Turkey Vultures are a daily sight as they soar, dip and bank across the Museum’s airspace.

Note the small head, gray flight feathers, and rather long tail on this Turkey Vulture sailing over the Museum.

The slightly smaller Black Vulture, while seen at least once a week here at the Museum, is not as frequently encountered as the Turkey Vulture.

A short tail, small head, and white or gray primaries (the feathers at the tip of the wings) are trademarks of the Black Vulture. Black Vultures flap their wings more often, and more rapidly, than do their larger relatives, Turkey Vultures.

Hardly a day passes without seeing or hearing a Red-shouldered Hawk at the Museum. They are most often encountered while they’re perched in the woods silently watching below for prey.

A Red-shouldered Hawk sits quietly in the swamp between Catch the Wind and Explore the Wild.

Red-tailed Hawks are seen above at least once a week in winter, but there is a two month period during summer when they may not be seen at all. Whenever they do show up, a Red-shouldered Hawk is often there to greet and escort them out of the airspace.

Although larger and more powerful than Red-shouldered Hawks, Red-tailed Hawks are often chased out of the Museum's airspace by the smaller hawk.

This Cooper's Hawk was seen January 28th hunting over Catch the Wind.

Copper’s Hawks have successfully nested here at the Museum for the past two years. I see one of these brazen, bushwhacking, aerial hunters nearly every week of the year, certainly every month. Last week was a double; I saw one (most likely the same hawk) on two different days. Each time, the hawk was hunting from above, settling down into the pines north of the Lemur House.

On February 3rd, a tap-tap-tap-taping sound high in a Loblolly Pine in Catch the Wind signaled the workings of a Brown-headed Nuthatch excavating a nest hole. A pair of these tiny pine dwelling nuthatches had dug two holes in a pine not fifty feet from this location last year, only to give it up (or lose it) to a pair of Carolina Chickadees several weeks later.

One nuthatch quickly exits the hole as the other waits to inspect his handywork.

This pair seems to be a bit ahead of themselves. Last year’s nuthatches were first spotted on February 20 as they had just begun excavation. From the apparent depth of the current hole it appears as though they’ve been working on this one for several days, if not more.

I’ll keep you posted on their progress.

Ravens are large birds, much larger than crows. I would compare their size to that of a Red-tailed Hawk, although their wings are not as broad as the hawk’s wings. Their call is distinctive, especially the croaking call. Listed as Very Rare in our area (Triangle), they are being reported with increasing regularity. I’ve seen a raven on more than one occasion at Occoneechee Mountian Natural Area in Hillsborough, NC but not here in Durham.

Upon the realization that there was a raven nearby, I halted my futile attempt at photographing Butter-butts (Yellow-rumped Warblers) and went off to investigate. The call had come from the area between Catch the Wind and Explore the Wild, above the Lemur House. As I walked up the trail I saw, through the pines, a large black bird fly off in a southerly direction. The bird had the unmistakable wedge-shaped tail of a raven. I quickened my pace, I wanted a photo.

As I came up through Catch the Wind I saw the raven harassing a Turkey Vulture beyond the trees near the Traveling Seeds Exhibit. The bird was moving farther away from me. I moved faster.

A minute (hours) passed before I again saw the raven, this time the bird was quickly moving towards the southwest and was some distance from where I stood. I managed to squeeze off two shots before it disappeared over the pines. Unfortunately, neither image is Pulitzer material, but they’ll have to do.

Common Raven flying over Museum.

From the direction that the bird was heading it must have flown right over the main building of the Museum.

The following day I was alerted by a radio call from Joe Nucilli of the Facilities Department that there was a group of vultures hanging out near the swamp between Catch the Wind and Explore the Wild. I was on my way.

As I walked upon the scene, there were Turkey Vultures circling above and a small group of Black Vultures in the trees; there was something dead in the swamp.

Four of the seven Black Vultures in the swamp between Catch the Wind and Explore the Wild.

Looking closer, I noticed one of the vultures next to a drain pipe which is close to the base of the dike that supports the trail. The bird was feeding on a carcass, a Raccoon.

A Black Vulture feeding on a Raccoon carcass (the animal's ribs are visible just in front of the bird's feet).

Turkey Vultures often find a carcass, but it’s the Black Vultures that usually finish off the animal. Turkey Vultures have a highly development olfactory nerve (they can smell well) and it’s usually the smell that draws them in to a dead animal; the Black Vultures follow them in.

Vultures usually hang out in groups in search of carrion and perch together in trees at a kill site or at their night-time roosts. One of the hazards inherent in these large birds traveling and roosting in groups can be seen in the image below.

Communal roosting has its hazards especially when you perch below a large bird like a vulture. The "whitewash" on this bird's feathers is excrement from a bird perched above it.

This was the same location that I had heard the raven calling from the day before. The raven that I saw had been harassing a Turkey Vulture. Was it a coincidence that I had seen the raven at this spot the day before, and that it had been chasing a vulture. Ravens eat carrion, are well know for scavenging whatever food they can find, and are often accused of being “mischievous.” I think it reasonable to suggest that the raven had been attracted to the activity around the raccoon, stopped in to investigate (or for a bite) and chased off a vulture or two when it left, just for spite. But I could be wrong.

]]> http://blogs.ncmls.org/greg-dodge/2009/12/18/the-raven-and-the-vultures/feed/ 0 http://blogs.ncmls.org/greg-dodge/2009/07/15/missing-feathers/ http://blogs.ncmls.org/greg-dodge/2009/07/15/missing-feathers/#comments Wed, 15 Jul 2009 12:36:23 +0000 Greg Dodge http://blogs.ncmls.org/?p=83 Many birds are currently molting their flight feathers (wing and tail feathers). Some have completed their molt while others are still in the process of doing so. I’ve found various wing feathers floating in the Wetlands, on the path around the Explore the Wild/Catch the Wind loop, and at the Bird Feeder Exhibit.

All birds molt. The wear and tear of daily life necessitates the replacement of old, worn feathers. While the contour feathers (the body feathers on the back, head, belly…) are replaced each year at various times of the year, depending upon the species, most flight feather molt occurs during the breeding season, usually while there are still young on the nest. Birds not only have to expend enormous amounts of energy at this time of year dealing with the building of nests and the rearing of young, they must also cope with the energy consumption associated with the growing of new flight feathers. It’s definitely worth the expenditure though – birds can’t fly without feathers!

The wing and tail feathers usually molt sequentially, especially in larger species like hawks, owls, and herons. In the wing, the molt begins with the innermost primary and works its way outward. The secondaries are next, starting with the outermost feather and working in towards the body. The tail feathers are replaced in order from the center outward.

So, if you see a large bird coming into the Wetlands and it appears a bit ragged (missing some feathers in the wing or tail), you’ll know what’s going on. The bird is molting. By the way, only the adults molt their flight feathers at this time of year, so any bird you see that’s missing feathers in its wings or tail will be an adult bird, unless, of course, a young bird has lost a feather due to an encounter with a predator, or has had a heated argument at the bird feeder.

The first image of Turkey Vultures here (TV-1) shows the bird nicely completing its molt. The next to last primary on its left wing is coming in as well as two new secondaries. The tail molt looks to be complete, or nearly so. The bird in the second image (TV-2) apparently hadn’t received the memo about sequential molt and appears to have lost several primaries in each wing at the same time. The tail needs some attention as well. It’s not unusual, however, to see a bird missing so many feathers in its wings or tail as to make you wonder how it can stay aloft!

July is a month in which some species of bird begin to move south. We may see a few early migrants during the next few weeks. Keep your eyes open!