Friday, August 7, 2015

Purple Martin Family Life - Dr. Phoebe Prather, Senior Biologist

Purple martins peeking out of nesting cavities (photos by Chris Gardner).


The Tejon Ranch Conservancy has wrapped up its 2015 purple martin survey season.  There are four main ridges on the Ranch that provide optimal habitat for nesting purple martins (Cordon, Middle, Winters, and Tunis).  With the help of two of our dedicated volunteers we were able to conduct multiple visits to each of the four ridges throughout May, June and July, allowing us to track the nesting phenology of the martins over a three month period and get a better estimate on the number of breeding pairs in our survey areas.  This year we found a total of 23 breeding pairs.  The nesting period was staggered among the pairs.  We found nests that had fledglings taking their first flights next to nests that still had very young nestlings still in the tree cavities quietly chirping for food.  

Adult male purple martin holding a large insect (photo by Chris Gardner).

We witnessed the dynamics of purple martin families and the care provided to their fledglings as they learned to fly.  A tremendous amount of purple martin noise is the first sign that you have stumbled upon a family group and we witnessed the following behavioral pattern each time.  The patriarch perched on the tip of a snag, calling constantly while his fledglings learned to fly around him.  The matriarch soared in the air around her kids, the grace and beauty of her flight contrasted with the uncoordinated flight of the young.  Her soft call notes acted as guidance.  Slowly the fledglings would tire and one by one join their papa on the snag.  As the last ones came in for a rest the male’s call shifted into full song as he welcomed his mate back to the perch.  As she landed, she joined her mate in song.  At songs end, the family would fall quiet as they all rested and watched over the canyon.  But as with toddlers of all species, they would not sit still for long.  Soon the fledglings were off once again, mama following behind and papa chirping from the sidelines.  


(photo by Chris Gardner).
As we sat on ridges watching and listening, we witnessed not only the fledging of purple martins but several other species as well.  It was the season of families and noisy babies.  Our days were filled with the squawking’s of fledglings of multiple species.  The young of oak titmice, ash-throated flycatchers, house wrens, and American kestrels were all going through the process of learning how to be independent but still needing the comfort and security of their parents.  It turns out to be a very noisy process.  Western bluebird families flitted among the grasses calling as they searched for insects.  Young kestrels swooped through the air, squeaking out their high pitched klee-klee-klee call while the family unit gathered on snags of dead oaks.  Fledgling red-tailed hawks soared with their parents, screaming for food even though they were now of equal size.  Just for good measure, a raven family would join in since there can’t be red-tailed hawks without ravens.  The raucous noise of two species would fill the canyon.  Sometimes I wanted to just yell at them to be quiet and sit still so I could hear the bird that was the target of my search.  But of course I didn’t, I just sat and took it all in.  How often does a person get to experience such incredible behavioral observations.
Adult female purple martin (photo by Chris Gardner).

Last year I wrote a blogpost on the natural history of the purple martin.  This year I want to showcase some amazing photos taken by our outstanding volunteer, Chris Gardner.