Banding in Nicaragua: The Birds

As a follow up to my introductory post, I'd like to share some highlights of the birds at Finca Esperanza Verde, and the importance of shade coffee to their survival.

Even more so than the areas we visited in Panama last year, Finca Esperanza Verde and other shade coffee farms are critical to preserving biodiversity of birds and other wildlife in Nicaragua. We were stunned at the deforestation. It's not due to human development, but to agriculture (mostly non-commercial) and cattle grazing. Shade coffee farms appeared to be one of the only land uses that preserved a lot of trees.

During our brief stay, we counted well over 100 species, including nearly two dozen species of migratory songbirds that breed in North America but winter in the tropics. Over 30 species of migrant songbirds have been recorded at the finca, and the overall bird list is approaching 300 species.We observed or banded several species new to the finca ourselves. We banded about 70 birds of over 30 species at Finca Esperanza Verde. For most of the time, we were banding right in the coffee production area.

Here's where we banded. The shorter dark green

shrubs in the foreground are coffee, interspersed with
taller native trees providing shade and habitat.

You know you're off to a good start when the
first bird you band is a Collared Trogon
(Trogon collaris).

The most common North American migrants banded at FEV are Yellow-bellied Flycatcher, Wood Thrush, Worm-eating Warbler, Wilson's Warbler, Kentucky Warbler, and Ovenbird. Although we captured multiple individuals of those species, we rarely if ever saw the other species, with the exception of Wood Thrushes, in our birding walks through the finca. On the other hand, Baltimore Orioles, Chestnut-sided Warblers, and Tennessee Warblers were very common in the coffee production areas, but we didn't capture any. This underscores how well banding supplements surveys for censusing an area. Other common North American migrants included Black-throated Green Warbler, Black-and-white Warbler, and Summer Tanager. The species I've listed in bold are among the 25 priority species targeted by the MoSI program.

Wood Thrushes (Hylocichla mustelina) are the most commonly banded birds at the finca -- migrant or resident.

Yellow-bellied Flycatcher (Empidonax flaviventris).

Worm-eating Warbler (Helmitheros vermivorum).

My husband Darrin weighing a bird with a spring scale.

At times, it was all a blur!

Kentucky Warbler (Oporornis formosus).

Although a limited number of birds have been banded at FEV, especially compared to stations operating for more days per year, between-year recaptures are beginning to occur. North American migrants which have returned to the same tiny areas to spend the winter include Wood Thrush, Wilson's Warbler, Louisiana Waterthrush, and Kentucky Warbler. The fact that these birds are showing strong wintering site fidelity emphasizes the importance of habitat preservation in the tropics. By extension, it also suggests that shade coffee is providing habitat that is worth "coming back to" for these migrants, and that the habitat quality is sufficient that the birds were in good enough shape on departure to survive their northbound journey and consequently return the following year.

Wilson's Warbler (Wilsonia pusilla), a species
showing wintering site fidelity at the finca,
being recaptured in multiple winters. We
also found them common in shade coffee farms in
Panama.

Resident birds are being recaptured between winters,
too. Here Curtis shows off a recaptured Spot-
breasted Wren -- he banded this bird
himself at FEV two years previously!

It's pretty cool seeing familiar birds in unfamilar lands, and especially interesting to see Tennessee Warblers sharing a tree with Keel-billed Toucans, or Chestnut-sided Warblers hopping around with Elegant Euphonias (we also called these "Extraordinary," "Superlative,"or "Especially Elaborate" Euphonias). And seeing tropical birds in the hand is even cooler. Only North American migrants received U.S.-issued bird bands. Resident birds got special site-specific bands, since there is no established banding entity in Latin America coordinating the banding programs there. For each resident bird, we took extensive notes on plumage, measurements, and breeding condition. There is no standard reference for how to determine the age and sex of most tropical birds (in fact, there is no field guide for Nicaraguan birds), or detailed information on life cycle events. All of this data is valuable!

Crimson-collared Tanagers were one of my favorite resident
birds that I banded. But they sure did bite!

Also vying for top spot was this brilliant Blue Bunting.
FEV is at the southern edge of their breeding range,
and this was the first recorded for the finca.
The next day, we caught a female.

Darrin's favorite was this Rufous-browed Peppershrike,
a tropical member of the vireo family. How about
those orange eyes?

We caught and measured, but did not band, a number of species of hummingbirds. The most common was Long-billed Hermit, shown above. We also handled Violet Sabrewing, Rufous-tailed Hummingbird, Stripe-throated Hermit, Violet-crowned Woodnymph, and Stripe-tailed Hummingbirds. I've written more about the resident birds we banded, and given some further details on how FEV compares with other shade coffee farms, at my blog Coffee & Conservation -- with more colorful photos, too!

