What is a Brewer's Sparrow?

                                                       Brewer's Sparrow [B Schneider Photo]

 What is a Brewer's Sparrow?  That question was asked many times by NB birders after its presence was announced from Quispamsis about 10 days ago.  I can guarantee everyone had to look it up in their favourite bird guides.  The Brewer's Sparrow had never been seen in New Brunswick before.  No wonder birders were shocked and excited.  It became a 'lifer' for almost everyone who saw it.

A small, streaked, faded-looking sparrow appeared at the feeders of a new NB birder in January,  2023.  Being a new birder, she called for help.  It was quickly identified as a Clay-colored Sparrow until our more expert birders started scrutinizing its appearance.  After just 2 or 3 days, and checking with other experts, it was announced that this was indeed a Brewer's Sparrow.  Brewer's, Clay-colored and to some extent, Field Sparrows are very similar Spizella sparrows.  One needs to look very closely to differentiate a Brewer's from a Clay-colored especially when the bird is out of 'context', i.e., out of its normal range and habitat.  

                                                Brewer's Sparrow  [B Schneider Photo]

The Brewer's Sparrow (Spizella breweri) is a small-to-medium sized sparrow (13-15 cm long).  It is the same size as the Clay-colored but smaller than the Song and Field Sparrows.  It is a member of the Passerellidae family.  It was discovered in 1850 by John Cassin who named it in honour of the Boston physician and naturalist, Thomas Mayo Brewer.  Its original range was thought to be western North America in sagebrush country but in 1925 a montane race was discovered in the Canadian Rocky Mountains.  That led to the two distinct races of this species, the sagebrush-dwelling race (breweri) and the montane race (taverneri).  This has led to two nominate groups of this species, the Southern race and the Northern or Timberline race.  These two groups are sometimes listed as subspecies; Spizella breweri breweri for the sagebrush group and Spizella breweri taverneri as the montane group.  Time will tell what the taxonomists will do (if anything) with these two groups.

The Brewer's Sparrow is the drabbest of North American sparrows.  I will describe the taverneri race as having broader black streaks on its back, a darker gray breast with more contrast between gray breast and white belly, a slightly longer tail, and a shorter, stubbier bill.  For the rest of this description, I will be discussing the breweri race which our visitor represents.  The Brewer's Sparrow shows a faded brownish gray overall appearance. It looks small with a long tail and very striped.  Its breast is washed all over with a light gray.  It has a brown cheek patch which is not heavily outlined, a white line under the cheek patch and a dark malar stripe.  The eye has a weak complete white eyering.  The crown is brown streaked with a weak central line.  The nape is gray streaked.  The back is streaked gray brown and there are two weak wing bars.  The legs and feet are pale pink.  The bill is short and pink with a dark tip.  

                                                        Brewer's Sparrow  [B Schneider Photo]

Both genders have similar plumage.  The appearance in summer is affected by wear on the feathers and fading from the sun.  Juveniles look much like the adults but are more streaked and buffier in colour.

This species is so similar to the Clay-colored Sparrow that it is no wonder it was mistaken at first.  The Clay-colored Sparrow has a white central crown stripe, a gray nape, and distinct dark borders to its cheek patches as well as dark whiskers.  

The ranges of the two races of Brewer's Sparrow are different.  The winter range of both races overlap in southern Texas, Arizona, New Mexico, California and northern Mexico.  The summer ranges are different.  The breweri race breeds over most of the western part of the US east of the mountains in sagebrush and scrub habitats.  The taverneri race breeds in summers in the north in brushy habitat at treeline in mountains in Canada (Yukon and NW British Columbia) and eastern Alaska.  The Brewer's Sparrow does wander sometimes out of its range.  According to 'Sparrows & Finches of the Great Lakes Region and Eastern North America', it has been recorded in Minnesota, Illinois and Michigan.  It has been accidental to Massachusetts (Bent).  

