"Flicker Dance"

     The Northern Flicker is a common and widespread breeder throughout the state of Connecticut. They can be found in a variety of habitats such as open forests, semi-open country, suburban neighborhoods and urban parks.

     Flickers have unusual feeding habits, especially for a woodpecker. They spend a great deal of time on the ground foraging and probing for ants, a key component of their diet.   

     Early last spring, I had the opportunity to photograph these ground feeding woodpeckers at Keney Park in Hartford. Nothing seemed out of the ordinary on this particular morning, birds were well-spaced, their bills stuck into the dirt and focused solely on ants. The flickers stayed busy, I continued to take photos. Suddenly, without any provocation, two of the birds flew over to one another and met face-to-face. With bills held slightly upward, they began to bob and weave in a comical dance, flashing their yellow tail feathers at each other.

     What type of odd behavior was I observing? According to the Birds of North America Online, it is a combination of territory establishment, pair formation and nest-site selection. I noticed something else odd as I looked over my photos from my morning visit; there were two females dancing! What I was surprised to learn is that both sexes defend nest trees and mates aggressively. Below are some of my photographs from Keney Park as well as a professional description of this incredible dance behavior from the Birds of North America Online.   

Both sexes defend nest trees and mates aggressively. Agonistic behavior is highly ritualized in flicker “dance” (Fig. 6). Typically, 2 birds of same sex pair off in mock “fencing duels,” using their bills as “foils,” while a member of the opposite sex looks on. This dance is prevalent during early phases of the breeding cycle (territory establishment, pair formation, and nest-site selection), but is also seen infrequently and at lower intensities at other times (Short 1982). Displays that comprise the dance are clearly agonistic (Noble 1936) and function in territorial defense, but territorial establishment and pair formation are so integrated in flickers that these displays may also play a role in pair formation; this remains poorly understood.Typically, 2 birds of the same sex face one another on a branch with their bills held at a slightly upward angle (about 30° from horizontal). Each bird quickly swings its head back and forth and bobs it up and down, such that the bill appears to trace a circular or Figure-8 pattern in the air (Kilham 1959, Lawrence 1966, Short 1972). The swinging and bobbing give the appearance of a mechanically animated toy, and are usually accompanied by in-rhythm Wicka Calls from both dancers. The red nuchal patch is usually erected in Yellow-shafted Flickers. Intensity of the dances varies greatly: the dance of 2 birds (same sex) is likely to have relatively low intensity and may even be silent, but the arrival of a third bird (opposite sex) immediately intensifies both the dance and the Wicka accompaniment. In very intense interactions, which are common, the dancers flick their wings and spread or rotate their tails such that the yellow, or red, ventral surfaces of the flight feathers are clearly visible to the opponent. Bursts of dancing and Wicka-calling might last 5–10 s, followed by a 30-s period of quiescence, followed by another burst of dancing where all participants seem compelled to join in. Bouts may last nearly half an hour (but usually are shorter) and may be joined and rejoined over a period of many hours. We have observed sustained series of dance bouts go on essentially all day, involving the same participants. Variation in the dance is substantial: the apparent context, number of participants, location, intensity, duration, whether the wings and tail are spread, whether Wickas accompany animation, pattern traced by bill, etc., can all vary. No data are available that demonstrate the range of variation or its meaning.

"Dancing duels" often do not result in physical contact but instead one bird simply flies away. If one bird does not fly away after many minutes of dancing, the two rivals may peck and claw at each other and perhaps end up in a rolling fight on the ground (KLW). This usually results in a long period of one bird chasing the other, displacing it from perch to perch in short flights until eventually the "loser" flies away out of apparent exhaustion.

What Could These Ducks Be Eating?

 

     No matter where you may find yourself birding in Connecticut, it is always important to be aware of you’re surroundings. Keeping focused in the field can often lead to discoveries that would otherwise go unnoticed.

     Last week at Riverside Park, I caught sight of a small mussel washed up along the banks of the Connecticut River. As I admired the beauty of the mussel in my hand, I thought back to a sighting I had of a female American Scoter at this very location. It spent the entire month of January feeding and resting just off the boat launch. I remember asking myself, why does this bird favor this part of the river? What could it possibly be eating down there?

