The Linnaeus Arboretum, located on the campus of Gustavus Adolphus College in St. Peter, might not be on many birders’ radar in terms of a Minnesota birding hotspot. True, it’s a public garden space surrounded on all sides by human development, from large academic buildings to suburban houses and apartments to agricultural fields.
I would being doing the location a disservice, though, if I didn’t include it on my list of favorite birding areas. Having spent seven years at Gustavus (four as a student and three as arboretum naturalist), I’ve birded the arboretum on countless days at all times of the year and amassed a birdlist comprising 174 species — not bad at all for an area comprising 125 acres. Granted, the Linnaeus Arboretum boasts a variety of habitats; deciduous forest, coniferous woods, cattail wetlands, and even a 70-acre tall-grass prairie are all found in the arboretum in addition to the formal gardens and tree collections. Throughout my career at Gustavus, I’ve been privileged to showcase this landscape to thousands of visitors, and have led birding hikes for a vast number of groups of all ages and interests.
As Gustavus Adolphus College sits on top of the western ridge of the river valley, anywhere in the arboretum can be a good spot for viewing migrating birds as they follow the Minnesota River flyway in both spring and fall. Beginning in early to mid-March, Bald Eagles are common sights above the arboretum (and the rest of campus) as they follow the river north; other raptors — including Red-tailed Hawks and Turkey Vultures — join them by the third week of March. Goose flocks soon follow; and while Canada Geese are still the most commonly sighted, flocks of Greater White-fronted and Cackling Geese are annual sights as well (in addition to a flock or two of Tundra Swans). The last week in March is usually a good time to see hundreds (if not thousands) of migrating American Robins across campus; look for them (and Cedar Waxwings) feeding on residual crabapples in the arboretum. In early April, watch for returning Yellow-bellied Sapsuckers, Eastern Phoebes, and Eastern Bluebirds flitting around the scattered trees south and west of the Interpretive Center (this area attracted a singing Eastern Meadowlark that stuck around for a month in 2006), and by mid-April several sparrows begin showing up as American White Pelicans, Double-crested Cormorants, and both Great Blue Herons and Great Egrets can be observed in the skies overhead. In late April, Brown Thrashers become nearly abundant in the arboretum as the birds forage across the lawns with Northern Flickers and the occasional Hermit Thrush.
The floodgates of spring open up in May, and migrating sparrows — including White-throated, Harris’s, and White-crowned — peak during the first week (look for them especially at the feeders behind the Interpretive Center). By mid-May you should be able to find a nice assortment of species throughout the arboretum; a walk along the wooded trails north of the Borgeson Cabin can produce a variety of warblers in addition to migrating flycatchers, thrushes, and other passerines. For some reason, the treeline between the woods to the east and the Coneflower Prairie to the west attracts a singing Lark Sparrow or two each May, as Indigo Buntings begin to show up in the same area toward the end of the month. Even the small wetlands have produced some interesting birds in May, including an American Bittern in 2006 and a calling Sora in both 2007 and 2010.
Fall migration can prove just as exciting, although as in other locations the return trip appears to be more gradual for most species instead of peaking within a single week; late August to mid-September is more or less the mirror image of mid- to late May for migrating songbirds in the arboretum. Particularly of interest in fall however is the Coneflower Prairie; similar to other prairies in southern Minnesota, this grassland holds its share of migrating sparrows in early to mid-October (including 19 Le Conte’s Sparrows observed in 2010 during the second week of October). In early November, check the coniferous woods west of the Jones Northern Forest Ponds for roosting owls; Great Horned, Barred, and Long-eared Owls were all present here for at least a few days at this time in 2010 (listen for the mobbing calls of Black-capped Chickadees and both White-breasted and Red-breasted Nuthatches to direct you to them).
I’ve also seen my share of rare birds in the Linnaeus Arboretum, in case the above still hasn’t convinced you to make a visit. These include: an adult Northern Goshawk flying over the arboretum in January 2005, a Golden Eagle flying over the Interpretive Center in October 2004, a White-eyed Vireo behind the Interpretive Center in November 2008, two Northern Mockingbirds four years apart from each other in almost the exact same location south of the Borgeson Cabin in 2005 and 2009, a breeding-plumaged male Smith’s Longspur in the Coneflower Prairie in April 2011, Red Crossbills in late October/early November in 2004 and 2006, a flock of up to 45 White-winged Crossbills during the winter invasion of 2008-2009, and a Hoary Redpoll at the feeders behind the Interpretive Center in March 2009.
Bob’s birdlist from the Linnaeus Arboretum:
Greater White-fronted Goose
American White Pelican
Great Blue Heron
Great Horned Owl
Great Crested Flycatcher
Northern Rough-winged Swallow
Cape May Warbler
Black-throated Green Warbler
American Tree Sparrow
Le Conte’s Sparrow