Once again, I am struck by the importance of shade coffee to birds and biodiversity. Nicaragua is one of the poorest countries in the western hemisphere, with an unemployment rate over 50%. Outside of the few urban areas, there is little work other than farming. Growing quality coffee under shade in an ecologically responsible way requires a lot of extra work for farmers who are essentially trying to provide for their families after decades of devastating civil war. Many Nicaraguan farmers don't consider the effort worth it -- because consumers are not willing to pay more than a few cents extra for organic or shade-grown coffee.

I can't state it any plainer than this: if you are buying inexpensive, grocery-store coffee you are contributing to the destruction of bird habitat and the decline of migratory songbirds. Bird conservation and great coffee are two of my passions -- and they go hand in hand. That's why I began writing Coffee & Conservation, where you can learn more. On Saturday, May 16, there will be a "Caffeinated Conservation" bird walk here on campus focusing on the connection between coffee and migratory birds; watch the EIC web site for more details.

Banding in Nicaragua: Introduction

Sunset at Finca Esperanza Verde.

I'm back from Nicaragua. It was a busy and rewarding trip, and as promised I'll share with you some highlights of the banding we did at Finca Esperanza Verde (FEV), a shade coffee farm in the central highlands east of Matagalpa. Although it is a widely used tool in North America, bird banding in Latin America is limited by a severe lack of funding, materials, and trained personnel. This situation should be of concern to bird lovers here in the U.S. -- remember that most of "our" breeding birds spend more time on the ground in the tropics in winter than they do here in the breeding season. Yet very little is know about the winter ecology of our birds in the tropics, or its link to overall population health.

To address these questions, the Institute of Bird Populations (IBP) started a program in 2002 called MoSI (the acronym comes from the Spanish "Monitoreo de Sobrevivencia Invernal" or Monitoring Overwintering Survival). Around 150 bird banding stations are located across the American tropics, and the goal is to learn more about physical condition, habitat use, and survivorship over the winter, and how various factors impact subsequent breeding activity. The protocol for these stations requires banding for five, three-day periods each winter. Currently, there are not enough trained banders in the area to operate a bona fide MoSI station at FEV, but any data on the winter ecology of migrant and resident birds is helpful. At FEV, this was the fifth year of a banding project initiated by John Connors and John Gerwin of the North Carolina Museum of Natural Sciences.

Shade coffee at Finca Esperanza Verde. Can you tell
what is coffee and what is natural vegeation?

Most people are aware that deforestation is a big problem in Latin America, and much of it is due to agriculture. Coffee is an understory shrub that naturally grows under the shade of other trees. These types of coffee farms provide very good habitat for birds and other biodiversity, often closely resembling the composition of fauna in natural forests. However, in the last decade or so new types of coffee have been developed that can be grown without the protection of shade, in higher densities, and with higher yield. This "sun coffee" not only results in forests being cleared for intensive coffee growing, but these varieties require high levels of fertilizer, pesticide application, and deplete tropical soils. Thousands of acres of forest in Latin America have been cleared for growing "sun coffee." Bird research -- including bird banding -- has helped us understand the importance of shade-grown coffee to migratory and resident birds. I have read a lot of this research, but nothing can quite compare to participating in it myself!

Mariamar and my husband Darrin get ready to process
a bird at the "Yellow Trail Banding Station" at
Finca Esperanza Verde.

We joined Curtis Smalling, biologist with North Carolina Audubon and Mariamar Gutierrez, Central American coordinator for MoSI for two days of banding in a section of the coffee farm that had not been maintained in several years. After that, we were joined by Dr. Lynn Moseley and her students from Guilford College for three days of banding in the active coffee production area. During breaks, the students heard short lectures on tropical ecology, birds, and the various uses of banding. Curtis talked about monitoring breeding birds in North Carolina through the Monitoring Avian Productivity and Survivorship program, also run by IBP. Mariamar talked about MoSI. And I gave a talk about how I use banding to do stopover ecology research.

Here I am discussing RRBO's work on stopover
ecology with other members of the group from Guilford
College.

And here I am having my talk interrupted by local
campesinos who use this trail to travel between
villages.

We banded for a couple hours each morning, and a couple of hours in the late afternoon, avoiding the mid-day warmth. The first couple of days we were limited in the number of nets we could open because of windy conditions. Despite our modest efforts, we banded about 70 birds of over 30 species, both residents and wintering migrants. In my next post, I will talk about what species we banded and post more photos!

