Tuesday, March 30, 2010

PostHeaderIcon Don't mind us while we rest for a bit...

Maganrord isn't going away, but you might not see much of us over the next week or so. LadyBird and I are moving into our gorgeous new apartment and that's going to take up much of our time and effort in the coming days. Having a new household together is an exciting step for us (we live together now, but our space is small and unsightly) and other priorities, bird blogging included, will be pushed to the back of the queue, if only for a short while.

BourbonHawk, for her part, is encumbered by a rather taxing social schedule.

But we'll all be back before you know it.

Odds, ends:

We've still got a tiercel. Yesterday, I saw him repeatedly but unsuccessfully dive on a smaller bird, probably a starling over the gardens on Officer's Row.

A third dead western gull has turned up on the roof of the new industries building, where our young tiercel stages his bloody adventures. Although these dead gulls are likely the victims of gull on gull violence, I wouldn't mind at all if someone with the authority to do so would go up there and see if the fatal wounds appeared to be gull or falcon inflicted.

We're still watching a certain crow pair on the island. They have a preferred tree and they have been observed defending it.

Speaking of corvids, our ravens may soon receive an awful surprise. The National Park Service may move to destroy their existing stick nests to interrupt reproductive efforts. Ravens will use these nests over and over again from year to year, maintaining and improving them each time around. It's unclear how many nesting seasons these structures have seen but it's probably more than a few.

We know that ravens may be expanding beyond their prehuman range by establishing themselves on Alcatraz, and we have closely reviewed studies showing the degree to which our snowy egret and black crowned night heron colonies face predation by voracious gulls and ravens. Still, we at Maganrord unanimously find that we cannot agree with management policies aimed at thwarting the ravens.

Thanks so much to all of you for reading us, writing us and helping us out with a wealth of knowledge that we've been using to mitigate our obviously amateurish attempts at bird investigation. We'll be back soon!

Upward and onward!

Wednesday, March 24, 2010

PostHeaderIcon Tiercel still around, cryptic, gleefully terrorizing the WEGUs

Our tiercel has become very secretive, but when he is visible, he's having a great time.

He goes about life doing exactly what I might were I given an hour in a falcon's body. Our bird passes the time by messing with gulls in extravagant aerial combat.

We observed him doing so yesterday around 6 pm near the dock.

On a more boring note, I've finally begun to identify which subspecies of Canada goose are present on the island. So far, it's just the 'common' variety. Booooring. I have seen one pair of smaller geese on the island. I'm hoping to have pictures of those up soon, hopefully with an identification.
Sunday, March 21, 2010

PostHeaderIcon Tiercel remains elusive, except to a few unfortunate WEGUs

It was a big ol' day for birding on Alcatraz. Heavily attended bird docent training and new natural resources folks. Lots of chatter here and there about falcons and snowy egrets. WEGU love and WEGU war. Crows and ravens interacting over BourbonHawk's salty commentary. The usual.

So here we go. After not witnessing a falcon all day, I quietly admitted to myself that our avian celebrities had grown tired of the birder paparazzi corps hounding their every move, ceaselessly poking their crops with spotting scopes and camera lenses. Their issues with gulls and ravens and the adult female being perhaps less than enamored with her male associate's juvenile brown plumage may have also been factors.

Due to a scheduling mixup, BourbonHawk and I were on the hook to work an eleven hour day. Though it wasn't ideal, it did give us the opportunity to roam the island freely for the hour between the end of the day tour on Alcatraz and the beginning of our acclaimed night program.

Our "inbetween hour" is great for birding because there is literally no one around to bother the birds or to pollute your apprehension of the vocalizations around you.

I decided to scope out the extreme north end of the island, near the power plant and the model industries building. BourbonHawk reasoned that if a falcon did try to establish itself on Alcatraz, especially if it was solitary, it would choose to live away from the large concentration of gulls on the south end and the hulking and aggressive raven pair that resides in the cypress trees adjacent to the cell house.

It wasn't long before that logic was rewarded.

None of our pictures were great (as will happen when you're messing with 80x zoom and an animal soaring too high to be close enough to photograph or moving way too fast to yield clear shots when it's close) but this one of an oblivious gull and our peregrine lurking in the background captures the character of his adventure this evening.

He was out to screw with some western gulls and they hated it. In previous encounters, the gulls seemed lively and aggressive, apparently outmatching the falcons with their numbers and their persistence. Today, the tiercel, which seemed to be perhaps half the size of the gulls it was chasing, had the mob on the defensive.