The photo below shows the crown stripe and the weak eyering of the Brewer's Sparrow.

                                            Brewer's Sparrow  [B Schneider Photo]

Brewer's Sparrows eat mainly insects and have been shown to be useful controllers of crop pests.  Studies have shown that they eat plenty of plant lice, caterpillars, spiders, beetles, ants, and wasps.  Their diet includes mainly weed seeds in winter.  

Brewer's Sparrows act very secretive around their nests.  They will stay on the nest until the last second and then flair up and quickly disappear in the vegetation, often running along the ground.  They build their nest very close to the ground (less than 1 metre) but not usually on the ground.  The nest is made of dry grass stems and roots and lined with small rootlets, fine grasses and animal hair.  It is supported on the loose vegetation around it.  The average inside diameter of the nest is 50 mm with a depth of 30 mm.  The female lays 3 to 5 bluish glaucous eggs which are speckled and splotched on the large end with dark browns or gray.  The female incubates the eggs 11 to 13 days.  The young fledge in 8 or 9 days and the young depend on the adults for food and protection for several days.  There are often 2 broods per season.

                 Brewer's Sparrow Nest [Source Life Histories of North American Birds by A. C. Bent]

The Brewer's Sparrow is usually quite silent on its wintering grounds except for a tsip call note.  On the breeding grounds it is very vocal uttering long series of trills and buzzes.  Some notes are high and melodical while others are long and buzzy like its cousin, the Clay-colored Sparrow.  They sometimes engage in flock trilling.  On listening to its song on my electronic device, I wish we had them here in summer so we could listen to them!

The drab coloration of this species of sparrow and its shy manner account for its not getting much attention.  I wonder how well we would know it even if we lived in the west or southwest.  However, in migration it does migrate in large flocks.  In times past it was regularly seen in flocks of 50 or 100 individuals.  It has been seen wintering in Texas accompanied by White-crowned Sparrows, Black-throated Sparrows, Vesper and Savannah Sparrows.  At other times these large flocks have been observed to spend a lot of time bathing.   Quoting from Bent, p. 1213, these sparrows 'seem to be spending most of the forenoon hours every day in the mesquites along the overflow ditches, thoroughly wetting the plumage in the shallow streamlets and then perching in the green canopied branch-work above to preen at great length.  Sometimes such bathing parties would be perfectly quiet save for the sound of fluttering wings.  Then again certain individuals would break into prolonged singing...'

The Brewer's Sparrow has declined in some parts of its range due to habitat loss.  It is also vulnerable to cowbird predation.

As of today, February 6, our Brewer's Sparrow visitor is doing well, having survived -35ºC temperatures with high winds two days ago.  

A Good Day Birding

 

                                                                Green-tailed Towhee

On January 3, a day in which the weather was balmy with almost no snow, a friend and I drove the 2-plus hours to Sackville.  Several rare birds including a mega rarity had been reported from there.  Our trip down was uneventful for birds with mainly crows and ravens added to the list except for a Gray Jay which flew across the road in front of us.

At Sackville we missed the exit from the highway and went beyond to the first turn around and came back to where we saw a group of cars parked on the side of the road. That was the clue to where the rare Green-tailed Towhee might be.  It had been reported from the marsh behind the local high school for about the last 3 weeks.  We parked on the side of the big highway, got our gear ready and walked about 100 yards on a very good trail to where three people were gathered.  Having someone ahead of you who already knows where the bird is located is a big help.

                                                            Green-tailed Towhee

The habitat was a  large fresh water marsh with edges growing up in sedges, rushes, grasses and some bushes including red osier, wild roses and alders. Near where the bird was usually found was a gazebo which was heavily laden with full bird feeders. The bird was obviously being well taken care of.  The Green-tailed Towhee was far from home.  It would normally spend summers in the interior area of western US and it would winter in Mexico.  

