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11 July 2010 @ 04:10 pm
Purple Martin Banding  
The temperatures stayed hot through the weekend, and it already warm and humid when I left at 8:00 on Saturday to go birding. My first stop was the ponds on the east side of Eagleson in Emerald Meadows; I found two Black-crowned Night Herons perching in the trees above the water, though it was impossible to get close enough to photograph them without any intervening branches. I drove over to the pond on the west side of Eagleson shortly after, although the word "pond" doesn't really describe it anymore. When I first started going there, the pond consisted of a large clay pit filled with water. In fact, it was the Common Terns fishing there which attracted my attention, together with a few Least Sandpipers, Killdeer and Spotted Sandpipers probing the muddy edges of the water. Now, the cattails and vegetation have almost entirely choked the whole pit, leaving a small water-filled channel in the middle. It is no longer possible to see the ducks and shorebirds in the channel from the road, and I fear its days as a shorebird magnet are over. However, there is still an open mudflat at the south end of the channel, and here I found a couple of Killdeer and a Lesser Yellowlegs. There may be some hope for this spot yet.

I heard a Savannah Sparrow singing while I was watching the yellowlegs; when I turned around I was surprised to hear him singing in the grassy area behind me. This grassy area is bordered by four newly built roads, and one of the roads already has houses being built on it. I assume the developers will destroy what's left of that grassy block and put up more townhouses, but the Savannah Sparrow singing away was completely unaware of the threat to its habitat.

Savannah Sparrow

I walked along the road until I found him on a post quite close to the road. I was surprised at how close I was able to get to him, and my heart broke for him the entire time I spent photographing him, knowing that when he returns to his home next spring he will find it completely changed.

Savannah Sparrow

After leaving the pond I went to Dick Bell Park to see the Purple Martins. One of my friends got some really good shots while attending the banding session there last weekend, and I thought I'd go over to the park to see these swallows. When I got there I noticed that the houses were not on top of the poles, as usual, but were about four feet above the ground. I hadn't realized that the banding sessions take place every Saturday during the month of July, and that one was just starting as I arrived.

The martin houses are located on private property belonging to the sailing club, but the gate was open so I went in. It was a little after 10:00 and already the day was sweltering hot. The banding took place at a table beneath a canopy, and I watched as the bander held the young martins and applied the silver bands to one of their legs. Before returning the chicks to the martin houses, an assistant gave them some clear fluids through something like an eye-dropper bottle to help them keep up their strength. When he was done, he returned the youngsters to the nest box, closed it up, and moved on to the next martin house. After opening up the front of the house, he put the nestlings in a wooden box where they remained while their siblings were being banded.

In the martin house

These nestlings are flightless, and are only just beginning to develop flight feathers. They need to develop quickly before the martin families fly south for the winter in late August.

Purple Martin nestlings

At this young age, the babies looked quite awkward, as if they are not quite sure what to do with their legs and wings yet!

Purple Martin nestling

It took a long time for the purple martins to be banded, and during that time the houses remained lowered at waist-height on the pole. This upset the parents' routine, for although they kept hunting for food and bringing back mouthfuls of insects, they wouldn't feed the chicks while the houses were lowered. Instead they landed on the top of the pole and in the trees close by, as though waiting for the houses to be returned to their normal place. When this didn't happen, they ate the insects themselves, then flew off to obtain more.

Purple Martin (male)

Both the males and females feed the young; both were seen coming to the nest boxes with insects dangling from their bills.

Purple Martin (female)

The Purple Martin is the largest North American swallow. The male is a glossy blue-black colour, both above and below, and is the only swallow in North America with such colouration. While Purple Martins breed in temperate zones across North America, in the east they nest almost exclusively in man-made birdhouses. The Purple Martin is unusual among birds that use nest boxes in that several pairs will nest in a single box with multiple compartments.

Purple Martins suffered a severe population crash in the 20th century, most likely as a result of the spread of European Starlings across North America. Starlings and House Sparrows compete with martins for nest cavities. As such, martin houses require ongoing maintenance, as European Starlings and House Sparrows will fight with martins over nest sites. Starlings have even been known to kill Purple Martins, especially the vulnerable nestlings. Unmonitored Purple Martin houses are often overtaken by these aggressive, non-native species. The bander explained that he regularly checks the martin houses in the spring for these intrusive species. If found nesting there, he destroys their nests.

Purple Martin (male)

I left after spending close to an hour watching the bander work and the adult martins fly down to deliver food their young. It was quite hot, and even the birds were trying to keep cool. Because they do not have sweat glands, one of the only ways birds can get rid of excess body heat is through the membranes lining the mouth and tongue. On hot days I see many species doing this, particularly crows sitting on telephone wires and even flying with their mouths open.

European Starling

Despite the heat, I decided to check Shirley's Bay before heading home. I parked in the lot off Carling Avenue rather than heading over to the boat launch; the trails here pass through some nice open scrubby areas and I thought I would look for some butterflies. A few were flying, and I was happy to come across a female Northern Broken-Dash basking in the sun.

Northern Broken-Dash

I saw few of any other species, and none of the butterflies I saw paused for any length of time. I was surprised to see two different clearwing moths along the trails, including one nectaring on some purple Cow Vetch. I am not sure whether it was a Hummingbird Moth or a Snowberry Clearwing; like a hummingbird, it fed while hovering just above the flower, beating its wings so fast that they became a blur. I tried to take a couple of pictures but it was difficult to capture such a tiny moving object.

The only other creature of interest was this large toad sitting in the path. I almost stepped on him before I realized he was there; he didn't even move!

American Toad

I didn't spend much time at these trails, as the heat and humidity were becoming intolerable. This is another place I would like to spend more time exploring, once the temperatures return to normal, to see what other butterfly species I can find.