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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...
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This data release is composed of seven datasets regarding colonial seabirds and forage fish at two seabird nesting colonies on Gull and Chisik Islands in lower Cook Inlet, Alaska. These data were collected to detect changes in the breeding population of Black-legged Kittiwakes and Common Murres on two nesting colonies in lower Cook Inlet and to compare those counts to baseline counts from 1995-1999. They are part of an ongoing study in lower Cook Inlet, Alaska to assess the recent status of forage fish and seabirds (2000-2020).
Egg production by desert tortoises was estimated at two sites in San Bernardino, California: Ivanpah Valley in 1980 and 1981 and Goffs in 1983, 1984 and 1985. Mean clutch frequencies were estimated for 1980 (1.60) and 1981 (1.10) from mass changes observed among sexually mature females weighed every 1-2 wk. Mean clutch frequencies in 1983 (1.89), 1984 (1.57) and 1985 (1.75) were estimated from periodic X-rays of females. Clutch sizes were also determined from radiographs. Tortoises at Goffs typically laid 1-2 clutches during May and June, but one female failed to lay eggs in 1984 and single tortoises laid three clutches in 1983 and 1985. If tortoises laid two clutches, the second was faintly visible in X-rays within...


    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 Assessing the Status and Trends of Seabirds and Forage Fish in Lower Cook Inlet, Alaska Predation of Common Murre Eggs at Two Seabird Colonies in Lower Cook Inlet, Alaska Common Murre Disturbance Data on Gull Island, Kachemak Bay, Alaska Assessing the Status and Trends of Seabirds and Forage Fish in Lower Cook Inlet, Alaska Common Murre Disturbance Data on Gull Island, Kachemak Bay, Alaska Predation of Common Murre Eggs at Two Seabird Colonies in Lower Cook Inlet, Alaska