Approaching quietly with as little disturbance as possible, we set up our cameras and waited with the other people pointing unobtrusively to where the bird was apparently hiding.  We stood there with anticipation waiting for it to appear.  After about 20 minutes a beautiful adult Green-tailed Towhee showed itself as it fed in the ditch among the reeds and bushes.  What a photographic opportunity!  That was the mega-rarity we had come for.  We were able to quietly watch it for about 10 minutes before it returned to hiding.  On the way out was a beautiful White-throated Sparrow.  My friend was able to pick a few rose hips to feed her birds at home while I identified the Speckled Alders we walked past.

                                                                          Great Egret

The next species on our rare bird list for the trip was a Great Egret that had been hanging around the marshy and pond areas of town for over a month.  Checking birding Facebook sites from the day before we knew it had been feeding near St. James Street at the retention pond.  As we were searching for the area another friendly birder led us to the proper area and the best place to park.  Thanks, Gary!

                                                                        Great Egret

There was a large pond in that area with a wonderful network of trails.  We walked along quietly for 100 metres and I spotted the tall white bird hiding among the cattails.  Moving along further gave us a good view as it started wading and feeding.  A Great Egret is no longer super rare here but one in winter certainly is.  This individual appeared to be doing well but one wonders how long it can survive when the ponds freeze over.  

The third rarity was a Yellow-breasted Chat which had been feeding fairly regularly at a feeder in town.  The feeders of this house were visible from the street.  We sat in our car and watched the feeders three different times during the day but did not see the rare visitor.  Also missed that day was a Northern Mockingbird which also was in town.  We did not know where it was hanging out so we did not try to see it.  We were sorry to miss it though.  

                                                                    Yellow-breasted Chat  

                                                                    Northern Mockingbird

After such good birding in town we drove to the ‘official’ marsh, the Tantramar Marsh where we traversed muddy roads looking for whatever birds we could find.  That did not disappoint.  We saw many Ring-necked Pheasants who were feeding in barn yards, in the yards of houses bordering the marsh and in other border areas.  A few Mallard ducks rounded out our list on the marsh.  We saw an Iceland Gull along one road.

                                                            Ring-necked Pheasant

                                                                        Iceland Gull

With time and daylight fleeting we headed for the highway and the long drive home.  That ended a very good outing and a great day birding.

Mactaquac Christmas Bird Count 2022

 

                                                    Red-tailed Hawk - Immature

The Mactaquac Christmas Bird Count was held on January 1, 2023.  New Years Day is the traditional time  to hold this count which has been done for the last 35 years in a 24-km circle extending from Keswick to Upper Kingsclear and French Village to Granite Hill.  The weather was bad this year so the numbers of birds counted were a bit low since a lot of the small birds remained in hiding.  The temperature ranged from 2ºC to 4ºC and it rained all day with at least 60% of the day experiencing heavy rains.

Thirteen people braved the weather and covered their sectors.  Conditions made it tough to get out of the car as much as normally happens.  Three people recorded the birds at their feeders that day.  The group collectively spent 29 hours and covered 480.5 km on the roads.  These brave citizen scientists deserve a big 'Thank You' for their contributions that day!  See below for a list of the birds seen.

