Posts Tagged ‘ecology’

Coatis and programmers in the desert

September 25, 2012

An update from the May Portal trip (which occurred immediately after my Giant Kangaroo Rat foray):

Recent USU graduate, Ben Morris, who had been working with the Weecology lab for the past few years, finally made it out to our field site, just before starting his Ph.D. with the Hurlbert lab at UNC! Ben spends most of his time on the computer being a ninja at utilizing ecoinformatics and big data, but he proved quite worthy in the field. We also saw a coati in the middle of the desert. Not sure what it was doing out there, but it didn’t look too happy… (sorry, no coati pictures to prove it!)

Ben and onychomys

Ben weighs a grasshopper mouse.

Ben measures the hind foot length of a kangaroo rat.

Portal Squee: Nesting Cactus Mice

September 25, 2012

This post is way overdue, but the photos are so cute that I couldn’t help myself. Back in March 2012, when Glenda Yenni, Xiao Xiao and I travelled to Portal to count the winter plants, we discovered cactus mice (Peromyscus eremicus) nesting in a box that we were using to hold firewood. When we took the wood out of the box, there was a flurry of activity and a big fluffy nest inside!

Peromyscus eremicus in a box

A scared cactus mouse runs around the box.

What was even more interesting was that the nest had a two (eartagged!) adults  pair with 2 different ages of offspring! There were 3-4 subadult mice along with 2-4 teeny tiny juveniles (it was hard to count in the dark with all the running around). The juveniles were small enough (although they did have hair) that they remained attached to the nesting female when she ran out of the nest.

I mentioned this to Karen Mabry, who sometimes helps out at Portal, and she suggested that although not much seems to be known about Peromyscus eremicus, they may be “more monagamous” than some other species mice. Some other Peromyscus species are known to be socially and genetically monogamous, and have sometimes been confirmed as nesting with sisters (rather than a male-female pair), which could potentially explain why there were 2 different ages of juveniles in the nest box.

Peromyscus eremicus in nest

Female cactus mouse peers out of nest.

(Photo credits: Glenda Yenni)

Adventures with Giant Kangaroo Rats

June 25, 2012

No, there are no Giant Kangaroo Rats at Portal – but there are a few pockets where they occur in California. In late May, I travelled to the Carrizo Plain National Monument with graduate researcher Tim Bean (who visited the Portal site in December 2011) to work on his project with Giant Kangaroo Rats (GKR; Dipodomys ingens). Tim is studying the relationship between habitat quality and species distribution models and has 8 trapping grids located throughout the Monument in locations predicted to be great for GKR and poor for GKR.

CPNM

This area of Carrizo is probably more like the historic landscape. Here we captured 3 species of Kangaroo Rat: Giant, Short-nosed, and Heerman’s.

Carrizo itself is the largest remaining “intact” piece of San Joaquin Valley desert-grassland; most of the valley was converted to agriculture in 20th century. Carrizo escaped irrigation because of it’s higher elevation, out of the Central Valley. It’s home to a suite of threatened & endangered species, such as the San Joaquin Kit Fox, Blunt Nosed Leopard Lizard, San Joaquin Antelope Squirrel and a suite of unique plant species.

GKR is the largest species of Dipodomys and is federally and state endangered due to extreme habitat loss. It is estimated that the population in Carrizo Plains NM was down to a few hundred in the early 1980s, but is now estimated to be somewhere in the tens to hundreds of thousands – so it appears the GKR story may have a happy ending. There are a few other remnant populations of GKR, but Carrizo is (by far!) the largest of them.

Here I’m holding a Giant Kangaroo Rat for scale – watch out! They scratch with their sharp little claws! Also, note the awesome field biologist vest.

A close up of a Giant Kangaroo Rat.

brome grass hay piles

GKR make large ‘hay piles’ of brome grass seeds on top of their mounds. It is unknown if the seeds remain in these ‘open’ caches, or if they are later removed to a burrow or pit cache.

Because of their sensitive status and relatively high capture rates, we conducted the field work all night, in the dark. Carrizo NM gets quite hot during the day, and we didn’t want to risk killing any rodents in heated up metal Sherman traps (extra-long). In most of Tim’s trapping grids, we only captured GKR (and a few late-evening antelope ground squirrels). At a few sites, however, that seem to represent more undisturbed Carrizo Plain habitat, we also captured Short-nosed Kangaroo Rats (Dipodomys nitratoides) and Heerman’s Kangaroo Rats (Dipodomys heermani) (both still larger than the Merriam’s and Ord’s we capture at Portal; 80-100 grams).

A Short-nosed Kangaroo Rat.

At the sites predicted to be poor GKR habitat, we mostly captured small pocket mice such as the California Pocket Mouse (Chaetodipus californicus) and the San Joaquin Pocket Mouse (Perognathus inornatus).

San Joaquin Pocket Mouse – it’s cute and orangey! A weird side note is that they smell kind of sweet, like kettle corn… CAUTION: Don’t try this at home. In order to avoid disease, you should never sniff dusty rodents or any dusty place they may have defecated.