Learn more:

• This article in Living Bird discusses the MoSI program, featuring Nicaragua.
• The problems with "sun" coffee.
• Birds and coffee plantations.
  

A tropical adventure

A trip to anywhere in the tropics is always high on my list of great things to do. Over the last 7 years or so, my husband Darrin and I have volunteered our time to a number of organizations operating in the tropics -- usually doing bird surveys or otherwise assisting local ecologists. Our newest opportunity will be next week in Nicaragua.

The bulk of our time will be spent in the montane coffee-growing region of Matagalpa. Some of you know that I have a passion for excellent coffee, and write an entire website devoted to the issues surounding sustainably-grown coffee. Coffee grown under shade in an eco-friendly manner is critical for tropical biodiversity, and for so many of the migrant birds that breed in North America and winter in the tropics. Those of you who are members of Cornell's Lab of Ornithology may have seen the recent article on shade coffee in BirdScope in which I was quoted.

Darrin and I have been invited to participate in an on-going bird banding project initiated by the North Carolina Museum of Natural Sciences. In Matagalpa we will be visiting Finca Esperanza Verde (FEV), a shade coffee farm near the village of San Ramon (click on the map to enlarge). We will be banding first with other researchers, and then assisting a group of college students from North Carolina. This project helps to document the birds that use the finca -- both resident species and those that nest in North America but winter in the area, or are on their northbound migration. For example, the most frequently banded North America wintering species at the finca is the Wood Thrush. One of our North Carolina colleagues, Curtis Smalling of North Carolina Audubon, will be working specifically with Golden-winged Warblers.

We will not only band birds, but of course also observe and census birds at FEV. Counter Culture Coffee in Durham, NC sources coffee from FEV and other farms in the San Ramon area; coffee from FEV was one of the top ten coffees in the prestigious 2007 Cup of Excellence program. I'll be providing feedback to Counter Culture about the birds on the farm. I'm excited to admit that I assisted Counter Culture with their choice of the Emerald Toucanet as the bird on their Cafe San Ramon packaging (left). Darrin and I have seen this species at other shade coffee farms in Panama, and knew it was on the finca's bird list.

After we leave FEV, we will be traveling back toward the colonial city of Granada, near the shores of Lake Nicaragua. After a few birding stops en route, including another shade coffee farm, we will be settling in for several days at Domitila, a private wildlife reserve. Domitila represents one of the last and best preserved dry tropical forests in the country. At both FEV and Domitilia, we will be conducting insect surveys, focused on dragonflies and damselflies, to assist with the Insects of Nicaragua inventory being conducted by the Museo Entomológico de León (Entomological Museum of Leon). There is still much to be learned about Nicaraguan insects now that the country is peaceful after so much civil war. We can attest that even well-studied countries like Panama turn up surprises. On our last two trips there, we photographed at least one undescribed species of damselfly, and took the first photograph of a live specimen of another species that was described over 30 years ago. Who knows what we might turn up in Nicaragua!

When we return, I will be writing an article on the importance of shade grown coffee to birds, incorporating my experiences, for Birder's World Magazine.

Of course, I will also share as much as I can with you here at Net Results. Be patient: for most of the trip, we will not have Internet access (or electricity, or hot running water!), so I will have to wait to return home to post updates when I am not busy catching up and getting ready for spring migration.

Winter Bird Population Survey, Year 17

I have always hated winter. I don't like being cold and have always found Michigan summers far too short. But here I am, and when life gives you lemons...you know the story. When I first started working here at UM-Dearborn, I began a standardized winter bird survey. This makes it the longest-running survey by the Rouge River Bird Observatory. I have just completed year number 17. I cleverly called this endeavor the Winter Bird Population Survey, since it was patterned after the Winter Bird Population Study protocol, developed many decades ago. In short, I walk through the campus natural areas roughly twice a week between 20 December and 20 February, always completing my survey before noon, and record every bird I encounter. The final tally includes the average number of individuals encountered per visit (abundance) and the number of visits in which a species was encountered (frequency of occurrence). This all sounds very mundane, and generally it is in the short run. But the beauty in long-term data is often not seen for many years. In 1992, who would have anticipated the importance of counting such a common and ubiquitous species as the American Crow? For an entire decade, I dutifully counted crows, woodpeckers, and chickadees, birds I encounter so often that I sometimes had to concentrate on actually "seeing" them. The occasional Northern Shrike or even Fox Sparrow were much more fun and interesting. Then came West Nile virus and suddenly -- no crows. The profound impact of this disease on local crow numbers would not be quantifiable without the years of baseline data. After ten years of fluctuating but generally stable numbers, the average number of crows per visit was just under 12. The winter after the first breeding season in which West Nile virus occurred (2002), I counted a total of only 18 crows, which worked out to 1.2 crows per visit. I haven't counted double-digits over an entire winter survey period since then. This winter, I only recorded crows on one survey, when I saw four birds. The average for the past seven years has been 0.5 crows per visit, a drop of 96%. My many years of data have also revealed interesting trends in the numbers of woodpeckers, once ash trees began to succumb to Emerald Ash Borers. I'm also able to look at numbers of overwintering robins and how their numbers change over the course of a season and the decline of American Black Ducks here in winter. Other species don't seem to reveal anything particularly compelling...yet. In the 17 years of the survey, I've averaged 38 species a year. This year I had a record 45 species. Remarkably, four were new to the survey:

