special? The reason grasshopper mice are notably more aggressive than our other species is that grasshopper mice are predators – yes, predators. They will eat seeds when resources get scarce and cache seeds in their burrows (Ruffer 1965), but they actively hunt insects, small rodents, arthropods, and even reptiles. They even hunt scorpions – see for yourself. The video below shows in sequence an adult, a subadult, and a juvenile attacking a scorpion. The adult knows to chew off the stinger quickly. The younger ones….well, it’s definitely a more difficult experience for them, though they eventually get their meal.

Why can these mice withstand scorpion stings? Without getting into sodium ion channel-level detail , basically they have a special protein that binds to the scorpion’s neurotoxin that changes how it works (Rowe and Rowe 2008)– as a result not only doesn’t the sting hurt, it actually ends up numbing the area of the sting (Rowe et al 2013).

Grasshopper mice also have surprising social relationships. There are a variety of reports that male and female grasshopper mice form strong pair-bonds and that both sexes participate equally in offspring care (McCarty and Southwick, 1977) and make the nest burrows together (Ruffer 1965). Grasshopper mice have a calling behavior using sounds that are almost ultra-sonic (Hafner and Hafner 1979). Though members of a family group have similar calls, every individual has unique call characteristics, which means that Grasshopper mice may be able to use these calls to communicate with family members over long distances (Hafner and Hafner 1979). When they call, they stand on their hind legs and throw their heads back:

Some mammalogists cannot see past the reeking, bitty little animal with the magical stinking poo that seems to get on you no matter how hard you try to avoid it. But when I see a grasshopper mouse, I see a little mouse who thinks it’s a coyote. I see some cool evolution at play that takes a normal mouse and turns it into a scorpion-resistant killing machine. I also see a brave little mouse fearlessly taking on a scary world. There’s something about it that just makes me smile. And then I go get some hand sanitizer.

 

Scientific Studies Cited in this Post:

Hafner, M.S., and D.J. Hafner. 1979. Vocalizations of Grasshopper Mice (Genus Onychomys). Journal of Mammalogy 60:85-94

McCarty, R., and C. H. Southwick. 1977. Patterns of parental care in two cricetid rodents, Onychomys torridus and Peromyscus leucopus. Animal Behaviour 25:945–948.

Rowe, A. H., and M. P. Rowe. 2008. Physiological resistance of grasshopper mice (Onychomys spp.) to Arizona bark scorpion (Centruroides exilicauda) venom. Toxicon 52:597–605.

Rowe, A. H., Y. Xiao, M. P. Rowe, T. R. Cummins, and H. H. Zakon. 2013. Voltage-Gated Sodium Channel in Grasshopper Mice Defends Against Bark Scorpion Toxin. Science 342:441–446.

Ruffer, D. G. 1965. Burrows and Burrowing Behavior of Onychomys leucogaster. Journal of Mammalogy 46:241–247.

 

 

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How do people use the Portal Data?

October 27, 2017 by

Every so often, someone asks me for a Portal reading list to come up to speed on what we know about the site. This seems like a simple questions, but it is actually pretty difficult. We define a “Portal Paper” as a paper using data collected at the study site (whether or not Portal Project people were involved), or data collected near the study site if that data was collected by the project or with substantive assistance from our project. Over the years, the site has contributed to over 120 papers and book chapters (our current estimate is 123, but we still find older papers that we didn’t know existed).

How the Portal Data is used has been changing in recent years. Historically, most papers were by people affiliated with the group. As we’ve blogged about before, starting in 2009 we have been working on making our data openly available through  number of venues. We post all of our data on the Portal GitHub Repo and we have also published two Data Papers through Ecology’s Ecological Archives. The nice thing about Data Papers is that they are indexed and cited just like regular scholarly papers, which is important because it allows us to 1)  document that the Portal Project is a valuable scientific resource to the community (which theoretically may be helpful on grant applications) and 2) let us here at the Portal Project keep informed of results coming out of the site that we’re not involved in.  So, how are scientists, external to our group, using our openly available data? Google Scholar lists 22 citations between the 2 data papers. (For the non-academics, citing other papers is in our own papers is an important part of scientific publishing. It allows us to give credit to those whose ideas, data, or methods we are working with. It also allows to us provide proof or support that statements we make in our papers are supported by things other people have been finding. Google Scholar is a database that keeps track of these citations). Here’s the breakdown of what Google Scholar says has been citing our Data Papers:

RplotAll the site focused research (papers that use our data as the primary focus of their analysis) was done by  or in collaboration with someone affiliated with the project. If other researchers are using our data, so far they tend to either use it as part of a meta-analysis (i.e. as one of many data points in the analysis) or to make a figure for their statistical or conceptual paper that has an empirical example of what they are talking about. (Three papers cite a Data Paper for reasons that defy classification. After reading their paper I have no idea why they cited us)! This number of citations listed by Google Scholar is probably a little lower than the database’s actual use in papers because data citations for meta-analyses often get shoved off into the supplementary materials and are not indexed by Google Scholar as a result. Our usage in meta-analyses is probably higher, but it is unlikely that we’ve missed a paper focused solely on data from our site.

We are hoping to increase Portal’s usability and we have some things in the works, which we will blog about later, that we hope will make it easier for people to get the data they need to use Portal as part of their analyses. We love seeing the data used but know that the history of the site and all the manipulation changes can make it difficult to figure out how to extract the data you need.

 

The Portal Weather Station

October 20, 2017 by

For the history of the project, weather monitoring has always accompanied the collection of rodent, plant, and ant data. At first, this was done manually. Portalites from 1980 to 1989 measured rain in a rain gauge, and used something called a hygrothermograph to measure temperature and humidity.

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Hygrothermograph

Then things started to get fancy. In 1989, an automated weather station was installed. This is the desert though, and leaving expensive toys out in the rain, dust and lightning takes it’s toll.

Sunset in the desert jungle

At least the lightning storms leave us with some nice scenery after they try to blow up our weather station.

All things considered, our weather stations have stood up pretty well. The first lasted from 1989 until 2002. And the station from 2002 is still limping along, although it’s had its moments (it tends to have a bit of a tantrum after being struck by lightning). We connected to the dataloggers for those stations directly. That is, as part of their monthly duties, the rodent RA has to connect to the datalogger, download the data, and bring it back to the lab for checking and appending to the database.

Anticipating the 2002 station’s impending demise, in August 2016 we upgraded to a new station, and took the opportunity to make some improvements.

2016 station

The majestic new station

Of course we continue to collect data on precipitation, temperature and humidity. But we’ve also gotten to add a wind sensor (wind speed and direction), pyranometer (solar radiation), and barometer (atmospheric pressure). Having these additional data means that we can also calculate things like evapotranspiration, sunshine hours, and windchill. We have also added a new program to collect fine-scale precipitation data during storms. When a precipitation event begins, the datalogger begins recording total precipitation every 5 minutes until the storm ends.

The addition of a cellular modem is another major improvement. Rather than downloading it monthly in the field, we access the data remotely. The data trickle in to  our data repo whenever edits are made to trigger a new build, or at least once a week, and quality control happens automatically. Our station has a Wunderground account (from whence the fancy little widget in the sidebar comes). And we’ve mounted the phenocam (featured in an earlier post, and another widget in the sidebar) to it.

Aside from just being darn cool, the upgrades have improved our data collection. We can see what the weather has been at our exact location at any time. That means we can know what to expect from the plants before we go for a census (as much as that’s possible). And we can communicate with the datalogger at anytime. If something is wrong with the weather station, we’ll know immediately. It may be possible to fix the problem remotely. If not, the rodent RA can plan to fix it while she’s down there, instead of discovering the problem at the site, waiting until the next month to fix it, and losing at least a month worth of data. And we can always send new programs to the datalogger, if we want to add new data tables make improvements.

Find our weather data, updated sub-weekly, on the Portal Data github repository.

A Vegetation History

October 11, 2017 by

My Portal story begins in 1991 when Jim Brown offered me the opportunity to be the Portal postdoc. Among other things, this meant I organized the yearly ant census in which we spent about 2 weeks counting the abundance of ant colonies on the experimental plots. In one of my first summers, I hired Don Sias to help with the census. Don was a non-traditional student and had previously traveled extensively throughout the southwest. One day he mentioned to me that the vegetation in the San Simon valley looked pretty “beat up”. By that he meant the vegetation, dominated by shrubs, had the look of a grassland that had become desertified.

August 2015

I was intrigued by Don’s comment for two reasons. First, Brown and Heske (1990) had recently described a significant increase in grass cover on Portal plots that removed kangaroo rats and mentioned that the site was “near the zone of natural transition from desert to grassland”. Second, while desertification is often associated with overgrazing, Heske and Campbell (1991) found no difference in vegetation across the Portal grazing fence despite 11 years of livestock removal – why hadn’t the grasses recovered with livestock removal if the site had once been a grassland?

