Tyler M. Harms‎ > ‎

Research



Landscape-level habitat associations and predicting species occurrence

    The question of how species are distributed on the landscape has always been an interesting topic in ecology.  As land cover and use continues to change across Iowa, it's important to identify areas of high conservation priority for species so that land managers and biologists can focus research as well as habitat restoration and management efforts.  I'm currently working with colleagues with the Iowa Department of Natural Resources and at Iowa State University to evaluate landscape-level habitat associations and predict occurrence of wildlife in Iowa, particularly Species of Greatest Conservation Need (SGCN) listed in the Iowa Wildlife Action Plan.  This research will produce a series of maps that predict areas of high species' occupancy, extinction, or colonization as shown below.

Map predicting occupancy of Grasshopper Sparrow (Ammodramus savannarum) in Iowa.  Areas of blue designate low occupancy and yellow designate high occupancy.


Impacts of haying on grassland bird species of conservation concern

    Grassland birds are one of the most imperiled groups of birds and several populations have exhibited significant declines in the last three decades. These declines can be attributed to the loss of native grassland habitat to agricultural development leaving <4% of native tallgrass prairie habitat across the Great Plains. As a result, several studies have examined different aspects of population ecology and habitat associations of grassland birds throughout the Midwest and Great Plains. More specifically, studies have examined the effects of different grassland management practices on grassland bird population dynamics. Mowing and haying are two management practices that are commonly implemented on grasslands in Iowa, both on public and private lands. We are currently assessing the influence of vegetation characteristics and management activities on grassland bird species at Camp Dodge Army Base located near Des Moines, Iowa.  This study will provide valuable information on the impacts of haying on grassland bird abundance, information that can be used by not only land managers on Camp Dodge but across Iowa. Knowing the impacts of haying on grassland bird populations will better allow us to assess the utility of haying and mowing as a grassland management practice in Iowa.


Iowa Multiple Species Inventory and Monitoring Program


    Long-term monitoring of wildlife populations at the state level is crucial to effective conservation. The Iowa Multiple Species Inventory and Monitoring program was developed in response to concerns about the lack of information on population trends, distribution, and habitat requirements of Iowa wildlife, particularly Species of Greatest Conservation Need (SGCN) highlighted in the Iowa Wildlife Action Plan. This program was started by the Iowa Department of Natural Resources and is now a cooperative program between the Iowa DNR and Iowa State University. The goal of the MSIM program is to conduct standardized statewide surveys for wildlife of several taxonomic groups to provide a basic inventory of Iowa's wildlife populations and serve as a baseline for comparison of future monitoring efforts. Each year, a team of 25 technicians conducts surveys for wildlife in nine taxonomic groups; birds, mammals, reptiles, amphibians, odonates, butterflies, fish, freshwater mussels, and terrestrial snails. Surveys are conducted on randomly-selected public properties that are stratified by habitat type. We conduct surveys for each taxonomic group according to protocols outlined in the Iowa Multiple Species Inventory and Monitoring Technical Manual. Each year, we also conduct both terrestrial and aquatic habitat assessments at each surveyed property. The combination of the species and habitat data collected will allow us to evaluate habitat associations of different wildlife species and ultimately provide guidance on habitat management decisions to conserve wildlife populations in Iowa. We can use species data to compare current and historic distributions across Iowa to determine where to focus conservation efforts and can also establish population trends. See the above link for more information about the program.

  
Population ecology and monitoring of secretive marsh-birds in Iowa

    Many populations of marsh-birds are declining across North America and, as a result, several species are of heightened conservation status at both the state and federal levels. In Iowa, for example, four species of marsh-birds (American Bittern [Botaurus lentiginosis], Least Bittern [Ixobrychus exilis], King Rail [Rallus elegans], and Common Moorhen [Gallinula chloropus]) are listed as Species of Greatest Conservation Need (SGCN) by the Iowa Wildlife Action Plan (see http://www.iowadnr.gov/wildlife/diversity/plan.html). To further compound this issue, traditional survey programs such as the Breeding Bird Survey (BBS) are inadequate at monitoring population trends of these birds due to their secretive nature and thus, low detection probabilities. The lack information on these birds and the absence of effective survey methodologies led to the development of the North American Marsh Bird Monitoring Program (see http://ag.arizona.edu/research/azfwru/NationalMarshBird/). The main goal of this program is to develop a standardized set of survey methodologies that can be implemented across the U.S. to can information about the status and trends of secretive marsh-birds in North America. I conducted research examining the distribution and abundance of secretive marsh-birds in Iowa. My project had three facets; 1) estimate population densities of secretive marsh-birds in Iowa, 2) evaluate habitat associations of secretive marsh-birds in Iowa relative to wetland characteristics, and 3) examine temporal variation in responses to call-broadcasts of secretive marsh-birds in Iowa. I've published results on the density and abundance of secretive marsh birds in Iowa (Harms and Dinsmore 2012, Waterbirds), their habitat associations (Harms and Dinsmore 2013, Wetlands), and am working to publish results on seasonal and time-of-day influences on detection rates. This research has provided valuable information on distribution and habitat associations to land managers in Iowa and will help refine marsh bird survey protocols for Iowa and the Midwest.

This research is funded by the Iowa Department of Natural Resources' (DNR) State Wildlife Grant and Wildlife Diversity Program Small 
Research Grant.  Click here for a link to a summary of our research and findings published by the Iowa DNR.