Fall Migrants Already
Ro Wauer, August 8, 2004, The Victoria Advocate, © 2004
The appearance of a female black-and-white warbler in my yard on July 27 suggested an earlier than normal southbound migration this year. Although this warbler species nests in woodland areas not far to the north of the Golden Crescent, any warblers that enter our area after mid-July can be considered a migrant. This is especially true for females, because females of most bird species usually remain on their breeding grounds longer than the males. Males of many species are well known for their habit of departing early, leaving the ladies to finish raising the babies.
Hummingbird males always leave early. They are considered little more than "promiscuous rakes," departing their breeding grounds almost immediately after breeding. Even male rufous hummingbirds, a species that is little more than an uncommon migrant and winter resident in South Texas, can be found in mountain meadows of Mexico by early July. Rufous hummingbirds nest only in the extreme northwestern United States and north into Alaska.
There are numerous other bird species considered "early" migrants. Examples include most shorebirds and many ducks, especially those that nest on the northern tundra. These birds usually arrive on their nesting grounds in early spring, raise a precocial family, and must leave before winter weather sets in. Sometimes circumstances, such as nest destruction in the far north where time does not permit a second try, can lead to an earlier than normal movement toward the south.
Some of the earliest of the southbound migrants reaching the central Texas Coast area include species that nest just north of our area. A few examples include broad-winged hawk, eastern wood-pewee, northern rough-winged swallow, yellow-throated and black-and-white warblers, Louisiana waterthrush, and field sparrow. Some usually late southbound migrants to reach South Texas include house and winter wrens, hermit thrush, orange-crowned and yellow-rumped warblers, scarlet tanager, and white-crowned sparrow.
One of the very best references to our local bird's status and their movements through our area is Mark Elwonger's little book, "Finding Birds on the Central Texas Coast," subtitled "What to look for, how, when, and where to look," is available from the author at firstname.lastname@example.org. The bird distribution list included with this book can also be obtained from ornifolks.org. Elwonger's book also includes 19 of the best bird-finding sites in the Central Texas Coast area.
Is there any significance to an earlier than normal migration period? Any response to that question would be analogous to a meteorologist explaining why Hurricane Claudette hit our area earlier than predicted in July 2003. However, everything about nature has an explanation. And most explanations regarding bird migration relates one way or another to weather conditions. But one explanation is that an earlier or more severe than normal stormy period in the Arctic or elsewhere in northern North America could speed the departure of many species, resulting in their arrival into Texas earlier than normal.
Whether that occurrence suggests weather patterns to the south, such as whether or not we can expect a colder or warmer winter than normal, does not relate.
What does relate, however, is the greater than normal number of waterfowl, sandhill cranes, and some of the more northern songbirds in South Texas when wintertime weather patterns just north of our area are extremely cold. For instance, ducks and geese can occur in huge numbers in South Texas when weather conditions in northern Texas and further north produce heavy snows and frozen lakes and bays. It is far too early to predict winter bird numbers.