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:
  Animals Horned Toads--Arizona Vertebrates Wildlife Wildlife Crossings Wildlife Crossings--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.
  
  
• Format:
  PDF
• Funding:
  JPA 05-017T / KR05-0494TRN
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:85e0af2bf2a1aa8aec69fabd6c943f7cb62a87d46d0e6aabc62e4c15ede56881
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/18027/dot_18027_DS1.pdf
• File Type:
  [PDF - 694.47 KB ]