A Lawrence's Warbler today and a look at my records for the various hybrids of Blue winged Warbler and Golden winged Warblers

Lawrence's Warbler, Belchertown, MA, May 5, 2020

Lawrence's Warbler, Belchertown, MA, May 5, 2020

Lawrence's Warbler, Belchertown, MA, May 5, 2020

Lawrence's Warbler, Belchertown, MA, May 5, 2020

Lawrence's Warbler, Belchertown, MA, May 5, 2020

Although the weather has overall been less than stellar for migration, the warblers (and others) have slowly been arriving. I will cover all the arrivals for the first week of the month in another post but this post will look at the Lawrence’s Warbler I found today as well as my previous sightings of this hybrid as well as other hybrid records (Brewster’s and others) of Blue Winged Warblers and Golden winged Warblers I have had in Hampshire County. First a look at the Lawrence’s Warbler I found today in Belchertown. I originally didn’t plan on headed back out again after a full morning of birding but the weather was nice enough to entice me to go out again.  I decided to see if I could relocate a Blue winged x Golden winged Warbler hybrid I saw a few days ago and perhaps get some better photos then what I got with the iPhone through binoculars.  The breeze made it a bit difficult to find some birds but I eventually heard a Blue winged Warbler song and after a bit of looking I was amazed to be looking at a Lawrence's Warbler.  I got a bunch of photos before the bird disappeared back into some dense thickets during which it gave a very quiet Blue winged song.  As always it can pay dividends to check every single Blue winged Warbler that one finds singing.

There are two main hybrid forms of Blue winged Warbler and Golden winged Warbler and they are known as Brewster's Warbler and Lawrence's Warbler.  When first discovered both of these hybrids were thought to be unique species but it was found that they were hybrids instead.  Lawrence's Warbler is the rarer of the two hybrids and the one that seems to be the less variable in appearance of the two.  In addition there are other hybridization that are an odd mix of Blue winged and Golden winged that don't fit into the two forms mentioned above.  Both the Blue winged Warbler and Golden winged Warbler are part of the vermivora branch of warblers (which also contained the now extinct Bachman's Warbler...more about that in a future post).  Genetically the two remaining representatives of this branch are very close which explains the myriad of hybrids.  Below I will look at each of the different hybridization I have come across in Hampshire County over the years.

Lawrence's Warbler, Belchertown Land Trust Trail, Belchertown, May 14, 2012

Lawrence's Warbler, Belchertown Land Trust Trail, Belchertown, May 14, 2012

Lawrence's Warbler, Mineral Hills Conservation Area, Northampton, MA, May 14, 20

As mentioned above the Lawrence's Warbler is the rarer of the two forms of hybrids and I have only had this hybrid on three previous occasions before today in Hampshire County:

4/29/09 at Herman Covey WMA
5/14/12 at the Belchertown Land Trust trail
5/13/17 at Mineral Hill Conservation Area in Northampton (the only one I didn't find)

Brewster's Warbler, UMASS, Amherst, MA, May 5, 2012

Brewster's Warbler, Hampshire College, Amherst, MA, May 5, 2012

Brewster's Warbler, UMASS, Amherst, MA, May 17, 2012

Brewster's Warbler, UMASS, Amherst, MA, May 11, 2014

Brewster's Warbler, Quabbin Park, MA, May 13, 2017

Brewster's Warbler, Sweet Alice Conservation Area, Amherst, MA, May 3, 2018

Brewster's Warbler, Sweet Alice Conservation Area, Amherst, MA, Jun 13, 2018

Brewster's Warbler is the more likely of the two forms of hybrids and I have had the following records in Hampshire County:

5/5/12 at UMASS (individual continued through 5/27)
5/5/12 at Hampshire College
5/11/14 at UMASS
5/8/16 at UMASS
5/13/17 at Quabbin Park
5/31/17 at the Belchertown Land Trust trail
5/3/18 at Sweet Alice Conservation Area (individual continued through 6/13/18)

Blue winged x Golden winged Warbler hybrid, Quabbin Park, MA, May 4, 2017

Blue winged x Golden winged Warbler hybrid, Quabbin Park, MA, May 4, 2018

Blue winged x Golden winged Warbler hybrid, Sweet Alice Conservation Area, Amherst, MA, May 8, 2018

Blue winged x Golden winged Warbler hybrid, Sweet Alice Conservation Area, Amherst, MA, May 7, 2019

Blue winged x Golden winged Warbler hybrid, Rail trail, Amherst, MA, May 8, 2019

Blue winged x Golden winged Warbler hybrid, Quabbin Park, MA, May 16, 2019

Blue winged x Golden winged Warbler hybrid, Belchertown Land Trust Trail, Belchertown, MA, May 3, 2020

Blue winged x Golden winged Warbler hybrid, Piper Farm Conservation Area, Belchertown, MA, May 5, 2020

In addition to the two main hybrid forms there are those that obviously have some genetics of both species but don't fit into the two main forms.  Typically the individuals looks mainly like Blue winged Warblers but have yellow wing bars/patches and occasionally have unusual facial markings.  I have had the following sightings of these 'other' hybrids over the years.

5/3/17 at Quabbin Park (continued through 6/11/17 and showed up for the next two years, so far) 
5/4/18 at Quabbin Park (presumed same individual as above, present through 6/21/18)
5/8/18 at Sweet Alice Conservation Area
5/7/19 at Sweet Alice Conservation Area (continued through 5/8/19)
5/8/19 at the rail trail in Amherst (continued through 5/15/19)
5/10/19 at Quabbin Park (presumed as individual continued from 2017, seen through 5/23/19)
5/3/20 at the Belchertown Land Trust trail
5/5/20 at Piper Farm Conservation Area

Golden winged Warbler, Quabbin Park, MA, May 31, 2017

Blue winged Warbler, Belchertown, MA, Apr 30, 2016

As a point of reference I have attached a photo of a normal looking Blue winged Warbler and a Golden winged Warbler that I have seen in Hampshire County.  Blue winged Warbler is a typical breeder but Golden winged Warbler is exceedingly rare now and I have only had it in the county on five occasions ever.  It has gotten so rare now that it is a review species for the state. 

I have entire album of hybrid warblers at the following link:  Hybrid warblers