He dove and attacked, spiraled downward and extended his talons. He made solid contact with a gull which survived unscathed but not without making an awful, wrenching gull vocalization that I'd never once heard before.

I'll probably be guilty of anthropomorphizing the young tiercel, as he attacked these gulls that must have seemed monstrous to him and drove them down in irregular spirals, but he really appeared to be enjoying himself. Harassing relative giants with impunity looks like a fun thing to do.

And it was a lot of fun to see. It's also good to know we've got at least one falcon making use of Alcatraz island.

Odds, ends:

A crow was seen harassing one of our ravens in a tree on the agave trail. We took video. BourbonHawk forwards an apology for the salty sailor language in her narration.

WEGU love. Very safe for work and appropriate for all children under 8 years of age. Note the human giggles in the background.

Snowy egrets are back! Best vocalizations on Alcatraz, hands down! Audio/video in the coming days.

Saturday, March 20, 2010

PostHeaderIcon They should be saving it for the peregrines and ravens

I'd thought the purpose of colonial nesting was to guarantee each participating bird the protection afforded by thousands of comrade kin, each bird sharing the goal of a productive and drama-free summer nesting season. From time to time, the gulls appear to have a different idea.

See for yourself in three parts what happens when two colonial WEGUs disagree over who has the rights to a morsel of chicken:

Usually, gull fights last mere seconds, perhaps a minute. In this case, it would span more than 27 minutes of blood and mandibles. Though these gulls fought over chicken, they played for keeps. They gnawed on necks, attempted to snap or damage wings, and bit into faces and eyes as they brawled. On multiple occasions one bird would force the other to the ground where it would lie motionless, seemingly defeated and dead, only to have it twitch back to life a moment later and take its turn as the aggressor.

Sorry for the shaky camera work. Honestly, this stuff has an effect on my stomach. The comments visitors made as they watched, audible in the background, were notable as well, especially the jokes about placing bets.

My work week on Alcatraz starts tomorrow. We will be watching the for the falcons and blogging accordingly.
Sunday, March 14, 2010

PostHeaderIcon Falcon dines again (Also: Comments Fixed!)

Our apologies to those of you who have complained about difficulties in posting comments. Obviously that's not what we're going for. We made a few changes that we hope will help. Write back to us at our maganrord email if you have any further difficulties.

Now to the meat of it.

She looks happy. As usual, there are more pictures of all sizes on my flickr.

Sorry for the graininess on these photos and videos. These photos were taken utilizing a ridiculous level of optical and digital zoom. I love my camera. It's not the $3,000 body and lens setup I dream of, but somehow this combination of 80x zoom and a tripod can yield somewhat intelligible images at great distances.

It's unknown what this prey item was. Several white feathers fell from the smokestack as she ate. Several of my final images of her eating show her standing on a white feather, presumably from her quarry.

Here are a few very short videos of her dining.

I guess it wouldn't be a proper MAGANRORD post without a falcon video with semi-humorous narration.

In the following video, she finishes up and departs.

I was truly struck by just how red the meal left her beak and talons.

Also, the white feathers invite a bit of curiosity. The only prey item available that yields consistently white feathers is a gull, and our gulls are probably a little too big for her. Pigeons can be lightly plumed, so that's possible, though every feather I saw was as white as snow so I'm a little bit skeptical of that possibility. Our snowy egrets haven't returned yet, so they're ruled out.

Peregrines do scavenge and dead gulls have been turning up on Alcatraz. There were two such departed on the roof of the new industries building this afternoon.

Whatever the prey was, the female filled her crop and there were leftovers:

If the female abandoned her bird without finishing it, it may have been a large bird, like a gull or it may reflect her assessment of available prey. Slim pickings will mean a thoroughly devoured corpse. Abundance means she eats her preferred parts and leaves leftovers for others to scavenge.

Who says corvids and falcons can't be friends?

Also, meet this guy:

I saw him duke it out with another WEGU in a half hour brawl over what a visitor who witnessed the madness said was just a morsel of food. The whole thing made me positively squeamish and I think it led to some rather shaky camera work as I recorded the encounter.

I'm going to post our 26 minute video in the coming days. I don't expect that anyone will watch it but I do want to make a point about the gull's way of life. It's awful. It's not all mating and gloriously forcing down huge starfish. It's a lot of senseless violence. Ounces of blood and a half hour of combat leaving both gulls exhausted seems like it isn't worth a bit of chicken, which is readily available to these gulls.

