Friday, April 30, 2010

First Robin Egg of the Year

Posted by Kirk


You may have read earlier in the week how some robins at work built a nest in an interesting location. They put the finishing touches on this nest on Monday and I've kept an eye open for any signs of activity at the nest. Today we saw the female sitting on the nest some so at the end of the day I went to have a look at the nest. Sure enough, she had laid the first egg.


Because the nest is a little above eye level the easiest way to look inside is with a mirror. This is a little pocket mirror I can hold but for even higher up nests we have a bike mirror mounted on a pole. It works like a charm.

If you have a nest in your yard this spring and would like to take part in some Citizen Science you can help researchers learn more about birds though Cornell's Nest Watch Program. Warner Nature Center locally is a training site for Nest Watch as part of our partnership with Cornell.

You can get certified to be a nest watcher online and then submit your data so it can be part of the effort to better understand birds. Not only is nest monitoring interesting and personally rewarding but you can help everyone understand more about our feathered friends.

Happy nest watching.

~Kirk
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Tuesday, April 27, 2010

Phoebe Day 3: No new egg?

Posted by Kirk
I was teaching all morning so I didn't have time to check out our Phoebe Webcam before heading off to a local school. When I returned, I checked the image expecting to see a third egg. Songbirds typically lay one egg per day and do so in the morning. When I checked the camera all I saw was a bird. The phoebe was on the nest.


Or so it seemed. The time stamp on the image seemed to be about 15 minutes off. I waited twenty seconds and refreshed the image but sure enough, it was frozen. I went down to nudge the computer that uploads the images and when I did I could see the live image below.


There are still only two eggs in the nest. Why didn't the phoebe lay a third egg this morning? When I spoke with staff who were on-site all day they indicated that the phoebe had spend much of the day sitting on the eggs and moving them around. It would seem incubation may have begun. Usually birds do not sit on the eggs until all of them have been laid. This way, incubation starts at the same time and they all hatch at the same time. Why start incubation with only two eggs? A usual clutch size is four or even five eggs. Because the old nest in this location fell down, the phoebes had to build a new one. Building a new nest is energy intensive and in some cases can mean a reduced clutch size. Two eggs may be all we get in this nest.

I did notice two male and two female Brown-headed Cowbirds hanging out in a tree very close to this nest. Cowbirds lay their eggs in other bird's nests. There's a good chance that if another egg does appear it will be from a cowbird and not from the phoebe.

Check back to find out. Tomorrow morning should be interesting.

~Kirk
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Monday, April 26, 2010

Robin Nest: location, location, location...

Posted by Kirk 2 Comments
When I came into work this morning I noticed something odd. There is a fly though feeder right outside the front door to the nature center and something was different about it. There was a nest inside.

I hadn't noticed it at the end of last week and when I talked to staff who had been there on Saturday they hadn't seen the nest either. I quick look confirmed that it was indeed the nest of an American Robin. There were robins hanging around the feeder on Saturday so they were probably just starting to build. I'm amazed how fast they put this together. According to The Birder's Handbook: A Field Guide to the Natural History of North American Birds, both the male and female work together to make the nest which could account for how quickly it was built. The female lays between 3 to 7 eggs with 4 being average number. The eggs are incubated between 12 and 14 days and the birds fledge from the nest 14 to 16 days later.



What a great location. Robins have adapted very well to human structures but this one seems pretty ideal. It even has a roof and a great view. It is tempting to make some joke about nesting close to food seeing as how the nest in literally IN a bird feeder but baby robins eat insects and adults dine on larger items such as berries and works. It will be fun to monitor the nest and watch the young birds fledge. I used a mirror to look in the nest today and there weren't any eggs yet. The mud was still wet. This nest is about 15 feet from our active Eastern Phoebe nest which we have a nest cam on. It will be a fun spring watching these two nests. I'll keep people posted on this one as well.

~Kirk
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Two Eastern Phoebe Eggs in the nest.

