Desert Tortoise (Gopherus agassizi)
Desert Tortoise (Gopherus agassizi)
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type | Age-Specific |
|---|---|---|---|---|---|---|---|---|---|
| Growth Rate | PL(mm) = 7.25(Age) + 50.1 | linear regression equation relating plastron length (PL; 48-221 mm) to Age (1-26 yrs) | Both Male and Female | Both Adults and Juveniles | 15 animals; repeated measurements | Rock Valley, Nye County (elev., 1020m) | Exposure Factor Datasets | 0-26 yrs | |
| Age at Sexual Maturity | yr | Female | Adult | Not Reported | Rock Valley, Nye County (elev., 1020m) | Exposure Factor Datasets | |||
| Clutch or Litter Size | determined by x-ray examination of females | eggs/clutch | Female | Adult | 3 animals | Rock Valley, Nye County (elev., 1020m) | Exposure Factor Datasets |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type |
|---|---|---|---|---|---|---|---|---|
| Body Weight - Mean | g | Both Male and Female | Not Reported | 41 animals | Beaver Dam Slope, Washington County (elev., 3200-3500 ft) | Exposure Factor Datasets | ||
| Population Density | 0.25 | #/acre | Both Male and Female | Not Reported | Not Reported | Beaver Dam Slope, Washington County (elev., 3200-3500 ft) | Exposure Factor Datasets | |
| Home Range | 50 | acres | Both Male and Female | Not Reported | NE | Exposure Factor Datasets | ||
| Clutch or Litter Size | eggs/clutch | Female | Not Reported | Not Reported | Beaver Dam Slope, Washington County (elev., 3200-3500 ft) | Exposure Factor Datasets | ||
| Time of Mating/ Laying | early summer | laying | Female | Not Reported | Not Reported | Beaver Dam Slope, Washington County (elev., 3200-3500 ft) | Exposure Factor Datasets |
| Exposure Endpoint Type | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type |
|---|---|---|---|---|---|---|---|
| Clutch or Litter Size | range of mean clutch size over 3 years in two sample groups | eggs/clutch | Female | Adult | 10-25 | Yucca Mountain, Nye County (elev., 1000-1500m) [lat., 36^o51'; long., 116^o25' W] | Exposure Factor Datasets |
| Exposure Endpoint Type | Endpoint Description | Units | Sex | Sample Size | Location | Type | Age-Specific |
|---|---|---|---|---|---|---|---|
| Growth Rate | mean yearly growth rates using calculated carapace lengths over 4 yr intervals; range of 4 site-specific means | mm/yr | Both Male and Female | 38 - 112 animals/site | Western and Eastern Mojave, Sinaloan and Sonoran deserts | Exposure Factor Datasets | 4-8 yrs |
| Growth Rate | mean yearly growth rates using calculated carapace lengths over 4 yr intervals; range of 4 site-specific means | mm/yr | Both Male and Female | 36 - 105 animals/site | Western and Eastern Mojave, Sinaloan and Sonoran deserts | Exposure Factor Datasets | 8-12 yrs |
| Growth Rate | mean yearly growth rates using calculated carapace lengths over 4 yr intervals; range of 4 site-specific means | mm/yr | Both Male and Female | 12 - 41 animals/site | Western and Eastern Mojave, Sinaloan and Sonoran deserts | Exposure Factor Datasets | 16-20 yrs |
| Growth Rate | mean yearly growth rates using calculated carapace lengths over 4 yr intervals; range of 4 site-specific means | mm/yr | Both Male and Female | 25-69 animals/site | Western and Eastern Mojave, Sinaloan and Sonoran deserts | Exposure Factor Datasets | 12-16 yrs |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type | California Counties | Error |
|---|---|---|---|---|---|---|---|---|---|---|