Stay tuned.
Wednesday, March 10, 2010

PostHeaderIcon Could Alcatraz have three peregrine falcons!?!

If the last seven months of falcon watching have taught me anything, it's that I'm an amateur. I can record digital images, think, read stacks of books and write for days, but the fact is that we at MAGANRORD are new to this.

With that level of humility in mind, I want put forward the possibility that there might be at least three peregrine falcons visiting or residing on Alcatraz. Two would be juvenile. One is mature.

All pictures and video included/linked to were recorded between Monday, March 8 and Wednesday March 10. For more views of each of these three potentially distinct birds, please click on the links I provided. Sorry about the timestamps indicating the images were taken in early January 2008. As it turns out, the Canon repair facility can't fix your jammed optical assembly without resetting your camera's internal clock.

From here on out, I'll keep it pithy.

Bird one:

Note the dark brown, the shape of the helmet, heavy and unbroken breast streaking.
Click here for more pics of this bird and write back with your thoughts on this one. Is this a female?

Bird two:

Note white patches on each breast, which far from being a trick of the wind or the angle were observed on back to back days on different outings. Also, the shape of the helmet, the size of the beak in relation to the size of the body.

Bird three:

Since November, we've been observing her the most. Before today, we hadn't spotted this individual in a week. We'd figured she'd left us to participate in seasonal raptor migration. We're glad to know she's still around.

Note mature features (slate/blue plumage, very lightly marked upper breast).

More pictures of her here. There are still more pictures of this individual in MAGANRORD's back posts.

As a bonus, here's video taken by BourbonHawk and I of our familiar adult female chilaxing in her favorite cypress tree:

Monday, March 8, 2010

PostHeaderIcon Falcons? Yeah, we've got that

We fretted too soon. And then we did it again. Details and pictures to come.

The female and her boy companion had given us absolutely regular observations for months on end. Failing to observe them for a few days seemed like a good indication that they had moved on, but it might not be so.

Yesterday, we spotted the male perching on the water tower, though he disappeared before either of us could snap a picture. It was good to know Alcatraz still had a rad new apex predator to observe, even if we were hoping for a pair.

A few of the raptor experts from the Golden Gate Raptor Observatory have very generously shared their considerable knowledge and insights with us. Based on what they've told us, the falcons may both leave or our cougar female may fly north to mate, leaving her immature ally to brave Alcatraz all on his own. It may also be possible for him to mate with her just where she is. Nesting season will tell.

If she has left, it would explain why the falcons have become far less visible of late, especially as she was always much easier to observe than he was. The vast majority of Alcatraz falcon photos in the MAGANRORD archive feature her but it's been at least a week since we've seen her hopping around in her preferred cypress tree.

But she may not be gone yet.

Today, we had more birders from GGRO visiting us and they made some curious observations. Most importantly, they observed two falcons perching on the water tower, vocalizing to each other and then engaging in aerobatic falcon flirting, in which the male and female take to the air to dive, dart and fly in tight spirals in close proximity with each other and at great speeds.

Oddly, they reported that both birds displayed juvenile plumage. This Alcatraz falcon does not.

Now we're forced to consider a set of strange scenarios. Perhaps the adult female has moved on and a juvenile has joined him. It would explain the observations of the visiting GGRO birders and it would explain why the falcons have become so much harder to observe over the last week or so.

A less demanding explanation might just be that a trick of light or an unfortunately placed shadow interfered with the ability of our visiting birders to see the female clearly. Through the unfortunate light/shadow/haze/lack of contrast, her slate blue features may have appeared brown.

At any rate, I didn't see the female today. But I did see this guy:

Brown. Very heavily marked chest. More pictures of him in all sizes are up on my flickr.

More investigation is required here. We'll post anything we find.

Odds, ends:

The ravens have been especially visible over the last couple of days as they soared all over the island. I saw them over and over again on every single outing.

Here's Lucky the WEGU, incurring more adult gull wrath with her begging.

She's still going strong.

