Philadelphia Vireo: Always Rare on Migration in Central Park (1900-2021)

Updated: May 27, 2021

Philadelphia Vireo by Doug Leffler

26 May 2021

Spring Bird Notes: Migration is winding down until birds start to return headed south in August. Keep your eye on the weather for Saturday, 29 May - looks like rain for the morning (if so we will cancel the morning walks). Otherwise the weekend looks fine including Memorial Day Monday. The last evening walk is on Thursday 27 May at 5:30pm with Ms. Sandra Critelli. See the SCHEDULE page of this web site for meeting locations/info.

Our group found a Philadelphia Vireo on Sunday 23 May, and again on Monday 24 May. This species has always been rare on migration in North America, but more on this in a moment. On both occasions the vireo was feeding on/in the flowers of a Honey Locust, Gleditsia triacanthos, a tree native to the central/southern USA. In Central Park several other non-native trees/shrubs (including Turkey Oak Quercus laevis, Tree-of-Heaven Ailanthus and Cotoneaster - all of Eurasia) are important food sources for migrants.

In this week's Historical Notes, we send 20th century articles on the rarity of the Philadelphia Vireo on migration in our area including Central Park, as well as Prospect Park (Brooklyn) and parts of the Bronx. We include notes/comments from Ludlow Griscom of the American Museum (the 1920s) and John Kuerzi (the Bronx County Bird Club), and John Bull (American Museum - 1964). Bottom line is that the Philadelphia Vireo has always been uncommon to rare...but more common on migration in autumn (peak 15-30 September) than spring (peak 20 to 30 May).

Some migrant species of birds that were common in the past are less common now (Red-headed Woodpecker); others that were rare in the past are common now (most herons and egrets). The Philadelphia Vireo is one species that has never been common while birders have been watching: Why?

Philadelphia Vireo in Central Park on 23 May 2021 by Anindya Sen

(below) the same Philadelphia Vireo in Central Park on 23 May 2021 by Sandra Critelli

(below) a different Philadelphia Vireo in Central Park on 6 Sept 2010 by Deborah Allen

Bird Walks for late May 2021

All Walks @ $10/person

Directions to All Meeting Locations can be found here

1. Thursday, 27 May at 8:30am. Bird Walk. Dock on Turtle Pond. $10. Directions to All Meeting Locations can be found here

1a. Thursday, 27 May at 5:30pm. Bird Walk led by SANDRA CRITELLI. Boathouse Cafe; 74th street/East Drive $10. Last evening walk for the spring.

2. Friday, 28 May at 8:30am. Bird Walk. Conservatory Garden; 105th street and 5th Avenue (uptown!) $10. Directions to All Meeting Locations can be found here

3. Saturday, 29 May at 7:30am and again at 9:30am. Bird Walk. Boathouse Cafe; 74th street/East Drive $10. If you do the 7:30am walk, you get the 9:30am walk for free.

4. Sunday, 30 May at 7:30am and again at 9:30am. Bird Walk. Boathouse Cafe; 74th street/East Drive $10. If you do the 7:30am walk, you get the 9:30am walk for free.

5. Monday, 31 May at 8:30am [MEMORIAL DAY]. Bird Walk. Strawberry Fields (IMAGINE MOSAIC) at 72nd st. and Central Park West (inside the park) $10. Directions to All Meeting Locations can be found here

Call (718-828-8262) or Email us with questions:


The fine print: Our walks on weekends meet at 7:30/9:30am at the Boathouse Restaurant (approx. 74th street and the East Drive). Please note: the Boathouse is not one of the buildings that surround the nearby Model Boat Pond - people make this mistake all the time! Fridays we meet at Conservatory Garden; Mondays at Strawberry Fields - check the "Meeting Points" page of this web site for exact meeting location.

Our home phone is 718-828-8262...and Deborah's cell is: 347-703-5554. Email is ( 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) near 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 in April 2021 according to the owners. 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 aim to please.

