the common yellowthroat (geothlypis trichas) is a new world warbler .
they are abundant breeders in north america , ranging from southern canada to central mexico .
common yellowthroats are small songbirds that have olive backs , wings and tails , yellow throats and chests , and white bellies .
adult males have black face masks which stretch from the sides of the neck across the eyes and forehead , which are bordered above with white or gray .
females are similar in appearance , but have paler underparts and lack the black mask .
immature birds are similar in appearance to the adult female .
first-year males have a faint black mask which darkens completely by spring .
there are 13 races of this bird .
these races differ mainly in the males' facial patterns and the brightness of the yellow underparts .
the southwestern forms of this bird are the brightest and the yellowest below .
the breeding habitats of these birds are marshes and other wet areas with dense low vegetation , and may also be found in other areas with dense shrub .
however , these birds are less common in dry areas .
females appear to prefer males with larger masks .
common yellowthroats nest in low areas of the vegetation , laying 35 eggs in a cup-shaped nest .
both parents feed the young .
northern races are nocturnal migrants , wintering in the southern parts of the breeding range , central america and the west indies .
southern forms are largely resident .
this species is a very rare vagrant to western europe .
these birds feed on insects , which are usually captured in dense vegetation , but sometimes caught in midair .
the common yellowthroat's song is a loud twichety twichety twichety twich .
its call is a soft jip .
despite a decline in numbers in some areas , which is due to loss of favoured habitat , this species is still very common .
routes of migration vary based on the season and location of common yellowthroats .
during fall migration , from august to october , common yellowthroats in canada , western , eastern , and central u .
s .
, and regions outside of the united states all have unique migration routes .
when migrating in the fall months , all adults and immature individuals tend to arrive at their migration destinations around the same time .
migration differences in timing and routes are also seen during the spring months from early february to late may in these same groups across the united states , canada , and other areas .
however , males generally arrive at their destination site before the females during the spring migration months .
during both fall and spring migration , many birds take time to rest during a stopover period .
some individuals stay at their stopover destinations for several weeks or months while others spend only a few days resting before they continue on in their migration patterns to their final destination .
one place of study on common yellowthroat migration that is unique and worth noting is appledore island , maine .
common yellowthroats here typically migrate to this island during the spring months displaying distinct patterns of movement and stopover ecology .
analysis of the common yellowthroat spring migration from april to june was observed by researchers from the department of biology at canisius college in buffalo , new york to determine patterns of migration and time spent resting on the island before continuing on their journey .
birds returning for more than the second time arrive earlier than birds migrating to the island for their first time .
every year , males tend to arrive on the island an average of five days earlier than females weighing more than the females upon arrival .
one possible explanation for the early arrival of males to this island is the ability of males to set up territories before the females arrive .
this could give them better access to resources and a higher likelihood of finding a female mate .
however , both sexes spend about a week on the island before leaving .
migration of common yellowthroats in florida has also been extensively studied .
in florida , the common yellowthroat can be found more often in the southern peninsular region rather than the northern panhandle region closer to the mainland of the united states .
peak migration times of the birds in this region are during the last week of september through the second week of october .
not as much is known about spring migration in florida , but the patterns appear similar to that of the autumn migration .
future studies are needed to understand specific migration patterns of common yellowthroats in other parts of the united states .