• Common Goldeneye (photo below) -- not unusual in winter on the Rouge River, but a first for campus;
• Red-shouldered Hawk-- first record in Dearborn for December or January;
• White-winged Crossbill --part of the remarkable irruption I discussed in my last post; and
• Brown-headed Cowbird.

The cumulative total for the WBPS is now 67 species. Thirty-one species have been seen in 12 or more years (70% of the years) and are thus considered our core winter residents. Eleven species have been recorded only once, with the rarest being last year's Hoary Redpoll. I tend to begrudge every time I have to bundle up and spend the next several hours in the cold counting birds. I knew when I started the WBPS that a long-term data set would have applications in tracking numbers of resident birds. But already seeing interesting and relevant results has certainly helped motivate me to get out the door on some of those bitter mornings. Hoping to count crows.

A winter of finches

Every so often, a long cold winter is made worthwhile when we get visitors from the boreal north. I'm talking about "winter finches." A number of species move south when their preferred food source becomes scarce in the northern parts of their range. These birds all have a few favorite tree seed species, and trees tend to produce seeds in cycles (up for one or more years, down for another one or a few). This helps us predict when we might see certain winter finches, and in what numbers. The folks in Ontario create an excellent, detailed winter finch forecast every fall. I encourage you to read a recent copy to get a feel for which bird and tree species are involved.

This winter has been terrific for winter finches. The most impressive and special has been the push of White-winged Crossbills. While they are found nesting in Michigan's Upper Peninsula, they are very rare in southern lower Michigan; Dearborn had only a handful of records before this winter. This year, they've been found in nearly every county and in big numbers. It's unlikely an event like this will ever occur again in my lifetime. I've had big flocks in my neighborhood, even my yard, but a reliable group has been working the Douglas firs at a local office building (White-winged Crossbills specialize in soft cones like spruces, hemlocks, and some firs). Here is a male (above) and female (below) taken there by Mike O'Leary.

Pine Siskins were some of the first finches to arrive in early winter and have stayed around in large numbers -- they are often present at feeders. While a couple individuals are found every year, we have not had this type of invasion here in Dearborn since the late 1970s. Pine Siskins will sometimes nest in southern areas after a big invasion year, so I will not be surprised to hear of some breeding in southeast Michigan this summer. We have had only a handful of siskins at any one time here on campus, but scores of them at our feeders at home a few miles away. So far, we've banded over 60 the last couple of weekends. Some are dull, but some are quite beautiful when you get to take a look in the hand.

Common Redpolls have also been very abundant. On campus, they have been busy extracting the tiny seeds out of the small cones on the black alders around Fairlane Lake. Few have come to the feeders. At home, we've had only a few at our feeders as well. Here are a couple of males -- young males and females tend to have little or no pink on the breast.

Last but not least is Purple Finch. We usually see a few Purple Finches every fall during migration. This fall was no exception, but we have heard few reports of many Purple Finches in the area in the subsequent months. It seems like they passed by, went somewhere else, or didn't make it this far south in any numbers. This is the only one I've seen, a male at my feeder. That's a male House Finch below it. Notice the distinct curve to the upper bill of the House Finch. It's quite straight in a Purple Finch, and a good structural clue to telling the two species apart. Here is a guide to identification.

I admit, I loathe winter. But knowing I could easily find and observe these special species has made going out not only bearable, but actually a lot of fun.

European Goldfinch: established in the U.S.?

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

In the fall of 2002, Ford Motor Company planted sunflowers on a 20-acre lot they owned at Hubbard and the Southfield Freeway (M-39) service drive, near their world headquarters. Ford has continued to plant sunflowers, sorghum, and/or a wildflower mix on up to 10 properties scattered across Dearborn. 

