Use of Bioacoustic Technology to Evaluate Habitat Use and Road Effects on Two Anuran Amphibians in the Boreal Region of Northeastern Alberta

• Author / Creator

  Annich, Natasha C

• Habitat loss and fragmentation are thought to be leading causes behind local to global amphibian declines. Recent expansion of the energy sector in the western boreal forest of northeastern Alberta raises concerns for amphibians that occupy this landscape. Methods for monitoring anuran amphibians typically involve call surveys to detect vocalizing males during the breeding seasons. I used passive acoustic monitoring with autonomous recording units (ARUs) to maximize detections of uncommon and common species. ARUs were deployed in the Lower Athabasca Planning Region (LAPR) of northeastern Alberta during the months of April to August (2012 – 2016). ARUs collected acoustic recordings of the soundscape that were processed through human listening of raw recordings and through use of an automated recognizer to identify the unique vocalizations of the Canadian toad (Anaxyrus hemiophrys, Cope 1886) and boreal chorus frog (Pseudacris maculata, Agassiz 1850). I generated a predictive generalized linear model using logistic regression to identify breeding habitat used by the Canadian toad in northeastern Alberta. I did this using a combination of remote sensing from ARUs and landscape characteristics collected from satellite and LIDAR technology. I found that the presence of this species is associated with fen wetland and upland edge habitat, along with the occurrence of coarser soils that allow toads to dig below the frost line during winter months. A positive relationship between presence and the proximity of roads was seen in the model, indicating that suitable habitat for toads exists near roads. This model had good predictive capacity and accuracy, and would be an effective tool for locating additional breeding locations for this species of concern. I also used ARUs to understand if boreal chorus frogs show a negative response to roads and associated noise pollution, a major cause of habitat degradation. I used call intensity codes as a measure of the relative abundance of chorus frogs and evaluated if road metrics, calculated with spatial data layers, influenced relative abundance. Boreal chorus frog abundance was shown to be positively influenced by road proximity, suggesting that the species breeds in roadside ditches. I further examined acoustic interference by passing vehicles, by measuring the full chorus amplitude (dB) for boreal chorus frogs before, during and after a vehicle passage. No significant difference in chorus amplitude could be detected, indicating that this species is not affected by traffic noise. It seems this anuran is not affected by roads and human activity on roads in this system. In conclusion, I provide an argument for the use of passive acoustic monitoring for surveying temperate anuran amphibians. ARU detections greatly increased the sample size of sites and dates surveyed, as well as expanding the ecological questions that I could address. Future monitoring and conservation plans for anurans in the LAPR are encouraged to use the findings of this research and to continue to use and develop methods for acoustic sampling.

• Subjects / Keywords

  • Boreal forests
  • Habitat use
  • Road effects
  • Boreal chorus frog
  • Bioacoustics
  • Canadian toad
  • Human impacts

• Graduation date

  Fall 2017

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3VX06H3K

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.