Nesting season could find western screech owls, American kestrels, passerine songbirds and other migratory birds sitting on eggs or feeding fledglings in Miller Park.
In the wake of the Audubon complaint, the project has now been pushed back from a planned April 15 start to July, according to city officials. It should take about six months to complete.
The operation would remove 275 non-native trees about 30 percent of the canopy along the small creek-side park that is a favorite among residents of the Yalecrest area. It also would re-establish native ground cover and shrubbery, as well as restore the streambed and shore up its banks.
Funding for the $765,000 undertaking comes from Chevron through the Utah Division of Water Quality as mitigation for Chevron's ruptured pipeline in June 2010 that sent oil down Red Butte Creek.
Great Salt Lake Audubon faults the project in a number of areas, most notably its timing.
Scheduling tree removal during nesting season and streambed work during high flows reveals a lack of expertise, said Audubon acting president Heather Dove.
"They have billed this as a restoration project but are approaching it like a landscape project," she said.
The Miller Park restoration plan has come under intense scrutiny by some residents who don't want trees, sometimes adjacent to their backyards, cut down. However, earlier this year, the Yale-crest Community Council and city officials seemed to reach a compromise on the scope of tree removal.
In late March, the Audubon's Dove alerted city officials, who apparently were not aware of the Migratory Bird Treaty Act, among other things.
"Additionally, Great Salt Lake Audubon is very concerned that during project planning, Salt Lake City was not aware of and did not consider the direct and indirect impacts construction would have on migratory birds," Dove said.
In an interview, she added that the contractor hired by the municipality is not following common practices that begin with wildlife studies.
The Audubon is not against the project, she said, but suggested that it take place from mid-August through January during non-breeding seasons for migratory birds in Utah.
Salt Lake City will now embark on a survey in Miller Park to identify migratory bird nests, said Emy Maloutas, the city's open-space lands program manager. Once the survey is completed the project will get a new start date, she said.
"The intent of this project is to improve habitat," she said. "This riparian [stream] area is a really important bird area."
The project seeks to remove three non-native tree species along Red Butte Creek: Siberian elm, black locust, and Tree of Heaven. It also includes planting of native trees, shrubs and plants.
Maloutas said trimming back the canopy is important because the non-native trees are choking out native species, including ground cover and shrubs.
Further, she noted that by re-creating a native Utah stream ecosystem, Miller Park will be a better bird refuge.
The U.S. Fish and Wildlife Service also has been in communication with Salt Lake City, said Melissa Burns, migratory bird coordinator.
"As a general rule, we recommend no habitat alteration between April 15 to August 15," she said. "But if there is habitat alteration and birds are not harmed, that is not against the law."