Radar shows large migration in Minnesota, Wisconsin and N. Dakota last night

This is a capture from all of the midwest radars from about 5:00 am this morning when migration was winding down for the night. Many birds migrate at night for several reasons. It is colder so they don't overheat as easily, they are less likely to be preyed upon and under clear night skies the stars can be use as navigational aids.

The circles on the map represent large flocks of birds migrating past doppler radar sites. There are a couple of interesting things to note. First off, the migration last night seemed to be heaviest in Minnesota, Wisconsin and North Dakota. At first I was thinking that this could be good news for bird watchers looking for new migrants. However, that explanation doesn't make sense. We haven't seen many of the migrants yet as they are still further south. I think what we are seeing on the radar is primarily migratory waterfowl heading further north out of the states and up into Canada.
it is also interesting to take a close look at the the Green Bay and Duluth radar returns. They show that the birds do not like to travel over the open water of the great lakes but rather prefer to follow the shoreline.

This all stands in contrast to tonight's current radar composite which as of 9:15 pm CDT shows massive migration movements in the South Eastern US and very little in the upper midwest.

~Kirk

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19 More birds for the year list...

Wow time for a birds year-list update again. I last wrote about my year-list on March 24. Now, 19 days later I've added 16 more birds to my list. Migration anyone?

March 28
With a spare hour in my day I headed out to Reservoir Woods in Roseville. In a quiet pond I discovered my first Wood Duck of the year. There were also mallards and hooded mergansers in the same pond.

March 29
The 29th was a fun day a work. We took a little hike down to the lake and saw the first Golden-crowned Kinglet of the year. I also saw my first of the year Sandhill Crane which was fun as I'd been hearing them for weeks. It looks like they are going to nest on site again this year.

March 30
The next day saw the return of the Eastern Phoebe to Warner Nature Center which is always a sure sign that spring migration is beginning to pick up. The same day while taking our volunteers on a training hike I saw the first of the year Turkey Vulture fly overhead.

March 31
On my way home I saw the first of the year Great Blue Heron dropping into a wetland.

April 1
I'd been keeping my eyes open and finally one morning spotted the first of the year Fox Sparrow scratching around under the birds feeders.
That same evening I happened to drive past the Colonnade Building on hwy 394 and could make out a Peregrine Falcon hanging out on a ledge. My drive happened to take me through the 169 & 62 overpass and I was sure to check out the Osprey nest on top of the highway lights there. Sure enough, there was an Osprey on the nest.

April 4
While at my aunt and uncle's house in Eagan on the weekend I saw a migrating raptor land in a tree in their back yard. When it flew off it was below us and we could clearly see the white where the tail meets the rump that signaled we'd just seen the first of the year Harrier.

April 5
Always a good day when you can add three birds to your year list. I saw Tree Swallows on the way to work and an American Kestrel on the way home. Both were hunting from rural power lines. While on a hike in the middle of the day I found a Winter Wren sulking around under some brush.

April 7
Not exactly my favorite bird but still fascinating in the evolutionary adaptations, Brown-headed Cowbirds showed up on the 7th.

April 10
Surprising but true, I didn't see my first Purple Finch of the year until April 10. I also saw a Common Goldeneye while showing kids how to use a spotting scope on a hike.

April 12
We headed down to the lake today at work to put our solar powered pontoon boat into the water. While we were down there four fighter jets came over the nature center very low. They circled around four or five times and we realized they were getting into formation for the fly-over of the Twins season opener in the new stadium. After the jets left we saw the first of the year Northern Shoveler on the lake. There was a small group of them. They were the first ones we've seen in many years. There were also a couple of Killdeer which is a species I hadn't see yet. On the way back to the building I also saw my first of the year Yellow Bellied Sapsucker.

All told for the year that brings me up to 62 species of birds within the state of Minnesota and a good chunk of migration is still to come.

~Kirk

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Phoebe Nest Cam Preview

Every year we have Eastern Phoebes that nest at the nature center where I work. I know of at least five locations where they nest on the property and I'm sure there are more. The photo above is of an Eastern Phoebe shortly after it showed up this spring. I took this photo out the window of our front entry way. I was excited to see a phoebe in this tree as it is the closest tree to a nest that has been occupied for several years. This is also the nest we have wired up with a nest camera in a joint project with the Cornell Laboratory of Ornithology.

The camera is not "live" yet but I have access to the images. I thought I saw the bird fly to the nest on April fifth but by the time I got to the computer to look there was nothing on the nest.

I checked an hour later and it did look like some things had been moved a bit. Interesting but not conclusive.

This time of year the phoebes are still checking out possible nest sites. Eastern Phoebes are one species that will reuse nests from previous years.

This morning, one of our naturalists, Kelly Amoth, came to me and said she had just seen a bird fly to the nest. I quickly brought up the webpage and sure enough there was the bird. It was captured on at least three screen grabs and the camera takes them every 20 seconds.



This is a good sign and I hope the pair of birds hanging out near this nest choose to use it.

I'll be sure to keep everyone up to date on what happens with the nest.

~Kirk

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First Spring Wildflowers

Spring is blooming. I snapped these two photos today of the first spring wildflowers I've spotted. Above is a Trout Lily. I just love these little flowers. I think their leaves are even cooler than the flower. Earlier this week people began to see Rue Anemone blooming along the trails and I was finally able to get out and see it. Here it is below. The delicate flowers eventually fade to white.

