Warblers (11), Red-breasted Nuthatches + Eastern Screech-owls: August 2020

Mourning Warbler on 23 June 2020 in St. Lawrence County by Deborah Allen
Red-breasted Nuthatch at the Pinetum (Central Park), 22 October 2018 by Deborah Allen

19 August 2020

Bird Notes: We've got an OWL WALK (Thursday evening, 20 August) at Inwood Hill Park meeting at 7:30pm - details, and photos, below. Weather is supposed to be cool and dry with light winds on Thursday night - ideal for finding Eastern Screech-owls.

Last Friday-Saturday (15-16 Aug) the fall migration finally arrived in the form of warblers! Our group tallied 11 warbler species on Saturday. Just as importantly we found 7 Red-breasted Nuthatches, an irruptive species - meaning when we see them on migration it is not by ones and twos but by the dozen. In this week's Historical Notes we present (a) an explanation (hypothesis) why Red-breasted Nuthatches head south in large numbers ("irrupt") in some years, and are hardly seen in others. Is it related to climate, or food abundance in the north (seeds), or a good breeding year and simply more birds around to head south? In (b) scientists seek to explain the irruption of all winter finches such as Pine Siskins, Evening Grosbeaks (+Red-breasted Nuthatches) and others as the result of a favorable year for seed production with good breeding success: winter finches stay "home" in the boreal forest in such years. If this is followed by a year in which there is poor seed production due to drought, excessive warmth or simply "exhausted" trees - all of which affect seed production, winter finches migrate south in large number or "irrupt" - and we seen them in our area in large number. Finally, historical note (c) is an obituary of Farida Wiley (1887-1986) who led bird walks in Central Park for approx. 45 years (1938-1982). The obituary gives a wonderful glimpse of how birding in the park changed during that time...a highly recommended read.

Mexico. Male Gray Silky-flycatcher, between Los Pescados & El Conejo, Veracruz (MX). Tuesday February 18, 2020 by Deborah Allen

Eastern Screech-owl at Inwood Hill Park (Manhattan), 15 August 2019 by Deborah Allen

Bird Walks for mid to late August

All Walks @ $10/person - All walks in Central Park

Directions to All Meeting Locations can be found here

1. Saturday, 22 August at 7:30am and again at 9:30am - Boathouse Cafe; 74th street/ East Drive $10

2. Sunday, 23 August at 7:30am and again at 9:30am - Boathouse Cafe; 74th street/ East Drive $10

If you do the 7:30am walk you can do the second (9:30am walk) for free. You get two for one. Weekend walks will continue through August and into December. If there is interest/demand, we will add Monday and Friday morning walks starting in mid to late August. Let's see how this develops, or not...


3. Thursday evening, 20 August at 7:30 pm at Inwood Hill Park [Manhattan] for Eastern Screech-owls. We will be out for about 90 minutes...bring a light mosquito repellent (10% or less deet) for bare legs/arms. Bring a tiny flashlight (and if not, don't worry use your phone as a flashlight...and I will have a powerful flashlight - good for photographers). Meet at 7:30pm at the Indian Road Cafe (It may be closed due to Covid 2019, but if it is open it has nice bathrooms; air-con...has a bar and also restaurant). Here is a map and if you plug in your starting point, you should get directions:


Otherwise, this is the web site of the Indian Road Cafe: http://www.indianroadcafe.com/

And here is the address of the corner where we meet at 7:30pm:

600 W 218th Street in 10034

If you are driving, give yourself an hour to find a parking space...this is important!

Call/Email us with questions: rdcny@earthlink.net

Virginia Rail at Pelham Bay Park in the Bronx by Deborah Allen on 4 June 2020

Eastern Screech-owl at Inwood Hill Park (Manhattan), 13 Oct 2019 by Jonathan Slifkin

The fine print: Our walks on weekends meet at 7:30/9:30am at the Boathouse Restaurant (approx. 74th street and the East Drive) through mid-March 2020. Please note: the Boathouse is not one of the buildings that surround the nearby Model Boat Pond - people make this mistake all the time!