Posted by Kirk
I had my suspicions when the mother was roosting on the nest all weekend. Sure enough when I got into work this morning there were two eggs in the nest.


Eastern Phoebes lay one egg per day, usually in the morning. This means that one of these eggs was laid this morning (Monday) and one was laid yesterday (Sunday.) Eastern Phoebes typically lay four to five eggs. It should be interesting to watch the nest for the eggs of Brown Headed Cowbirds. This particular nest site was parasitized by cowbirds last year and while walking in to work this morning I could hear cowbirds calling very near this nest.

Brown-headed Cowbirds do not make their own nest, rather, they lay their eggs in other birds nests so the other bird will raise their young for them. Last year the Eastern Phoebe must have realized there were too many eggs in the nest because she kicked two eggs out of the nest. Unfortunately, she picked the wrong two eggs and threw out two of her own.

We'll see what happens this year.

You can also follow our Eastern Phoebe nest on Cornell's NestCam site.

~Kirk
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Saturday, April 24, 2010

Eastern Phoebe Webcam shows bird now sleeping in nest...

Posted by Kirk

I just checked the webcam on our Eastern Phoebe nest and it looks like the female phoebe is now sleeping in the nest at night. In case you are wondering, the camera is equipped with infrared lights so we can see the nest at night. Will she lay an egg tomorrow? It should be soon now. I'll be posting regular updates from egg laying through fledging. Be sure to stay tuned!

~Kirk
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Friday, April 23, 2010

Junior Duck Stamp Contest Winner Revealed!

Posted by Kirk
I had the pleasure of attending the 2010 Junior Duck Stamp Competition finals today. Here's a round-up.

The event was held at the Science Museum of Minnesota. This was only the second time in the history of the competition that it was held outside of Washington D.C. There were approximately 200 people in attendance.


All of the works being judged today were by kids who had won their respective state competitions so as they pointed out many times. Everyone who had their work in this part of the competition was already a winner.

When the event began, all 53 of the final works of art were laid out on long tables. The judges and the public were welcome to take a close look.


In the first round of judging, the judges could each place a poker chip on five different pieces. If any one judge voted for the piece it went on to round two. Below is a nice painting of a Ring-necked Duck painted by Christine Swanson from West Lynn, Oregon. You can see one of the judges has placed a chip on it so it made it to the next round.
With five judges each placing five chips, the end of the first round brought the total down to 25 still in the running.

For the second round, the judges could each place two chips which cut the finalists down to just 10 paintings. For the third round, each judge could only place one chip which would mean only five would progress to the final round. Here the judges are inspecting the ten works and trying to decide which five should advance.


One thing to notice is that they all have what appears to be magnifying glasses in their hands. This is not the case. The hand lenses they have to not magnify the image, they shrink it. Some of the painting the kids did were simply stunning paintings but they may not have been the best choice for a duck stamp. Let's look at an example. I mentioned in my earlier post that I love this painting by Jiwon Shin from New Jersey.


The work itself is magnificent and if I had to strictly grade the quality of the work in a regular painting contest I would say it just edges out Christine's painting shown above. However, look at what happens when you shrink the images to the size of the duck stamp.



Suddenly they look very different. When they are the size of the actual stamp, it doesn't matter how detailed the one on the right is, the bird has become hard to see against the busy background. The simpler background in the first one makes the bird much more striking. This is why the judges use the shrinking hand lenses. They need to see what the image will look like as a tiny stamp. This is no ordinary art contest. Forgetting that the image will be small was probably the biggest mistake that took paintings out of the running.

The forth round was based on scores. The five works were paraded past the judges one by one. They then had to give it a score, 1-5. After all five were scored, the one with the highest points won. Here's the judges scoring the piece that eventually won.


Those numbers total up to 23 which was just one more point than the second place finisher.

And the winner was...

This wonderful painting of a male Hooded Merganser by Rui Huang from Ohio.



This painting got the highest score. Four of the five judges gave it a 5 while one judge gave it a 3.

