Wednesday, July 14, 2010

kites in flight

Close to my home, there's a trail that runs alongside a creek that I once thought equal to the Silk Road in its length and difficulty. When you're a seven-year-old with abysmal hand-eye coordination and short legs, even the smallest rise can seem like an insurmountable obstacle. But now that I'm older (and to my bitter regret, not significantly taller), the trail isn't terribly exciting. It's fairly level, doesn't branch off, and leads to the top of a dam where you can picnic and realize, belatedly, that you've probably trespassed onto someone's backyard.

It's a popular destination for octogenarian hikers and dog lovers, which in and of itself should be a huge turnoff. My dog has the unfortunate tendency to pick fights with any dog that's over 35lbs and breathing. Hiking this trail with Zap the quintessential Aussie cattle dog usually brings the threat of severe damage to my camera and binoculars as I attempt to pull Zap---lunging with hackles bared---away from oncoming canine traffic.

What continually lures me back to this trail is not just its proximity to my home (though that does score huge points because paradoxically, I am lazy but like to bike), but also its scenery and wildlife. The creek feeds into dense thickets of Coast live oak trees and meadows of grasses and prickly forbs. The combination of water, grass, and trees means that on any given day I can see warblers (Townsend's in the winter), flycatchers (like the Pacific-slope flycatcher), woodpeckers, and even the occasional heron or egret. There seem to be quite a few rodents as well, judging from the wide scattering of burrows and runways.

This plentiful base of songbirds and small mammals supports a wide range of raptors. Mark H. is an excellent local birder who can even distinguish the calls of male and female house finches, and for years, he's been monitoring the breeding effort of White-tailed kites. The kite is a meadow specialist. Thus, its reproductive success reflects the health of our local grassland habitats. Lately, Mark has been seeing an alarming decline in the number of White-tailed kite breeding pairs, but one of the pairs has consistently nested in the vicinity of the trail.

Generally, I have a tough time identifying raptors, so to my inexpert eye, the White-tailed kite looked less like a hawk than it did the lovechild (lovechick?) of a seagull and a tern. It even forages using a fluttering flight similar to that of a Caspian tern. 

I've been keeping a loose eye on the pair over the past month, and they appear to have fledged several chicks. The kites favor a sycamore snag as a perch for preening and calling to each other. Recently, I captured one of the adults mid-flight approaching the snag.

Shortly thereafter, the adult settled down onto its snag lookout:
The adult kite had been flying with a juvenile (ostensibly its offspring), so when it perched, it looked around and called for a bit. Like most sulky and unresponsive teens who have perfected the art of selective hearing, the juvenile was nowhere to be found and refused to show up.
What was amusing was that there were two juvenile kites perched on the snag with a young Cooper's hawk in a nearby sycamore. But when the adult kite approached, both juveniles decided to book it. Unlike their parents' minimalist black and white wardrobe, juvenile kites have a rusty, buffy necklace running across the top of their chest.
On this unfortunate bird, the rusty coloration looks more like last night's meatball sauce spilled all over a bib. The juvenile Cooper's hawk had a much more impressive appearance with its sharp vertical mahogany streaks down its snowy chest. It seemed pretty pissed that I had the effrontery to approach it, and kept calling to another Cooper's hawk in the distance.
This is a brilliant example of the stink-eye, which I will try to emulate the next time a driver almost sideswipes me while I'm biking. I don't expect to be nearly as successful. If only I had a ferocious-looking yellow iris...

Tuesday, July 13, 2010

oceanside redux

There are two other sites that I cover at Vandenberg. The first is called Lompoc Landing, and assuming that I got this correctly, it's a new site. The other one is called either Pocket's Cove or Cabrillo Beach, and I manage to jumble the names continuously. Both of these sites are much more accessible than Purisima Point (recall: 30 minute slow, sinking walk through the sand)---in fact, I get to park my car right next to my observation point (OP) for Lompoc Landing.

Vandenberg's coastline gradually grades from hard bottom to soft bottom shores, meaning that it transitions from zones where the substrate is rocky, and, well, hard, to areas where the seafloor is just the loosest assemblage of fine sediment. My sites mostly encompass hard bottom shore, also known as "live bottom" because a hard seafloor in the benthic zone (areas that are shallow and near-shore) supports kelp forests which provide the nutritive base for marine life.

Lompoc Landing has perhaps the rockiest outcroppings of my three sites, and the largest raft (i.e. group) of pigeon guillemots. Pigeon guillemots tend to float on the water with occasional spurts of showboat-y preening displays where they tuck their upper bodies into the water, and roll drops of water between their flailing wings. It's cute, and even endearing up to a point, but guillemots have the annoying habit of diving infrequently (at least to my inexperienced eye) so that I'll try to telepathically encourage a particular guillemot to dive. After all, I may see thirty-some guillemots on the water, but if none of them dive, then I've effectively gotten skunked on a survey round.

So this photo below was a kind of bittersweet semi-victory. I didn't see this fellow dive, but it was close to the guillemot colony and had a fish in its bill. It rafted along the surface for a bit, but didn't get around to eating the fish. Ostensibly a chick or a mate was going to benefit from an offering of plump, shiny fish.

A large group of cliff swallows has a roost near the Lompoc Landing OP. The OP itself is situated atop a fairly steep cliff-face, so it is fitting that it is graced with the acrobatic flight of so many swallows (cliff, and, I suspect, Northern rough-winged). The cliff swallow below is flying above a dirt two-track completely surrounded by ice plant (pernicious, nasty stuff, that).