The fields have always attracted a lot of birds -- I wrote about the numbers seen on this year's Christmas Bird Count. The very first winter the original field hosted an unusual bird: a European Goldfinch (Carduelis carduelis), a bird not native to North America. European Goldfinches are common in the pet trade, and it's not too unusual to hear about sightings of escaped or released pets. Unlike members of the parrot family, European Goldfinches are very hardy and can survive northern winters. The sighting occurred during a time when I had been hearing more and more reports of European Goldfinch sightings, especially in the Chicago area. Curious, I posted a page on the RRBO web site requesting sightings from the upper Midwest. I also kept my eyes on the various Internet birding lists and regional publications.

That there were a lot of European Goldfinches out there readily became apparent. I compiled over 400 reports, of which 298 were from Illinois, Wisconsin, Indiana, and Michigan. There was a clear concentration in southern Wisconsin and northern Illinois, a pattern of radiation from the "epicenter" that was more pronounced north than south, and a smattering of reports over the rest of the four states.

It is believed that the bulk of these European Goldfinches -- as well as a handful of other European cage bird species that were reported in the same areas -- originated with a bird importer in the greater Chicago area. From a number of independent reports I received, this importer had apparently deliberately released these species on more than one occasion over time. Believe it or not, as long as the birds are legally imported, there is no federal law prohibiting their release, even if they are not native.

Since 2003, there have been reports of nesting European Goldfinches in northern Illinois. They may also be nesting in southern Wisconsin. Great Tits (Parus major), another one of the species involved in the alleged releases, have also nested in southern Wisconsin and northern Illinois! European Goldfinches nest earlier in the year than American Goldfinches and appear to be ecologically benign, although non-native species frequently end up having unanticipated impacts on ecosystems. Whether the breeding population will grow and persist is not known. In the early part of the 20th century, there were a couple of established colonies in New York, founded by deliberate releases. They eventually died out. However, the proliferation of non-native plant species -- many of which are the natural foods of European Goldfinch -- may prove to be a boon for the species this time around.

I don't believe the majority of the Michigan sightings (or the many Ontario reports I've gotten) of European Goldfinches are attributable to same source. The geographic and chronological patterns do not seem to fit. Some are likely just escaped pets. Many others may be deliberately released birds. Some pockets of reports came from areas with higher populations of people that practice eastern religions, which sometimes advocate setting birds free to accrue merit in the afterlife. Employees at my own local pet store, which often carry European Goldfinches for sale, reported to me that these and other cage birds are sometimes purchased by people of various ethnic backgrounds with the intention of releasing them. I presume this is the source of the Dearborn European Goldfinch.

I ended up writing a detailed account of the reports I received, including background on the ecology and history of European Goldfinches in the U.S. and additional information on their future, in a paper that was just published in North American Birds; you can click on the link to download a PDF copy:

Craves, J. A. 2008. Current status of European Goldfinch (Carduelis carduelis) in the western Great Lakes region. North American Birds 62:2-5.


List of updates on this post:

• June 2009: Nesting European Goldfinch in Illinois.
• July 2009: Nesting European Goldfinch in Wisconsin.

Photo of European Goldfinch in France by Daniel (ParaScubaSailor) at Flickr under a Creative Commons license.

Dearborn CBC

RRBO has been coordinating the Dearborn portion of the Detroit River Christmas Bird Count (CBC) since 1995. The count is held each year on New Year's Day. This year, the 53 species found in Dearborn on count day tied our previous high total. A Wood Duck at the Ford Rouge Plant was a new species for the Dearborn portion of this count. The big news this winter has been the push of White-winged Crossbills into our region. Unfortunately, none were found on count day, but they were found in several locations in the days following the count, so they are added as "count week" birds. This is also a new species, bringing the cumulative species total to 85. Here's a photo of a male crossbill taken by my husband Darrin O'Brien in our east Dearborn back yard on 3 Jan. We were lucky enough to have a flock of 26 crossbills, and a few Pine Siskins, visit the spruce trees.

One of the annual challenges is counting the hoards of birds that hang out at the nine or so sunflower/wildflower fields planted by Ford Motor Company around Dearborn. After trying several strategies, we now devote a single team (usually Darrin and I) to spend most of the day concentrating on getting accurate counts of birds in the fields. This helps prevent double-counting if the birds move from field to field, and allows a team to spend the necessary time to make good estimates on what are sometimes very sizable flocks of sparrows or finches.

This year was made a bit easier, as the largest field, on the south side of Hubbard at Southfield, was not planted this year. Another, at Southfield and Rotunda, was plowed under in fall. Still, we had our work cut out for us. The photo below is the field on the north side of Hubbard at Southfield. I've underlined myself in red! This field had the most birds this year. It took us a long time, but we feel comfortable with our count of over 2400 House Sparrows here. These fields have a lot of benefit to wildlife, but the downside is that they have certainly helped boost the House Sparrow population, which has skyrocketed in the last few years. Our final total of nearly 3500 House Sparrows set a new high record.