| Clutch or Litter Size | 3.56 | estimated by x-raying females | eggs/female | Female | Adult | 9 | Fenner Valley, Goffs (elev., 680m) {lat., 34^o51'N; long., 115^o09'W] | Exposure Factor Datasets | San Bernardino | 1.94 SD |
| Metabolic Rate | range of mean field metabolic rates, estimated using doubly labeled water | kJ/d | Female | Adult | 9 | Fenner Valley, Goffs (elev., 680m) {lat., 34^o51'N; long., 115^o09'W] | Exposure Factor Datasets | San Bernardino | ||
| Time of Torpor or Hibernation | Sept. - Mar. | Female | Adult | 9 | Fenner Valley, Goffs (elev., 680m) {lat., 34^o51'N; long., 115^o09'W] | Exposure Factor Datasets | San Bernardino |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type |
|---|---|---|---|---|---|---|---|---|
| Metabolic Rate | see citation | figure of seasonal changes in metabolic rates | L CO2/kg/d | Male | Adult | 6-11 | Desert Tortoise Natural Area, California City (elev. 869-945 m) [lat., 35^o10'N, long., 118^o10'W] and Ivanpah Valley (elev., 866-914 m) [35^o39'N, 115^o15' W] | Exposure Factor Datasets |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type |
|---|---|---|---|---|---|---|---|---|
| Population Density | range of 95% confidence intervals | #/km2 | Both Male and Female | Both Adults and Juveniles | 2 yrs | western Mojave desert, Kramer Hills | Exposure Factor Datasets | |
| Survival/ Mortality | 2.9 | annual mortality rate for subadults and adults between 1980 and 1982 | %/yr | Both Male and Female | Both Adults and Juveniles | 2 yrs | western Mojave desert, Kramer Hills | Exposure Factor Datasets |
| Population Density | range of 95% confidence intervals | #/km2 | Both Male and Female | Both Adults and Juveniles | 2 yrs | Colorado desert, Chemehuevi Wash and Valley | Exposure Factor Datasets | |
| Survival/ Mortality | 2.2 | annual mortality rate for subadults and adults from 1975 and 1982 | %/yr | Both Male and Female | Both Adults and Juveniles | Not Reported | Colorado desert, Chemehuevi Wash and Valley | Exposure Factor Datasets |
| Exposure Endpoint Type | Endpoint Value | Sex | Life Cycle Stage | Sample Size | Location | Type | Lab |
|---|---|---|---|---|---|---|---|
| Time of Mating/ Laying | Apr.-May and Aug.-Nov. | Both Male and Female | Adult | 50 | Exposure Factor Datasets | Laboratory | |
| Time of Nesting | May-July | Female | Adult | 50 | Exposure Factor Datasets | Laboratory | |
| Time of Torpor or Hibernation | Oct. - Apr. | Both Male and Female | Adult | 50 | Exposure Factor Datasets | Laboratory |
| Exposure Endpoint Type | Endpoint Description | Units | Sex | Life Cycle Stage | Sample Size | Location | Type | California Counties |
|---|---|---|---|---|---|---|---|---|
| Clutch or Litter Size | range of means for 3 yrs; based on x-ray examination (overall range = 1-8) | eggs/clutch | Female | Adult | 20-26 animals | Ivanpah Valley, Goffs | Exposure Factor Datasets | San Bernardino |
| Clutches or Litters per year | range of means for 3 yrs; overall range = 1-3 | clutches/yr | Female | Adult | 20-26 animals | Ivanpah Valley, Goffs | Exposure Factor Datasets | San Bernardino |
| Exposure Endpoint Type | Endpoint Value | Endpoint Description | Units | Sex | Sample Size | Location | Type | Age-Specific | Lab |
|---|---|---|---|---|---|---|---|---|---|
| Body Weight - Mean | BW = 0.00049(CL)^2.795 | Body Weight (BW;150 - 1500 g) and carapace length (CL; 100-300 mm) relationship | g | Not Reported | 7 data points, each based on the average of 4 animals | Exposure Factor Datasets | 0-3 yr post-hatch | Laboratory |
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