hawthorne/walker lake area mineral county, nevada 1–2 september 2007
DESCRIPTION
Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007. Participants: Zachary J. Valois, SLCC Kelsey A. Neeley, volunteer. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/1.jpg)
Hawthorne/Walker Lake areaMineral County, Nevada1–2 September 2007
![Page 2: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/2.jpg)
Participants:Zachary J. Valois, SLCCKelsey A. Neeley, volunteer
We traveled over 1,500 miles to sample the Walker Lake / Hawthorne area Our primary goal was to find one of the remaining species needed for DNA sequencing, Paruroctonus simulatus, at its type locality.. Over 60 scorpion specimens were collected in the Hawthorne area, representing four genera and six species. The Great Basin habitats we encountered were Lahontan Basin Salt Shrub, Tonopah basin, and sagebrush foothills. On the way back to Utah, we spent several more days collecting in other areas in Nevada and southern Utah, collecting an additional 50+ samples. The two-day trip was partially funded by the NSF REVSYS grant.
![Page 3: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/3.jpg)
The majority of the foothills in the area are characterized by
exposed fossilized marine rock, and deposited sand/salt (saltwater flowed from Mono Lake during the Pleistocene).
Over time, wind deposited pluvial sediment from ancient
Lake Lahontan and Walker Lake up onto the foothills
creating a mix of varied microhabitat.
![Page 4: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/4.jpg)
This valley is ancient Lake Lahontan, now partially filled by Walker Lake (surface
elevation 3,960 feet, barely visible the far right) and the Army Depot at Hawthorne.
The lake was extensive during the Pleistocene and went through several dry
periods during the last 10,000 years, even with flow from salty Mono Lake to the south (elevation 6,380 feet) via the
pass at the far left. These dry periods and surface winds account for the dune
systems that now cover much of the area, including evidence of volcanic activity
from the Aurora-Bodie volcanic field, about 4.5–2 million years ago. Small
cinder cones dot the landscape in the distance. In this photo you can see how
erosion exposes the older strata. The high peak at the right is Mount Grant, 11,240
feet.
![Page 5: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/5.jpg)
If you look closely, you can see recent scorpion tracks imprinted in the sand. Interestingly, several other tracks—including this set—reveal that scorpions often pass over—i.e., follow— each other’s tracks, including their own. It seems they do this more often than walking in opposing, or different directions. Individuals often moving in large (3´–8´), seemingly sporadic, circling patterns, crossing over their own tracks. If one individual happens to cross another scorpion’s tracks, they will often follow for several feet, either walking directly along the previous tracks or circling in the direction the tracks were going. I was not able to confirm if this behavior was linked to a specific sex, or even consistent within the same species. The few scorpions we observed that were actively following another's tracks were generally following their own species (Paruroctonus boreus, and in this photo P. becki). Oddly, males were usually found following other males than females, and vice-versa. This behavior likely correlates with pheromone markers. Observations throughout other parts of the year might reveal if this behavior is related to courtship.
![Page 6: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/6.jpg)
![Page 7: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/7.jpg)
The scorpion entering from the top right appears to have followed the track of the scorpion that entered from the bottom right.
![Page 8: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/8.jpg)
A burrow of Paruroctonus becki. Note the fanned mouth of the burrow.
![Page 9: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/9.jpg)
Left photo: P. boreus burrow
Right photo: P. becki burrow
![Page 10: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/10.jpg)
Species diversity and density greatly decreased in the flat areas. This could be due to unfavorable microhabitat and lack of shelter and possibly related to decreased prey availability. Paruroctonus becki was by far the most common species in the flat, bare terrain. The occasional Hadrurus spadix and Vaejovis cf confusus could be found in this type of microhabitat as well.
This small ridge is a “bench”, an ancient shoreline of Lake Lahontan.
![Page 11: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/11.jpg)
The exposed lava rock proved to be the ideal microhabitat for Paruroctonus simulatus and Hadrurus spadix.It turns out that P. simulatus was not nearly as psammophlic as initially thought, with the majority being found in coarse sand, along with areas of high amounts of eroded, exposed rock.
![Page 12: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/12.jpg)
Paruroctonus becki and P. boreus were prevalent in the loose sand.Vaejovis cf confusus was also occasionally seen. Note the aeolian pluvial deposits covering the underlying volcanic rock.
![Page 13: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/13.jpg)
Anuroctonus phaiodactylus and Vaejovis cf confusus were most abundant in the loose, more densely vegetated foothills (high amounts of shrubs and brush, as opposed to the grass-dominated plains) and mountain baselines and bajadas. Paruroctonus boreus was also of considerable density in this microhabitat.
![Page 14: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/14.jpg)
Paruroctonus simulatus
A lone adult male.
3 Adult females, and…
![Page 15: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/15.jpg)
Paruroctonus simulatus feeding on an early-instar Paruroctonus species, probably P. becki.
![Page 16: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/16.jpg)
Paruroctonus becki
Juvenile male inviting an alate ant to dinner. Subadult male.
Second-instar female.
Adult female.
![Page 17: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/17.jpg)
Subadult male Hadrurus spadix
![Page 18: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/18.jpg)
Vaejoviscf confusus
Female
Male
![Page 19: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/19.jpg)
Top left: adult male; top right: juvenile (about fourth instar) male; bottom left: adult female; bottom right: adult female.
Note the pallid coloration of P. boreus from this region.
Paruroctonus boreus
![Page 20: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/20.jpg)
Adult male Anuroctonus phaiodactylus
![Page 21: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/21.jpg)
Transition into Mojave Desert scrub further southeast, where we found some Vaejovis cf confusus. Rock flipping revealed only the one species.
Tikaboo Valley, Lincoln County, Nevada.
![Page 22: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/22.jpg)
Adult male Vaejovis cf confusus
![Page 23: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/23.jpg)
Adult male Vaejovis cf confusus
![Page 24: Hawthorne/Walker Lake area Mineral County, Nevada 1–2 September 2007](https://reader035.vdocuments.net/reader035/viewer/2022062814/568166bb550346895ddac260/html5/thumbnails/24.jpg)
We give special thanks to Lorenzo Prendini, Jeremy Huff, David Sissom, Warren Savary,Darrin Vernier, Richard Haradon, and foremost Kari McWest.