Red-eyed Vireo for comparison to Philadelphia Vireo by Doug Leffler

Here is what we saw last week (brief highlights):

Thursday, 20 May (Dock on Turtle Pond at 8:30am): David Barrett received info that a Cerulean Warbler was on the east side of Turtle Pond - so off we went leaving the second year/green male Orchard Oriole singing his heart out at Turtle Pond. We found the area with the warbler - it was up in a birch tree with a bunch of other warblers. I played the chip calls from my tape and it came in over our heads to land in a pine tree. Unfortunately because it was motionless (just sitting and listening) only a few people could find it...but it did continue singing a bit. Frustrating sometimes - to bring a good bird in close and then...Anyway, 17 total warbler species including two adult male Bay-breasted Warblers.

Deborah's List of Birds for Thursday, 20 May: Click Here


Friday, 21 May (Conservatory Garden at 105th st. at 8:30am): 14 Warbler species today - but the most fun were the two Yellow-billed Cuckoos that came flying in (and if you were there at 7:30am, there were three...for a total of five today). An eye-level female Blackburnian Warbler on the rocks of the Blockhouse (foraging in a cherry tree) was a treat for all who remained to the end.

Deborah's List of Birds for Friday, 21 May: Click Here


Saturday, 22 May (Boathouse Restaurant at 7:30am/9:30am): Eleven (11) warbler species today - we are starting to wind down the migration. However, we found an Olive-sided Flycatcher and a Yellow-billed Cuckoo, and lovely Scarlet Tanagers.

Deborah's List of Birds for Saturday, 22 May: Click Here


Sunday, 23 May (Boathouse Restaurant at 7:30am/9:30am): Ten (10) warbler species BUT for the second walk, at 11:30am, we found a Philadelphia Vireo foraging in the flowers of the Honey-locust tree just west of Belvedere Castle. We would be lucky enough to find this same bird again tomorrow (Monday) in a different Honey-locust. We also had a Yellow-billed Cuckoo (and please come to the earlier walk you'll see more birds) and Scarlet Tanagers.

Deborah's List of Birds for Sunday, 23 May: Click Here


Monday, 24 May (Strawberry Fields [Imagine Mosaic] at 72nd street and Central Park West at 8:30am): It was surprisingly good today - and cool. We had 13 warbler species as well as repeat offenders: the Philadelphia Vireo and the Olive-sided Flycatcher continuing to perch on the same tree just west of the Humming Tombstone.