After the event I had an opportunity to talk to the judge who gave it a 3 to find out why his score differed and it shows an interesting insight into how judges look at the work. He really liked the winning entry but he pointed out that while the painting is wonderful it had what he considered a sort-of natural history issue. The Hooded Merganser pictured is shown in beautiful breeding plumage. Breeding plumage appears in the spring but the leaves shown along with the bird are clearly autumn leaves. From an educational standpoint he felt that detracted some from the image and he preferred the second place image that showed both the male and female hooded merganser. Word to the wise, these are the kind of details judges take into consideration.

The event was fantastic and it was wonderful to see so many talented young artists from across the country. Be sure to buy your duck stamp even if (especially if) you are not a hunter. Funds from the duck stamp program raise about $25 million each year to fund wetland habitat acquisition for the National Wildlife Refuge System. Every stamp counts. Even if you only hunt these birds with a camera or binoculars, everyone should help out preserving the habitat that where they live.

~Kirk
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Thursday, April 22, 2010

April 2010 Twin Cities Naturalist Podcast

Posted by Kirk
Back from a short Hiatus, the Twin Cities Naturalist Podcast returns! Thanks for listening to this month's show. We discuss phenology, interview a special guest, do the community calendar and of course, there's the trivia challenge.

You will need the newest version of Flash Player installed on your computer to see and use the podcast player.




If you have flash installed already the player will appear below.




On the show this month our special guest is Ron Windingstad of Audubon Minnesota. Ron talked with us about the Chimney Swift Conservation Project.

Events mentioned on the Community Calendar are:
Wishes for the Sky, April 25
Kids Bird Watching Fair on May 8th
Urban Birding Festival of the Twin Cities May 13-16

~Kirk & Paul
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Wednesday, April 21, 2010

Leucistic American Robin Photos

Posted by Kirk 4 Comments
One of the fun things about my job as a naturalist is that people send me photos of what they are seeing in their neck of the woods and people do see some wonderful things.

Ann, who lives in Forest Lake, Minnesota, sent these two photos of a rather interesting looking American Robin that frequents her yard. It has a white back, white tail, white wings, white head, etc. yet is clearly an American Robin.

This is known in the scientific realm as a partially leucistic American Robin. What I find fascinating is that I've actually seen a robin with nearly the exact same pattern of leucism before. There are dozens of examples of this particular pattern online. See here, here, here, here and here for just a few examples.

So why isn't this an albino robin? Well, many people would argue that it is. They would use the term "partial albino" but technically albinism is a genetic condition that wipes out the body's ability to create the pigment melanin. Since albinism is genetic it is always systemic, i.e. affecting all of the animal. Ann's photos clearly show that this is not the case.


If this was a true albino, it would also have white legs, white beak, and white breast. It would also have those famous pink albino eyes. None of this is true for this bird. Especially noticeable, the breast is the normal rusty red color of an American Robin.

How do we get a partially white animal then? Enter Leucism. Leucism results from defects in pigment cells. It can affect just one cell or all of the cells on an animal. This means we can get a bird with just one odd white feather or, as in this case, lots of white feathers. We can even get a leucistic bird with all white feathers but normal colored eyes, beak and legs.

For more reading on color aberrations in birds you can download my favorite and oft cited journal article on the topic, Not Every White Bird is an Albino: Sense and Nonsense About Color Aberrations in Birds by Hein van Grouw. Wonderfully, it is available for free download.

~Kirk
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Tuesday, April 20, 2010

Simply Stunning Juinor Duck Stamp Entries!

Posted by Kirk
This Friday my naturalist duties take me down to the Science Museum of Minnesota for the 2010 Junior Duck Stamp Competition. The judging ceremony will begin at 10 a.m. and is open to the public at no cost. If you can't make it to the event be sure to check out the top picks from each state online. The competition is open to kids in grades K-12. Sales of duck stamps raises 25 million dollars a year to fund wetland habitat acquisition for the National Wildlife Refuge System.

