Use of simulated highway underpass crossing structures by flat-tailed horned lizards (Phrynosoma mcallii).

Details

• Creators:
  Painter, Mikele L. ; Ingraldi, Michael F.
• Corporate Creators:
  Arizona. Game and Fish Dept. Research Branch
• Corporate Contributors:
  Arizona. Department of Transportation ; United States. Federal Highway Administration
• Subject/TRT Terms:
  • Wildlife crossings
  • Wildlife
  • Vertebrates
  • Animals
  • Wildlife crossings--Arizona
  • Horned toads--Arizona
• Publication/ Report Number:
  FHWA-AZ-07-594
• Resource Type:
  Tech Report
• Geographical Coverage:
  Arizona
• Edition:
  Final report; June 2005-Feb. 2007.
• Corporate Publisher:
  Arizona. Department of Transportation
• Abstract:
  The flat-tailed horned lizard (Phrynosoma mcallii) occupies a restricted range in the Lower Sonoran Desert of ; southwest Arizona, southeast California, and adjacent land in Mexico. Because they exhibit behavior patterns ; that include basking and remaining motionless when danger approaches, flat-tailed horned lizards are ; particularly susceptible to mortality on roads. Therefore, roads and new road construction are recognized as ; threats influencing the long-term persistence of this species. The propensity for flat-tailed horned lizards to ; use culverts as road crossing structures to avoid vehicle-caused mortality is unknown. From 2005-2006 we ; studied flat-tailed horned lizard use of a variety of simulated road crossing structures. The study objectives ; were to 1) determine if flat-tailed horned lizards will pass through culverts of sizes commonly used in road ; construction, and 2) compare and describe the characteristics of culverts used by flat-tailed horned lizards to ; those not used. We built a testing facility with six culverts of three dimensions and two interior lighting ; options. All culverts were 40 feet long; the three types included 24-inch diameter steel culverts, 36-inch ; diameter steel culverts, and 4-foot tall by 8-foot wide box culverts. One of each type of culvert was lit with ; skylights, and one of each type of culvert had only natural light from the ends. Light and temperature ; conditions in the culverts were evaluated during the study. Out of 54 flat-tailed horned lizards placed in the ; testing facility, we observed 12 complete crossings. The 36-inch diameter culvert without skylights was used ; five times. The 24-inch diameter culvert with skylights was not used, and other culvert designs were each ; used once or twice. Results indicated that flat-tailed horned lizards can use culverts as road crossing ; structures, but the evidence did not reveal a strong selection for or against any culvert type. ; Recommendations for employing appropriate road crossing structures are discussed.
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• Format:
  PDF
• Funding:
  JPA 05-017T / KR05-0494TRN
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/18027/dot_18027_DS1.pdf
• File Type:
  [PDF - 694.47 KB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:85e0af2bf2a1aa8aec69fabd6c943f7cb62a87d46d0e6aabc62e4c15ede56881