Deborah's List of Birds for Monday, 24 May: Click Here

Warbling Vireo 19 May 2012 Central Park Deborah Allen


Vireosylva philadelphia. PHILADELPHIA VIREO [1924]. In 'The Auk' for April 1924, p. 347, I recorded four observations of this species in the fall of 1923, an unprecedented occurrence. In the past few years other fall records have come to hand. It is now time to put on record data regarding its presence in spring. In the first place the recently published gives two recent spring records for the Bronx, which Mr. Kuerzi, after thorough inquiry, regarded as reliable. The spring of 1927 will long live in the annals of Central Park ornithology as a notable one for the variety and abundance of transients. A great wave on May 11 brought 66 species to the Ramble. In the late afternoon I paid the Park a second visit, and came upon a group of seven beginners in bird study staring into a hawthorn bush. They asked me to identify a bird which was feeding in it, and I exclaimed with surprise at seeing a Philadelphia Vireo about six feet above the ground some fifteen feet away. It was obvious that some of these people had never even heard of the bird, but a pleased smile overspread the countenance of one man who flourished a Reed's 'Bird Guide' in my face, which was open at the colored picture of this species. He had been studying the bird carefully for some time and had obviously identified it correctly. I give this incident in detail, as illustrating the possible disadvantages of the ordinary rules of conservatism. All the more experienced observers had "done" the Ramble in the morning without finding one of the most notable birds of the day. It must be admitted that if any one of the seven original discoverers of this Philadelphia Vireo had reported it on uncorroborated testimony, the record would never have been given definite credence. I devoted the rest of the afternoon to rounding up four other bird-students, and a half hour later we had another ideal observation. There was another considerable flight on May 18. Entering the Ramble about nine A.M. almost the first bird I saw was a Philadelphia Vireo feeding in a small wild cherry. Five minutes were devoted to making as certain as humanly possible that my identification was correct, when I rushed off to secure corroboration from as many witnesses as possible. Fortunately I found that keen and competent student, Mr. Frank E. Watson, lurking in a deep thicket, nursing an illusion that he had glimpsed a Mourning Warbler. I had no difficulty in persuading him to forget it temporarily, and we returned with Mrs. Davis to the wild cherry tree. The bird was, of course, not there, but after an anxious fifteen minutes quartering of the vicinity, it was finally relocated and studied at leisure. Later on this individual was seen by several other people, including Mrs. Chas. N. Edge and Mrs. Clarkson Runyon, Jr. One would have supposed that two records of the Philadelphia Vireo would have sufficed for one spring, but on June 1, a day when there was a small late flight, Mr. Charles Johnston found another individual in the Ramble in the early morning. This careful and conservative observer studied his example with great care for some time, and was familiar with this species in life, as already recorded by me in 'The Auk' note referred to above. I have not the slightest doubt that his identification was absolutely correct. Mr. Arthur Janes also has kindly sent me a detailed account of a bird observed on May 14 at Scarsdale, which can only have been this species.

Published data from various sources in recent years seem to indicate that the Philadelphia Vireo has increased as a summer resident in the northeastern parts of its range in the Maritime Provinces of Canada, together with certain of the rarer Warblers. Suffice it here to say that I think the evidence presented warrants the statement that the Philadelphia Vireo is becoming a regular transient in this region, and can no longer be regarded as excessively rare. The increase in records in recent years cannot be ascribed solely to the admitted increase in competent observers.

Ludlow Griscom

Tennessee Warbler for comparison by Doug Leffler

Philadelphia Vireo in the New York City Region [1923]. In my recently published 'Handbook' to the birds of this region I discoursed at some length on the extreme local rarity of this Vireo. Two days after the appearance of this book or to be exact, on September 16, 1923, I discovered one on the "Point" of the Ramble in Central Park, New York City, in some low bushes where I had found one two years previously. It was very leisurely in its movements and was only 25 feet away at about the level of my eyes when I spied it. It objected strongly to my presence, and scolded me harshly, gradually working nearer as it did so. A big wave of migrants had arrived overnight, and the scolding attracted a crowd of Warblers. At one time an adult male Tennessee Warbler was less than two feet from the Vireo, affording a faultless opportunity for comparison. What was undoubtedly the same individual was found in the same place the next day at noon. Later that same afternoon Mr. Charles Johnston found a Philadelphia Vireo in the same place, and reported an ideal study of it. His visit to the Park and his discovery were entirely independent of my own, of which he was entirely ignorant, and consequently I regard his observation as an excellent corroboration of mine. Dr. Robert Cushman Murphy observed another individual most excellently on October 3 near Bronxville, Westchester Co., N.Y., and Mr. George E. Hix found another on September 23, in Van Cortlandt Park which was studied at leisure, and reported at a subsequent meeting. Thus, the Philadelphia Vireo was observed four times last fall, whereas there are only eight other records for the immediate vicinity of the City in all previous years. I am much obliged to the gentlemen mentioned for permission to use their observations.

LUDLOW GRISCOM, American Museum of Natural History.

Occurrence of Vireo philadelphicus [Philadelphia Vireo] in Mercer County, New Jersey. On September 21, 1876, I took an adult male of this species in an orchard in Princeton, and on the 28th of the same month I saw two others in the same orchard together, one of which I obtained. This proved also an adult male. These are the only instances that have come under my observation during six years at this point. W. E. D. Scott, Princeton. N. J.

Blue-headed Vireo for comparison by Doug Leffler