I am completely blown away by the talent displayed by the kids this year. All of the states put in a good showing and it will be hard to select the finalist. The adult winner has already been chosen and I have to say there are a number of entries in the Junior Duck Stamp competition that at least to my eyes are superior to the winning adult entry. Granted, I don't have access to the originals, only digital versions but they are stunning none the less.

Here are my top two picks. I can't decide on a top entry until I can see them in the flesh on Friday. First off is the Ohio entry. The names of the kids have been withheld to keep the judging fair so I can't properly credit the image at this time. Take a look.

This is wonderful work and shows incredible talent. It is a masterful depiction of a Hooded Merganser but it is more than that. It has character and a developed artistic style. I feel like I could pick this artist's work out of a crowd because of that style.

My second top pick is from that hotbed of east coast birding, New Jersey. The New Jersey entry is simply stunning in that it looks so incredibly real. It looks just like a photograph. Every person I have shown it to has said, "Oh come on, that's a photo." I can't say enough good about this one either. Everything is perfect.


I don't envy the judges on Friday. There are so many good entries. I'd be remiss if I didn't plug our local artist here as well. I think Minnesota is putting in a great entry this year. Here's the winner from the statewide Minnesota competition. Very nice work.

It will be exciting to see who wins. While all of the entries are great. I'd say there are about 10 states in the running for the top spot. For what it's worth, here are my top ten picks in alphabetical order. Georgia, Illinois, Louisiana, Minnesota, Mississippi, Montana, New Jersey, Ohio, Oregon, West Virginia. Go look at them for yourself and let me know if you agree.

Be sure to come to the event on Friday or check back to see who wins.

~Kirk
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Monday, April 19, 2010

Space Shuttle Re-entry over Minneapolis Tuesday AM

Posted by Kirk 3 Comments
Those of you who follow the blog know my inner geek lets me include space as part of the natural world. I just have to pass along this very cool and rare opportunity. As you may know, the US space shuttle program is coming to an end and the shuttles will soon be retired. There are very few opportunities left to watch the shuttle orbit overhead. There are even fewer opportunities to watch one land. The landing flight of the space shuttle does not usually take it over Minnesota but the current shuttle mission is scheduled to re-enter the earth's atmosphere right over the twin cities. This is known as a rare descending node re-entry. Here is the current predicted ground track. It also takes the shuttle over Chicago.

The ephemeris online shows the shuttle will first appear over the twin cities at 6:14 AM and will transit and disappear by 6:19 AM. The prime sighting will be at exactly 6:16 when the shuttle will be 67° high in the sky and passing within 43 miles of St. Paul. The shuttle should appear roughly from the north. Sunrise is at 6:20 tomorrow so it is hard to say whether we will be able to see the shuttle streak across the sky like a meteor of fire or whether it will be washed out against a brightening sky. If you go out to watch, be sure to listen as well. The shuttle will be traveling at supersonic speeds and will produce a double sonic boom. It takes about 1 minute 30 seconds for the sound to reach earth after the shuttle passes overhead.

The shuttle was supposed to land on Monday but the landing was scrubbed due to poor weather. The old route would not have taken it over Minnesota. If weather is poor at Kennedy Space Center in Florida the shuttle will land in California and we'll unfortunately miss the show.

I'll be up for it. We'll see what the weather has in store.

~Kirk
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Thursday, April 15, 2010

Fireball Meteor Over Midwest Last Night

Posted by Kirk
If you were lucky enough to be outside last night around 10:00 pm you may have witnessed this fireball meteor that flew over the midwest last night. The video was captured on a dashboard camera of a Howard County (Iowa) Sheriff Department cruiser.



The meteor was also picked up on Doppler Radar out of LaCrosse WI. It shows up best looking at the storm relative motion view at 10:10 pm. This shows the meteor at a height of between 6000 and 12,000 feet. There were reports of sonic booms. The Twin Cities was cloudy at the time but people saw the meteor in Minnesota, Iowa, Wisconsin, Illinois and Missouri.


