The Birders Report

Osprey Nesting Pair Update

by Larry Jordan on June 3, 2010

Osprey Male In Nest photos by Larry Jordan

This is the male Osprey of the pair nesting atop the bridge I reported on at the end of March when they were mating. I wanted to follow up on the pair and their nestlings, now almost exactly two months later.

When I arrived I saw one of the adults standing on the edge of the nest as I drove under it. By the time I had parked the car and walked out on the bridge with my camera, it had flown so I concluded that they were no longer brooding the nestlings.

According to Birds of North America Online, both parents incubate the eggs but the female does the brooding, which is continuous for the first couple of weeks, then intermittent for a couple more.

Osprey may lay from 1 to 4 eggs but most of the time three, laid at two to three day intervals. The eggs are incubated for a month. So if this pair laid three eggs beginning on April 1st, the nestlings would be about four weeks old.

When this male flew back into the nest and looked around, he looked down at one point and shifted position. Like he was tending to nestlings, unseen by me.

Then he took off and I got a descent in-flight shot of him (my first in-flight digiscoped shot) although he was quite far off.

You can see in this flight shot that this is the male because he lacks the darker, more obvious necklace seen on the female in the previous post.

I observed no nestlings in the hour and a half I was there and the adult bird only visited the nest twice. Neither visit was for feeding the young. I was hoping they would pop their little heads up so I could see how many there were but no luck.

I will take another trip to the bridge soon. In the meantime, check out the other great Skywatch Friday posts.

{ 9 comments }

Nuttall’s Woodpeckers Feeding Nestlings

by Larry Jordan on May 30, 2010

Nuttall’s Woodpecker Female With Insect for Nestlings photos by Larry Jordan

I went out this morning to look for cavity nesting birds in the oak trees around my house and found these Nuttall’s Woodpeckers feeding theire nestlings. I was actually watching a cavity that was occupied by Acorn Woodpeckers last year, when a chattering Nuttall’s flew over my head.

I watched as the boisterous bird landed on the side of a nearby oak tree and disappeared around the backside of the tree, only to fly away shortly afterward.

Following her lead, I found this well worn entrance.

Within minutes, she arrived with more food for the nestlings.

Ooh, a nice fat grub!

I observed at least two discernible nestlings vying for food but these woodpeckers typically have clutches of four or five eggs.

The interesting thing was that the female would entice the chicks to stick their heads out of the nest to grab the treats from her beak. This behavior made me think that perhaps the nestlings were close to fledging.

The male Nuttall’s Woodpecker, on the other hand, stuck his head into the cavity entrance almost every time he came to feed.

Here he comes with a beak full of goodies (he’s the one with the fancy do).

According to Birds of North America Online, the male Nuttall’s Woodpecker excavates a new nest cavity each year, pretty much by himself. Then he incubates the eggs over half the time, including over night.

How’s that for being a good mate ladies?

Another interesting observation I noticed looking at the photographs was that many times the adult and nestling close their eyes during the food exchange. With those beaks being so close to their eyes, I imagine this is to protect their eyes from being poked with a beak.

The non-migratory Nuttall’s Woodpecker is found only in California and northern Baja California where they occupy predominately oak woodlands.

You may have noticed that the nestlings in all the photos have a red patch on top of their heads. Both male and female Nuttall’s Woodpecker have this patch until their first molt making it impossible to know how many of this brood are male or female.

I will check tomorrow to see if they are still in the nest cavity. I am curious about the feeding behavior. Until then, check out the other great bird photos at Bird Photography Weekly.

UPDATE Sunday, May 30, 8:40am – The nestlings are still in the nest but they seem to be sticking their heads out farther now

{ 10 comments }

Yard Birds for Wordless Wednesday

by Larry Jordan on May 26, 2010

Go check out all the other great Wordless Wednesday posts!

{ 5 comments }

Red-tailed Hawks Nesting Atop High Power Lines

by Larry Jordan on May 23, 2010

Red-tailed Hawk Nesting photos by Larry Jordan

This Red-tailed Hawk has been nesting on these high votage power lines for at least three years now. I have watched them raise three chicks to fledge each of the last two years and they are well on their way this year.

I thought I would use this as an opportunity to see the difference in digiscoping these birds at different magnifications with my Kowa 883 Prominar spotting scope. The photo above was shot at 20x magnification at a shutter speed of 1/640 of a second. All the images were shot at ISO 1000, using the Nikon D90 with an AF Nikkor 50mm 1:1.8D lens with the shutter speed compensating for the difference in magnification.

This tower is, to my best measurement using Google Earth, about 100 yards from the road where I took the photos. Here’s what it looks like using my Kodak Easy Share V1253 point ‘n shoot.

You can just see the nest on the right hand side of the tower on the left, at the towers narrowest point.

Obviously the lower the magnification, the better the image, so I try to digiscope most shots at 20x magnification if at all possible. The next three images were shot at 40x magnification but I think the quality is still pretty good. The shutter speed at this setting was 1/200 of a second at ISO 1000. None of the images have been cropped.

You can see the chicks are still covered with down but their feathers are growing out rapidly.

You can see the little tail feathers sticking up on the chick on the left side. Click on images to see full size.

At maximum magnification of the Kowa 88mm 20-60x zoom eyepiece, you get images like the two below. Not quite as sharp but I think they’e pretty good being a football field away from the subject.

These were shot at ISO 1000 and a shutter speed of 1/125 of a second.

I will be posting a page with my digiscoping set up information soon. In the meantime, get on over to Bird Photography Weekly for some great bird photos!

{ 16 comments }

Next Posts Previous Posts