The most significant weather system this season passed through southern Minnesota in late March, spawning tornados and hail storms that killed or injured hundreds of birds, primarily waterfowl and raptors. Otherwise, generally unremarkable weather resulted in generally unremarkable migration. Passerines were suspected of direct overflight to their breeding grounds after encountering severe weather conditions to the south of Minnesota. The month of May especially had many days of clear skies, no rain, and southerly winds.

Lake Superior produced several Red-throated Loons as usual but the Pacific Loon in Duluth was unexpected, since all but three previous occurrences on Lake Superior have been in fall. May records of the Clark's Grebe are becoming routine, even as the differentiation of this species from Western Grebe remains anything but so; individuals that are intermediate between Clark's and Western have been known to occur but are rarely documented as such in Minnesota. Compared to recent years, reports of the Snowy Egret were up significantly and stretched all the way to Kittson County! Only two Little Blue Herons were found. For five consecutive springs Cattle Egrets have remained relatively scarce compared to the excellent showing of spring 1993. In Meeker County, one White-faced Ibis was identified with certainty. The flock of seven Plegadis at “the Great-tailed Grackle spot” was probably this species as well, but prudently was found acceptable only at the genus level.

The single Black-bellied Whistling-Duck in Steele County appeared wary and presumably remained in the same slough for over a month; unfortunately, word did not get out to the birding community until late June. There has been a steady increase in extralimital reports throughout the 1990s (The Loon 67:247–248) and its arrival date is congruent with May 1998 records in Iowa and Wisconsin. Based on reports from at least 13 counties this spring, the Ross's Goose is firmly established as a Regular species. Astute observers are providing high counts, locations, and dates for peak waterfowl migration. After the unusually warm winter of 1997–98, distinguishing early migrants from overwintering waterfowl becomes virtually impossible.

An adult Mississippi Kite flying over refuge headquarters at Agassiz NWR was most unexpected. Frank Nicoletti conducted the second spring census of raptor migration from 24 February – 29 May at Enger Tower in Duluth; highlights included a subadult Mississippi Kite, another Red-shouldered Hawk (one was seen last year in late May), an immature dark-morph Broad-winged Hawk, 16 dark-morph Red-tailed Hawks, and several “Harlan's Hawks” among the total of 7,795 raptors seen during 435.5 hours of counting on 87 dates.

Virginia Rails arrived much earlier than normal in several locations. Like last spring, only two reports of the Common Moorhen were received. Apart from the variety seen at Agassiz NWR and various first county records, shorebird migration was unremarkable. No Piping Plovers were detected as migrants; the only report was from their last known breeding site on Pine-Currys Island. The counts of 20 and 19 American Avocets are noteworthy; most of Minnesota's high counts occur during spring migration (The Loon 70:11–20). Peak numbers of the Wilson's Phalarope in northwest Minnesota were somewhat encouraging.

At least two Parasitic Jaegers were seen off Park Point over a two week period in late May; although still expected only in fall, jaegers have now been reported in seven out of the past ten spring migrations. For the fifth consecutive spring, the Little Gull was not found in Duluth, where it formerly occurred regularly. The only report was from Minnesota Lake, where an adult had been seen one year earlier. One or two adult Black-headed Gulls were found in the general area where they have occurred on both sides of the Minnesota-Iowa border in the past (Kent and Dinsmore 1996, Birds in Iowa, p. 178). Several other unusual larids were found, including two California Gulls in the northwest region. The early movement of gulls noted by Bardon (see winter report) resulted in unusually high numbers of Herring and Thayer's Gulls in the Twin Cities area during March and into April, along with three Iceland Gulls. Another Iceland Gull and a first-year Great Black-backed Gull were both later than usual in Duluth. On the early side, a well-documented Forster's Tern was found in Houston County on 28 March!

The serendipitous discovery of Minnesota's first Eurasian Collared-Dove recalls the adage “chance favors the prepared mind.” As the story goes, the observers stopped to orient themselves using a Big Stone County map and noticed an unusual-looking dove feeding on the ground! The North American population is expanding exponentially and more Minnesota records are a certainty. The apparent decline in numbers of Short–eared Owls noted last spring continued into 1998. Nocturnal surveys for calling Boreal Owls in northeastern Minnesota were disappointing.

For the second consecutive spring, a Say's Phoebe was discovered in Clay County. Although its status remains Casual in Minnesota, this species is a good candidate for nesting in western regions; it has nested in North Dakota as close as the city of Grand Forks (1994) and in rural Cass County (1990 and 1991). Nesting has never been confirmed in Minnesota, although it was suspected at Blue Mounds State Park in 1974 (The Loon 47:13–15). The two Scissor-tailed Flycatchers were an unusual number for spring. The Bewick's Wren in Sherburne County attracted many observers during its eight week stay; the last state record (1990) was in the same county. The total of seven Northern Mockingbirds was identical to last spring's excellent showing.

Except for record early Blue-winged, Black-throated Green, and Pine warblers, plus several first county records, there were few noteworthy warblers. Only one Summer Tanager was reported; in recent years, the Western Tanager has actually been easier to find! The late April/early May migration pattern of the Spotted Towhee through the southwest region appears well established, but its status elsewhere in the state during spring migration remains poorly understood. The two Field Sparrows found along the North Shore were unexpected, as was the Chestnut-collared Longspur in northern St. Louis County. The small colony of Great-tailed Grackles straddling the Minnesota-Iowa border at Grover's Lake Wildlife Management Area in Jackson County is destined for infamy; the only two previous Minnesota records (June 1982 and April 1993) involved single birds. Continuing a pattern from the winter season, White-winged Crossbills persisted farther south than usual and Hoary Redpolls were widely reported but rarely documented.

Readers and contributors to “The Season” will have noticed that records of Empidonax flycatchers during spring and fall migration are generally not published unless the birds are vocalizing. This is a concerted effort to improve the accuracy of our database. Similar efforts are underway to minimize confusion among the Catharus thrushes in April and the Troglodytes wrens in early spring. Documentation will also be requested routinely for Regular species that may be difficult to identify and for those species with borderline Regular/Casual status in Minnesota. Regular species for which details are needed are shown in boldface type on the seasonal report form, and further instructions are given on the first page of the form. The compilers and editors want to include your records, so please document them!

Unconfirmed and Undocumented Reports: Mississippi Kite in Duluth, adult California Gull in Lac Qui Parle County, White-eyed Vireo in Hennepin County, Yellow-throated Warbler in Hennepin County, Worm-eating Warbler in Goodhue County. This section does not include records found Unacceptable by the Minnesota Ornithological Records Committee.

Temperature and Precipitation Summary: Temperatures in March were close to average except in northern regions where it was 2.4–2.9 degrees warmer than usual. April and May were both significantly warmer than normal in all nine districts, as reported by the Minnesota Extension Service and the State Climatology Office. April was 4.0–6.6 degrees above normal throughout the northern and central regions, while the statewide average for May was 5.8 degrees above normal! Although April was slightly on the dry side, the rest of the season had near normal precipitation. The greatest departure from normal was in the northwest during May, where rainfall was about three inches above the long term average.

Acknowledgments: Frank Nicoletti provided a summary of the spring hawk watch in Duluth. Kim Eckert and Anthony Hertzel summarized reports called in to the MOU “hotlines” in Duluth and the Twin Cities, respectively. Median arrival and departure dates were calculated by Paul Budde.