Canada Goose	2
Mallard	17
Gadwall	6
Common Goldeneye (Bucephala clangula)	2
Common Merganser (Mergus merganser) B	11
Bald Eagle (Haliaeetus leucocephalus) B	8
Sharp-shinned Hawk	2
Red-tailed Hawk	5
Rough-legged Hawk	2
Ruffed Grouse (Bonasa umbellus) B	4
Wild Turkey	43
Ring-billed Gull (Larus delawarensis) B	1
Herring Gull (Larus argentatus) B	5
Great Black-backed Gull (Larus marinus) B	11
Rock Pigeon	266
Mourning Dove (Zenaida macroura) B	20
Red-bellied Woodpecker	1
Downy Woodpecker	9
Hairy Woodpecker	9
Pileated Woodpecker	1
Gray Jay (Perisoreus canadensis) B	2
Blue Jay (Cyanocitta cristata) B	74
American Crow (Corvus brachyrhynchos) B	188
Common Raven (Corvus corax) B	10
Black-capped Chickadee	154
Red-breasted Nuthatch (Sitta canadensis) B	9
White-breasted Nuthatch B	12
Brown Creeper (Certhia americana) B	1
European Starling   (Sturnus vulgaris) B	637
American Tree Sparrow (Spizella arborea) M	19
Song Sparrow   (Melospiza melodia) B	1
Dark-eyed Junco   (Junco hyemalis) B	27
Northern Cardinal	6
Pine Grosbeak   (Pinicola enucleator) B	4
American Goldfinch   (Carduelis tristis) B	13
Evening Grosbeak	79
Yellow-throated Warbler	1
duck sp.	1
Finch spp.
Gull spp.	1
Total No. Birds		1664
Total No. Species		36
Seen during count period -
No. Participants	13
Mammals
.White-tailed Deer	29
Muscovey Duck (domestic)	1
Pigs running loose	6

This was a raptor year.  8 Bald Eagles, 5 Red-tailed hawks, 2 Rough-legged hawks, and 2 Sharp-shinned Hawks is a generous number of raptors.  They certainly were coping with the weather.  The count shows a paucity of small birds.  There hasn't been a big movement of finches into the area yet this winter and the results show it.  There was a lot of open water so it is surprising to see low numbers of waterfowl.  The European Starling count is very high because in our sector we saw a murmuration of Starlings.  There was a huge flock flying as one body rolling and turning in the sky close to us, a beautiful sight.  We estimated 500 birds in that group. 

                                                                    Rough-legged Hawk

 

The Yellow-throated Warbler was seen at a feeder and is a rare vagrant to this area from the south-eastern US.  It should be wintering in Florida, Mexico or the Caribbean Islands. About 25 to 30 of these individuals have been seen here since 1975.  This one will depend on feeders for its survival.  

The Red-bellied Woodpecker is notable and reflects the minor movement of this species into the province this fall from its normal habitat in the south-eastern US northward to about Massachusetts.  

                                                            Yellow-throated Warbler

Green-tailed Towhee

                                            Green-tailed Towhee   [Marbeth Wilson Photo]

A Green-tailed Towhee was found in Sackville on the Christmas Bird Count on 17 December, 2022.  What an amazing species to find in our region and what a stroke of luck for the 3 birders who found it!  This species occasionally strays away from its tight home range but they usually only make it to the central US and occasionally to the east coast from southern Maine to North Carolina.  Sometimes they stray to the Great Lakes region.  This record represents only the second time it has been found in New Brunswick.  The previous was seen in Saint John in 2002 where it frequented a feeder area from January to mid-March.   I saw it when it was first found on 11 January.  

The Green-tailed Towhee (Pipilo chlorurus) is a member of the Passerellidae family (American sparrows).    The 'Pipilo' is the name for the towhees and the 'chlorurus' identifies it as the Green-tailed Towhee.  The full scientific name means 'colourful chirper'.  This species was first described in 1839 by John James Audubon when he called it Fringilla chlorura.  It has had 4 name changes since then.    

                                        Green-tailed Towhee  [Marbeth Wilson Photo]

The Green-tailed Towhee is the smallest of the towhees of which we have 9 species.  These are large chesty sparrows with rather long rounded tails.  Towhees are ground feeders and their flight is generally low to the ground and is several quick flaps followed by a short, flat-winged glide.  Towhees usually show no sexual dimorphism which is the case in this species.  The Green-tailed Towhee is the only entirely migratory towhee.