Another group of birds that has begun to overwinter in these fields are blackbirds. Last year the Rotunda and Southfield fields had a staggering 1300 Brown-headed Cowbirds. This year the blackbird flock was more modest. Here's about half of them. Most were Red-winged Blackbirds, along with some cowbirds and a single Common Grackle. Raptors have taken advantage of all the small birds in these fields, and once again we have a wintering Merlin here. We had plenty of opportunities to watch it hunt!

If we have time in the afternoon after going through the sunflower fields, Darrin and I hit a few other spots. We had this female American Kestrel dining on a mouse near Miller Road and Wyoming.

It's always nice to have a hot cup of coffee when adding up the numbers back at the EIC on campus. Here I am with Jerry Sadowski (in the Crocs that match the rest of his outfit!), Greg Norwood (in ball cap), and Gary Hutman, all veterans of the Dearborn count. Jerry and Greg are in charge of counting on campus, and Gary covers Rouge Park (in Detroit, but within the larger count circle).
The final story is the continuing saga of the lack of crows since West Nile Virus wiped them out in this area. Up to 2003, it wasn't unusual to count well over 200. That year, we counted 18. Since then, we haven't had more than 8 in any year. Blue Jay numbers, however, have remained pretty constant.

You can view the results of all past Dearborn CBCs on the RRBO web page.

Five years of Christmas Bird Counts at Humbug

It's hard to believe that I have been doing bird surveys at the Humbug Marsh Unit of the Detroit River International Wildlife Refuge for five years. The Refuge was established in 2001 and includes a patchwork of properties along 18 miles of the lower Detroit River. The 410-acre Humbug Marsh unit, straddling Trenton and Gibraltar, was acquired in 2003 after a lengthy battle with developers. It represents the last mile of undeveloped land on the U.S. mainland side of the Detroit River. RRBO's partnership with the U.S. Fish & Wildlife Service and the Refuge began in 2004. Although this area is within the Rockwood Christmas Bird Count (CBC) circle (itself established in 1974), it had never been accessible for bird surveys. Since 2004, RRBO has completed five CBCs at Humbug, as well as two North American Migration Counts, four years of Breeding Bird Atlas work, and two major insect surveys. December 27 was our fifth CBC at Humbug. The day started with very thick fog, making waterfowl counting difficult. Some years, much of the river is frozen and a lot of waterfowl gather in the channel between the mainland and Humbug Island. This water stays open due to the warm discharge from the Trenton Power Plant just upstream. Humbug Island is to the right in the photo below, but the thick fog bank in the center is completely obscuring Grosse Ile. The day ended up breezy and very balmy, with record-breaking temperatures over 60F. This melted much of the snow we'd had in the previous weeks. In the southern portion of the Refuge, an old road was removed over the summer. In its place: thick muck and deep water-filled ruts covered in sloppy snow and thin ice. We were unable to fully cover this area because we just couldn't walk through it. Still, we had a nice adult male Sharp-shinned Hawk at this spot. The Humbug Marsh Unit is not yet open to the public. When my husband Darrin O'Brien and I do the CBC there under RRBO's special use permit, we are alone to walk the many acres. There are a few new, formal trails, but usually we just have to follow deer trails or bushwhack. The northernmost part of the property is an old brownfield. It's quite open and in the winter has the fewest birds. Here I am traipsing across the middle of it. We had 47 species at Humbug for the day. Highlights included two Bald Eagles, a Yellow-bellied Sapsucker, one American Crow (the first on the Humbug count in five years!), three Brown Creepers, one Winter Wren, five Golden-crowned Kinglets, three Hermit Thrushes, an Eastern Towhee, a Purple Finch, and six Rusty Blackbirds. The rusties were also the first we've had there in winter, and we were happy to see them because it is a species in significant decline. We had over 200 American Robins, and over 50 White-throated Sparrows (Humbug is a great site for wintering white-throats). In the midst of it all, I was able to take a short break on one of the new benches along the river. The cumulative species total for the five years is a respectable 74. Only 16 have been seen all five years, in large part due to the variable mix in waterbirds influenced by river conditions. Unusual species have been Gray Catbird in 2005 and Common Yellowthroat in 2007. The species total will undoubtedly grow as habitat is restored and, when the unit is fully open to the public, the number of participants on the count increases. January 1 is the date for the Detroit River CBC, which includes Dearborn. I'll post a report on that count next week!

