The Magnolia Warbler is a small bird that breeds in dense conifer stands. Males and females have different facial and breast patterns, and the species uses a range of forests during migration.
The breeding male has a black mask and streaked black necklace, with a white wing patch. The female has a gray head with a white eyering and thin wingbars, plus yellow underparts with moderate streaking.
At Manomet, Massachusetts, researchers analysed 46 years of bird-banding data from 1970 to 2015. Using arrival-date quantiles, they compared early and late spring migrants and measured the length of the seasonal passage window.Across all species, the median spring arrival date advanced by an average of 1.04 days per decade. Changes in passage duration appeared separately from shifts in the median date.
Magnolia Warbler spring passage duration contracted by 0.48 days per decade (SE 0.22). Across all species, mean spring passage duration changed by only +0.07 days per decade. Passage duration describes the span between early and late arrivals at the study site, while stopover duration measures how long an individual stays.
An extinction-risk assessment has not been added yet.
The long Manomet record showed a species-specific contraction in Magnolia Warbler spring passage. Tracking early and late arrivals across many years reveals changes that a median arrival date alone would not show.