I took these photos with the new cameras we got for my digital nature photography summer camp I teach. I think they will work well. Woodland wildflowers are a passing friend in the year. They bloom early before the leaves come out on the trees and then fade away. It is a wonderful example of evolution in action. I also saw the beginnings of cranesbill a.k.a. wild geranium on the trails and it should be blooming before long. The magnolia in my yard is about to bloom as well. Maybe tomorrow or this weekend. The flowers have already started to open. Welcome to spring!

~Kirk

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Today's Solar Storm Could Affect Bird Migration

At 0800 UT, (1:00 am Central Standard Time) a large burst of solar wind hit the earth and triggered the largest geomagnetic storm of the year thus far. There are a couple of scales to measure how big a disturbance it created. One of them is the Geomagnietic Storm scale used by the NOAA. On this scale, the burst registered as a G3 or a "Strong" storm. (G5 is the strongest.) A burst this strong can cause aurora as far south as 50° longitude! Unfortunately for sky watchers tonight, the storm looks like it has subsided from "strong" category so probably no aurora in the Twin Cities or other mid latitude cities tonight. Activity has already fallen to G1 or Minor level. Here's the graph of the storm strength from the NOAA/NWS Space Weather Prediction Center.

It is interesting to note that the storm peaked at night just as many birds were migrating. Why is this important? While reading up on the scale I learned that even at the minor level, migratory animals are affected by geomagnetic storms. Birds can sense the magnetic field of the earth and use it for navigation during migration. Geomagnetic storms disturb the field and confuse birds who rely on it as a navigational aid. Since spring migration is starting to gear up I wonder what effect this storm will have on birds heading our way? Could we end up with some strange migrants who get off course?

The effects on migration would likely be temporary as birds use multiple tools to aid navigation. Birds migrating under daytime overcast skies with no sun are most likely to be affected. If a magnetic storm remains at level G1 or higher AND there is persistent cloud cover we could expect some birds to get off course. The longer it lasts, the further off course they could become. The afternoon NOAA GOES satellite image of visible could cover did show cloud cover over a good portion of North America while the storm was still at G1 levels.

For night migrants, cloud cover isn't an issue. Multiple research studies have shown that when geomagnetic information and celestial information disagree, the geomagnetic information is dominant which is bad news for migrating birds under clear night skies during a geomagnetic storm. It looks like as of sunset tonight the storm has subsided so birds are in the clear for tonight. Hard to say when the next big storm will come.

~Kirk

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Which sub-species of Fox Sparrow do you have?

The fox sparrows showing up this week got me thinking about these fascinating birds again. Did you know that there is a lot of disagreement over this chunky sparrow? Is it one kind of bird or many different closely related species? The AOU currently recognizes 18 sub species.

Minnesota's own Robert M. Zink at the Bell Museum of Natural History has taken a very close look at these migrants that show up each spring. He wrote the page turner, The Geography of Mitochondrial DNA Variation, Population Structure, Hybridization, and Species Limits in the Fox Sparrow (Passerella iliaca). If you subscribe to JSTOR or happen to have issue Volume 48 issue 1 of the Journal Evolution from 1994 sitting around then you too can read all about subtle differences in the DNA of Fox Sparrows from around the country. More recently he published The recent Evolutionary History of the Fox Sparrows which was published in the AUK in 2003. Wonderfully, you can download this as a pdf for free from the Field Museum. I learned that according to analysis of DNA, Spizella arborea or the American Tree Sparrow is the closest relative of the fox sparrow. Makes sense. Back to the fox sparrows...

I look forward to seeing Fox Sparrows each spring and I love their foraging behavior of scratching at the ground with little backwards jumps. I took this quick and dirty video of the first fox sparrow to show up under the feeders at work.



As I hinted at before, there's some disagreement it seems about which species of bird is in the video above. "Officially," meaning according to the AOU, there is only one kind of Fox Sparrow. The scientific name is Passerella iliaca. There are four generally accepted sub-species however. Now depending on whether you are a splitter or a lumper this will either excite you or make you say, "Here we go again."

The four major sub-species of Fox Sparrow are:

• The Red Fox Sparrow (P. i. iliaca ) Generally central and east coast. This is the brightest red thus the name.
• Slate-colored Fox Sparrow (P. i. schistacea) Found in the Rocky Mountains. It has a tiny bill with a gray head and mantle, brown wings, brown breast streaks, and a russet tail.
• Sooty Fox Sparrow (P. i. unalaschcensis) Found on the west coast. It is generally browner than the Red Fox Sparrow.
• Thick-billed Fox Sparrow (P. i. megarhyncha) Found in the Sierra Nevadas. It has a particularly thick bill, thus the name.

So clearly what we have here in Minnesota is a Red Fox Sparrow right? Well, kind of. Research such as that done by Zink reveals that the "Red Fox Sparrow" is actually made up of even smaller groups. There are actually two distinct groups, the Eastern Fox Sparrow (Passerella iliaca iliaca) and the Yukon Fox Sparrow (Passerella iliaca zaboria). What's the difference? The Yukon has a browner malar stripe and a grayer head. That's in general. It can be very hard to distinguish them in the field. Range is probably the best way for the general observer to tell them apart.

So, which do we have in Minnesota? We're close to the divide but in general it seems the birds in Minnesota and to the west are Yukon Fox Sparrows while birds in Wisconsin all the way to the east coast are Eastern Fox Sparrows.

If you're a life lister, be sure to note fox sparrows you see in other parts of the country. They may some day be split into separate species.

~Kirk

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Foxy

I'm happy to report that the Fox Sparrows finally showed up this morning. In honor of their arrival, here's some Jimi Hendrix.



~Kirk

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