Also, MAGANRORD is in clear danger of becoming a falcon blog. As such, you can expect some posts on our raven pair in the near future. We're interested in who they are, how they go about their lives on Alcatraz and we'll even be taking a quick look at the park's policy of attempting to oil (destroy) the ravens' eggs each season.
Saturday, March 6, 2010

PostHeaderIcon Photos from the week:

Our Canada Geese are back in a major way. On a recent survey around the island I counted at least 10 pair. A large portion of them will surely nest on the island. These are what I can only assume are the same pair that come back to the Rec Yard every year:
Canada Geese in the Rec Yard

Another Rec Yard resident is our "World Famous" Black Phoebe:
World Famous Black Phoebe of the Rec Yard
We have these guys all over the island, but without fail you can find this one sitting on the same perch on the fence, day after day.

On Tuesday morning, it was raining pretty steadily and on our way up the hill we encountered the male raven on a new (to us) perch:
Male raven, croaking and keeping dry
Under the eaves of Building 64. He was croaking loudly and one can only assume trying to stay dry.

On the way down the hill at the end of the day we saw that the female had decided to join him.
Ravens, huddled from the rain
Friday, March 5, 2010

PostHeaderIcon Dead bird update

It's not the tiercel. It's a western gull. BourbonHawk will post a picture soon.

BourbonHawk: And here's a picture:

Thursday, March 4, 2010

PostHeaderIcon Two days without falcons

the header says it all.

Oh, and we saw a few gulls harassing a pair of great blue herons near the dock.
Wednesday, March 3, 2010

PostHeaderIcon Where did they go?

Where are our falcons?

There are times when the prospect of failure gives you sense for your own investment in an endeavor, even if you're just an observer.

I would very much like to see the peregrines establish themselves permanently on Alcatraz but recent observations leave me worried that any raptor pair making a home on a small island populated seasonally by two thousand western gulls faces an arduous task; I hope that our falcon pair hasn't failed already. More on that in a moment.

There is the aforementioned tendency of the gulls to take to the sky in alarm whenever the falcons soar over their roosts. In one such instance, I saw several gulls actually attacking one of the falcons in midair.

There is also a certain reckless aggression practiced by the pair and especially by the male. The ravens are certainly enemies of the gulls but they trespass on the gulls very selectively and very, very carefully. The ravens may harm the gulls by occasionally taking their eggs and young but they are deft enough to avoid being mobbed in large groups.

On the other hand, the male falcon thought that it might be wise to nearly take the head off the female raven as she was soaring by. Far from doing anything to provoke him, she seemed not to notice him until she suddenly dove to evade the attack.

On that same occasion (Monday, March 1st 3:45-4:45pm) I saw the female falcon on the railing of the water tower, stationary, apparently watching the male's antics. He would fly up, join her on her perch, hop around and then take to the sky for a few more laps of ill advised adventure.

As he aggressively darted in, around and through a cloud of angry gulls over the recreation yard and the new industries building on the west side of the island, the female only watched his maneuvers. After one energetic run, he failed to rejoin her. The gulls quieted down and their numbers in the air fell to just a few.

Ten minutes later, I spotted a dead bird on the roof of the new industries building. I reported it to our wildlife biologist and I'm at least 95% sure that it's a western gull but even with binoculars it's difficult to be sure. Tomorrow, I'll have the right hardware to make a final determination. Stay tuned.

Yesterday, in all of my outings, I saw only the female and only for a small part of the day. Today, we saw neither falcon. It's the first time in many weeks that I haven't seen either bird. They are so habit driven and preferential to the same few haunts (the water tower, the power plant, a couple of cypress trees) that it's worrisome not to have made a single sighting on any of our outings.

I know with only one falcon-free day that it's far too early to fret, but the recent conflicts with the gulls and the ravens have left me with the sad expectation that these birds won't succeed in establishing themselves. The gulls have become more numerous since the falcons arrived in November and they have become more assertive. I wouldn't be shocked if one of the falcons fell in a bloody adventure, or if they decided Alcatraz and its thousands of large gulls wasn't friendly to their reproductive prospects.

Here's to pleasant surprises of all kinds.

Odds, ends:

I got my camera back today. Expect visual media. Uh, lots.

I checked in on Lucky the WEGU today, and (s)he is alive and well, chasing adult gulls and begging for food, as is his/her pattern.

We observed a group of four crows on the island today, marauding around, soaring and executing a number of funny diving maneuvers. BourbonHawk can tell a crow from a raven at great distances and if she can't see the birds, she can tell from their calls. I, on the other hand, have some work to do.

That's it for today.

More soon.

Contact Maganrord

maganrord (at) gmail.com