The Green-tailed Towhee is 15.7 to 18.0 cm long with the male being slightly larger than the female.  Generally it looks like a large sparrow with a rusty cap, whitish throat, black malar stripe, and a greenish back and tail.  More specifically the head shows a rusty crown; forehead, lores, and malar stripe gray to dark gray; supraloral and submoustachial stripes and chin and throat white; face gray or greenish-grey; nape, mantle and rump greenish-grey or greenish-brown; tail greenish tinged with yellow-olive; wing greenish olive with a yellow bend in the carpal edge.  For the underparts, the chin and throat are white; bill is black but the base of the lower mandible can be white or bluish-white; legs and feet dull brown or grayish; iris dark reddish brown.  Females are like the males but can be just slightly duller.

The first winter bird resembles the adult but with a duller crown.  The juvenile is heavily streaked with dark brown and with a white throat with contrasting dark brown malar stripe.  The tail and wings show a greenish cast.  

The range on the Green-tailed Towhee is mostly the western and south-western US and Mexico.  It breeds from south-central Oregon, south-eastern Washington, southern Idaho, south-central Montana, Wyoming and sometimes South Dakota south through California, Nevada, Arizona, New Mexico east to central and western Colorado, Oklahoma and Texas.  It winters in the southern parts of California, Arizona and New Mexico southward as far as central Mexico.  Preferred habitats include dry shrubby hillsides with low brush interspersed with trees and chaparral up to 2400 metres elevation.  It likes sage brush and open piñon-juniper.  In winter it prefers low weedy brush and dry gullies with mesquite.  

Green-tailed Towhees are secretive birds like most towhees.  They prefer to stay hidden in low thick vegetation.  When disturbed they will fly low away or drop to the ground and run away looking like a mouse.  In breeding season the male will show himself while he sings from the top of a shrub.  The song starts with short introductory notes followed by trills.  It can be described as a warbled 'wheeet clur cheeweee-churr'  or sometimes it is a rapid wheezy sound.  On listening to the play-back I could hear something similar to the 'tow hee' of the Eastern Towhee.  The call note is a 'keek' sound or sometimes the bird makes a cat-like mewing sound.  

Green-tailed Towhees nest on the ground or in low shrubs usually lower than 3 feet above ground.  The nest is a large loose cup made of twigs, grasses, weeds, bark strips and lined with fine grasses, rootlets and animal hair.  Three to four eggs are laid and are white with heavy brown to gray dotting on the large end.  The female incubates the eggs 11 to 13 days.  Green-tailed Towhees eat mainly insects and seeds.  They will sometimes feed on berries and small fruits.  They forage on the ground under thick vegetation where they scratch in the leaf litter often doing a 2-legged scratch.  In their normally dry habitat they drink morning dew from the leaves.  They will come to feeders but typically feed on the ground under the feeding tray.

Similar species do not occur here so one would have no trouble identifying this species (assuming a good knowledge of the field guides).  In its native habitat a similar species is the Olive Sparrow but it is smaller and has a brown-striped crown.  

Green-tailed Towhee populations have declined somewhat probably because of the conversion of their favourite mesquite habitat into agriculture lands.  It does like burned-over land so our drier climate might favour this species.  Presently in most of its range its population remains relatively stable.  

A group of towhees is termed a 'teapot'.  We would have to go to Arizona to see a teapot of Green-tailed Towhees but it is awfully nice to be able to see one here in NB today.  

White-eyed Vireo

 

                                                White-eyed Vireo  [Jim Carroll Photo]

The White-eyed Vireo is a very rare spring and fall visitor to New Brunswick.  Our first record was an immature bird banded at Kent Island in September, 1980.  It has been seen nearly every year since then with most sightings being near the coast lines, the Grand Manan archipelago, St. Andrews, Saint John, Miscou, etc.  The adult bird shown above was seen in the Lorneville area in October, 2022.  

Vireos are members of the Vireonidae family.  There are 15 members of this family all in the genus, Vireo.    Here in NB we normally have 5 species; Yellow-throated, Blue-headed, Red-eyed, Warbling and Philadelphia Vireos.  Vireos grace our spring, summer and fall landscape with their song and plumage.  They are important members of our ecosystems. 

