Saturday, November 18, 2017

A Most Unexpected Irruption plus Sparrows of the Eastern US

[Southeast Michigan. Spring/Summer 2017]

Predictability and balance are the cornerstones of what passes as normality. A state that, uncontestably, marks our preferred state of stable, daily existence (or dare we say "drudgery"?) . 


However, it is the very unpredictability in birding that imbues it with the thrill of discovery. And, except perhaps the occasional rarity chase, there is seldom a more thrilling occasion in birding than the mystical event known as an "irruption". Irruptions are caused by an ecological imbalance that results in a sudden upsurge or "invasion" of a species into a region where they are normally absent. 


The astute reader will surely be profoundly aware of the Razorbill irruption in the Gulf of Mexico that this blogger had the distinct pleasure of witnessing in the Winter of 2012. And, now, we are pleased to report on the irruption of Dickcissel into Southeast Michigan in the summer of 2017 -- the full list of species includes this iconic species plus a delightful collection of sparrows:


  • Dickcissel
  • Eastern Towhee
  • Field Sparrow
  • Song Sparrow
  • Swamp Sparrow
  • Savannah Sparrow
  • White-throated Sparrow
We start with what appears to be a grosbeak-like, sparrow-colored songbird:




Seen at the I-94 Service Road in Macomb Co., this was a maiden sighting of this species for this blogger. A species of prairie grasslands in the American heartland, this songbird's last irruption to this region was in 2012.




Various theories have been postulated as to the reasons behind an irruption -- a shortage of food, or a drought; maybe climate change and warming temperatures, or perhaps lack of suitable nesting conditions. Whatever the reason, their arrival is celebrated and observation opportunities fully availed.

Next, a large sparrow - the Eastern Towhee:






A loud songster, this sparrow with a bold black hood, red eyes and brown flanks is hard to miss.





Field Sparrows give themselves up by virtue of their "bouncing ball" song. A thin white eyering and pink bill and legs are also distinctive.






Far more commonly found is the 
Song Sparrow:







Swamp Sparrow is aptly named and never found far from marshy areas:



Savannah Sparrow, on the other hand, is seen in grassy areas:








Finally, White-throated Sparrow was observed in migration at Lake St. Clair:




These bold sparrows can be fairly common in migration:




Baltimore Oriole is our bonus bird. Here seen at Wetzel SP.



The underlying causes behind ecological forces are not always clear to us. However, the resulting symptoms -- such as irruptions and invasions -- are not only observation opportunities but also natural history events that warrant further scientific investigation.

Tuesday, November 14, 2017

Hawks, Gulls and Herons feautirng Bonaparte's Gull and Sharp-shinned Hawk

[Lake St. Clair Metropark. Aug/Sep 2017]

Not every post need center around flashy songbirds or intriguing shorebirds. The avifauna universe has many more riches to offer including familiar gulls, herons and hawks. Yet these -- unheralded as they are -- are neither scarce nor exalted and barely attract a second look from the otherwise insatiable birder. This, then, is the subject of this post -- for, commonplace need not equate with uninteresting as we consider the following eclectic set: 
  • Bonaparte's Gull
  • Great black-backed Gull
  • Ring-billed Gull
  • Herring Gull
  • Caspian Tern
  • Green Heron
  • Great Blue Heron
  • Sharp-shinned Hawk
  • Red-tailed Hawk
  • Northern Flicker
We start with Bonaparte's Gull:




In August, this delicate gull is an early migrant and the extensive grey-brown on the wings indicates that this is a juvenile. The slender bill and pink legs are distinctive.


From a dainty gull to a brawny one -- the Great black-backed is our largest:



This particular individual is a sub-adult.

Indubitably, the most numerous gull is the Ring-billed:



Commonly found at this venue -- these opportunistic feeders, however, are equally at home in the suburban sprawl of SE Michigan.


A juvenile Herring Gull is our 4th gull in the series:



Caspian Tern tend to more skittish than the gulls and the juveniles miss no opportunity to get a free lunch:




From the larids, we move on to the herons -- Green Heron was spied at Textile Rd Pond as well as Lake St. Clair:



An erect crest betrays this small heron's excitement while hunting:



Great Blue Heron is at the other end of the Heron spectrum -- large and imposing:



This heron took advantage of a high vantage point:



On the predator front, a female Sharp-shinned Hawk was observed hunting a squirrel:




Note the squarer tail and rounder head that distinguishes it from Cooper's:


While this raptor is a woodland hunter, Red-tailed Hawk favors open ground: 






Other familiar species included a splendid flyby of Canada Goose:


A female mallard in the wet grass:


And a foraging Northern Flicker:


To conclude, we offer a bonus mammal -- a white-tailed deer and fawn:




While we may harbor positive bias towards our favorite bird families such as warblers and buntings, we must however acknowledge that even the humbler gulls and herons can offer interesting insights into the natural history of our environment.