ARBORETUM NEWS (NATURALISTSNOTES)

Early Spring Migrants

SUNDAY, MARCH 30, 2014

What a long cold and snowy winter! Today could be the first 60 degree day since last October, almost five months of cold. Not only did we have more than our usual amount of subzero days, but we had more than 10 inches of snow above average. Everyone seems to be tired of winter and anxiously awaiting the arrival of warmer spring weather.
So how do spring migrants respond to this colder and snowier long winter? Just about the same as they usually do. Robins are one of the first noticeable early migrants to show and sure enough you could step outside during the last week of February or early in March to hear a chorus of Robins calling, in spite of the solid cover of snow. Sandhill Cranes returned within a few days of their usual arrival date. Hearing the calls of Cranes and Robins was a precursor that spring weather was coming, even though the early birds this year were seen walking around on our plentiful snow.
Birds are often more influenced by lengthening day light than by immediate weather conditions, such as our prevalence of snow. As dawn has gotten steadily earlier and sunset a few minutes later each day, the number of spring migrants has steadily increased. Yesterday the call of newly arrived Bluebirds could be heard across Longenecker Garden. Our resident pair of Sandhill Cranes was observed walking on the fire lane on the east side of Curtis Prairie, while additional Cranes were heard calling. The Woodcocks have been doing their “sky dance” displays in Curtis Prairie for a couple weeks now. It is hard to imagine these early arriving ground feeding birds probing through the snow into the still frozen ground to feed on worms, which have not yet made an appearance. Hopefully the ground will thaw out a bit with this warmer 60 degree weather and the worms will appear so the woodcocks can feed.
A trip to lower Mud Lake near McFarland revealed lots of early spring migrating waterfowl are congregating in one of the few bodies of open water in Dane County. The current of the Yahara River opens up Mud Lake much earlier than the other still frozen lakes in the Madison area. Among the numerous waterfowl are lots of Pintails, Scaup, Widgeons, Redheads, Mergansers, Buffleheads, Goldeneyes and even a few big White Pelicans. Several juvenile and adult Bald Eagles were taking advantage not only of the open water to go after fish, but also the plentiful duck dinners now available.
Another large white bird, not easily confused with the White Pelicans, are the remaining Snowy Owls. This has been a banner winter for Snowy Owls all across the eastern United States and Wisconsin has had its fair share. At times four to six Snowy Owls could be seen at one time right in Rural Dane County. I spotted one on top of a utility pole just this week. The question everyone is asking is when will they leave to return north to the arctic tundra? My hunch is as long as food is more plentiful here we will still have a few Snowy Owls. What a treat to have these majestic Snowy Owls to brighten our long winter.
Of course, some migrants have yet to return because their food supply is not yet available. One normally early spring migrant, the Phoebe, is an insect feeder. With virtually no insects out yet, the arrival of Eastern Phoebes seems to be delayed by at least a week or two. The insect eating swallows have not yet arrived either. It will probably be another month, toward the end of April or even early May, before the big influx of the insect eating warblers, vireos and other Neotropical spring migrants arrives.
So with the arrival of some early spring migrants and our first 60 degree day in over five months, it is finally beginning to fee and sound like spring is here. Do not be too quick to put away your winter coat. The forecast for next week includes some colder days and maybe even some April snow!
Levi Wood, Arboretum naturalist

Located between Lake Wingra and the West Beltline Highway at 1207 Seminole Highway, the University of Wisconsin-Madison Arboretum features the restored prairies, forests and wetlands of pre-settlement Wisconsin. This 1,260-acre arboretum also houses flowering trees, shrubs and a world-famous lilac collection. Educational tours for groups and the general public, science and nature-based classes for all ages and abilities, and a wide variety of volunteer opportunities for groups, families and individuals are available.