Wednesday, May 16, 2012

North American Migration Count 2012

The North American Migration Count takes place the second Saturday each May. It aims to take a "snapshot" of migration, and is compiled on a county basis. My husband Darrin is the coordinator for Wayne County, and as usual we covered the city of Dearborn together on May 12.

Spring migration this year got off to a great start the first week in May. We had very good numbers of early migrants the last week in April into the first week in May. There was a nice influx that included some mid-season migrants on May 3. Within a few days, however, things began to slow down. On migration count day, we tallied a disappointing 70 species on campus. Warblers in particular were very scarce, with only ten species. Yellow-rumped Warblers had been dwindling, but were absent on count day. Many people commented on the high numbers of White-crowned Sparrows this season, but on count day we had only a few, and no White-throated Sparrows. Our best bird on campus was a Gray-cheeked Thrush, the first of the season.

Darrin taking a quick break on campus during the count. Sometimes,
having too few birds is more tiring than having too many!
We added eight more species at other locations in Dearborn. The original Ford "sunflower field" at Hubbard and Southfield had a minimum of two dozen Bobolinks on May 7, but none stuck around for the count.

The Rouge River at Kingfisher Bluff behind Henry Ford
Community College.
Northern Rough-winged Swallows are nesting in the terra cotta
tubes poking out of the bank at Kingfisher Bluff behind Henry
Ford Community College.
The best bird of the day was an Orchard Oriole at Porath (Kielb) Park. This 11-acre property in a sparse residential area adjacent to railyards and an industrial border of Detroit was once a clay mine for bricks. In the 1940s, fill material from construction of I-94 was added. A federal brownfields grant was used to clean up contamination (still no digging allowed, according to warning signs) and it was turned into a park by the city in 2005. There are a variety of native plants there, but aside from a trail that is mowed through it, the park has not been maintained very well and it's becoming weedy and overgrown.

In addition to the oriole, Porath had two very good butterflies. One was a Common Checkered-Skipper (Pyrgus communis), a southern species that has been seen in southern Michigan with increasing frequency the last few years. Not only is this an uncommon species, this is a pretty early date to see them here. It's unlikely that the larvae (the stage in which they hibernate) can survive here overwinter, so the individuals we typically see are migrants from the south, or perhaps some progeny from these migrants which appear later in the season. Their host plants are in the mallow family, and I have seen them most commonly in vacant lots or neglected fields that are infested with velvet-leaf (Abutilon).

Here is my bad documentary photo of a Common Checkered-Skipper at
Porath Park. Click here for a much nicer shot of one in my Dearborn yard last fall.
We also saw another uncommon butterfly, an "Inornate" Common Ringlet (Coenonympha tullia inornata) When we found our first county record in 2003, it represented a substantial southern range expansion in the state (PDF of my note in the newsletter of the Michigan Entomological Society here). This species now shows up all over the place in southern Michigan, moving south here as it has in New England and Ontario in the last decade or so. I failed to get a photo, but here's one Darrin took last fall in Oakland County.

Both the skipper and the ringlet have been observed on the UM-Dearborn campus as well.

A table of results from the Wayne County North American Migration Count, with links to complete results, is available on the RRBO web site. Once we have data from all the other field participants, I'll put up the 2012 results at that location as well.

Monday, May 7, 2012

Chimney Swift tower!

Chimney Swifts are probably familiar to most people: twittering "flying cigars" in our summer skies, feeding on aerial insects. Like other species of swifts, Chimney Swifts spend most of their time in the air, even mating and bathing on the wing. Chimney Swifts breed across much of eastern North America, and winter in the Amazon basin of northwestern South America.

Patient observers might note individual birds disappearing into tall chimneys during the breeding season. Chimney Swifts make a small nest of twigs, held together and glued with saliva to the inside wall of a chimney-like structure. Only one pair will nest per chimney or structure, but there may also be a few non-breeding swifts, some of which (usually young from a past year) may "help" the breeding swifts feed the young in the nest. Chimney Swifts use chimneys and similar structures outside the breeding season, too. During migration, especially in fall, many hundreds of swifts might use large chimneys to roost in overnight.