Our home phone is 718-828-8262...and Deborah's cell is: 347-703-5554. Email is (rdcny@earthlink.net). If you are lost and trying to get to the bird walk, call Deborah's cell phone...but remember on weekends there will be 2-3 other people calling who are also lost - please be patient. If in doubt about whether a walk will take place or not the morning of the walk: check the main landing page of this web site as well as the "Schedule" page - if the walk is cancelled, information will be posted there by 6am the day of the walk, and usually by 11pm the night before. If still confused and as a last resort, call us at home - if no one answers it means we left for the bird walk. We end all our Central Park walks (except Fridays) at the Boathouse at about noon; you can get a cup of coffee and a muffin there (around $6 total) - though the Boathouse is closed right now and will re-open...no one knows quite yet. Walks last about 3 hrs (less if hot or rainy), and you can leave at anytime - we won't be offended. If you need directions/help to your next destination, just ask someone on the walk - we are a helpful group.

Rough Grouse, St. Lawrence County in upstate New York by Deborah Allen on 22 June 2020

Bald Eagle from 16 September 2016 at Pelham Bay Park (PBPK) in the Bronx. Bald Eagles begin migrating south to Florida in August after spending the summer in Maine, and will then nest in FLA. On 17 August 2020, three of us including Patrick Horan and Deborah Allen watched a fourth-year Bald Eagle, just like the one above, steal a fish from an Osprey.

Here is what we saw last week (brief highlights)

Sat-Sunday, 15-16 August 2020 (Boathouse Restaurant at 7:30am and again at 9:30am): Please note: the bathrooms at the Boathouse are NOT open. However, we do pass two other sets of bathrooms on the walk. Saturday was the first big day for southbound (autumn) migration - though overall numbers were low for most species, we did get a very good 11 Warbler species. Our most significant find came towards the end of the walk when we called in (using my recorded chip sounds) a first-year Mourning Warbler (photo below), sex undetermined...We also found the season's first Prairie Warbler and Chestnut-sided Warblers. In addition we added Blue-grey Gnatcatcher (first of season) and Least Flycatcher. However, however one cannot forget that we found 7 Red-breasted Nuthatches (RBNUs), again using calls from my tape/speaker. The first ones in the region were seen on 13-14 August in Connecticut, and then one in Queens on 14 August. In "irruption" years, on average, we see the first RBNU in mid-July, and rarely, in late June (see historical note #3 below). This year we have had a hot summer, with almost all days with winds from the south until this past Thu-Fri nights (14-15 Aug), when winds switched to coming from the north, and the weather immediately became cooler and less humid. Like surfers on a wave came the migrants - all those different warblers and the RBNUs. Will more flights of RBNUs follow? You'll have to join us for a bird walk to see...and see how much fun they are as they come in very close to us, sometimes 3-4 at one time. On Sunday, 16 August, it rained...and was miserable. However, several nice people showed up (happy birthday Andrea Hessel MD)...and the most significant birds we found were three RBNUs together at the Pinetum..

Deborah's List of Birds for Sat. 15 August: https://tinyurl.com/y4p9c6ny

male Yellow Warbler by Deborah Allen at Pelham Bay Park in the Bronx on 6 June 2020

Mourning Warbler (hatch-year) at Shakespeare Garden on 15 Aug 2020 by Deborah Allen



Winter Movements of Sitta canadensis (Red-breasted Nuthatch) in New England: A Multiple-scale Analysis

W. Herbert Wilson Jr and Bets Brown

Northeastern Naturalist March 2017: Vol. 24, Special Volume 7: Winter Ecology: Insights from Biology and History, pg(s) B135- B146


We analyzed 55 years of abundance data (1960-2014) for Sitta canadensis (Red-breasted Nuthatch) to seek patterns of winter irruptions on temporal and spatial scales. This species shows an erratic pattern of irruption into southerly areas from its northern breeding areas. Irruptions show a broad geographic synchrony. At the narrower level of the state or province and even more so at the level of individual counts, correlations of abundance in adjacent areas become weaker. The abundance of irruptive birds is best considered a mosaic. At the regional scale, correlations of Red-breasted Nuthatch abundance with irruptive northern finches that also depend on conifer seeds are weak to absent. The data suggest that birds irrupt because of failure of conifer seed production on the breeding grounds, not because the birds are seeking masting conifer stands to the south.

