Hibernaculum Use by a Population of Desert Tortoises (Gopherus agassizii) in the Sonoran Desert

1995 ◽  
Vol 29 (3) ◽  
pp. 361 ◽  
Author(s):  
Scott J. Bailey ◽  
Cecil R. Schwalbe ◽  
Charles H. Lowe
Keyword(s):  
Sonoran Desert ◽  
Gopherus Agassizii

Agassiz’s desert tortoise (Gopherus agassizii) activity areas are little changed after wind turbine induced fires in California

2018 ◽  
Vol 27 (12) ◽  
pp. 851 ◽  
Author(s):  
Jeffrey E. Lovich ◽  
Mickey Agha ◽  
Joshua R. Ennen ◽  
Terence R. Arundel ◽  
Meaghan Austin
Keyword(s):  
Wind Turbine ◽  
Sonoran Desert ◽  
Gopherus Agassizii ◽  
After Effects ◽  
Burned Areas ◽  
Energy Facility ◽  
Before And After ◽  
Annual Activity ◽  
Risk Of Exposure ◽  
Activity Areas

Wind turbine-induced fires at a wind energy facility in California, USA, provided an opportunity to study the before and after effects of fire on a population of protected Agassiz’s desert tortoises (Gopherus agassizii) in the Sonoran Desert, a species and ecosystem poorly adapted to fire. We compared annual activity areas (AAs) of tortoises in 2011 and 2013, before and after two 2012 fires, with those of tortoises in adjacent areas unaffected by the same fires. Tortoises in both AAs affected by fire or unaffected by fire occupied the same general AAs in 2013, after the fires, as they did in 2011, before the fires. Some tortoises had both their 2011 and 2013 AAs completely or almost completely within the areas burned by the 2012 fires, despite the proximity of unburned habitat. None of the tortoises with 2011 AAs subsequently unaffected by the 2012 fires shifted their AAs into burned habitat in 2013. For the fire-affected group of tortoises, the mean percentages of 2011 and 2013 AAs burned by the 2012 fires were not significantly different, showing fidelity to the burned areas. Tortoises in both groups generally occupied consistent AAs, even post fire, placing them at potential risk of exposure to unfavourable burned habitat.

scholarly journals Micro-geographic variation in burrow use of Agassiz’s desert tortoises in the Sonoran Desert of California

2020 ◽  
pp. 177-188
Author(s):  
Kristy Cummings
Keyword(s):  
Geographic Variation ◽  
Sonoran Desert ◽  
Radio Telemetry ◽  
Gopherus Agassizii ◽  
General Aspect ◽  
Annual Cycles ◽  
Local Geology ◽  
Burrow Use

Little has been published regarding the burrowing habits of Agassiz’s desert tortoises (Gopherus agassizii) in the Sonoran Desert of California. We monitored the interactions of tortoises with their burrows, and other tortoises, via radio-telemetry at two nearby sites between the Cottonwood and Orocopia Mountains, from 2015-2018. We examined how annual cycles of drought and non-drought years, behaviourally affected how tortoises use their burrows (i.e., burrow fidelity, cohabitation, and location), including the timing of the tortoise brumation period. Burrow locations were strongly dependent on local geology and topography, with a tendency to orientate in conformance with the general aspect of the landscape. The timing of brumation was similar to records for G. agassizii throughout their range (with a few exceptions). There was no difference in the estimated number of burrows used per 30 days between the active seasons (2017 and 2018) at the Orocopia site, despite the occurrence of drought in 2018.

Habitat Use by Desert Tortoises (Gopherus agassizii) on Alluvial Fans in the Sonoran Desert, South-Central Arizona

Copeia ◽  
2008 ◽  
Vol 2008 (2) ◽  
pp. 414-420 ◽  
Author(s):  
J Daren Riedle ◽  
Roy C. Averill-Murray ◽  
Clayton L. Lutz ◽  
Darren K. Bolen
Keyword(s):  
Habitat Use ◽  
Sonoran Desert ◽  
Gopherus Agassizii ◽  
Alluvial Fans ◽  
South Central ◽  
Central Arizona

Reproductive Output and Clutch Phenology of Female Agassiz's Desert Tortoises (Gopherus agassizii) in the Sonoran Desert Region of Joshua Tree National Park

