2012 continues to be an excellent year for observing warblers in Manhattan. An ardent birder (with flexible hours to leave work and chase rarities!) would have had multiple chances to get 35 of the 36 warblers that regularly pass through Manhattan in either spring or fall migration, and one chance — this last Wednesday the 19th in Strawberry Fields — to get the remaining one, the Golden-winged Warbler. [Note that after this entry was published, another Golden-winged appeared briefly on September 29th in the Maintenance Meadow.] The complete list:
|18||Cape May Warbler|
|27||Black-throated Blue Warbler|
|33||Black-throated Green Warbler|
Starr’s walks have produced 34 warbler species, an stellar total with plenty of chances left to see the other two (Golden-winged Warbler and Connecticut Warbler, both fall migrants that have appeared within the last week in Central Park).
Of course, some warblers are more common than others. The eBird site allows you to graph the “frequency” of bird species in a given area. The “frequency” of a species is defined as the percentage of lists submitted in a given week on which the species appears.
For a common warbler, consider the Yellow-rumped Warbler. It’s peak frequency occurs historically the first week of May, when 69% of birder-submitted lists have at least one Yellow-rumped on them. Think you’ve seen a lot of American Redstarts lately? This is no surprise, as the Redstart has its peak frequency of 68% during the second week of September.
A warbler of mid-range rarity is the Chestnut-sided Warbler, which peaks at about 30% in the spring and 23% in the fall. Another would be the Black-throated Green Warbler, a bit easier still at 43% in the spring and 24% in the fall. The Nashville Warbler peaks at 31% during the first week of May and 9% during the fall.
Now for the hard warblers. Most of these are rare enough to merit a text alert to NYNYBIRD or a posting on ebirdsNYC. The Cape May Warbler peaks at 17.6% during the second week of May. The Bay-breasted Warbler peaks at 13.4% in the third week of May. Neither gets above 3.4% during the fall season. The Blue-winged Warbler only peaks at 12.9% in the spring, in the last week of April, yet most would consider it a much easier find than the other two. I certainly would not put out an alert on it in season.
Other hard warblers would be the Blackburnian Warbler and the Prairie Warbler — both peak at around 23% in the first week of May and do not get above 6% in the fall.
The Hooded Warbler is very hard to get. It peaks at 7% during late April and early May, and less than 3% in the fall. The Mourning Warbler peaks at 6.7% in the spring and is little-seen in the fall (at least until this year). The Worm-eating Warbler is only a tad easier (using pre-2012 records), peaking at 10% in the first week of May. This year a very cooperative Worm-eating Warbler hung out in the Upper Lobe from early July through early September, making the species appear much more common than it usually is.
The six toughest warblers are rarer still. Some are not recorded every year in Central Park. Here they are, along with their peak frequencies:
Starr’s walks have had four of these six!
What makes 2012 so unusual is that many of these rarest warblers were reported frequently and seen often. Prothonotary Warbler was reported at least five times in Central Park (the first one occurred on Starr’s walk and our group was treated to great views in the Loch), and there was a Prothonotary that lingered at Bryant Park for over a week. Cerulean Warbler was reported four times in Central Park (one was found by Starr by the Meer) and once in Riverside Park. Yellow-throated Warbler had a widely-seen appearance in Riverside Park and at least two others in Central Park (Starr helped re-find the first one in Central Park and many in her group got to see it). A Kentucky Warbler lingered around the Shakespeare Garden area for over a week beginning in late April; another appeared in May in the North End. In late August, yet another lingered by the Loch. This is amazing, considering how many years that the Kentucky Warbler does not appear in Central Park at all. And yes, our group got to see the Kentucky Warbler at both ends of the Park.
Just a week ago a Connecticut Warbler was sighted on the lawn in Bryant Park, offering great, unobstructed views to those many who responded to the bird alert quickly. Prior to that there were two other Central Park reports in which the bird was seen only briefly by a single reporter. Then this morning, Sunday, September 23rd, another was found in Tupelo Meadow. Over 30 birders assembled and waited 90 minutes for the bird to reappear, after which they saw it walking through the tall vegetation just north of the meadow.
So what’s going on? Why so many more observations of rare warblers? We should not be too quick to extrapolate from one year of experience and a handful of sightings. It is possible that some species are responding to climate changes with different migration paths. I am not qualified to speak to this issue.
I do know that more birders are embracing technology and reporting what they see. They post their lists to eBird, which not only does a super job of organizing what they’ve seen but also allows other birders to immediately learn of rarities as soon as they are reported. They post to local news groups such as eBirdsNYC and state-level boards such as the one run now by the American Birding Association for New York, formerly called Birdingonthe.net. Those with smartphones can post right from the field. So, though there may not be more rare birds, there probably are more reliable rare bird reports than ever before.
Not only do more birds get reported publicly but also reports are timelier, allowing more birders to get to the bird before it flies away. The fastest and simplest system for Manhattan birders is NYNYBIRD, which works with any cell phone that can send and receive text messages. Within seconds of a sighting you can alert all subscribers as to what you saw and where you saw it. This morning’s Connecticut Warbler was reported on NYNYBIRD, and within ten minutes dozens of birders had arrived in Tupelo Meadow to see it. A fuller explanation of NYNYBIRD can be had here.
2012 is giving Central Park birders many rare and memorable sights. Starr and Lenore look forward to helping you enjoy more of them in the coming month.