| Abstract: | Coastal horned lizards (Phrynosoma coronatum) have undergone severe declines in southern California and are a candidate species for state and federal listing tender the Endangered Species Act. Quantitative data on their habitat use, abundance, and distribution are lacking, however. We investigated the determinants of abundance for coastal horned lizards at multiple spatial scales throughout southern California. Specifically, we estimated lizard distribution and abundance by establishing 256 pitfall trap arrays clustered within 21 sites across four counties. These arrays were sampled bimonthly for 2-3 years. At each array we measured 26 "local" site descriptors and averaged these values with other "regional" measures to determine site characteristics. Our analyses were successful at identifying factors within and among sites correlated with the presence and abundance of coastal horned lizards. These factors included the absence of the invasive Argentine ant (Linepithema humile) (and presence of native ant species eaten by the lizards), the presence of chaparral community plants, and the presence of sandy substrates. At a regional scale the relative abundance of Argentine ants was correlated with the relative amount of developed edge around a site. There was no evidence for spatial autocorrelation, even at the scale of the arrays within sites, suggesting that the determinants of the presence or absence and abundance of horned lizard can vary over relatively small spatial scales (hundreds of meters). Our results suggest that a gap-type approach may miss some of the fine-scale determinants of species abundance in fragmented habitats. |
| Genre: | Article |
| ProdID: | 70024450 |
| Citation Author: | Fisher, R. N.; Suarez, A. V.; Case, T. J. |
| Citation Contributing Office: | |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 215 |
| Citation Issue: | 1 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Conservation Biology |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 11 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Spatial patterns in the abundance of the coastal horned lizard; 2002; Article; Journal; Conservation Biology; Fisher, R. N.; Suarez, A. V.; Case, T. J. |
| Citation Start Page: | 205 |
| Citation Volume: | 16 |
| Citation Year: | 2002 |
| Type: | citation/reference |
| Text: | Spatial patterns in the abundance of the coastal horned lizard; 2002; Article; Journal; Conservation Biology; Fisher, R. N.; Suarez, A. V.; Case, T. J. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.1046/j.1523-1739.2002.00326.x |
| Date Other: | Tue, 1 Jan 2002 00:00 -0600 |
| Publisher: | |