A tale of strange tails

Bill deformities and tumors are not the only abnormalities noted in the birds we band here at RRBO. Feather color abnormalities are pretty common, but today I'd like to focus on a rarer plumage oddity: weird tails.

The tail feathers of birds, known as "rectrices" or "rects", help with flight, balance, and often sexual display or as a means of signaling and communication. The songbirds we band at RRBO have pretty standard tails -- usually 6 pairs of generally graduated feathers. Every so often, we find an exception.

The tail below belongs to a young (hatching-year, or HY) White-throated Sparrow banded on 5 October 2008. The central rect on the right side was around 10 mm longer than the other feathers. All the rects were fully grown in, so it wasn't a case of the other feathers having not reached their full length.


Also this fall, we got this HY Carolina Wren with a funny paddle-like extension on the central rect. We first caught it on 25 August. The extension was apparent, but the bird was still undergoing its fall molt. However, it was recaptured several times, including in early October, when this funky paddle was still there.


Notice also the odd lines in some of the feathers that look like breaks, or as if the feather was folded. These types of "growth bars" or "fault bars" can occur if feather growth is interrupted, often by a shortage of food due to drought, extended periods of rain, or other environmental conditions. Usually this slow-down of growth creates a fault bar that appears more like a faded line. The Hermit Thrush below has one of these kinds of fault bars, a rather extreme example. In the thrush, the fault bar is an even line across all the feathers. The only time a bird normally grows all its tail feathers simultaneously is as a nestling, so the presence of a fault bar like this can often be used to help age a young bird (although this same pattern can occur in adults that accidentally lose all their tail feathers).

The Carolina Wren above was not our only paddle-tailed bird. In October 2004, we banded the HY House Wren shown in the next two photos. There are several interesting things about the tail of this bird. Five of its rects had the same kind of paddle-like tip (it was worn off in one of them); these extended about 5 mm past the "normal" ends of the feathers.

All the tail feathers were fully grown in except for the three on the right in the photo below. Any feather that gets pulled out will begin to regrow immediately. Several weeks prior to capture, this wren had lost these three feathers which were now nearly replaced. Note how much fresher and blunt-tipped they are compared to the three feathers on the outer left.

In many species of birds, HY individuals have more pointed outer rects than do adult birds. This is an especially useful tool to help age warblers -- I'll do a post in the future with some better examples of how we use feather shape to help age birds. Finally, note that the wren appears to have one extra tail feather. The tip of the second feather on the left looks split in two, but you can see the feather has only one shaft.

Wrens and sparrows haven't cornered the market on extra tail flourishes. We occasionally capture Cedar Waxwings that not only have those pretty little red waxy tips on their wing feathers (specifically the secondaries, or inner wing feathers), but also on the tips of their rects. I've also heard these waxy tips may occur in rare instances on the outer wing feathers (primaries) or the row of feathers over the wing feathers (greater coverts). The function or purpose of these waxy tips -- wherever they occur -- is not known.

We always keep our eyes peeled for these interesting little oddities.

RRBO in the Dearborn city calendar

That's right, I'm Ms. September.

A few months ago, the city of Dearborn had a contest. Residents were asked to submit short essays on why they loved Dearborn. The authors of winning entries would have their photo taken for the 2009 city calendar.

I wrote about my favorite thing about Dearborn: the great birds here on campus and the Rouge River Bird Observatory! Here is the page out of the new calendar. It features Dana Wloch, yours truly, Greg Norwood, Beth Johnson, and Mike Perrin out on the lakeside trail, and an inset of me holding a flycatcher accompanied by an excerpt from my essay. I'm a bit disheveled, which is typical for me on banding days.


You can see the entire two-page spread by downloading this PDF. This calendar goes out to every household in Dearborn -- great visibility for RRBO!

Recovery -- a rare event!

Since not very many banded birds are re-found away from the place they are banded, the majority of what we learn from banding birds comes from data we gather when we band them, and when we recapture birds on site. Nonetheless, every so often we hear about a recovery of one of our banded birds. These reports come from the USGS Bird Banding Lab, which administers bird banding in the U.S. We just got one this week, and it is quite special!

A Northern Waterthrush banded here on campus on 30 April 2007 was recaptured and released at Cedar Grove Ornithological Station in Sheboygan County, Wisconsin on 21 October 2008. The map below shows the location of Cedar Grove with a red marker, and our location in blue (click to enlarge).