When I returned to Albuquerque, I recall asking Jim about the vegetation history of the site. He said that he wasn’t sure and encouraged me to see what I could figure out. That led me to the U.S. General Land Office Surveyors notes. The surveyors described the dominant vegetation they traveled through as each mile-long section line was surveyed. Many, but not all, of the lines near our site were surveyed between 1875 and 1883 and the most common description was “good grass”. However, when the surveyors came back to complete their work in the early part of the 20th century, the descriptions were dominated by the words “scattered shrubs” while grass was not mentioned at all. This change in vegetation coincided with large introductions of livestock into the San Simon valley in the late 1880’s, and then a major drought in the early 1890’s that resulted in tremendous livestock mortality due to starvation.

Our understanding of the recent vegetation change at the site can help to explain the observed shifts in grass cover observed at Portal both over time and across the rodent treatments. It also prompted further investigations into desertification and the role of livestock in affecting soil compaction as a mechanism that helps to explain why reversals of desertification (a recovery of perennial grasses) can require several decades. Finally, it illustrates how careful observations by students and researchers that visit the site can lead to interesting questions and new discoveries.

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I’ve been very fortunate to have worked on the Portal system for almost 30 years. Change seems to be the constant at Portal – you never know what you’ll see and how things have changed since the last visit. This complex system continues to be a source of inspiration as we try to understand it (or, as Morgan says, “unravel her mysteries”).

Portal: Then and Now

October 4, 2017 by

A lot can change in 40 years.  This is perhaps never more apparent than when you find a box of old photographs, and start comparing then to now.  When the Weecology lab immigrated from Utah to Florida in 2015, just such a box surfaced: a glimpse back in time to the beginning of the portal project.  I did my best to re-create some of these photographs—trying to line up horizons and mountains—to show how the site has changed over 40 years.

One thing is immediately apparent: the shrubs have grown up.  The left side of these photographs were taken in 1977 (photographer unknown), and the right side in 2015 (photographer Erica Christensen).  What happened to the rows upon rows of aluminum flashing, indicating the location of the rodent fences?  I assure you the fences are still there, they’re just obscured by the jungle.

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The fact that you used to be able to see clear across the site is shocking to the modern research assistants. These days, part of the training for new RAs taking over work at Portal is receiving a map from the previous RA with routes drawn in for the best paths between plots. Navigation is not trivial.

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Erica, circa 2012, demonstrating the problem (photographer Sarah Supp)

Other locations at the site don’t look too different from how they looked in the ‘70s. Grass cover comes and goes depending on the strength and timing of monsoon rains every year, but some plots don’t seem as affected as others by the shrub explosion.

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While shrub encroachment is an annoying obstacle to a human, it is a major ecological shift to a rodent. This was the topic of a 1997 paper by Brown, Valone, and Curtin, where they found a 3-fold increase in shrub cover between 1980 and 1995 by analyzing historical aerial photographs. The authors also noted a concurrent decline in rodent species affiliated with arid grassland (banner-tail kangaroo rat and silky pocket mouse) and an increase in species affiliated with arid shrubland (desert pocket mouse and Bailey’s pocket mouse). It looked like the grassland species were on their way out and the shrubland species were taking over. However banner-tails and silkys continue to be found at the site, despite the fact that shrub cover has increased, if anything, since 1995. They’re now quite rare; these days we pretty much only see them when the rains align just right to give us a “grassy year.”

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Nobody tell this adorable silky pocket mouse we’re a shrub habitat now

Those of us who have worked at Portal know that things are always different every time you go down, and yet some things never change. Which is why we keep going, keep collecting data: even after 40 years there is still a lot to learn.

Reference:
Brown, J.H., Valone, T.J., and Curtin, C.G. (1997). Reorganization of an arid ecosystem in response to recent climate change. Proc. Natl. Acad. Sci. 94, 9729–9733.

2017 Summer Plant Census

September 29, 2017 by

Twice a year the Portal crew gets a little larger, and spends a few extra days, and we count plants on all 384 quadrats. Despite some of us being in our second decade of visiting the site, and everyone on the plant crew being intimately familiar with most of the species at the site, and that the rodent RA has been watching the plants grow and giving us monthly updates, we still never really know what we’re going to find once we get out there. The desert does what it wants.

