Monday, October 19, 2015

Introducing Craves’s Giant Barn Owl!

I recently received a great honor: a new (albeit extinct) species of owl was named after me. Craves’s Giant Barn Owl (Tyto cravesae) was recently described based on fossils discovered in Cuba by my great friend William Suárez. The bird was described in a recent paper published in the journal Zootaxa, Systematics and distribution of the giant fossil barn owls of the West Indies (Aves: Strigiformes: Tytonidae) by William, formerly a curator of the National Museum of Natural History and now living in the U.S., and Storrs L. Olson of the Smithsonian Institution.

An artist's rendering of Ornimegalonyx
at the Museo Nacional de Historia Natural
de Cuba. Even bigger than Tyto cravesae!
Photo by Darrin O'Brien.
The bones of this owl were discovered in a cave complex in Cuba by William in 1998, and subsequently in several other locations in Cuba. The paper reviews and revises previously described species, with two of those being synonymized with two others. Thus Tyto cravesae becomes the fourth extinct giant barn owl described from the West Indies.

These owls were all larger than Tyto alba, the common Barn Owl found across much of the world today, including in North America. Based on the bones found, Craves's Giant Barn Owl was likely somewhat larger than a Great Horned Owl. There were also even larger prehistoric owls in Cuba in the genus Ornimegalonyx, estimated to be a meter or more tall!

The cave deposits date from sometime in the late Pleistocene (the epoch ranging from 2.5 million to around 12,000 years ago), and include the bones of prey items.  Craves's Giant Barn Owl fed on large rodents and small mammals. The lack of other predators on mammals besides giant birds in the West Indies is the main reason these owls evolved into such large forms. "My" owl probably often preyed upon hutias, a group of rodents endemic to the Caribbean region; one species identified with the Tyto cravesae bones was that of the Cuban or Desmarest's Hutia (Capromys pilorides). The giant Antillean owls probably became extinct due to the loss of their prey species.

I got to know William during several U.S. licensed trips to Cuba in the early 2000s in which I assisted with and lead bird surveys throughout the island. William is a leading authority on Caribbean birds and mammals, both living and extinct. He has written or co-authored many papers as well as a book, and described and named several other new genera and species of birds. Over the years, we kept in continuous touch both as friends and colleagues.

In the paper describing Tyto cravesae, the section describing the naming of the species states: "After Julie Craves, of the University of Michigan-Dearborn for her dedication to avian conservation and her boundless appreciation of Cuban friends and birds." 

No matter what he has encountered, William has persevered with remarkable optimism and good humor. His strength and accomplishments have been a continual source of inspiration to me.  I am incredibly honored that he chose to name this new species of owl after me, when the true honor has been mine, simply having the opportunity to be his friend.

Julie Craves and William Suárez at the Big House, August 2014.
Read more at the BirdWatching Magazine blog, where William and I responded to questions from editor Chuck Hagner. In 2002, I also wrote an article for the magazine, The Birds of Cuba. In 2003, colleague Kim Hall and I published a paper on some of the survey's findings in the Journal of Caribbean Ornithology, Notable bird sightings from Cuba, winters 2002 and 2003 (pdf).

Monday, October 12, 2015

Yellow Rail - Dearborn species #261

Another new species has been added to the Dearborn checklist. I received, through a chain of 6 people, a clear photo of a Yellow Rail at the Ford Rouge Plant from October 8. It was at a building near the Dearborn Truck Plant. There is wetland/pond habitat at the visitor center of the plant, adjacent to the truck plant that the bird may have been attracted to. I do not have permission to post the photo, but there is no doubt of the identity of the bird. 

I have no information how long/if the bird remained, but there is no public access to most of this facility. The photo showed the bird near a building. This could indicate it was injured, but I have heard of rails, including Yellow Rails, showing up in unusual locations like this during migration. Yellow Rails often try to flee by running and hiding rather than flying, yet may appear so tame as to emerge from marsh vegetation at an observer's feet. Thus, a good photo of an ambulatory rail doesn't necessarily indicate that the bird needed "rescuing."

Yellow Rails are secretive, marsh-dwelling birds that are hard to find even at known breeding locations, such as Seney National Wildlife Refuge in the Upper Peninsula. The species is listed as State Threatened in Michigan.

