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These data were compiled to evaluate the reproductive ecology of Agassiz's desert tortoises (Gopherus agassizzi) in the Sonoran Desert of California using two populations within Joshua Tree National Park, including five reproductive seasons that spanned 20 years (1997-1999, 2015-2016). Compared to their conspecifics inhabiting the Mojave Desert, the reproductive ecology of G. agassizii in the Sonoran Desert is understudied. Climatic variation between the two deserts can affect reproductive ecology, including fecundity and clutch phenology. Mature female tortoises (straight-line carapace length ≥ 20 cm) outfitted with radiotransmitters were located and X-radiographed approximately every 10-14 days during the reproductive...
In the northern Colorado Front Range, fire suppression during the 20th century is believed to have created a high hazard of catastrophic fire in ponderosa pine (Pinus ponderosa) forests. Since the early 1990s, resource managers have increased the use of prescribed fires to re-create fire regimes and forest structures similar to those of the pre-Euro-American settlement period in order both to reduce fire hazard and to improve forest health. To improve understanding of historical fire regimes, we conducted a study of fire history along an elevational gradient from \sim1830 to 2800 m in ponderosa pine forests in the northern Front Range. Fire-scar dates were determined from 525 partial cross sections from living and...
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These data were acquired from 7 study sites distributed across the range of Gopherus agassizii. Data were collected from 1997 to 2002 as part of three separate studies, although data were not collected at all sites in each year. Radio-transmitters were attached to the carapace of 151 females and VHF radio-telemetry was used to relocate animals to assess reproductive status. Egg production was determined from X-radiographs taken weekly/biweekly intervals (depending on the study) using a portable X-ray machine between April and July or August of each year. In addition, the mean carapace length (MCL) of each tortoise was measured at each time of capture or recapture using calipers (mm). A nesting event was recorded...
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These data were compiled to evaluate reproductive output of Agassiz's desert tortoises (Gopherus agassizzi) in relation to environmental and individual-level variables. We collected data from four study sites in the Sonoran Desert of California, including two separate populations within Joshua Tree National Park, one population located on the northern versant of the Orocopia Mountains, and one population located at the extreme western end of the Coachella Valley. These data represent eight reproductive seasons that spanned over 20 years (1997-2000, 2015-2018). These data were compiled and added to a larger database with additional records collected by other scientists from eight other study sites in order to detect...
Natural selection may result in local adaptation to different environmental conditions across the range of a species. Understanding local adaptation, in turn, informs management decisions such as translocation to restore locally-extinct populations. We used a landscape genomics approach to detect genetic signatures of selection related to climatic variation among desert bighorn sheep populations across their indigenous range in the western United States. This approach allowed us to investigate broad patterns of both neutral and adaptive genetic variation across very different environments. Analyses suggested that ancestry and isolation by distance were the most significant forces driving genetic variation in desert...


    map background search result map search result map Reproductive ecology data for female Agassiz's desert tortoises (Gopherus agassizii) in Joshua Tree National Park, USA Agassiz's desert tortoise and egg data from the Sonoran Desert of California (1997-2000, 2015-2018) Mojave Desert Tortoise (Gopherus agassizii) Morphometrics and Egg Data from Seven Sites across the Mojave, (1997-2002) Reproductive ecology data for female Agassiz's desert tortoises (Gopherus agassizii) in Joshua Tree National Park, USA Agassiz's desert tortoise and egg data from the Sonoran Desert of California (1997-2000, 2015-2018) Mojave Desert Tortoise (Gopherus agassizii) Morphometrics and Egg Data from Seven Sites across the Mojave, (1997-2002)