Bird Notes

From Jim Cox

Tough Spring

Nature has a way of tossing some nasty things at you once in a while. 

Spring 2013 was one of the least productive years on record for the Brown-headed Nuthatches on Tall Timbers. The exceptional warm weather we had in January and February quickly gave way to the wet and cold of March as frontal system after frontal system came through the Red Hills. 

Nuthatch responded by initiating nests earlier than ever – a nest found with five eggs on February 21 beat the previous record for an early nest by a full week. Great start, seemingly, but then the birds shut down as the onslaught of rain and cold mounted from late Feb through the middle of March. Very few nests were initiated during this period of time when typically more than 50% of the nests are initiated each year. Many birds that had initiated in late February simply gave up on the effort – including at least four cases where the young were simply abandoned.

Surely one of the most unusual casualties was a female nuthatch that died in attempt to give life to a clutch of five eggs. The nest was initiated after the cold and rain on March 19, but the inclement weather can take a lot out of these birds, especially when they are nesting. The five eggs represented about half of the total body mass of the female. It’s well known that the health of females coming into the breeding season can be diminished when birds have difficulty finding food and temperatures consistently dip into the low 30s.

Fortunately, nuthatches have very high annual survivorship, and low recruitment for a single year can be offset quickly. Those that abandoned nests may have averted the fate of the unfortunate female pictured above. 

Rare and Getting Rarer

The Stoddard Bird Lab also has been working on a bird that is quickly becoming one of the rarest in North America – the Florida Grasshopper Sparrow. This resident of open prairies in Central Florida used to occur in the hundreds on three different public landholdings. At present, only one of the sites still has a significant population, estimated to be about 100 total birds, while the other sites have gone from supporting hundreds to almost none during the past 5-10 years. The Stoddard Bird Lab helped develop a project looking at the effects of prescribed fire on the site that still has a sizeable population and is quickly trying to train a dog, Lily, to help find nests. Knowing how nesting success varies in relation to winter, spring, and summer burning is critically needed information, but finding a nest often takes hours or days for a well-trained biologist. 

Our approach has been to try to locate nests of the Northern Grasshopper Sparrows that occur in our region, where it is not endangered, and then train the dog on these. A site near Bainbridge, GA, holds a fairly large breeding population that we are working regularly, and we hope to have Lily ready for the 2014 nesting season. Dr. James Tucker has returned to the Lab to head up this project with support from the U.S. Fish and Wildlife Service.

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