Coast Horne Lizars Phrynosoma coronatum Tracey K. Brown, Ph.D. California State University, San Marcos Zoological Society of San Diego
Reptiles collare lizar leopar lizar siewiner rattlesnakes whipsnakes Horne Lizar Preators Mammals cats ogs coyotes foxes grasshopper mice roun-taile groun sqrl. humans Birs roarunners kites harriers several hawk spp. several owl spp. kestrel caracara ravens after Brattstrom, 1996 from Pianka an Hoges, 1998 foun in U.S. known bloo squirting known no bloo squirting from Pianka an Hoges, 1998 from Sherbrooke (1981)
Coast Horne Lizars Phrynosoma coronatum California Horne Lizar (P. c. frontale) San Diego Horne Lizar (P. c. blainvillii) Northern Peninsular Horne Lizar (P. c. schmiti) Central Peninsular Horne Lizar (P. c. jamesi) Ceros Islan Horne Lizar (P. c. cerroense). Cape Horne Lizar (P. c. coronatum) Grismer an Mellink, 1994 an Brattstrom, 1997 suggest P. coronatum to be a monotypic taxon from Jennings an Hayes, 1994 from Jennings an Hayes, 1994 Desert horne lizar Phrynosoma platyrhinos Current Status both subspecies are state an feeral species of special concern liste in many species an habitat plans estimate P.c. blainvillii extirpate in 25-45% of range (Brattstrom, 1992; Jennings & Hayes, 1994) estimate P.c. frontale extirpate in 35% of historical range (Jennings & Hayes, 1994) P. coronatum Life History Traits may live several years in wil (seen 8) females (95 mm SVL) typically larger than males (80 mm SVL) oviparous - generally only one clutch per year takes about 1½ years to reach maturity not territorial, have variable home ranges
Horne Lizar Seasonal Activity ault males typically emerge first, seen late March early April, active until July females emerge April, active until Sept. April - June peak ault activity months hatchlings appear July/Aug, active until Nov. have seen aults uring warm winter weeks Fisher et al., 2002 Horne Lizar Daily Activity activity varies seasonally unimoal in early spring, late summer bimoal late spring, early summer soil temp. range 21 to 54 C, mean 40 C mi-morning early summer best catching!! Typical Search Methos visual pros: no setup time, fairly efficient, can vary strategy (ranom vs. systematic) cons: w/o volunteers can be costly pitfall an funnel trapping pros: one person, tacit monitoring, permanent (with repair) cons: costly, time to put in, maintain, remove roa-cruising pros: one person, great if roas on site - efficient cons: risk of roa mortality Capture Success of Texas horne lizars, P. cornutum by ifferent methos Month Pitfall Funnel Search Roa Total Total 7 5 12 2 26 Hours 470 470 224 4 1168 Effort 0.015 0.011 0.054 0.526 0.022 from Fair an Henke (1997)
Fisher et al., 2002 stuy 21 sites, 256 arrays, 2-3 years bimonthly caught 578 lizars most important factors: soil type, presence of Argentine ants percent chaparral Horne Lizar Capture Rates 1995 activity season 31 aults, 3 juveniles, 150 hatchlings 1996 activity season 19 aults, 61 juveniles, 56 hatchlings 2000, 2001, 2002 activity seasons, 20 aults, 18 juveniles, 5 hatchlings (16 ha) 1990, 1991 activity seasons 11 aults, 2 juveniles, 12 hatchlings (4 ha) (from Hager, 1992)
HABITAT USE PATTERNS OF COAST HORNED LIZARDS HABITAT USE PATTERNS OF COAST HORNED LIZARDS Restoration Plots CONTROL N HERBICIDE W REMOVAL + HERB. S GRAZED E All Ranges $ $$ $$ $ $$ $ $$ $ $ CONTROL HERBICIDE W REMOVAL + HERB. GRAZED N S E 100 0 100 200 300 400 500 Meters 100 0 100 200 300 400 500 Meters Home Range Comparisons P. coronatum Habitat Usage of P. coronatum N Mean aily istance (m) Plot 4 55.6* (26.1) Home Range 50% Kernel (m 2 ) 3,038.3** (910.7) Home Range MCP (m 2 ) 16,593*** (16,934.8) Home Range Size (m 2 ) Unisturbe Burne Graze 17,136 ± 4,001 20,906 ± 5,048 31,260 ± 6,086 Non-plot 6 109.1* (42.7) 5,216.3** (1851.3) 42,129.2*** (28,969) # Conspecifics Overlappe 1.1 ± 0.2 1.0 ± 0.5 3.5 ± 1.2 Alberts, Grant an Lemm, 1995, 1997,1998 Major Plant Associations Daily Cover Salvia mellifera (black sage) Eriogonum fasciculatum (Ca. buckwheat) Lotus scoparius (eerwee) Rhus ovata (sugar bush) Keckiella antirrhinoies Artemesia californica Salvia apiana Summer Aestivation Salvia mellifera (black sage) Eriogonum fasciculatum (Ca. buckwheat) Rhus ovata (sugar bush) Overwintering Salvia mellifera (black sage) Eriogonum fasciculatum (Ca. buckwheat)
Threats to Horne Lizars habitat loss, fragmentation, egraation (grazing agriculture) Argentine ant (Lineptihema humile) introuce preators (cats, ogs, chilren) roa kill irt an asphalt past curio an pet trae