Due to the prevalence of mild south
winds these last few weeks, banding at the Muskegon Lake Nature
Preserve has been especially productive since late September. While
few neotropical migrants remain in Michigan after October 1, most
species of sparrows and other temperate migrants peak this
month.
Among these, White-crowned Sparrows have been particularly numerous. On average, we catch our first White-crowned Sparrows on September 25. Numbers of adults peak on October 7, and immatures peak five days later. Seasonal totals over the previous six autumns have varied from 13 in 2012 to 160 in 2011. This year, White-crowned Sparrows were first captured on September 26, and they have remained plentiful since then. With exactly 200 banded so far this season, we have handily surpassed the previous record.
Among these, White-crowned Sparrows have been particularly numerous. On average, we catch our first White-crowned Sparrows on September 25. Numbers of adults peak on October 7, and immatures peak five days later. Seasonal totals over the previous six autumns have varied from 13 in 2012 to 160 in 2011. This year, White-crowned Sparrows were first captured on September 26, and they have remained plentiful since then. With exactly 200 banded so far this season, we have handily surpassed the previous record.
White-throated Sparrows, our most common species, have also been quite plentiful, and our first Fox Sparrow appeared on October 9. Lincoln's Sparrows (above photo) are relatively scarce in Muskegon County, so seven banded at the preserve this fall is a respectable figure.
However, our most
interesting record has been the first capture of a Clay-colored
Sparrow at the preserve. This adult was banded on October 8.
I have been continuing the annual
Wastewater Shorebird Surveys three days each month. Numbers and
diversity during each session have remained above average, but totals
have steadily dropped since the big August concentrations. Twenty-three species have been seen this fall.
To help assess the justification and efficacy of the gull removal program at the Wastewater lagoons and landfill, I am also carefully counting all the gulls during each survey. While Ring-billed and Herring Gulls obviously constitute the vast majority, several other species occur fairly consistently during the cooler months. The highlight today was this adult Mew Gull along the west lagoon.
Finally, a waterbird count at Hoffmaster State Park this morning produced 241 southbound Bonaparte's Gulls.
- Brian Johnson
To help assess the justification and efficacy of the gull removal program at the Wastewater lagoons and landfill, I am also carefully counting all the gulls during each survey. While Ring-billed and Herring Gulls obviously constitute the vast majority, several other species occur fairly consistently during the cooler months. The highlight today was this adult Mew Gull along the west lagoon.
Finally, a waterbird count at Hoffmaster State Park this morning produced 241 southbound Bonaparte's Gulls.
- Brian Johnson
5 comments:
California is a really nice find, the MBRC website only has 22 records to date. I'd be interested in hearing more about the gull removal program.
As best as I understand, droppings from large numbers of scavenging gulls has created hazardous work conditions to employees working the landfill. Consequently, the Fish and Wildlife Service has authorized the destruction of all the Ring-billed Gull nests on the center dike at the Wastewater. Last summer was the second year of the program, and many thousands of nests have been destroyed. However, there have been concerns that the gulls foraging at the landfill are not the same as those being targeted for elimination. This is particularly true during the winter months when Ring-billed Gull numbers tend to be quite low.
Brian-
Helluva find on the CAGU. Sidenote: would you be willing to call me or post word of this species to Mich-Listers immediately when you find them in the future? There are many birders in Michigan who have been trying for years to see one without success (myself no longer included http://ebird.org/ebird/view/checklist?subID=S8296876 )
Also, isn't the sparrow in your top photo a Swamp Sparrow?
Good Birding,
Caleb
The sparrow at the top is definitely a Lincoln's, but the confusion is my fault. I should have posted a better image rather than one so horribly over-exposed that the chest streaking is hardly visible. Plus, the wing hides the streaking on the sides and flanks. However, this does highlight the importance of secondary characters. Both adult Lincon's and Swamp Sparrows are variable in plumage coloration and streaking - the latter species especially. I find the facial pattern helpful. The thin yet distinct malar and sub-auricular streaks combined with buff sub-moustachial stripe and auriculars typifies Lincoln's. Some Swamp Sparrows have chest streaks, but they are less fine, generally restricted to the upper chest, and have a different background color. Such birds usually have a partly yellow supercilium. Lincoln's Sparrows always have a solid gray supercilium. When Swamp Sparrows have an all gray supercilium, they also show very little streaking on the underparts. (Fall White-throated Sparrows also show a relationship to supercilium color and chest streaking.)
I find wing coloration to be more useful. My measurements indicate that the two species have the same average mass and tarsal length, and very similar wingspans and tail lengths. Juveniles of the two species are both streaked and very similar in appearance. However, Swamp Sparrows have a chestnut hue on their lesser, median and greater coverts, and on the inner secondaries. The same areas are plain brown on Lincoln's Sparrows. This is the best way of separating juveniles.
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