Wednesday, July 8, 2015

Peregrine Falcons nesting in Dearborn

[Update: The jury is still out on the band number and identity. Barb Baldinger writes: "We clearly saw 6/M, but want a better look. It could be 66/M and we only saw the second 6, the space and first 6 in the way the numbers are repeated. If that is the case, he is one of ours, Iggy from UD Mercy, Detroit, hatched in 2011."]
Dearborn regularly hosts Peregrine Falcons, mostly in winter. The most "famous" of these was a Kentucky-born female named "Ember" who hung around in 2010. We knew her history based on the color and alpha-numeric codes on her leg bands.

This site probably has the best explanation on how to "read" Peregrine leg bands. If one is able to get a clear look at the bands and is in the 13-state, 2-province (ND, MN, WI, MI, SD, NE, IA, IL, IN, OH, KS, MO, KY, SE MB, and NW ON) midwest region, the Midwest Peregrine Society's database can be searched for more information.

A favorite location for falcons around here are the Parklane Towers on the north side of Hubbard east of the Southfield Freeway. The tall concrete buildings must look like cliffs, and there is ample hunting in the planted fields, urban areas, and the concrete channel of the Rouge River nearby. In 2013, a pair of Peregrines were present at the towers. At least one was banded, but the bands could not be read. They apparently raised at least one chick.

Last year, a pair returned, but left again in May. One returned in the summer, for a few days but left again.

Two Peregrines were seen over the winter of 2014-2015, and by April seemed to be tending a nest on the roof of one of the towers. Last month, a juvenile bird was seen by the southeast Michigan Peregrine monitors, and the bands of one of the adults was read: black-over-red, 6 over M-- or (b/r) 6/M in shorthand. However, this combo did not get a hit in the database. Grrr....

As a bander, I know that some bird bands have a "silent" leading zero (e.g., the physical band shows 932-12345, but all associated data is really assigned as 0932-12345). There IS a falcon in the database under (b/r) 06/M, a male hatched on 12 May 2012 in Vernon County, Wisconsin named "Drew." He was part of a brood from two unbanded Peregrines nesting at the the Dairyland Power Cooperative's Genoa generating station, on the Mississippi River just south of La Crosse (where my husband grew up). The company has had a nest site 375 feet up on a smokestack at the plant since 1997 as part of a Peregrine restoration program.

Hopefully, Chris or Barb (the monitors) or an occupant of one of the buildings will get a better look or photo of the bands and we can confirm the identity.

I went by last week and found this interesting scene.

An adult falcon was watching the window washers start down the opposite building.
Perhaps I should have stuck around to see how that turned out!

Wednesday, July 1, 2015

Grasshopper Sparrows nesting in Dearborn

[Update: As of late July, the sparrows are still present. The vegetation is high enough that it is not possible to tell if they are feeding young without going out into the field, so we are unlikely to confirm this. However, their presence on territory this long indicates they have likely nested. Here's a link to an article Oakwood posted about the sparrows.]

On 26 May, long-time RRBO volunteer and contributor Mike O'Leary found several singing Grasshopper Sparrows in the vacant lot at Rotunda and Southfield. This lot was once the site of some Ford Motor Company buildings, which were torn down around 2003. It is now managed by the Oakwood Physical Therapy & Wellness Center. Even after all these years, the footprint of the old buildings on the easterly portion of the property closest to the Southfield Freeway and service drive can be seen.

Up to four singing males continued at the site in June. Grasshopper Sparrows are considered a Species of Special Concern in Michigan, a status just below the legally-protected status of Threatened. In addition to a significant population decline statewide, surveys have shown that their numbers have decreased 4% annually in Michigan from 1996-2007. During the Michigan Breeding Bird Atlas period in 2002-2007, Grasshopper Sparrows were only confirmed nesting in one western township in Wayne County. While Grasshopper Sparrows probably nested in Dearborn at some point prior to 1900 or so, there have been only a handful of records of spring migrants since the 1970s, and just one summer record of one individual. These territorial birds represent the first likely nesting in the city in modern times.

Low grasses and taller forbs (mostly sweet clovers, Melilotus ssp., and fleabanes,
Erigeron ssp.,) in the area favored by the sparrows.