The White-eyed Vireo (Vireo griseus) is a small active grayish-yellow bird that can often be mistaken for a warbler or a kinglet.  But close examination or the song can quickly identify this species.  It is 13 cm long and likes to stay hidden in thick bushes.  It often announces its presence by its explosive song.  That is the way I found my first White-eyed Vireo.  I was in South Carolina where it sometimes winters and there was this loud very unusual sound (noise?) coming from a thick small bush.  I tried unsuccessfully 2 or 3 times to see what it was and could not see that bird (at least I thought it was a bird!).  I started to give up but then stubbornly went back to find out what it was.  With more searching and crawling around on my knees the bird finally popped out and much to my surprise I was looking at a White-eyed Vireo.  I was delighted to find a new bird and to have it behave exactly as the literature describes it; secretive, explosive loud song, white eye.

                                                        White-eyed Vireo  [Internet Photo]

The breeding range of the White-eyed Vireo is the south-eastern US extending to the area south of the Great Lakes and  eastward to Pennsylvania and Massachusetts.  It winters in the southern-most part of its range and in Mexico, and the Caribbean.  Vagrants are found to the west and to the Maritime Provinces.  

The White-eyed Vireo often announces its presence with explosive song.  This hasn't been the case of the ones I have seen in the alder bushes near Lorneville probably because it was beyond the breeding season.   They popped out to see who was present but were quiet.  This species has a bold facial pattern with yellow spectacles and a white iris.  Examining photos of this species, the iris can be white, light gray or slightly yellowish.  The plumage is grayish-olive above, shows a gray back and two white wing bars.  The bird is white below with grayish on the throat and yellowish on the sides.  The bill is dark in colour and noticeably bigger and thicker than a warbler's bill.  The young of this species looks similar to the adult but has a brown or gray iris into the late fall.

The voice of this species is distinctive.  The bird is often heard before it is seen.  The song is loud, explosive and is described as wren-like.  I wound describe it as very varied and full of squeaks, 'chicks', and many other weird sounds.  The actual mating song begins and ends with 'chick'.  In fact, in Bermuda where it is common, the bird is known as the 'chick of the village' which is the people's interpretation of its song.  One thing is for sure, this species does not sound like any of our native species.

 The White-eyed Vireo builds its nest in thick tangled vegetation usually low to the ground.  It is usually built in the fork of a sapling and is anchored with strands taken from spider webs.  Both adults build the nest which is made of twigs, rootlets, strips of bark, grass, leaves, plant down, lichens, moss and bits of wasp nests.  They clearly are good engineers, using all materials at their disposal.  The nest is cup-shaped and is lined with fine grass and plant fibres.  The male serenades the sitting female incessantly from early spring to fall, just like our native vireos.  Four white eggs speckled with brown or black are laid and incubated by both adults for 13 to 15 days.  The young fledge in 9 to 11 days.  This species raises one brood in the northern part of its range and two in the southern part.  

This species is an insectivore with a varied diet.  It eats insects of many kinds and berries including caterpillars, moths, butterflies, beetles, ants, wasps, bees, grasshoppers, spiders, snails and sometimes small lizards.  It eats almost entirely insects in the breeding season.  During migration and in the winter it will eat berries and small fruits.

There have been slight declines in the White-eyed Vireo population since the 1960s.  Habitat loss has undoubtedly played a part.  The species is also susceptible to cowbird parasitism.  An interesting fact about the White-eyed Vireo is that it is one of only two perching birds in the US with white eyes.  The other is the Wrentit which is found in the western US.  

The White-eyed Vireo is also famous in archeology.  An approximately 400,000-year-old wing bone from a White-eyed Vireo is the only fossil record of any Vireo in North America.  So, the White-eyed Vireo has been around for a long time!

