Archive for September, 2011

Portal Plant and mapping adventures

September 28, 2011

Last March, a team from our lab (Sarah Supp, Kate Thibault, Zack Brym, and Maria Brym) trekked down to Portal to take on the rodent and winter annual plant surveys, along with officially mapping all sampling points at the site. Up to this point, any spatial data at the site was estimated using aerial photos or roughly done using the regular spacing of stakes. We were able to use a super-accurate system (ProMark3 GPS units) to get GIS data reliable with less than 2 cm error!

Green points are plot corners, Red points are the corners of plant sampling quadrats (0.25 m2 each), and yellow are the rodent trapping stakes.

We’re excited to now have this data available and we are leaving this weekend to tackle the summer plant survey along with the usual rodent trapping.

The desert pocket mouse continues its takeover at Portal

September 12, 2011

After trapping rodents August 26-28, it looks like the desert pocketmouse (Chaetodipus penicillatus, pictured below) is continuing do really well, as almost all the other species appear to be doing not-so-well, at least at our site!

Above, the desert pocket mouse is in a plastic bag (photo by S. Cobbold), before we take its measurements. Since we never know what is going to be inside a trap, putting it in a clear plastic bag before handling it gives us a chance to take a look at the animal and to get a good grip on it so it doesn’t escape. Sometimes we catch larger rodents (which can bite!) or other non-rodent animals (which could be venomous!).

Portal has been known for having very high diversity of rodents compared to many other locations; however, if someone had just begun trapping there this year, they would have concluded otherwise. For over a year now, we have been mostly capturing the desert pocket mouse and Merriam’s kangaroo rat (Dipodomys merriami), with only a handful of other species present (i.e. one or two grasshopper mice (Onychomys spp.), Ord’s kangaroo rat (Dipodomys ordii), or cactus mouse (Peromyscus eremicus). This month, there were ONLY Desert pocket mice and Merriam’s kangaroo rat and not a single individual of another species! I think this may be the only time this has ever happened in Portal Project history.

Stephanie Cobbold, a  graduate student at Utah State University in the Jim MacMahon lab, helped out with trapping this month. She studies the sensitivity of species traits to habitat characteristics using spider communities, and we spent our free time looking for spiders, scorpions, and other small arthropods. Since there is a lot of vegetation right now, we saw lots of interesting webs and also saw a scorpion capturing a smaller scorpion! If you’re interested in this side of desert life, check out her great blog post on the spiders of Portal Arizona!

Above: Stephanie Cobbold learns the differences between handling spiders and rodents!



September 2, 2011

Stowaway: (noun) One who secretly boards a vehicle (e.g. aircraft or car), to travel without paying and without being detected.

I guess this centipede (Scolopendra polymorpha ?) decided it needed a vacation from the desert! When Stephanie Cobbold arrived back in northern Utah Sunday night with me after our field collecting trip at Portal, she got a bit of a surprise. When she opened her travel bag, a centipede popped out and raced across the floor. After 24 hours, she was able to find, photograph, and preserve it. From tip of tail to tip of antennae, it was about 5.5 inches, or 13 cm!



Kangaroo rat video

September 2, 2011

In September 2009,  a remote camera was set up near a seed tray put out by Kate Thibault and undergraduate students from Furman University who visited the site as part of their “wild semester“. Kate later strung the photos together to create this fun insight into a hungry kangaroo rat’s night. If you look close, you can also see some a grasshopper mouse (Onychomys spp.) traveling past. Footage takes place between 12:30 am and 6 am September 20th. Enjoy!