Sunday, May 27, 2012

Answers To Recent Quizzes (on right side of page)....

.....and from top to bottom as you scroll down, here's the solutions to the quizzes (on the right side of the page):

1. In a general sense, the correct answer is "all of the above."

But any one of the three species could qualify as the latest arrival, depending on the year and where you see either Blackpoll, Conn. Warbler, or Canada Warbler in the spring.

Most important, note that typical annual returning times for songbirds (including wood-warblers such as those noted in the quiz) may vary from one year to the next. Predicting the abundance of night-time migrants has improved with the usage of radar technology, but knowing when warbler species arrive is an imprecise science.

Beyond spring arrival dates changing from one year to the next, vagaries associated with weather, wind direction (among other factors that vary from year to year during the migration season), always influence the timing of returning migrating songbirds. (To further qualify: note that Midwestern vs. East Coast wood-warbler species spring migration pathways and arrivals often vary, with fall migration offering a different set of migration and abundance dynamics for some warbler spp. in both of these areas.)

We merely know general spring returning dates that usually range from two to three weeks in length for most of the 30 to 35 long-distance warbler migrants (among the approximately 55 wood-warblers that nest in North America.

Given the above information as a general over-simplification, all the quiz birds — Blackpoll, Canada Warbler, and Connecticut Warbler — during most years are latter returning species.

In the most extreme and exceptional cases, Blackpoll and Connecticut may not return until early
June in areas where in other years they may be spotted as early as the first or second week of May (e.g., southern Wisconsin latitudes). As for Canada Warbler, it's usually not considered as late a returning migrant as Blackpoll and Connecticut Warbler, though there's always an odd spring when anomalous results occur for migration dynamics.

For example, this season, I noticed during my annual spring trek to Wisconsin that early vanguard species — such as Palm and Yellow-rumped — mixed together with latter arriving species in the migration parade — Blackpoll, Connecticut, and Canada. In fact, Blackpoll was reported in early May in Wisconsin alongside Yellow-rumped Warbler individuals. Later in the month (from May 10 - 18 when I was present in Wisconsin), I noticed the same two species together where they don't breed and were obviously transients.

So, in sum, this year's warbler migration produced an odd result, given no true early and latter migrant species conclusions could be suggested. 

2. Easy one. Yellow-rumped Warbler are one of the most typical wood-warblers to be seen in northern climes during the non-breeding season. In recent years, it's not unusual to note them on Christmas Bird Counts in upper Midwest and mid-Atlantic and/or southern New England states. Some hardy Yellow-rumped individuals may remain into January and, perhaps, throughout the winter from mid-Atlantic states west toward the Midwest.

Which other wood-warbler species might rarely to infrequently be seen in northern climes during the non-breeding season? Common Yellowthroat, Pine Warbler, Yellow-breasted Chat, and Palm Warbler are the other leading species of interest when an "odd-ball" warbler is seen upon a winter landscape. 

Tuesday, May 22, 2012

Does Connecticut Warbler return by late May? Is Connecticut Warbler rare?

Although Connecticut Warbler is not rare, its habit of being a stealthy, skulking, "shy" species results it in being heard more often than seen. In addition, it breeds in habitats that are often inaccessible to birders, including spruce-tamarack bogs and muskeg (as well as poplar woodlands and moist deciduous forests) in northern Minnesota, Wisconsin, Michigan, and central Canada. Individuals return as early as early May to, for example, southern Wisconsin, but it's been known to arrive as late as early June in irregular years. In general, as returning migrant, this species is considered a "late" arriving member of the wood-warbler family. Did you know this warbler was not described until Alexander Wilson did so in 1812? A nest for this species was not discovered until 1883, more than 70 years after Wilson's description. Even today, there are few to no rigorous, experimental studies of its general biology from the breeding or wintering ranges.