Prior to European settlement of North America, Chimney Swifts used hollow trees, caves, and narrow chasms. Their populations probably increased with the availability of human structures for nesting and roosting. However, in recent years Chimney Swift populations have undergone a dramatic decrease. In the U.S., this decline has been about 2.4% per year since the early 1980s; in Michigan the rate has been -1.5% annually (based on Breeding Bird Survey data).
Several factors are probably at play. Most important is a decrease in aerial insect prey, likely due to pesticide use, habitat loss, and a changing climate. Other species of birds that rely on aerial insects, such as Common Nighthawks and swallows, are also on the decline. Add to this a special problem for Chimney Swifts: chimney design has changed in modern times, with many chimneys being too narrow, or covered or lined, for swifts to use.

This has led many organizations and individuals to create artificial Chimney Swift nesting structures. This spring, Stephen Lisius constructed and erected one of these excellent towers behind the Environmental Interpretive Center as his Eagle Scout project.

Stephen designed the tower according to plans similar to the graphic above, which is available in the Chimney Swift Nest Site Research Project Information Handout (PDF). The tower was constructed off-site, and then erected onto a sturdy foundation that had been put in place the week before. Here's the tower in place:

The outside of the tower will be finished soon with weatherization wrap and shingles. Stephen also plans to install a camera, so if/when swifts discover and use the tower, we can see what's going on. We may have to be very patient -- some towers go for years before they are used. I'll keep you posted!

If you are interested in learning more about these towers or even seeing if you'd like to make one yourself, the book Chimney Swift Towers: New Habitat for America's Mysterious Birds is the go-to guide.

Meanwhile, you might consider one of the swift monitoring projects. The program called Swift Night Out is done each fall in the U.S. Bird Studies Canada has initiated a citizen swift monitoring program as well.

Chimney Swift photo by D. Irving under a Creative Commons license. Tower photo by Sara Cole, used by permission.

Monday, April 30, 2012

Moth program results

Our moth program with field guide author Seabrooke Leckie was a great success! We were a bit worried about the cool weather, but Seabrooke explained that many moth species overwinter as adults (rather than eggs, caterpillars, or pupae/cocoons). These cold-hardy species will fly in temperatures cooler than we were experiencing (in the mid-50s).

Seabrooke arrived in late afternoon, and we set up several sheets with different types of light (black light, mercury vapor). Moths are attracted to the lights and land on the sheets.

One of the sheet/light set ups.

We also soaked some rope in a mixture of red wine and brown sugar, and hung them out to attract species that feed on nectar and sap (many adult moths, however, do not eat at all). This mix should really be allowed to ferment, so we didn't have luck with that.

Stinky, sticky wine rope hanging from wood shed.
Seabrooke started out with a short presentation focusing on moths in the environment.

Then our group of about 30 people made the rounds of the sheets and collected moths in clear pill bottles. These were brought back into the building where Seabrooke identified them.

Seabrooke also helped my husband Darrin identify some photographs he had taken the last few years.

Our friend Don Sherwood has been raising silkworm moths. He brought along this Luna Moth to show everybody. I think this is probably one of the most beautiful moths in the world!

Here is our list of moths that came to the lights, with links to the species or genus at BugGuide, a great online resource for insect identification. Some very tiny moths ("micromoths") were only identified to genus.
The Curve-toothed Geometer. We released
all the moths at the end of the night.
  1. Unicorn Prominent (Schizura unicornus)
  2. The Gem (Orthonama obstiptata)
  3. Celery Leaftier (Udea rubigalis)
  4. Palmerworm Moth (Dichomeris ligulella)
  5. Featherduster Agonopterix (Agonopterix pulvipennella)
  6. Confused Woodgrain (Morrisonia confusa)
  7. Acleris sp.
  8. Common Acleris (Acleris subnivana)
  9. The White-Speck/Armyworm (Mythimna unipuncta)
  10. Dusky Groundling (Condica vecors)
  11. Olive-and-black Carpet (Acasis viridata)
  12. Epinotia sp.
  13. Eupithica sp.
  14. Bent-line Carpet (Costaconvexa centrostrigaria)
  15. Curve-toothed Geometer (Eutrapela clemataria)
  16. Red-banded Leafroller (Argyrotaenia velutinana)
  17. Gray-banded Leafroller (Argyrotaenia mariana)
There were also a couple of "get-aways" and some that flew near the sheets that we didn't catch.

Thank you Seabrooke for an excellent evening!

Julie Craves and Seabrooke Leckie.