Not all grasslands or fallow land is equal to the various species of grassland birds. Grasshopper Sparrows have a strong preference for habitat that is mostly grasses and forbs (herbaceous weeds) which are not densely distributed, interspersed with bare ground (up to 20%), and few or no shrubs. The portion of the site that once had buildings on it have numerous patches of bare ground or sparse vegetation on the former building footprint, and most of the sparrows have been found there.

Patches of bare ground are required by Grasshopper Sparrows.
Because it is adjacent to the freeway, the insect-like song of the Grasshopper Sparrows are very difficult to hear! The field is also full of dozens of nesting Savannah Sparrows, Red-winged Blackbirds, and Killdeer, among other species. They make quite a ruckus, but we believe there are still likely up to four singing male Grasshopper Sparrows and, due to their duration at the site and the persistence of the location of at least one of the males closest to the parking lot, they are likely nesting. Because we do not want to risk stepping on the ground nests of any sparrows or disturbance to any birds, we've restricted our regular surveys to the edge of the property after I made one thorough walk-through. After I notified Oakwood of this special bird, they instantly stepped to the plate and made plans to postpone any mowing of the field until August, after any young should be fledged and independent.

We will be keeping an eye on the sparrows to see if we can catch them feeding young in the next few weeks. Many thanks to Oakwood for the stewardship of these special birds.

Thursday, March 5, 2015

Winter Bird Population Survey 2014-2015

The 23rd year of RRBO's Winter Bird Population Survey has been completed. December started out pleasantly but the survey season ended with a snowy and bitterly cold February. Weather aside, it was a fairly average year. The 14 survey days over the late December to late February period was typical. Surveys totaled about 23 hours, which is 6 hours below the 29 hours that are average, but represent the shortage that took place on our Christmas Bird Count day.

The 34 species tallied was a little below the 22-year average of 38, but can be partially explained by some habitat changes and restrictions. Access to the Rouge River behind Fair Lane Estate was greatly restricted due to being fenced off for riverbank restoration; vegetation along this area also removed. The river was frozen much of the period, and no waterfowl were counted after January 1. No Belted Kingfishers were recorded; they have only been completely missed on a few other counts.

Heavy construction activity along Fair Lane Drive also impacted bird activity along eastern edge of survey area. This construction will be continuing through summer, and likely also have an effect on spring surveys.

Eleven species were found on all 14 survey days. In descending order of abundance they were: House Sparrow, House Finch, Northern Cardinal, Blue Jay, Black-capped Chickadee, Dark-eyed Junco, Downy Woodpecker, White-breasted Nuthatch, Tufted Titmouse, Red-bellied Woodpecker, and Hairy Woodpecker -- all feeder birds.

Despite the availability of feeders, most sparrows were recorded in numbers well below average. Only a single Song Sparrow was recorded, while the previous season total average is 13. One or two American Tree Sparrows were recorded several times, but the previous season total average is 34. White-throated Sparrows have been common winter residents here, especially over the past decade. A total of 25 were counted this year, with an average per survey of 1.7, the lowest numbers since 2002. The previous 22-year means were 80 per season and 6 per survey; these averages since 2003 were 157 and 9. Juncos were also counted in below average numbers, although not as drastic. I'm not sure exactly what might have contributed to the depressed numbers of ground-feeding seed eaters, except that a lot of understory vegetation has been removed and perhaps there is less cover.

Fruit-eating birds were largely absent. No Cedar Waxwings, Hermit Thrushes, or Yellow-rumped Warblers were recorded. Most days there were no American Robins present, the maximum number on a survey day was 3. This represents the second lowest number of American Robins in 23 years. Fruit-eating species were generally scarce on local winter bird counts this winter, so it's hard to tell what impact the removal of fruit-bearing non-native trees and shrubs that was undertaken by the university may have had on these numbers.

The highlight was probably the Pine Siskins that were present in small numbers through mid-January. They moved on from here (and other places locally) and had not moved back through on their way north by the time the survey period ended. This was the only one of the "irruptive" species present on campus this winter.

All the numbers from this year are on the RRBO web site, along with past counts and the history and methodology of the survey.