Red-breasted Nuthatch in Central Park by Jeff Ward (cell phone photo)

26 Sept 2015

Climatic dipoles drive two principal modes of North American boreal bird irruption

Courtenay Strong, Benjamin Zuckerberg, Julio L. Betancourt, and Walter D. Koenig

Proceedings of the National Academy of Sciences: Published online May 11, 2015


Pine Siskins [photo below] exemplify normally boreal seed-eating birds that can be sparse or absent across entire regions of North America in one year and then appear in large numbers the next. These dramatic avian "irruptions" are thought to stem from intermittent but broadly synchronous seed production (masting) in one year and meager seed crops in the next. A prevalent hypothesis is that widespread masting in the boreal forest at high latitudes is driven primarily by favorable climate during the two to three consecutive years required to initiate and mature seed crops in most conifers.

Seed production is expensive for trees and is much reduced in the years following masting, driving boreal birds to search elsewhere for food and overwintering habitat. Despite this plausible logic, prior efforts to discover climate-irruption relationships have been inconclusive. Here, analysis of more than 2 million Pine Siskin observations from Project FeederWatch, a citizen science program, reveals two principal irruption modes (North-South and West-East), both of which are correlated with climate variability. The North-South irruption mode is, in part, influenced by winter harshness, but the predominant climate drivers of both modes manifest in the warm season as continental-scale pairs of oppositely signed precipitation and temperature anomalies (i.e., dipoles). The climate dipoles juxtapose favorable and unfavorable conditions for seed production and wintering habitat, motivating a push-pull paradigm to explain irruptions of Pine Siskins and possibly other boreal bird populations in North America.

Pine Siskin at the New York Botanical Garden (Bronx) on 12 November 2008.

Autumn 2008 and Autumn 2019 were big "irruption" years for this species, but we are not expecting them this August-December.

Red-breasted Nuthatches - Central Park, NYC & NYBG (BX)

Date: 26 June 2018

by Deborah Allen

Prompted by the discovery of a Red-breasted Nuthatch in the Central Park Ramble Sunday Morning (24 June 2018) with a photo posted on twitter by @jian_birdcp (see https://twitter.com/birdcentralpark for details), Bob found at least three Red-breasted Nuthatches today in the extensive conifer plantings at the NYBG in the Bronx.

The last time Red-breasted Nuthatches appeared in NYC this early was in 2016, when we found two on Saturday June 25 at NYBG in the Bronx on our Saturday morning bird walk. The following day, Sunday June 26, again on our bird walk, Jeff Ward found one on the east side of the Ramble in Central Park

That same week in June 2016, others had previously reported seeing early arriving Red-breasted Nuthatches in New Jersey as well as Connecticut on their respective state lists. Autumn 2016 proved to be an irruption year for Red-breasted Nuthatches until mid-October when the numbers of birds reported declined significantly in our area.

Twitter, particularly the different alerts for each NYC borough, has been invaluable in getting immediate information out to interested persons - and has helped birders to communicate with each other in real time. Thank You to David Barrett for setting up these alerts.

There does not appear to be any correlation between irruptions of Red-breasted Nuthatches and irruptions of winter finches, as this 2005 post from the Delaware list points out:

"Probably the greatest year for winter finches was 1969-1970, which was also a good year for Red-Breasted Nuthatches. 1977 was another good winter finch year, but there were almost no RED-BREASTED NUTHATCHES found. 1982 was a good year for RED-BREASTED NUTHATCH, but there were only PURPLE FINCHES in the area. Despite all efforts, there doesn't seem to be a correlation between invasion years for RED-BREASTED NUTHATCHES and winter finches. You can get this information from looking at Christmas Count Data."

We also found fledged Cedar Waxwings this morning at the NYBG.

Deb Allen