A juvenile California Pocket Mouse at a “poor” GKR trapping site.

California Pocket Mice have stiff, white, spiny hairs on their rears.

Through the (desert) looking-glass

May 17, 2012

Between the March and April Portal trips, I fell through the looking-glass into the Namib Desert. Everything there felt so eerily similar to southeastern Arizona, yet also strikingly different. Compare the below photos from the Spitzkoppe, a large granite massif of volcanic origins in the western Namibian Desert, and of Portal (the Chircahuan mountains also are eroded granitic domes with volcanic origins!).

Spitzkoppe, the “Matterhorn of Namibia”

Chiricahua Mountains, with the Portal Project in the foreground, October 2007

Although I didn’t actually get to see or handle any small mammals while visiting the Spitzkoppe, there are diverse rodent communities in the Namib desert, as there are in southeastern Arizona.

Unidentified small mammal hole, Spitzkoppe.

Banner-tailed kangaroo rat (Dipodomys spectabilis) hole, Portal.

Both Portal and the Spitzkoppe are arid grassland deserts on the edge of small, isolated mountains. Both have acacia shrubs with white thorns, and both abound with spiny and woolly vegetation. However, Namibian shrubs are inhabited by weaver bird nests rather than cactus wren nests (but both are roundish with small, circular openings).

Weaver bird nests in an acacia, Spitzkoppe.

Cactus wren nest in a cholla, Portal July 2009

The large, eroded granite rocks are similarly enticing, easy to climb and explore, and also host populations of small cryptic scorpions, spiders, rodents, and lizards, although in Namibia, unlike Portal, you are likely to see groups of hyraxes. The surrounding plains are home to a variety of antelope and grazers (such as springbok, hartebeest, zebra, warthog and rhino, to name a few) rather than Coues white-tailed deer or javelina.

A very cryptic Agamid lizard, Spitzkoppe

Texas Horned Lizard, Portal (Photo courtesy of R.P. O’Donnell, May 2011)

Hyraxes are NOT large rodents, but are actually more closely related to elephants! These are Rock Hyraxes (Procavia capensis).

Euphorbia virosa, “poison tree”, in the Spitzkoppe. Although it looks similar to organ pipe cactus, this is NOT a cactus, but a member of the spurge family.

Experiencing another, similar desert was an amazing experience which I hope to repeat, but I eventually crossed back to my hemisphere and the right side of the looking-glass, where my world was again familiar and the research at Portal was waiting for me to return…In late April, we captured our first pack rat (Neotoma albigula) since Fall 2009 !

Neotoma albigula

Sarah documenting the Return of the Pack Rat.

There was no rain between March and April, so the vegetation was all going to seed and the soil was dry and dusty again. Rodent abundance and diversity continues to rise, however, so they must be caching all those valuable little seeds!

Nic Kooyers, a graduate student at Washington University in St. Louis, came to learn about the project and look for unique desert vegetation. Nic is especially interested in the evolution of plants that display variation in the production of secondary compounds, but he really liked the rodents, too.

NKooyers_krat

Nic weighing an Ord’s Kangaroo Rat (Dipodomys ordii).

 

Portal rodent-plant extravaganza: Day 4

March 13, 2012

My lab mates, Glenda and Xiao, and I left early Saturday morning to drive from northern Utah to Portal Arizona. It’s about an 18 hour drive, but the scenery is beautiful, so it’s not that bad. We stopped at Coral Pink Sand Dunes State Park along the way, near the Utah-Arizona border. I’d highly recommend a stop!

Between Sunday and Tuesday night, we repaired our trap shed, trapped 127 rodents and counted plants on 13 of the 24 plots. We still have a lot of work to do… Here are a few photographic highlights from the data collection so far:

A desert pocket mouse sits near some very scenic poppies.

Xiao and Glenda count plants on a poppy-filled plot.

Bees really dig the Gordon’s bladderpod (Lesquerella gordoni).

February trapping

March 9, 2012

I traveled to Portal again Feb 18-20, this time meeting a crew of people from New Mexico State University.

pp

Chaetodipus pencillatus, desert pocket mouse.

Karen Mabry has been especially helpful for finding volunteers and keeping Portal going through our lower-funding times. She also studies rodents, with most of her work with Peromyscus at the Quail Ridge Reserve in California. So she was excited to see that diversity at the site is returning quickly–we’re back up to 10 different species!–and that we caught several incredibly cute cactus mice (Peromyscus eremicus). We also continue to catch the harvest mice (Reithrodontomys megalotis and montanus), which was fun for visiting grad student Katie Smith, who studies the endangered salt marsh harvest mouse in California.

Katie Smith holds a small harvest mouse. Photo by J. Smith.

With so many experienced rodent-trappers, we were able to get through all the captures pretty quickly and leave extra time in the afternoon for Jane Smith to take some measurements for her project. Also an NMSU grad student, she has been investigating the effects of small mammals on soil organic carbon, using the experimental manipulations at our site.

