Sunday, April 13, 2014

The Blues Brothers and Other Backyard Bird Surprises

Blue grosbeak male
April is a time of great excitement among birders since migration of a vast army of birds begins from South and Central America to the US. This predominantly occurs northerly from the Mexican Yucatan Peninsula across the Gulf of Mexico to the coast between Texas and the FL panhandle. However when a weather front passes through, producing strong winds and rain from the West and Northwest, many birds can be forced to the east of their typical course and land in Florida. This is bad news for the birds since it is stressful, but good for Florida birders who periodically get to enjoy a "fallout" of marvelous birds from the night time skies. The next morning the birds can be exhausted and in need of rest, fresh water and food, and thus easier to observe than normally in a dense forest. 
Blue grosbeak and indigo males

We have recently had what I call a "mini-fallout" of birds along the SW FL coast. In our yard on Manasota Key we have had the pleasure of observing beautiful migrants including warblers such as hooded, parula, prairie, and even the rare Kentucky, orchard and Baltimore orioles, summer and scarlet tanagers, blue grosbeaks, a peewee, and lots of ruby throated hummingbirds. 

We maintain water drips that attract the birds by sight and sound and saw a pair of birds attracted to the water that might be termed the "blues brothers." The adult male indigo bunting turns a bright blue this time of year and although a few spend the winter in FL, most migrate in from the south heading to their breeding grounds to the north. The male blue grosbeak differs in having a much larger bill, a different blue color and rufous wing bars. This individual also appears to be molting its brown juvenile feathers and replacing them with blue ones. As its name grosbeak implies it also has a very large bill, the better to crack large seeds. 
Summer Tanager

But it is interesting that the indigo bunting always loses the adult male blue color in winter, whereas the adult blue grosbeak remains blue all year. This mirrors the difference between male plumage color in summer (permanently red) and scarlet tanagers (seasonally red only) and shows how strategies for camouflage and male-male territorial aggression vary even among closely related species. 

In our area of Florida we have few hummingbirds except during migration, so we enjoy them very much when we can see them. We have lots of nectar-rich red flowers planted for the hummers such as coral honeysuckle, firebush, Turk's cap hibiscus, shrimp plants, and cape honeysuckle. This particular hummer appears to be a female rubythroat, yet it has an unusual yellow throat patch which is likely due to pollen. 
Orchard oriole male collecting nectar

Orchard orioles are particularly attracted to local yards with flowers and fruit during migration; they seem to prefer gathering nectar from Cape honeysuckle and Turk's cap hibiscus. Orioles and summer tanagers are very fond of fruit such as ripe mulberries and strangler figs. This male orchard oriole is piercing a cape honeysuckle flower to obtain the nectar. This flower is derived from South Africa where its peculiar shape is well designed to accommodate the curved bills of the local sunbirds. Hummingbirds may be the only native birds that can reach the nectar the normal way down the corolla tube. Local birds and some insects such as honeybees pierce the base of the flower and steal the nectar. 

So enjoy this amazing time of year when many thousands of spectacularly colored birds are passing through our yards. This is a temporary show that will quickly pass as the birds move to their northern breeding grounds so don't miss it. 

Bill Dunson 

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