How rare is this? Of the 32 recoveries that have been reported to us since 1992, this is only the 14th to have been reported outside the state of Michigan -- you can view an interactive map of all out of state recoveries here. Typically, these birds are found dead. The most common reason, if one is given, is that the bird has been killed by a cat. This waterthrush is just the third bird that has been captured and released by another bander. The others were a Yellow-rumped Warbler we banded in May 1997 that was recaptured in Tallahassee, Florida in March 1998, and a White-throated Sparrow banded in October 1999 that was recaptured on the Bruce Peninsula in Ontario in April 2006 (not a typo!).

But several more factors make the recovery of this waterthrush even more unusual.

1. The warbler and the sparrow are short-distance migrants, wintering in the U.S. The waterthrush is a long distance migrant. After we banded it, it probably nested in northern Michigan or Canada, then it likely spent the winter somewhere in the West Indies or perhaps Central America (you can view a range map here). Then it went north, nested again, and was headed back south along the western shore of Lake Michigan when it was captured at Cedar Grove.
2. Cedar Grove is a hawk banding station. For over 50 years, raptors have been banded at Cedar Grove, and small songbirds are only captured incidentally!
3. I've banded 167 Northern Waterthrushes during spring migrations, but only one has had a bill deformity...this one! So I happened to have photographs of it, which are below.

This slight deformity apparently did not hinder the bird prior to it being banded. It had a lot of fat, and at 22.1 grams, it was the second heaviest waterthrush RRBO has handled in spring, with the average being 18.0 grams.

Update: I've heard from one of the banders in charge at Cedar Grove. He told me that because they do not really "process" songbirds, the waterthrush was not checked for fat or weighed, nor was any abnormality noted. Bummer. I've caught only a few birds banded by other people (the last one was a Ruby-crowed Kinglet in 2005), but -- perhaps because I'm so astonished that it happens at all -- I give them a really thorough going-over.

Most banded birds are found not by other banders, but by regular folks. Here's what you should do if you find a banded bird.

The results are in: Fall 2008 banding summary

I have posted the fall 2008 banding summary on the RRBO web site. The numbers on the right sidebar are also updated. Also updated on the RRBO site are tables on the most commonly banded species and all the species banded on campus since 1992.

Just because the banding season is over does not mean I won't continue to post here at Net Results over winter. I have some posts planned on interesting bird tails, more on our thrush research, updates on publications, winter bird survey results, the Christmas Bird Count, and whatever else might unexpectedly come up. Please stay tuned.

The finale?

The last week or so has been a drag -- poor weather and poor health has kept me away from the nets for many days. The last couple of weeks of banding area always a challenge. Frosty nights mean frosty nets:
You can see the layer of frost on these closed nets. Often they are actually frozen shut, but even if they can be opened, it's like hanging out a bedsheet:

Not an effective way to catch birds! Nothing can be done but sit it out and wait for it to get warm enough for the frost to clear.

We did have our first Purple Finch of the season last week. Overall, about 80% of the birds we band in fall are young (hatch-year) birds. Young Purple Finches, male and female, have female-like plumage. So it's always cool to get a nice adult male like this one:

Purple Finches really are on the purple side of red -- a dark pink or raspberry color that distinguishes them from House Finches, which are red or orangish-red. Also note that Purple Finches really don't have much streaking on their sides. The abundant streaks of House Finches makes them look "dirty." Once you really get a good look at a Purple Finch, you'll see that it's easy to tell the two species apart. Banders have another clue: House Finches are pretty docile, but Purple Finches BITE!

We also had the last of the Orange-crowed Warblers. Other than Yellow-rumps, these are usually the final warblers to pass through.

Chipping Sparrows are very common on campus. This young bird was in our nets last week. It still has streaky juvenal plumage, especially the streaky cap. (And, no, I didn't spell that wrong. "Juvenile" birds have "juvenal" plumage.)

I've updated the stats on the sidebar again. I hope to be able to get in a few more hours next week as I begin removing the nets for winter. In many cases, I'd leave them up and see if I could extend the season, but a scout group will be coming in to put down landscape fabric and wood chips in the nets lanes. This will greatly reduce the pre-season net lane preparation for the next several years. I'm thrilled about it, so no complaints from me!

After it's all wrapped up, I'll update the stats and point you to the RRBO web site, where I will post a full summary of the fall banding season.

RRBO in the Metro Times

The Metro Times has come out with its annual Best of Detroit results. Readers are polled on their favorite things and places around metro Detroit, and the staff also gives its picks. The Metro Times picked the UM-Dearborn natural area as The Best Urban Getaway for 2008. The write-up notes:

"More than 250 bird species have been recorded by the Rouge River Bird Observatory, housed at the center. The observatory studies the role of this natural-amid-urban area as a stopover for migrating birds."

Many thanks to the Metro Times writers for the shout-out!