Geology topics

Michael J. Wellik

Publications and source records attributed to Michael J. Wellik.

5 recordsLinked to original sources

USGS2026

Restoration of Gavia immer (common loon) in Minnesota—2025 annual report

In cooperation with the Minnesota Department of Natural Resources, the U.S. Geological Survey monitored 98 Gavia immer (common loon) focal territories and 43 nonfocal territories in north-central Minnesota in 2025. Focal territories are those sampling units from which study inferences can be made. Nonfocal territories were adjacent to focal territories and were observed to monitor common loon dynamics across an entire waterbody. In collaboration with lake associations and private citizens, we deployed 44 artificial nesting platforms to 44 focal territories, called treatment territories. Territorial surveys to monitor occupancy, nesting, and chick survival were completed between April 27 and August 14, 2025. We attempted to visit each focal and nonfocal territory once per week. At least 1 nest attempt was observed in 40 of 54 control territories and 37 of 44 treatment territories. In treatment territories, 14 nests were on an artificial nesting platform, and the remaining nests were on natural substrates. Chicks or other evidence of hatching were observed in 20 of 54 control territories (37 percent) and 28 of 44 treatment territories (64 percent). Twelve of those successful nests in treatment territories were on artificial nesting platforms.

Minnesota↗

USGS2025

Restoration of Gavia immer (common loon) in Minnesota—2024 annual report

In cooperation with the Minnesota Department of Natural Resources, the U.S. Geological Survey monitored 98 common loon ( Gavia immer ) focal territories and an additional 37 nonfocal territories in 2024 across 53 study lakes in Minnesota. Focal territories were those territories from which study inferences will be made, whereas nonfocal territories were observed to monitor common loon dynamics in territories adjacent to focal territories. In collaboration with lake associations and private citizens, we deployed 44 artificial nesting platforms within 44 treatment territories, and the remaining 54 focal territories were controls. We completed territorial surveys from April 29 to August 9, 2024, to evaluate occupancy, nest success, and chick survival. We attempted to visit each territory once a week. At least one nest attempt was observed in 41 of 54 control territories. Precisely one nest attempt was observed in 30 control territories, two nest attempts (first attempts failed) were observed in 9 control territories, and three nest attempts (first and second attempts failed) were observed in 2 control territories. At least one nest attempt was observed in 33 of 44 treatment territories. Precisely one nest attempt was observed in 25 treatment territories, two nest attempts (first attempts failed) were observed in 7 treatment territories, and three nest attempts (first and second attempts failed) were observed in 1 treatment territory. In treatment territories, 8 nests were on an artificial nesting platform; the remaining nest locations were natural. Chicks or other evidence of hatching were observed in 26 of 54 (48.1 percent) control territories and 21 of 44 (47.7 percent) treatment territories, with 7 of those successful treatment nests on an artificial nesting platform. This report includes no formal analysis, but we plan to analyze data after collection of all field data in subsequent years.

Minnesota↗

USGS2017

Tree species preferences of foraging songbirds during spring migration in floodplain forests of the Upper Mississippi River

Floodplain forest of the Upper Mississippi River is important for songbirds during spring migration. However, the altered hydrology of this system and spread of reed canary grass (Phalaris arundinacea) and emerald ash borer (Agrilus planipennis) threaten tree diversity and long-term sustainability of this forest. We estimated tree preferences of songbirds during spring migration 2010–2013 to help guide management decisions that promote tree diversity and forest sustainability and to evaluate yearly variation in tree selection. We used the point center-quarter method to assess relative availability of tree species and tallied bird foraging observations on tree species as well as recording the phenophase of used trees on five 40 ha plots of contiguous floodplain forest between La Crosse, Wisconsin and New Albin, Iowa, from 15 April through 1 June. We quantified bird preferences by comparing proportional use of tree species by each bird species to estimates of tree species availability for all 4 y and for each year separately. Species that breed locally preferred silver maple (Acer saccharinum), which is dominant in this forest. The common transient migrant species and the suite of 17 transient wood warbler species preferred hackberry (Celtis occidentalis) and oaks (Quercus spp.), which are limited to higher elevations on the floodplain. We observed earlier leaf development the warm springs of 2010 and 2012 and later leaf development the cold springs of 2011 and 2013. Yellow-rumped Warbler (Setophaga coronata), American Redstart (S. ruticilla), Warbling Vireo (Vireo gilvus) and Baltimore Oriole (Icterus galbula), and the suite of transient migrant wood warblers spread their foraging efforts among tree species in colder springs and were more selective in warmer springs. All three of the important tree species are not regenerating well on the UMR and widespread die-off of silver maple is possible in 50 y without large scale management.

Minnesota, Wisconsin↗

USGS2016

Evaluating the effectiveness of wildlife detection and observation technologies at a solar power tower facility

Solar power towers produce electrical energy from sunlight at an industrial scale. Little is known about the effects of this technology on flying animals and few methods exist for automatically detecting or observing wildlife at solar towers and other tall anthropogenic structures. Smoking objects are sometimes observed co-occurring with reflected, concentrated light (“solar flux”) in the airspace around solar towers, but the identity and origins of such objects can be difficult to determine. In this observational pilot study at the world’s largest solar tower facility, we assessed the efficacy of using radar, surveillance video, and insect trapping to detect and observe animals flying near the towers. During site visits in May and September 2014, we monitored the airspace surrounding towers and observed insects, birds, and bats under a variety of environmental and operational conditions. We detected and broadly differentiated animals or objects moving through the airspace generally using radar and near solar towers using several video imaging methods. Video revealed what appeared to be mostly small insects burning in the solar flux. Also, we occasionally detected birds flying in the solar flux but could not accurately identify birds to species or the types of insects and small objects composing the vast majority of smoking targets. Insect trapping on the ground was somewhat effective at sampling smaller insects around the tower, and presence and abundance of insects in the traps generally trended with radar and video observations. Traps did not tend to sample the larger insects we sometimes observed flying in the solar flux or found dead on the ground beneath the towers. Some of the methods we tested (e.g., video surveillance) could be further assessed and potentially used to automatically detect and observe flying animals in the vicinity of solar towers to advance understanding about their effects on wildlife.

California↗

USGS2015

Observation of sandhill cranes' ( Grus canadensis ) flight behavior in heavy fog

The behaviors of birds flying in low visibility conditions remain poorly understood. We had the opportunity to monitor Sandhill Cranes (Grus canadensis) flying in heavy fog with very low visibility during a comprehensive landscape use study of refuging cranes in the Horicon Marsh in southeastern Wisconsin. As part of the study, we recorded flight patterns of cranes with a portable marine radar at various locations and times of day, and visually counted cranes as they departed the roost in the morning. We compared flight patterns during a fog event with those recorded during clear conditions. In good visibility, cranes usually departed the night roost shortly after sunrise and flew in relatively straight paths toward foraging areas. In fog, cranes departed the roost later in the day, did not venture far from the roost, engaged in significantly more circling flight, and returned to the roost site rather than proceeding to foraging areas. We also noted that compared to mornings with good visibility, cranes flying in fog called more frequently than usual. The only time in this 2-year study that observers heard young of the year calling was during the fog event. The observed behavior of cranes circling and lingering in an area while flying in poor visibility conditions suggests that such situations may increase chances of colliding with natural or anthropogenic obstacles in the vicinity.

Wisconsin↗