The uncertainty seems especially high for the summer plant community. Some years we arrive to an ocean of grass, waving in the breeze. Those are the years we spend a lot of ‘quality time’ with each quadrat. Other years we arrive to a dustbowl. We walk around the site laying our PVC quadrat down and picking it back up again and saying ‘zero’ 384 times. [Okay, we don’t really ever get all zeros. But it feels like that when you’re out there.] And some years we show up to find some new arrivals, species that finally decided to show up after 40 years. Then we spend less time counting individual blades of grass, and more time pouring over our regional species list and plant ID guides.

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Summer 2014, Morgan, Tom and Erica counting Aristida adscensionis and Bouteloua aristidoides, a lot of it

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Summer 2015, ‘Who are you and where did you come from?’

 

This summer was pretty good for forb diversity. Forb species like Dalea, Cassia, Kallstroemia, Ipomea and Sida were relatively abundant.
DaleaCassia

Kallistromia

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In the summer we also measure shrub cover on the plots, so we get some bonus quality time with the plants.

 

There are lots of other bonuses to the summer plant census that make up for the brain-melting heat. As we’re walking around the plots, we get to see snakes (Mojave rattler, Common king snake, gopher snake, coachwhip, and Coral snake on this trip), horned lizards, turtles, tarantulas and exceptional insect diversity that are not out and about from October to May.

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And there’s nothing like a Portal monsoon sunset.

Portal Plant Census and Florida Hurricanes

September 18, 2017 by

Twice each year we head out to the site to do an intensive week of field work. We catch rodents as we do every month, but we also count every plant located in the 384 different plant quadrats, located across the site (for those who want more details: 16 quadrats per plot, locations marked with rebar, each 0.25 m^2 in size). Plants have been counted on these quadrats for nearly 40 years and we have been keeping the tradition alive. These extended trips occur sometime in August/September and March/April to match up with when most plants during that season are flowering or setting seeds (or as best we can given the constraints of the school year). Since the lab moved to Florida, the August/September census has gained an added piece of excitement: hurricanes.

Hurricanes?

Yes. Hurricanes.

Last year, as the crew was preparing to set out for Arizona, Hurricane Hermine  was lining up to hit Florida. Being the lab’s first hurricane experience (and the first hurricane to hit Florida since 2005), there was a lot of anxiety as the crew packed up to head out. Would they get out ahead of the storm? What would happen while they were gone?

The storm was an exciting experience for those of us who remained in Gainesville (in the ‘uh, wow, look at all those trees down’ way, not the ‘Whoo, let’s do that again’ way). Hurricane Hermine skirted Gainesville, delivering strong winds, rain, and some downed trees.

Hermine

Image from Wikimedia Commons. Image uses background image from NASA and hurricane tracking data from NOAA. The yellowish color were it hits land indicates it was a Category 1 at landfall. The star is the approximate location of the University of Florida

Though the Portal crew was out in Arizona, they did not escape without their own hurricane experience, though! Hurricane Newton hit Baja California and then came up to the Portal area for a visit.

Newton

Image from Wikimedia Commons. Image uses background image from NASA and hurricane tracking data from NOAA. The star is the approximate location of the Portal Project. The blue triangle indicates that Newton was a tropical depression by the time it got close to the site.

Despite my anxiety for the crew, they just got really wet.

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Ellen and Joan enjoying a tropical storm in the desert

We laughed about it and then forgot about all this until a couple of weeks ago when Hurricane Irma lined up on Florida as the Portal Plant Crew was preparing to head out to Arizona to count plants.

Irma

Hurricane Irma track. Gainesville was luckier than other places that received visits from Irma. It was only a tropical storm when it came by. Image from NASA, track data from NOAA, obtained from Wikimedia Commons

Shawn Taylor, one of Ethan White’s graduate students and regular Portal Plant counter, remarked on his déjà vu feeling in a message to the lab:

“Interestingly this is exactly how leaving for the fall plant census was last year as Hurricane Hermine was bearing down”

Now, any good scientist knows that correlation does not mean causation. Our sample size is also very small, with only two incidences so far. I’ll just say that it’s an interesting coincidence that Florida gets hit with hurricanes when the Portal Plant crew heads to Arizona in September. No one should contact FEMA to have “keep the Portal plant crew in Florida” added to their disaster preparation list. But at the very least, we probably need to add some “in case of hurricane” items to our summer plant census check list for next year!

Ode to six-legged wonder

September 8, 2017 by

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.