Thursday, April 26, 2012

Update on European Goldfinches

Update: This paper has been published! It's open access so you can read online or download the PDF; click on title below -

Craves, J.A., and N.M. Anich. 2023. ­­­Status and distribution of an introduced population of European Goldfinches (Carduelis carduelis) in the western Great Lakes region of North America. Neobiota 81:129-155. doi: 10.3897/neobiota.81.97736


People continue to leave me comments on my previous posts about European Goldfinches in the U.S. (see list of posts below). I am still keeping track, especially of breeding records. In addition to accumulating reports from proactive observers, I also periodically look through birding listservs and eBird records. Unfortunately, any Illinois records put in eBird are filtered out of public view, but the state reviewer is working on changing this. Even so, I still have over 50 records of well over 100 birds from the past few years just in southern Wisconsin and northern Illinois alone.

Here's a map from a previous post, showing the Wisconsin and Illinois counties highlighted in red where the bulk of reports of European Goldfinch come from.

In a previous post, I documented nesting in Waukegan, Illinois, which is in Lake County. Later, I found a report online of a family of European Goldfinches at Waukegan Beach on 13 August 2009, consisting of five birds: two adults, and two juveniles, with the fifth bird likely also a juvenile. The observer posted this photo on Flickr. The day before the photo was taken, another observer saw a minimum of 13 European Goldfinches foraging in a weedy area in what appeared to be two to four family groups in an area just adjacent to Waukegan Beach.

In 2011, European Goldfinches were reported nest-building at Waukegan Beach. A report in April 2012, just a couple weeks ago, also mentioned them gathering nest material. So it seems a breeding population is well-established in the Waukegan area.

These may not be the first European Goldfinches to have nested in Illinois, as there was also a report of birds nest building at Montrose Point in Chicago, Cook County as early as 2003.

In Wisconsin, the breeding population seems centered in the Racine area of Racine County. That is around 25 miles north of Waukegan. My previous post documented a juvenile in 2009 in the Racine suburb of Mt. Pleasant. Subsequently, I received a report in late July 2009: the Scheefs in suburban Racine reported on a juvenile showing up at their feeders shown in this post.

I also heard from Sarah Anspaugh of Racine, who took the photo below of a European Goldfinch family. A pair showed up at her feeder on 13 May 2009, appeared periodically through June, and on 8 July 8 there were 2 juveniles with them.

Jane Scheef of Racine contacted me again in 2010. The pair in her neighborhood arrived at her feeder on 29 June with 5 young in tow, shown in the photo below.

I think that an eBird report of six to eight coming to a feeder in Racine in late winter 2011 may be the same residence. The largest flock I have heard about was that of 30 on 4 December 2011, also in Racine (I think this checklist is the exact location).

Finally, in between Waukegan, IL and Racine, WI is Kenosha, WI, where a correspondent named Donna has had at least one pair of European Goldfinches at her feeders. In June 2011, she photographed them with three young. She recently wrote me that a pair is currently coming to her feeders.

Unlike American Goldfinches, European Goldfinches typically nest in May and June, so be on the lookout and keep sending those reports.

Here are my other posts:

Monday, April 2, 2012

Moth program with field guide author Seabrooke Leckie

It's with great anticipation that I announce an upcoming program, a joint effort between RRBO and the University of Michigan-Dearborn Environmental Interpretive Center. Seabrooke Leckie, co-author of the new Peterson Field Guide to Moths of Northeastern North America will be visiting on Sunday, April 29, 2012. She will be giving an informal program on moths, and will be setting up her nocturnal moth-attracting gear in the campus natural area to see what is around. Late April can be fairly early for a wide variety of moths at this latitude, but with the exceptionally warm spring, it's hard to know what to expect! Let's hope the weather doesn't turn too fickle.

I can't wait to see the new field guide. It will be released shortly before the program, and Seabrooke will be happy to sign your copy (she will have some available for purchase, or you can pre-order at Amazon). This book is sorely needed, and you can read more about the story behind it, what it will include, and see some sample plates at Seabrooke's web site.

Plus, I'm really looking forward to finally meeting Seabrooke in person. I first became aware of her through her former work as a bird bander at Tommy Thompson Park Bird Research Station in Toronto. They banded a Ruby-crowned Kinglet in 2003 that I recaptured here on campus in 2005. Since then, she and I have kept in touch through our blogs and social networking. Seven years is like forever in the ephemeral world of the Internet, so it feels like we have been friends a long time. I'm eager to met her ITRW ("in the real world"), as the kids say these days.

The program will take place from 8 PM until midnight at the campus EIC. A map and directions are on this page.

The program is free, and children must be at least 12 years of age to attend. We ask that you please RSVP by dropping us a note; you can do so by filling out the contact form on the RRBO web site.