Blue-winged Warbler

                Blue-winged Warbler Showing Black Eyeline and Bluish-gray Wings  [Jim Carroll Photo]

The Blue-winged Warbler (Vermivora pinus) is one of our rare visitors few get to see.  If you ever do find it, you won't forget it because it is so brilliantly yellow.  It is a deep medium yellow (cadmium yellow medium for those who paint) and not the cool lemon yellow often seen in many other species found here.  

The Blue-winged Warbler is a rare fall visitor found most often in the Grand Manan archipelago and along the east coast.  It was first reported here from Machias Seal Island in 1951.  The normal range of this species is more southerly.  The breeding range is the eastern half of the mid US states extending into the most southerly part of Ontario.  These birds winter from southern Mexico to Costa Rica and occasionally south to Panama and the West Indies.  They usually migrate at night and are a trans-Gulf migrant.  

The Blue-winged Warbler is a challenge to observe because it likes to forage in dense brush and thickets.  The only one I have ever seen was on Black Beach Road in the thick alders.  Its brilliant yellow looked like a yellow streak as it flew across the road.  In the spring the plumage of this species is startlingly beautiful.  The males and females are similar with the female being just a bit duller. The male has a yellow head, an olive-green nape, a black eyeline and thin black bill, olive-green back and rump and bluish-grey wings.  It has white wingbars and a brilliant yellow breast and belly.  The undertail coverts are white and the gray tail shows white spots on the outertail feathers.  The legs are dark gray or black.  Readers, we are describing a brilliant bird here.  The yellow is so bright that one often fails to see the other field marks except for the black eyeline and bluish-gray wings.  Considering this species does not give you much time to enjoy its beauty you have to be sharp-eyed to get a good look or photo of this one!

                                                    Blue-winged Warbler   [Internet Photo]

In the photo above note the black eyeline, the white under the tail and on the outer tail feathers.  The song of the Blue-winged Warbler is so distinctive the trained birder knows to stop and find what warbler species is making that buzzing sound. That is because we so rarely hear it.  The song is a beeee-bzzzz sound with the beeee being high and the bzzzz being low in pitch.  The bird also makes a long, high buzz ending with a tsi zee drawn out sound.  The call note is a snik sound.  This is one species song we should learn from the digital recordings available on the internet because this species is often heard before seeing and undoubtedly is missed because it likes to stay hidden.  

The Blue-winged Warbler nests close to the ground in well-concealed grass or blackberry canes or sometimes under a bush.  The nest is attached to upright stems of grass or weeds, especially goldenrod.  The nest itself is bulky but narrow and deep.  It is built by the female of dead leaves, grass, beech or grapevine bark and lined with plant fibres and animal hair.  Four to seven white eggs with fine brown spots are laid and incubated by the female for 10 to 11 days.  Both adults feed the nestlings which fledge at 8 to 11 days of age.  Blue-winged Warblers eat mainly insects and spiders.

What species would you mistake for the Blue-winged Warbler?  The Yellow Warbler, the Prothonotary warbler and the Pine Warbler.  The Yellow and Prothonotary Warblers do not have the black eyeline.  The Pine Warbler is much duller in colour and also does not have the black eyeline.  Differentiation should not be a problem in this brilliant species!

Any discussion of the Blue-winged Warbler is not complete without mentioning the fact that it hybridizes with the Golden-winged Warbler where their territories overlap.  First generation hybrids are called Brewster's Warblers.  These are fertile and will interbreed or will breed back to the Blue-winged species producing the second generation hybrids.  These are called Lawrence's Warblers.  It took many years to understand these relationships but the hybrid relationships and plumages are now clear.  Brewster's and Lawrence's Warblers are interesting but not separate distinct species.  We are not likely to see these hybrids here because we have so few Blue-winged Warblers and almost no Golden-winged Warblers.  I don't think we have any breeding records of either of these species.

The population of Blue-winged Warblers is expanding northward in the Great Lakes region.  Reforestation and thus the loss of open habitat may be a reason.  Urban sprawl in the northern US is also a reason for the range expansion but also a reason for declining numbers.