Davidson, D.W., Inouye, R.S., Brown, J.H. 1984. Granivory in a Desert Ecosystem: Experimental Evidence for Indirect Facilitation of Ants by Rodents. Ecology, 65(6), 1780-1786.

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.

 

 

The Spectabulous Spectabs of Portal

September 1, 2017 by

Much beloved by those who have worked at the Portal Project, the banner-tailed kangaroo rat (Dipodomys spectabilis) is one of the most charismatic rodents at the site (for us smammal lovers who think rodents can be charismatic, anyway). The fact that they have a nickname—spectabs—attests to this fondness. Look at that mighty tufted tail! Those giant, majestic furred feet! Weighing in at over 100 grams as adults, they are twice the size of our other kangaroo rat species (D. ordii and D. merriami). What’s not to love?

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Dipodomys spectabilis

As avid readers of the Portal blog might recall, the site used to be much grassier back in the day. At the start of the project in 1977, spectabs were running the show at Portal; we even had some plots that excluded only D. spectabilis because they were so dominant! For the spectabs, this was a desert paradise, as they tend to prefer grassier habitats. As the site became shrubbier, however, the reign of the spectabs came to a slow end in the 1990’s. Since then, a few individuals have popped up here and there but haven’t stuck around, often heading for greener (grassier?) pastures.

For me, experiencing Portal for the first time in the summer of 2015, D. spectabilis seemed more like a mythical creature than a real species. I resigned myself to the probability that I would never actually get to see this massive kangaroo rat species and would have to be content with its smaller (and equally adorable, mind you) congenerics.

Then Stephanie showed up.

Of course, rodents don’t arrive at the site wearing name tags; names have to be earned. In April of 2016, Erica excitedly reported back from the field that she had caught—you guessed it—a spectab. This young female, weighing only 70 grams, was the first spectab caught at the site since a quick resurgence lasting from 2008-2010.

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We assumed she was just passing through. Yet May arrived, and there she was. I finally went out in June, trying desperately not to get my hopes of finally seeing a spectab too high. Over to plot 11 I went, my heart was pounding a little faster than usual. One of the first traps I picked up was very heavy! I’d caught my first spectab! I made my volunteer take a picture of me with Stephanie. You can’t quite tell, but I was teary-eyed with happiness; that might sound a little embarrassing, but I don’t mind admitting it. I was so excited! It felt like I’d completed some type of Portal rite of passage.

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Ellen (that’s me!) with Stephanie, who is far less excited about this picture than I am.

I’m not sure when I decided that our new resident spectab needed a name, but I unilaterally decided on Stephanie and, somehow, it stuck. Most of us assumed she’d disappear pretty quickly; since the 90s, most of the spectabs that have been caught have quickly moved on. And especially since she was young, we figured she was just on some rodent version of rumspringa. But month after month, there she was. Same plot, nearly the same stake every time. Spectabs are known for their well-kept, cultivated mounds, and Stephanie’s was shaping up over in the northwestern corner of Plot 11.

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A typical spectab mound: raised, multiple holes, and well-manicured.

Soon there was talk of whether Stephanie would get a “boyfriend” or not, which rapidly devolved into thoughts of setting up a twitter account for her or making her a profile on that new-fangled dating app, Granvr: the Dating App for Modern Granivores. Stephanie continued to grow, and we started wondering if she would be the exception to the 21st-century spectab rule and actually stay around. In the end, she stuck around for nearly a year; February was the last time we saw her.

Or was it?

In June, our newest Portal RA, Renata, was in her second month of training. We arrived at Plot 11, and what came out of her trap but a spectab! In shock and excitement, I lurched forward and grabbed the bag with the discombobulated rodent out of her hands without thinking or asking (not my best moment, I admit…). Stephanie was back! Or so we thought. Our volunteer managed to capture a dynamic set of pictures that explains the series of events better than any prose can:

Image uploaded from iOS

“Stephanie!!!?!”

Image uploaded from iOS (1)

“Oh…hmmmmm.”

Image uploaded from iOS (2)

“That is definitely not Stephanie…”

Image uploaded from iOS (3)

“I shall name him Stephen!”

That’s right. I was holding a very scrotal male…definitely not Stephanie. Stephen hasn’t shown up again, and we assume he’s gone on his way.

Even though we have 40 years of data, the site is still reminding us that we have many unanswered questions. Where are these spectabs coming from? Where are they going? Why now? Will there be more? We sure hope so! And rest assured, we’ll report about them right here.

Portal Phenocam

August 25, 2017 by

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.