setophaga magnolia , commonly known as the magnolia warbler , is a member of the parulidae family of wood warblers .
this warbler was first discovered in magnolia trees in the 19th century by famed ornithologist alexander wilson while in mississippi .
this species is a moderately small new world warbler .
it measures 11 to 13 cm (4.3 to 5.1 in) in length and spans 16 to 20 cm (6.3 to 7.9 in) across the wings .
body mass in adult birds can range from 6.6 to 12.6 g (0.23 to 0.44 oz), though weights have reportedly ranged up to 15 g (0.53 oz) prior to migration .
among standard measurements , the wing chord is 5.4 to 6.4 cm (2.1 to 2.5 in), the tail is 4.6 to 5.2 cm (1.8 to 2.0 in), the bill is 0.8 to 1 cm (0.31 to 0.39 in) and the tarsus is 1.7 to 1.85 cm (0.67 to 0.73 in) .
the magnolia warbler can be distinguished by its coloration .
the breeding males often have white , gray , and black backs with yellow on the sides; yellow and black-striped stomachs; white , gray , and black foreheads and beaks; distinct black tails with white stripes on the underside; and defined white patches on their wings , called wing bars .
breeding females usually have the same type of coloration as the males , except that their colors are much duller .
immature warblers also resemble the same dull coloration of the females .
the yellow and black-striped stomachs help one to distinguish the males from other similar birds , like the prairie warbler and kirtland's warbler (which , however , have a breeding range to the south and east of the magnolia warbler's) .
the magnolia warbler is found in the northern parts of some midwestern states and the very northeastern parts of the us , with states such as minnesota and wisconsin comprising its southernmost boundaries .
however , it is mostly found across the northern parts of canada , such as in saskatchewan , manitoba , ontario , and quebec .
during the winter , the warbler migrates through the eastern half of the united states to southern mexico and central america .
the warbler breeds in dense forests , where it will most likely be found among the branches of young , densely packed , coniferous trees .
the magnolia warbler migrates to the warmer south in the winter , wintering in southeastern mexico , panama , and parts of the caribbean .
in migration it passes through the eastern part of the united states as far west as oklahoma and kansas .
during migration season , the magnolia warbler can be found in various types of woodlands .
the magnolia warbler undergoes multiple molts during its lifetime .
the first molts begin while the young offspring are still living in the nest , while the rest take place on or near their breeding grounds .
the warblers molt , breed , care for their offspring , and then migrate .
chicks hatch after a two-week incubation period , and can fledge from the nest after close to another two weeks when their feathers are more developed .
after about a month , the chicks can leave the nest to begin living (and later breeding) on their own since they are solitary birds .
magnolia warblers typically live up to 7 years .
this warbler usually eats any type of arthropod , but their main delicacies are caterpillars .
the warbler also feeds on different types of beetles , butterflies , spiders , and fruit during their breeding season , while they increase their intake of both fruit and nectar during the winter .
these birds also tend to eat parts of the branches of mid-height coniferous trees , such as spruce firs , in their usual breeding habitat .
researchers have observed two different types of song calls in male magnolia warblers .
their songs have been referred to as the first category song and the second category song .
females have not been observed to have a distinct song yet as the males have; while they do sing , they dont have separate songs for different situations .
in general , the male warblers use their songs during the spring migration season and during the breeding season: one is used for courtship and the other is used to mark their territory each day .
both males and females have call notes that they use for various alerts: the females have short call notes to signal when a human observer is watching them , and the males have short call notes to signal when any sort of threatening predators are close to their offspring .
according to the iucn red list , the magnolia warbler is on the list of least concern for conservation organizations because it is fairly widespread and common within its habitat and not at risk of extinction .
research has shown that a good percentage of warblers die from flying into television towers in their migratory path .
also , parts of their habitat have been denigrated as coniferous forests are cleared which causes the number of warblers living in a habitat to decrease , but they certainly are not greatly affected by the deforestation .
while the deforestation does decrease the warbler population in the specific area that it occurs in , the species is not significantly impacted overall due to the general abundance of the species throughout the region .
male magnolia warblers go to their breeding grounds about two weeks before the females arrive .
after the females come to the breeding grounds , both the males and females cooperate to build the nest for a week .
because of the difficulty of locating their nests among the forests dense undergrowth , it is hard to know whether the warblers re-use their original nests each breeding season , or whether they abandon them for new ones .
the nests are built in their tree of choice  different types of fir trees , such as abies balsamea (balsam fir) and picea glauca (spruce fir) .
the nest is made up of grass , twigs , and horsehair fungus , and they are relatively small , shallow , circular-shaped nests , barely exceeding 10 centimeters on all sides .
the nests are usually found close to the ground , commonly in the lowest three meters of the firs .
female magnolia warblers usually lay three to five eggs during each breeding season .
the female will not incubate her eggs until all of them are laid .
the female sits on the eggs for about two weeks before the eggs hatch .
the female is also the one that warms the newborn chicks by brooding , or sitting , on the nest; she is also the one who feeds the newborn chicks most frequently , though the males also engage in feeding the offspring at times .
because the males are technically as equally responsible for feeding the newborns as the females are , this means that the males are monogamous because they expend a large amount of energy looking for food for their young .
in order to keep the nest clean , females eat the fecal sacs of their newborns; as the chicks grow older , both parents simply remove the sacs from the nest .
the baby warblers are ready to fly out of the nest by the time they are ten days old .
