Habitat management for migratory and breeding birds at the Cat Island restoration project


This project will use information from the 2013 and 2014 shorebird field surveys to provide long term recommendations for habitat management at the Cat Island restoration project. Information from the monitoring project will also help document the Cat Island Project’s contribution to the removal of several Beneficial Use Impairments (BUI’s) in the Lower Fox River and Green Bay Area of Concern.


Monitoring data will be collected from April 2014 through November 2014, adding to preliminary data collected during 2013. Quarterly reports and a final report for the project will be prepared for the Wisconsin DNR, and information from the project will be included in a thesis submitted as partial fulfillment for a Master’s degree from the Environmental Science and Policy Graduate Program at the University of Wisconsin-Green Bay.

Study Design

Shorebirds will be sampled using a modified version of the standard International Shorebird (ISS) protocol, essentially a series of unlimited-distance counts from a georeferenced shoreline location where a significant area of potential habitat is visible. Counts at 6 specific points on the Cat Island causeway will be conducted no less than twice per week. Locations of target species will be mapped in order to document critical areas of bird use and potential effects of human disturbance. Surveys will start when ice and snow melt exposes potential shorebird habitat (sand, rock, or mud) and will persist through June 10 for spring migration. Fall migration counts will begin in early July and will end in mid-November. These dates correspond with typical shorebird arrival and departure dates in central Wisconsin (eBird 2012, Robbins 1991). Duration of counts is not specified by the ISS protocol, but start time and end time will be recorded for each visit. Even if no target birds are present at a site, observers will remain at each point count for a minimum of 20 minutes. All shorebirds, terns, and nesting water birds observed from the survey points will be recorded, along with distance and direction from the observer. Any arrival or departure by individuals or groups will be noted to the minute. Flyovers and flybys will be recorded but these birds will not be included in the analysis unless they had been clearly disturbed from feeding or resting areas by the observer. Terns flying but actively feeding are an exception and will be counted and included in analysis. A high quality spotting scope (30x power or greater) will be used in all cases to help identify species. Habitat and microhabitat variables will be evaluated during each survey. Bird locations will be classified as rocky shore, sandy beach, sand bar, upper beach, dry mud, wet mud, mud-water film (1-2cm), shallow water (2-8cm) and deep water (8+cm) (Skagen & Knopf 1994). Water depth will be estimated by evaluating how much of the bird’s legs are under water compared to average leg length for that species. Multiple pictures will be taken during each site-visit to monitor changes in exposed substrate and vegetation. Relevant cover types will be digitized into a GIS layer for subsequent analysis. Data will be analyzed with a generalized linear model using both categorical and continuous predictor variables. The goal of this analysis will be to identify site attributes that are important for feeding, nesting, and resting by migratory shorebirds in Green Bay and to describe temporal variation in the abundance of migrants. Landscape habitat variables will be evaluated using GIS and will be incorporated into statistical models. The data analysis will help guide the management plan for the Cat Island Restoration Project by identifying important habitat features and describing species interactions that affect use of these habitats. Comparisons of data in 2013 and 2014 will illustrate how birds use the structure in the absence of construction activities, which ceased in 2013.

Related Reports

Run Project Summary Report
View Umbrella-Projects
View Related-Projects

Great Lakes Restoration Initiative
Toxics and Areas of Concern
Reports and Documents
Findings of surveys of bird usage in restoration area - additional material will be included in graduate thesis
Project plan for bird assessment at Cat Island restoration project
Proposed monitoring to inform management of the Cat Island chain for migratory and breeding buirds