I’ve never captured so many birds before, but 11 of our 110 traps this month has birds in them rather than rodents! Pictured above is a white-crowned sparrow (photo by J. Smith). These were most common, along with black-throated sparrows and a canyon towhee.

Katie Smith, Kristin DaVannon, Sarah Supp, and Karen Mabry (left to right) process the rodents from the exclosure plots. Photo by J. Smith.

(Above) Kristen, an undergraduate student at NMSU, learns that handling rodents is fun! Photo by J. Smith.

The winter plant census is fast approaching, and many flowers were already beginning to bloom in February! I’m optimistic that it will be another beautiful spring. Keep posted for the plant update!

escholtzia mexciana

Poppies are already in bloom! Photo by J. Smith.

Lupinus coccinus.

January trapping update

February 14, 2012

One of the best things about working in the desert (especially when you’re doing long-term ecology!) is that things are always changing. After the recent drought, we saw a decline in biodiversity at the site that rivaled anything seen throughout the course of the 35 years of study, including the dominance of the rodent community by a very small-sized species (Desert pocket mouse, Chaetodipus penicillatus) which surprised us all. After some decent rains in 2011, diversity is slowly returning to the rodent community as we have been seeing more of the generalist species return. These species seem to be more transient at the site, popping up when conditions are right for them. I was still a bit surprised, however, to catch several plain’s harvest mice (Reithrodontomys montanus) in January! This is a species that I hadn’t seen in a few years, so it took me a moment to determine what I was seeing.

Another of the generalist species that has been popping up this winter is the cactus mouse (Peromyscus eremicus). We even found a nesting pair in our trap shed this past month! They were pretty cute, but since our trap shed has recently been inundated with other living things–pack rats and most recently, at least one rattlesnake and a badger living underneath the shed, I chased them out. I really don’t want the shed to seem like a larder for our resident rattlesnake. Pictured below, is my volunteer of the month, Loren Sackett, from University of Colorado at Boulder.

Loren studies prairie dog populations, genetic divergence and pathogens in the southwest. You can read about her adventures at the prairie dog blog.

Meanwhile, the rain seems to have slowed from earlier in the winter but the plants are still growing! We’re headed down to the site again in March to have another rodent-trapping-plant-field-extravaganza.

Above, Rumex, Erodium, and Guterrezia all green up. The vegetation at the site seems hard to categorize and we’ve had trouble finding just one or two field guides to use when we do the plant surveys. Luckily, over 25 years of work at the site has led to the compilation of an amazing  mini-herbarium of pressed plants and identifying characteristics that we can bring down with us when we do our plant surveys. I’m currently working to update this herbarium and have found several websites that are also really helpful for plant identification in the area, such as this NMSU website, this Arizona wildflowers website, and this New Mexico flora website. I’d love to hear any other suggestions of websites or books that are helpful for plants in the Portal area–please share!

Seed pods from Devil’s claw (Proboscidea parviflora) on the fence of a rodent exclosure, Chiricahua mountains in the background.

It was pretty small, but I’ve never seen a tarantula in January before!

Loren sets traps at sunset.

 

Summer in the desert

August 30, 2011

One thing that makes traveling to Portal each month so interesting is the speed at which the desert landscape can change. Southeastern Arizona has recently been in a major drought, but the arrival of summer monsoon rains seems to have helped green things up, at least temporarily.

Desert mushroom

Gopher snake on traps

Below, the first photo was taken on July 2, 2011 and the second photo was taken August 6, 2011. During that month approximately 11.4 cm of rain fell and transformed the dry, dusty ground into a carpet of green seedlings and flowers.

Some areas were covered in orange flowers (e.g., summer poppies, orange flame flower, and showy flame flower), purple flowers (e.g., silverleaf nightshade) and large caterpillars were abundant (I think mostly Sphinx moths).

In addition to the growth of new plant life, the summer rains have also led to flooding in the Chircahua Mountains where the fire left slopes unstable and vulnerable to washing away. Some of the forest roads remain closed and a short drive into Cave Creek Canyon makes it easy to see areas where the forest floor is buried under mud and debris washed down by flash flooding. Some locals, bloggers Azure Gate and Cave Creek Ranch, have posted updates and photos on conditions in the area.

In addition, the dry soil conditions and lack of vegetation on the bajada and in the valley seem to have allowed for increased erosion at our site as well. The gravel roads leading towards the Portal Project were washed out in places and erosion around the fenced plots meant that some gates were left > 12 cm above the actual soil surface or buried underneath mud and debris; both scenarios making it difficult or unlikely for rodents to actually find and use the gates. I’ll have to work at maintaining these gates over the next month as more rains are likely to occur.

Luckily, I had lots of help digging out rodent gates and collecting data by Elita Baldridge, a Ph.D. student in Ethan White’s lab who came to help out before we both headed to present at ESA after field work was finished.

I continue to be amazed at the “sea” of desert pocket mice (Chaetodipus penicillatus) that seem to be taking over–we’re even encountering control plots, where kangaroo rats should be dominant, with no kangaroo rats at all! Amazing.

Oh, and speaking of amazing…