2018 ◽  
Vol 37 (1) ◽  
pp. 40-57 ◽  
Author(s):  
Jeffrey E. Lovich ◽  
Shellie R. Puffer ◽  
Mickey Agha ◽  
Joshua R. Ennen ◽  
Kathie Meyer-Wilkins ◽  
...  
Keyword(s):  
Sonoran Desert ◽  
National Park ◽  
Reproductive Output ◽  
Gopherus Agassizii ◽  
Desert Region ◽  
Joshua Tree National Park

Influence of Selected Endomycorrhizae from the Sonoran Desert and Glomus intraradices on Growth Response and Gas Exchange of Hibiscus rosa-sinensis L. cv. Leprechaun

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 501d-501
Author(s):  
Jonathan N. Egilla ◽  
Fred T. Davies
Keyword(s):  
Gas Exchange ◽  
Sonoran Desert ◽  
Growth Response ◽  
Glomus Intraradices ◽  
Root Colonization ◽  
Gas Exchange Parameters ◽  
Hibiscus Rosa Sinensis ◽  
Low Phosphorus ◽  
The Relationship ◽  
Exchange Parameters

Six endomycorrhiza isolates from the Sonoran Desert of Mexico [Desert-14(18)1, 15(9)1, 15(15)1, Palo Fierro, Sonoran, and G. geosporum] were evaluated with a pure isolate of Glomus intraradices for their effect on the growth and gas exchange of Hibiscus rosa-sinensis L. cv. Leprechaun under low phosphorus fertility (11 mg P/L). Rooted cuttings of Hibiscus plants were inoculated with the seven mycorrhiza isolates and grown for 122 days. Gas exchange measurements were made on days 26, 88, and 122 after inoculation, and plants were harvested on day 123 for growth analysis. Plants inoculated with the seven isolates had 70% to 80% root colonization at harvest. Plants inoculated with G. intraradices had significantly higher leaf, shoot and root dry matter (DM), leaf DM/area (P ≤ 0.05) than those inoculated with any of the six isolates, and greater leaf area (LA) than Desert-15(9)1 and 15(15)1. Uninoculated plants had significantly lower leaf, shoot, root DM, leaf DM/area and LA (P ≤ 0.05) than the inoculated plants. There were no differences among the seven isolates in any of the gas exchange parameters measured [photosynthesis (A) stomatal conductance (gs), the ratio of intercellular to external CO2 (ci/ca), A to transpiration (E) ratio (A/E)]. The relationship between inoculated and uninoculated plants in these gas exchange parameters were variable on day 122 after inoculation.

Management of Dairy Waste in the Sonoran Desert Using Constructed Wetland Technology

1999 ◽  
Vol 40 (3) ◽  
pp. 57-65 ◽  
Author(s):  
Martin M. Karpiscak ◽  
Robert J. Freitas ◽  
Charles P. Gerba ◽  
Luis R. Sanchez ◽  
Eylon Shamir
Keyword(s):  
Sonoran Desert ◽  
Suspended Solids ◽  
Waste Treatment ◽  
Oxygen Demand ◽  
Dairy Wastewater ◽  
Chemical Parameters ◽  
Treatment Facility ◽  
Physical Chemical ◽  
Scirpus Validus ◽  
Surface Wetland

An integrated wastewater treatment facility, consisting of upper (solids separators, anaerobic lagoons, and aerobic ponds) and lower (wetland cells) subsystems, has been built to replace the lagoon at a dairy in Arizona, USA. The collection sump of the new waste treatment facility collects all dairy wastewater outflow. Wastewater is then pumped to solids separators, and flows by gravity to anaerobic ponds and aerobic ponds. The upper subsystem is expected to treat the water sufficiently so that the wetland cells may achieve further pollutant reductions. The lower subsystem, comprised of 8 surface wetland cells with an approximate surface area of 5,000 m2, receives outflow from the ponds. The cells are planted with cattail (Typha domingensis), soft-stem bulrush (Scirpus validus), and reed (Phragmites australis). After treatment is completed via the lagoons and ponds followed by the wetland cells, the wastewater can be reused to flush barns or to irrigate crops. Performance of the overall system is evaluated by measuring physical, chemical and biological parameters in water samples taken from selected locations along the treatment system. Chemical parameters studied include biochemical oxygen demand, pH, total suspended solids, nitrogen species. Biological monitoring included coliforms (total and fecal) and Listeria monocytogenes.

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