Friday, April 25, 2014

Magnificent Migrant Yard Birds

Male scarlet tanager
In late spring some migrant birds continue to amaze and delight those who are carefully observant of the new birds in their trees and shrubs. These neotropical migrants are moving northward to their breeding grounds and are sometimes diverted through Florida by nocturnal westerly winds that blow them off course. Particularly striking is the brilliantly colored male scarlet tanager when adorned in his breeding plumage. We enjoyed watching both the bright male and duller female eating fruit of both mulberry and strangler fig. 
Rose-breasted grosbeak (male) eating berries
Blue grosbeaks
Rose-breasted grosbeak (female)

In our yard the presence of rose-breasted grosbeaks at feeders and in fruit trees such as mulberries and strangler figs is pretty exciting since the adult males are brilliant red, black and white. They gorge on the mulberry fruits and stain their bills. The females are camouflaged, the better to protect them when they are sitting on eggs. The blue grosbeaks have a similar bill for cracking large seeds but their color is very different. I was particularly interested in some juvenile males which were molting from brown to their adult blue plumage. The habits of blue grosbeaks are quite different since they are more of a southerly grassland/shrub species compared to the northern mountain/forest dwelling rose-breasted grosbeak. 

A bird that feeds on somewhat smaller seeds is the painted bunting which does winter here but is also now migrating though. It has a much smaller bill which illustrates how selection can modify bill size to minimize competition among species. This greenish bird may be a young male but the differences between adult females and young males can be confusing. 

Painted bunting
Of course the warblers are the stars of the birding world and can be challenging in the fall, but their spring-time feathers are often very bright and distinctive. Here a male redstart stops for a bath in our yard. 

Male redstart, bathing
April and early May in Florida are so delightful for birders since they get to see a parade of colorful and interesting species as they return from a winter in the tropics. It is definitely an exciting time and represents the renewal of life across the whole spectrum of nature. 

Bill Dunson 

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