Hello all,

Many of you know that I am the eBird reviewer for the four Champlain 
Valley counties of Vermont.  And eBirders know that Philadelphia Vireos 
are usually flagged for review.  Pertinent to the ID conversation here 
started by Bridget is some information of expectations for that species 
and two species of flycatchers that are often flagged as well ..... 
Yellow-bellied Flycatcher and Olive-sided Flycatcher.

All three share a similar pattern in the Champlain regarding seasonality 
and geographical distribution.

The Champlain Valley counties include Lake Champlain, the Champlain 
Lowlands, and the Green Mountains (foothills and mountains).

Most of the ID errors of the three species occur with submissions to 
eBird from along Lake Champlain and from the Champlain Lowlands.

As a general theme all three species are as close to absent as they can 
be in June, August, and September in the Lake Champlain/Champlain 
Lowlands.  Virtually all reports during these three months to eBird are 
inadequately documented and/or prove to be in error.

In spring migration Philadelphia Vireos appear in the Lowlands in quite 
low numbers, mostly in the last two weeks of May.  ID errors and 
inadequately documented birds are very common during this period.   
During fall migration is when the species is most likely to be seen in 
the Lowlands, almost always in September.  For many birders this is one 
of the Fall highlight birds.  This is the peak time for their 
observation in the Lowlands, and well documented individuals seem to 
help other birders locate the species more easily as the month wears on.

With a few exceptions Yellow-bellied Flycatcher submissions during 
spring migration in the Lowlands are usually inadequately documented or 
errors.  Overall, the few documented individuals have been in the last 
three weeks of May.  Documented individuals are very sparse during fall 
migration, from the last week of August through the first two weeks of 

Olive-sided Flycatchers, of these three species, are the most scarce in 
the Champlain Lowlands; at least as reflected in the eBird data. They 
also have a high level of inadequately documented and mistakenly 
identified birds.  The very few documented reports are during the last 
three weeks of May during spring migration.  They are essentially absent 
in the Lowland during the Fall migration.

Overall, these three species need good quality documentation whenever 
located along Lake Champlain and the in the Champlain Lowlands. Thanks 
to Bridget Butler for getting this conversation going!

If only seen, multiple defining characteristics are important for a 
successful documentation.  Vocalizations (with no recordings) by 
themselves are inadequate for documentation, and for Philadelphia Vireo 
almost useless in most cases.  Audio recordings are best when there are 
multiple repeats of songs, and when the sonograms are clear.  Multiple 
photos are much better than a single photo.

As most of you eBirders know, the same bird is often reported by several 
birders.  The more birders that see what is likely the same bird at a 
location, the subsequent documentation of the bird can be somewhat less 
thorough.  But beware, every season there are instances where some 
birders will document a bird with the phrase "continuing bird", or "seen 
by others", or "known to be at location" ..... not knowing that the 
original observation was found to be in error or inadequately documented.

As most of us know these last three weeks of May have been an seemingly 
unrivaled Vermont bonanza of migrants, especially warblers and other 
passerines.  Included have been numerous reports of Philadelphia Vireos 
and Yellow-bellied Flycatchers.  For the most part I have been holding 
back on reviewing these submission until the flood is over.  In the near 
future I will work my way through the three species, looking at all the 
submissions during this spring.

Good birding all .....