At all three of my sites, the coastline morphs from hilly sand dunes to grass- and shrublands. Interestingly enough, the path to Lompoc Landing is bisected by Amtrak train tracks which seem to magically demarcate the border between dry upland and marine coast. Just past the tracks golden eagles, red-tailed hawks, and turkey vultures idly wheel through the sky. I'm guessing that this was a juvenile golden eagle perched on a telephone pole next to the train tracks based on the white patches visible on its tail when it was flying. I'm not at all sure about it though, so please correct me if I'm wrong. In any event, it's exciting to see a golden eagle---juvenile or otherwise---in Central California.

Red-tailed hawks are much more common, to the point where even I could recognize them despite my complete incompetence with raptor identification. I was able to get a shot of an adult with its beautiful, salmony-red tail.

Cabrillo Beach is my third site, and geographically, it is sandwiched between Lompoc Landing to the north and Purisima Point to the south. The other moniker for Cabrillo Beach (in addition to Pockets Cove) is Seal Beach, since there is a rocky outcropping that California harbor seals seem to favor as a haul-out point. Lately there haven't been too many harbor seals, but the abundant kelp beds at this site guarantee ample numbers of California sea otters. Like guillemots, otters will generally loaf about in the water, and don't seem to spend much of their time foraging, particularly later in the day. They'll float on their backs, carelessly trying to pry open mollusks on their chests, or devouring fish while ecstatically squirming through the water. But once in a while, a lone otter or two will break away from the larger group and forage. Here's an otter swimming close to shore, stopping to gaze curiously off into the horizon. Sea otters tend to be pretty hyperactive, so one way to distinguish an otter from a seal is its speedy, quick, constant motion.

True to its nature, the otter covered a lot of ground, continuously surfacing and then diving into the water. I managed to get a shot of its back as it dove into the water---you can see its vertebrae protruding below.

This otter was eventually victorious and got to eat a fish. Below, you can see its snout open wide.

And no discussion about marine life foraging at Vandenberg is complete without mentioning cormorants. I conduct surveys in three hour blocs (0600 - 0900, 0900-1200, 1200-1500, 1500-1800), and I do a maximum of two surveys a day, separated by a break of three hours. That day, I was doing a 1500 - 1800 survey at Cabrillo Beach, and though the weather was great, the conditions were far from optimal. Around 1700, there was substantial glare on the water, and for the most part, the marine predators avoided areas with high glare (probably because of low visibility).

As a whole, there generally isn't too much going on in that time span. The birds and mammals are most active at 0600, and foraging activity peters down as the day advances. I suppose that the key exception is the immediate approach of dusk, when mass amounts of Brown Pelicans will dive bomb the ocean from the air. Thankfully, even when most birds (i.e. alcids like the common murre and the pigeon guillemot) take a break, cormorants still deliver. Below is a picture of a cormorant barreling out of the water.

Friday, July 2, 2010

fishing for dinner

Central California has a spectacular array of wildlife and open spaces. We've become famous around here for our wines (i.e. Sideways) and our beaches. Generally, it's been the southern half of Santa Barbara county that's gotten the most hype, and the beaches here are standard SoCal fare: mowed, flat, with a long expanse of soft sand leading into the surf. But if you head up north for an hour (and brave a treacherous, windy stretch of the 101), you'll be rewarded by the sight of sandy dunes rising slowly above the earth, sprinkled with lupin bushes and wildflowers. In short, you get to see California beaches in their natural state.

This summer, I'm lucky enough to be working on a seabird monitoring program with PRBO Conservation Science. My supervisors, Dan R. and Julie H. (last names omitted for privacy), have considerable expertise surveying and managing marine wildlife at Vandenberg Air Force base. Vandenberg occupies a stretch of land that runs alongside the Pacific Ocean, so you have surf, turf, and rockets all in one space (take that Top Chef! Surf and turf challenges have nothing on this!).

One of my responsibilities is conducting foraging surveys where I sit at an observation point (OP) for 3 hours and scan the ocean in 15-minute intervals, identifying all animals that are diving into the water. I'm surveying three sites this summer, and each site has its own unique micro-habitat. Purisima Point is one of the three sites, and it takes a 30-minute hike alongside a Least Tern nesting colony to get to the OP. Usually I'm sweating and meandering my way toward the OP, trudging through sand and getting blown off course by windy gusts.

 The photo above is the last portion of my hike to the OP, and if you look closely at the sand dune in front of the background dunes (which are covered in vegetation), you see that the sand is actually being blown down the dune (which makes the border of the foreground dune somewhat blurry). This is a dynamic ecosystem that changes from week to week.

But the views along the way more than compensate for the slow sand trudge. At the least tern colony, Dan, Lynne (another intern), and I checked their nests which are shallow indentations in the sand (called scrapes). Many of the eggs have hatched into chicks, and as we approached the colony, adult terns began to attack us--ostensibly, they perceived us as predators out to gorge on their chicks.

Past the colony is my OP (observation point) where I conduct the foraging survey. I sit in a folding lawn chair, and use a 20-60X spotting scope and my binoculars. The OP sits up on the cusp of an iceplant-covered dune overlooking a cormorant roost.

This roost has a mixed species assemblage comprising Brandt's cormorants, Pelagic cormorants, and the occasional Double-crested cormorant. It's generally thought that cormorant feathers are not waterproof, and thus they air their wings out like the Brandt's cormorant is doing below to dry their feathers.

 There were also two Pelagic cormorant nests within view:

There is also a pigeon guillemot colony located nearby, and two guillemots were copulating on a rocky outcropping.

During the foraging survey, I saw cormorants and guillemots diving into the water (and occasionally emerging with fish), but this week, there was a special guest appearance of a Pacific harbor seal slowly bobbing through the water close to the OP.