     The mussel I found and photographed here is called an alewife floater. It is one of twelve species of freshwater mussels native to Connecticut. The alewife floater is still considered an abundant species in the Connecticut River, where it lives in mud, sand and gravel bottoms. Was this mussel sustaining the scoter in Hartford?

                      www.ct.gov/dep/cwp/view.asp?a=2723&q=325894&depNav_GID=1655

     Another question which came to mind while I was reading about freshwater mussels, involved the occurrence of overwintering Common Goldeneyes. Why are Common Goldeneyes found in such large numbers in Enfield, and absent elsewhere in Hartford County? With a coastal diet of primarily mollusks and crustaceans, is there a similar habitat or condition in Enfield that supports a healthy population of mussels, and in turn, a healthy population of Common Goldeneye?

South River Street Boat Launch
Enfield

                          

     To help answer these questions, I turned to Doug Smith of the University of Massachusetts Amherst.  http://www.bio.umass.edu/biology/conn.river/fwmussel.html

 He wrote,

 Paul,
 Well here's what might be happening. The Enfield rapids are shallow and
the substrate is rocky with sand and silt, especially since the old pier
wore away. Many years ago (over 30) I studied that section of the
Connecticut because it was a historical location for many mollusk
species, many since extirpated. What I did find was that section of the
river was the only one that still supported a decent population of the
Virginia river snail, Pleurocera (=Goniobasis, =Elimia) virginica, a
relatively large (10-20 mmm) snail living on the hard substrate (Smith,
DG, 1980. The Nautilus 94(2):50;http://www.biodiversitylibrary.org/item/34223#page/66/mode/1up). Two
mussels, Elliptio complanata and Anodonta implicata, were also fairly
common. Since about 1991, an invasive species of clam has become
established, the Asian clam, Corbicula fluminea, and is quite abundant
in the lower part of the river. It is possible that it has migrated
upstream to provide an additional source of food. Over the last twenty
years, due to clean up efforts, the populations of various mollusk
species have grown considerably and the last I heard was that the river
snail was everywhere and common in Enfield and elsewhere.

     With that being said, it is safe to assume the winter population of Common Goldeneyes will remain constant in Enfield for years to come. In an environment that is largely hidden, it is essential to annually monitor the health of the entire Connecticut River ecosystem. This will ensure that all living things, seen and unseen, will always flourish.  

Woodpecker Nest Cavities

 

     In the avian world, nesting is often considered a risky endeavor. Parasitism, predators and inclement weather can all play a factor in nest failure. But through time, woodpeckers have evolved a way to minimize those challenges by simply nesting indoors, in tree cavities.

     Woodpecker activity plays a vital role in the woodland environment, excavating holes for themselves as well as for other species of birds. Black-capped Chickadees, Tufted Titmice, White-breasted Nuthatches and Eastern Screech-Owls all depend on the woodpecker’s handiwork to nest.

     Woodpeckers typically select a dying tree wherein to nest. Its advanced state of decay aids in the cavity excavation process. However, some species like the Hairy Woodpecker prefer to nest in living trees, although it may use a dead limb if needed. A woodpeckers choice of tree species vary in Connecticut, but most favor oaks, maples, hickories, poplars and birch.      

     The construction of a new nest cavity takes place each year, approximately three weeks before eggs are laid. Woodpeckers chisel out a horizontal entrance tunnels until it reaches the trees heartwood. From there, it forms a sunken chamber in which to lay the eggs. The accompanying drawing clearly shows the finished product.

From A Guide To The Nests, Eggs, and Nestlings of North American Birds
Baicich &Harrison

     Since woodpeckers do not add any lining to the nest, eggs are laid directly on the chamber floor, or onto wood chips left over from the cavity excavation.

     I have provided some additional facts regarding woodpecker nest excavations from the web pages of The Birds Of North America, online version. 

Yellow-bellied Sapsucker

In Ontario, during 3,514 min of observation, males excavated 1,317 min, females 476 min; male excavation periods averaged 17.8 min.

Bill used to chisel out cavity, striking wood at rate of 100–300 strikes/min, periodically stopping to remove chips.

Male does nearly all excavation of nest; female spends much of time preening and resting and removes very little wood from cavity, but will become more involved in excavation if first cavity not successful.

Northern Flicker

Usually excavates nest cavities in dead or diseased tree trunks and large branches, in Wisconsin, 92% of nest cavities were in dead trees.

Nest cavity is excavated by “chiseling” away small chips of wood with bill; bird starts by clinging to trunk, using its tail as a prop, then perching on lower lip of nest opening as it works its way into interior. Periods of chiseling are interspersed with shorter periods of tossing chips from cavity opening; chips are also carried away in bill.