Conservation guidance for blanding's turtles in northwest iowa

Abstract

Blanding's turtles (Emydoidea blandingii) are currently threatened or endangered across their range in the United States and Canada due to habitat destruction and fragmentation. In Iowa, a recent survey from 2010 states that they currently reside in only 26 of the original 45 counties they historically inhabited. Due to the habitat differences across their range, developing survey protocols for the prairie pot-hole region of northwest Iowa is needed. Within Dickinson, Clay, and Palo Alto counties of Iowa, Blanding's turtles have been detected historically and contain a greater abundance of wetland habitats than the surrounding counties. The goal of this project was to assess different survey and capture techniques to inform future monitoring programs for Blanding's turtles in this region of Iowa. I used visual rapid assessments and hoop net trapping to detect, capture, and mark Blanding's turtles throughout the 2020 and 2021 field seasons. These surveys and trapping efforts were mostly conducted throughout the month of June, which is later than most literature would recommend due to reduced turtle basking behavior. However, due to the proliferation of submergent vegetation as the summer progressed, it seems likely that the detection of this species could be greater using these methods later into the summer as turtles venture out into more open areas of wetlands. In addition, these methods led to the discovery of multiple viable Blanding's turtle populations and new sites where the species is present. An additional spatial analysis concluded the presence of perennial streams in turtle home ranges which could be an important habitat factor for their existence in the boom-and-bust cycles of the prairie. Further research needs to be conducted using these methods for developing a more robust dataset to determine the effectiveness of this method. Long-term monitoring will be initiated using a field maps survey created by Iowa Lakes Community College students for increasing efficiency of data collection by managers and other professionals that encounter this species. In addition, funding for the purchase of 25 radio transmitters has been received for marking and tracking adult male and female turtles. These data will give a population-level understanding of future conservation action needed for their habitat management.