For the first time in 108 years, Iowa has a documented nest occupied by swift, fierce and graceful merlins.
“This is very cool, very exciting,” said Department of Natural Resources wildlife diversity technician Bruce Ehresman, who traveled April 17 from Boone to Iowa City to see the small falcons.
Though merlins have been wintering in Iowa for several years, Ehresman said the state’s last known merlin nest was recorded in 1908 in Linn County.
Ehresman said the merlins took over a crow’s nest in a tall spruce tree near a cemetery on the northeast side of Iowa City.
“If you fed their nesting requirements into a computer, it would spit out, as an ideal site, something very similar to the spot they’ve chosen,” he said.
The Cornell Lab of Ornithology’s website includes the following statement about their nesting preferences: “Merlins are increasingly breeding in towns and cities, where they often take over crow nests in conifers planted in residential areas, schoolyards, parks, and cemeteries.”
Dan McRoberts, who lives near the nest, was the first to identify the birds as merlins.
McRoberts, who worked as a park ranger before becoming a schoolteacher, said he had studied and observed raptors as a hobbyist during stints in Utah, Colorado and Alaska.
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While he and his wife were walking in late March, the merlins flew directly overhead. Their narrow pointed wings, their size (similar to a pigeon) and their calls aided their identification, he said.
The crows did not cheerfully abandon their nest to the merlins, according to McRoberts.
“A murder of crows harassed them for several days. They were really harried, and I thought they would move on. Then the crows cleared out,” he said.
McRoberts said he first noticed the merlins copulating on April 11. Though the female is spending more time in the nest, it’s not clear whether the merlins have begun incubating eggs, he said.
The merlins’ long absence as Iowa nesting birds “came as a complete surprise to me,” said McRoberts, who teaches second grade at Horace Mann Elementary School.
Though pesticide contamination reduced merlin numbers in the 1960s, their population has since stabilized and increased, according to the North American Breeding Bird Survey.
Larger than kestrels but smaller than peregrine falcons, merlins rely on speed and agility to prey on slower and less maneuverable birds.
Raptor expert Jon Stravers of McGregor, who has netted and banded thousands of raptors in his lengthy career, said merlins are the hardest to catch. “They have some kind of a fifth gear. They just come ripping in,” he said.
Given their relation to larger falcons, it’s not surprising that “they fought off crows to defend and claim a used nest,” said John Howe, executive director of the Raptor Resource Project, which was instrumental in restoring peregrine falcons to their native cliff top aeries in the bluffs of the Upper Mississippi River.