BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

The monarch butterfly (Danaus plexippus) is the focus of large-scale habitat restoration efforts because of recent population declines. From 2006-2017 we monitored monarchs at >400 sites throughout Iowa to link site occupancy and colonization/extinction dynamics to the presence of milkweed, site-specific habitat metrics, and landscape context at differing spatial scales. We used a robust design occupancy model in Program MARK and a hierarchical model selection approach to estimate site occupancy, extinction and colonization probabilities, and detection probability. Occupancy models revealed that monarchs responded differently to landscape features, environmental conditions, and local habitat conditions for site occupancy, extinction, and colonization probabilities. For site occupancy, the mean patch size of grassland at the 1-km spatial scale had a positive effect (β GrassPS1K = 0.94, SE = 0.54) while the percent of the landscape in woodland at the 200-m spatial scale had a negative effect (β WoodPL200 = −1.68, SE = 0.34). For extinction, there were additive effects of the percent of the landscape in woodland at the 100-m spatial scale (β WoodPLAND100 = 2.70, SE = 0.63), the interspersion of grassland at the 1-km spatial scale (β GrassIJI1K = −2.30, SE = 0.63), and litter depth (β Litter = 0.46, SE = 0.13). Finally, there were negative effects of the percent of the landscape in woodland at the 200-m spatial scale (β WoodPLAND200 = −4.67, SE = 1.37) and the interspersion of grassland at the 100-m spatial scale (β GrassPS1K = −2.02, SE = 0.70) on colonization probability. Detection probability was affected by the additive effects of canopy cover and monarch density; no other detection model was competitive. In the top model there was a positive effect of monarch density (β Density = 0.28, SE = 0.05) and a negative effect of canopy cover (β Canopy = −0.18, SE = 0.03) on detection probability. In Iowa, monarchs are widespread on conservation lands where they avoid sites with lots of canopy cover. Colonization and extinction processes are influenced by an interplay of landscape attributes across multiple spatial scales and site habitat attributes. Our study provides the first comprehensive insight into monarch use of conservation lands in Iowa, and predicted responses to important covariates may be useful for future conservation efforts.

The Shallow Lakes Restoration Project aims to restore eutrophic shallow lakes throughout the Iowa Prairie Pothole Region (PPR). We compared the vegetation taxa richness and frequency of taxa in three vegetation groups surveyed in 2016 and 2017 across non-restored sites, younger restorations, and older restorations. We also assessed the impact of these groups on numbers of breeding marsh birds. Restored wetlands had between 2.7 (95% CI 2.3, 3.2) and 4.7 (95% CI 3.9, 5.5) more species than non-restored sites among the three vegetation groups. Typha sp. was the most abundant emergent species. Lemna minor and Ceratophyllum demersum were the most abundant floating-leaved and submersed species, respectively. The frequency of submersed aquatic vegetation increased with years since restoration, while floating-leaved vegetation and Typha sp. peaked at 7 years post-restoration. The frequency of Typha sp. positively influenced Marsh Wrens and Yellow-headed Blackbirds. Water depth negatively affected Marsh Wrens, but water depth positively influenced Yellow-headed Blackbirds. Floating-leaved vegetation positively affected Virginia Rails, while water depth had a negative effect on this species. Our results indicate that after about 7 years further management of the vegetation and water levels may need to occur and should include maintaining appropriate conditions for breeding marsh birds.

Multipurpose reservoirs can be used to manage habitat for shorebirds during migration, an energetically costly event that may influence demographics and population numbers. This is particularly true for shorebirds that migrate through the interior of the United States, which has lost much of its wetland habitat. Shorebirds use aquatic systems during stopover periods during migration to rest and refuel. Understanding the factors that influence the probability of a shorebird remaining at a stopover area can inform decisions regarding reservoir management.We examined the influence of habitat and environmental covariates and body condition on the daily local residency probability of migrant least sandpipers (Calidris minutilla) at Saylorville Lake, a reservoir in central Iowa. We monitored 189 least sandpipers in fall 2016, 2017, 2019, and 2020 using radiotelemetry. Using a nest survival model, our most competitive model included significant negative effects of water level (β = -8.35, 85% CI = -11.18, -5.52) and body condition (β = -4.91, 85% CI = -6.82, -3.01) on residency probability. We calculated a mean daily local residency probability of 0.78 (95% CI 0.56, 1.00) and used this value to calculate a minimum stopover duration of 3.98 days (95% CI = 3.45, 4.46). Our findings indicate that the timing of water level management at Saylorville Lake can impact the residency probability of the least sandpiper. Drawing down water levels just prior to fall migration and maintaining water levels at or below the conservation pool level (254.8 m) can provide habitat for this species and likely other shorebirds.

Accounting for imperfect detection is an important process when obtaining estimates of density or abundance for breeding birds, and this is particularly true when researchers are monitoring birds to assess the success of restored wetlands. Due to the dramatic decline in areal cover and habitat quality, wetland restoration in the Prairie Pothole Region (PPR) is critically important to breeding birds. The Shallow Lakes Restoration Project (SLRP), a partnership between the Iowa Department of Natural Resources and Ducks Unlimited, Inc., aims to restore degraded shallow lakes throughout the Iowa PPR. We conducted unlimited-radius point counts with call-broadcast surveys for breeding marsh birds at 30 shallow lakes in various stages of restoration in 2016 and 2017. Our goals were to assess the impact of covariates on detection probability and estimate density of these species at non-restored, younger (1-5 years since restoration), and older (6-11 years since restoration) restorations. Detection probability ranged between 0.07 ± 0.009 (SE) for Red-winged Blackbird and 0.40 ± 0.09 (SE) for Common Yellowthroat. Percent cattail had a positive quadratic effect on detection probability for four species, with detection decreasing sharply as percent cattail increased and increasing slightly with 100% cattail cover. Wind speed negatively influenced the detection probability of Pied-billed Grebes but had a negative quadratic effect on the detection probability of Marsh Wrens. Both restored shallow lakes had greater densities of breeding Pied-billed Grebes, Marsh Wrens, and Yellow-headed Blackbirds than non-restored shallow lakes, but there was no significant difference between younger and older restorations. Including both habitat and environmental covariates on models for detection probability can improve the precision of estimates for density and should be considered when assessing bird populations pre-and post-restoration of shallow lakes.