~Kirk
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Wednesday, April 14, 2010

Eastern Phoebe Nest Building Video

Posted by Kirk
I mentioned in a post a few days ago that we were testing the web cam out for the Eastern Phoebe nest we have at the nature center. The camera is part of a partnership with the Cornell Lab of Ornithology.

On Friday, we changed the angle of the camera to get a better view. We then noticed the very next day that the nest that had been there for several years was gone. It either fell down or the birds knocked it down. This was not a bad thing, it was probably getting too high as the birds added on each year anyhow. The entire thing was probably seven inches high which is overkill. I was talking with co-workers near the window on Monday when I noticed birds flying into the corner of the building where the nest is.

I headed to the computer that runs the web cam and took some video. The camera usually only operates in still mode and uploads one photo to the Cornell nest cam website every 20 seconds. By capturing video, we gained not only a new perspective but new information as well. More on that after the video.



What you see here is not real time. I have edited out gaps between the birds visiting though those gaps were not long. These birds were really working. The next bird would appear about 20 to 30 seconds after the first bird left. We're seeing both the male and the female building the nest. There are a couple of cool things to note. First off, there are clearly TWO birds building this nest. I find this very interesting as my handy reference The Birder's handbook clearly states that for Eastern Phoebes, only the female builds the nest. I know these are two birds coming in because I could see them out the window but it is also documented in the video two different ways. First off there is behavior. If you watch closely, the two birds clearly have different skill levels at nest building. One bird carefully brings back mud and tucks it onto the base (an old electrical junction box) while the other bird comes back and simply drops nesting material and it usually just falls to the ground. This difference can be seen several times in the video. The other clear evidence that these are two birds is this screen capture.

One of the birds is banded. This bird is wearing a bird band, no doubt it is one of the bands from our active bird banding program at the nature center. We have banded the adults from this nest in the past. It would appear that one of these birds has used this nest site before though we will have to re-capture the bird at some point to be sure.

It will be fun to watch this nest site again this year and I'll be sure to let everyone know when Cornell starts posting the feed from this camera on their nest cam site.

~Kirk
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Tuesday, April 13, 2010

Get Those Hummingbird Feeders Up!

Posted by Kirk

I posted this morning about the Chimney Swift migration updates available online and figured I'd mention the fact that you can track the Ruby-throated Hummingbird migration online next week some time. I checked the website to see how the hummer migration is coming and to my surprise they are trucking north at a rapid clip. Check out the most recent map! There are none in Minnesota yet but one right across the river in Wisconsin. It looks to be almost directly across the river from the nature center! I'm guessing what we're seeing here is hummingbirds using the St. Croix River as a flyway. Time to get those feeders out.

~Kirk
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Tracking Chimney Swift Migration

Posted by Kirk

One sure sign that spring is really here in full force is the return of the Chimney Swifts. I love hearing their little chattering sound as they swoop around the sky. Thanks to the marvels of the information age you can monitor their northward movement and contribute sightings of your own at the Driftwood Wildlife Association's 2010 Chimney Swift Migration website.

As of the end of last week, they were half way up Missouri and heading north. They seem to be a week ahead of last year which would mean they should show up in the Twin Cities in about two weeks. If you are seeing them in your area and you live north of where you see a red dot on the above map be sure to send in your observation!

~Kirk
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Monday, April 12, 2010

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

Posted by Kirk
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...

Posted by Kirk
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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Friday, April 9, 2010

Phoebe Nest Cam Preview

Posted by Kirk

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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Thursday, April 8, 2010

First Spring Wildflowers

Posted by Kirk

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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Monday, April 5, 2010

Today's Solar Storm Could Affect Bird Migration

Posted by Kirk 5 Comments
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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Saturday, April 3, 2010

Which sub-species of Fox Sparrow do you have?

Posted by Kirk

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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Thursday, April 1, 2010

Foxy

Posted by Kirk
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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