Identifying Shell Middens With Historic Aerial Photos: An Example From California's Santa Cruz Island

2017 ◽  
Vol 14 (1) ◽  
pp. 113-122 ◽  
Author(s):  
Jon M. Erlandson ◽  
Kristina M. Gill ◽  
Amy E. Gusick ◽  
Adriane E. Dorrler
PaleoAmerica ◽  
2015 ◽  
Vol 1 (1) ◽  
pp. 113-115 ◽  
Author(s):  
Jon M. Erlandson ◽  
Kristina M. Gill ◽  
Torben C. Rick ◽  
Leslie A. Reeder-Myers

2010 ◽  
Vol 75 (1) ◽  
pp. 177-198 ◽  
Author(s):  
Jennifer E. Perry ◽  
Christopher S. Jazwa

Chert outcrops on eastern Santa Cruz Island were of vital importance to the inhabitants of the Santa Barbara Channel region because of their comparatively limited availablity elsewhere on the California Channel Islands. Temporally diagnostic artifacts and radiocarbon dates from associated shell middens suggest that chert quarries were exploited throughout the Holocene. The importance of these quarries has been well documented in regard to microlith production as part of the shell bead industry during the late Holocene. However, relatively little is known about local chert tool manufacture and exchange in earlier times. Systematic documentation of 26 known chert quarries, and sampling at associated shell middens on eastern Santa Cruz Island has resulted in the identification of significant spatial variability in chert exploitation through time. Whereas chert quarrying during the middle Holocene appears to have been opportunistic and dispersed throughout the landscape, comparable activities during the late Holocene became increasingly circumscribed as microlith production was intensified. These trends in chert procurement are interpreted in the context of temporal changes in subsistence, tool manufacture, and residential mobility on the northern Channel Islands, and have broad implications for spatial and temporal patterning in prehistoric lithic exploitation.


Oryx ◽  
2021 ◽  
pp. 1-10
Author(s):  
Kyana N. Pike ◽  
Stephen Blake ◽  
Freddy Cabrera ◽  
Iain J. Gordon ◽  
Lin Schwarzkopf

Abstract As agricultural areas expand, interactions between wild animals and farmland are increasing. Understanding the nature of such interactions is vital to inform the management of human–wildlife coexistence. We investigated patterns of space use of two Critically Endangered Galapagos tortoise species, Chelonoidis porteri and Chelonoidis donfaustoi, on privately owned and agricultural land (hereafter farms) on Santa Cruz Island, where a human–wildlife conflict is emerging. We used GPS data from 45 tortoises tracked for up to 9 years, and data on farm characteristics, to identify factors that influence tortoise movement and habitat use in the agricultural zone. Sixty-nine per cent of tagged tortoises used the agricultural zone, where they remained for a mean of 150 days before returning to the national park. Large male tortoises were more likely to use farms for longer periods than female and smaller individuals. Tortoises were philopatric (mean overlap of farmland visits = 88.7 ± SE 2.9%), on average visiting four farms and occupying a mean seasonal range of 2.9 ± SE 0.3 ha. We discuss the characteristics of farm use by tortoises, and its implications for tortoise conservation and coexistence with people.


Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 147
Author(s):  
Mariana Villegas ◽  
Catherine Soos ◽  
Gustavo Jiménez-Uzcátegui ◽  
Shukri Matan ◽  
Keith A. Hobson

Darwin’s finches are a classic example of adaptive radiation involving differential use of dietary resources among sympatric species. Here, we apply stable isotope (δ13C, δ15N, and δ2H) analyses of feathers to examine ecological segregation among eight Darwin’s finch species in Santa Cruz Island, Galápagos collected from live birds and museum specimens (1962–2019). We found that δ13C values were higher for the granivorous and herbivorous foraging guilds, and lower for the insectivorous finches. Values of δ15N were similar among foraging guilds but values of δ2H were higher for insectivores, followed by granivores, and lowest for herbivores. The herbivorous guild generally occupied the largest isotopic standard ellipse areas for all isotopic combinations and the insectivorous guild the smallest. Values of δ2H provided better trophic discrimination than those of δ15N possibly due to confounding influences of agricultural inputs of nitrogen. Segregation among guilds was enhanced by portraying guilds in three-dimensional isotope (δ13C, δ15N, and δ2H) space. Values of δ13C and δ15N were higher for feathers of museum specimens than for live birds. We provide evidence that Darwin’s finches on Santa Cruz Island tend to be generalists with overlapping isotopic niches and suggest that dietary overlap may also be more considerable than previously thought.


2006 ◽  
Vol 66 (4) ◽  
pp. 456-461 ◽  
Author(s):  
Victoria J. Bakker ◽  
Dirk H. Van Vuren ◽  
Kevin R. Crooks ◽  
Cheryl A. Scott ◽  
Jeffery T. Wilcox ◽  
...  

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