Tuesday, June 28, 2016

Joshua Tree National Park

My daughter Leslie came for a visit with her husband Daniel from Portland, Oregon. She expressed a desire to visit Joshua Tree National Park, 2-1/2 hours away to the north, east of Riverside (San Bernardino and Riverside counties). Marlene and I planned a route, and the four of us headed out for a long day road trip--even if temperatures well above 100F degrees were expected.

We entered the Park in the northwest end from the town of Joshua Tree (population 7400). We spent an hour in the Visitor Center in town before continuing on to the West Entrance Station. Entry fee (day or week) is $20. By 9:30 a.m. it was already 95F.

Joshua Trees are the typical plants of the Mojave Desert. They are giant yucca plants and not true trees. In most places the Joshua Trees were spread out enough that photos didn't really do justice to the odd prehistoric-like scenery. It would have been better to have a brief video as we drove past. But the photo below gives an idea of the 20 foot tall trees scattered about and standing above the otherwise knee-high gray scrub with the mountainous backdrop. Like well-spaced giant terracotta soldiers on the battlefield.

Joshua Trees
Soon the landscape turned to boulders weathering out of the ridges.

Quail Springs picnic area
Pencil Cholla
We pulled into a hiking and picnic area called Hidden Valley. We walked about 1/4 of the mile long loop trail.

Hidden Valley

Leslie and Daniel
There were very few birds. In June there would be very few birds anyway, even at dawn. But at mid-day the only birds I saw more than one individual of were Ladder-backed Woodpeckers, Western Scrub-Jays, and Black-throated Sparrows. I saw a Mourning Dove, a Northern Mockingbird, and heard a Rock Wren, but not much else.

Black-throated Sparrow in Mojave Yucca.

Silver Cholla

Foreground plants, left to right: pinyon pine, unidentified yucca, dollarjoint pricklypear.

This area had many interesting boulders. The scenery was constantly changing, but the players remained the same. It was all the same, yet all different--boulders and Joshua trees.

To Marlene, every boulder, no matter size or shape, somehow reminded her of an elephant, which delighted her to no end (she may have gotten too much sun). I refused to see any of her elephants, or anything else other than rocks, well, okay, except for this:

Hidden Valley Campground. "Flattened Bunny Hill" or "Roadkill Rabbit Ridge" (not official names).
After Hidden Valley we visited nearby Barker Dam. Even when full the little pond it created was probably only 6 feet deep. It appeared, though, that it had been dry for many months. The loop trail was exactly 1 mile. The temperature was now about 100F. Leslie, Daniel, and I made the hike. And we found some Indian pictographs. Marlene was smart and read a book in the shade.

Then we drove on and dropped elevation down into the Colorado desert and watched the temperature indicator steadily climb past 112F.

Cholla Garden. Likely Silver Cholla foreground, most are Teddy Bear ("Jumping") Cholla.
We drove back to San Diego County via the Salton Sea. We only spent about 20 minutes on the shore at the Salton Sea State Recreation Area on the north shore of the Sea. At 200 feet below sea level it was 115F.  Then through Borrego Springs for an early dinner. Up and over the mountains where it dropped to a comfortable 65F and a cool evening breeze pushed inland from the coast for the remainder of our trip home to Escondido.

All in all, a very long, hot, but enjoyable last day of the visit for Marlene and I with Leslie and Daniel.

Saturday, June 25, 2016

White-tailed Kite hovering

White-tailed Kites have always been one of my favorite raptors (read a previous post on my history with this species). Their hunting style is to hover-in-place over their prey, then drop down quickly to grab a mouse or vole out of the grass.

I am yet to get really good photos of this bird. But on May 30th I was able to get these photos that follow. It was still early on an overcast morning, and the bird was distant. But these three photos aren't too bad in showing their hunting behavior, hovering in place.

White-tailed Kite
White-tailed Kite
White-tailed Kite. Ramona, California. May 30, 2016. Greg Gillson.
White-tailed Kite

Wednesday, June 22, 2016

Red-crowned Parrot

I finally got good close looks and photos of a large parrot in San Diego. The only parrot on the official California bird checklist is the Red-crowned Parrot (Amazona viridigenalis). It has been established for years with a good population. But that doesn't mean it's the only parrot you can see, nor does it mean that it's the most-likely. There's an Australian Cockatiel that has escaped near my home and sometimes hangs out with the tame ducks at a retention basin here. This species generally doesn't survive long in the wild. And we're near Tijuana where there's a constant supply of escaped Mexican cage birds of every variety (especially, but not exclusively, colorful singing birds), so that with any unusual bird seen here that has a native range in Mexico one always has to wonder if it is an escapee from captivity.

Most parrots are found right in downtown. There are large night-time roosts at Point Loma and El Cajon. At dusk birds return after being dispersed throughout the area all day. But I live in the North County about 35 miles north of downtown. Parrots are far less common here.

Back in February 2014 I saw my first large Amazon parrot (parrots in the genus Amazona). I got some photos and determined they were likely Lilac-crowned Parrots (Amazona finschi). I know a bit more about their identification now, and still think I identified them correctly.

Both the Red-crowned and Lilac-crowned Parrots are endangered. A primary reason for their decline is deforestation in Mexico. And, although importation of parrots from Mexico into the US is illegal, these birds are still caught for the pet trade inside Mexico. Thus, after 40 years or more of escapes and breeding in the wild, the Red-crowned Parrot is more numerous in southern California and Texas than they are in NE Mexico where they are native and endangered. See this article from the Christian Science Monitor.

Red-crowned Parrot
Red-crowned Parrot (left) and hybrid(?) (right). San Diego, California. May 21, 2016. Greg Gillson.
While meeting at the marina for a pelagic trip I heard the loud, harsh screeching of the parrots and located them in a tree over the parking lot. They allowed me to approach quite near. It still wasn't easy to figure out an identification, though.

Of the two birds, neither showed the full bright crown of Red-crowned, but neither did they match Lilac-crowned. The bird on the left (above) has a darker eye. That indicates a young bird, so the restricted red on the crown is expected. The right bird has a definite white eyering, so that is the strongest indication of Red-crowned, as the eyering on Lilac-crowned is blue. And at least one of the birds clearly gave descending whistles among their other grating and screeching calls. That matches Red-crowned and not the rising whistle of Lilac-crowned.

Red-crowned Parrot
Red-crowned Parrot or hybrid with Lilac-crowned Parrot?
The only thing worse to a birder than an introduced bird is a hybrid!
Of course, there is the very real possibility of hybridization. The restricted darker maroon forehead on the above bird certainly fits Lilac-crowned, as does the green feathering along the upper mandible. But the white eyering and pale cere (fleshy area around the nostrils) only belong to Red-crowned.

On the other hand, the outer vanes of the base of the outer tail feathers show blue on Lilac-crowned. And the tail is longer. Neither of those is a match on the above bird. But that restricted dark red forehead. I could be talked into this bird being a hybrid.

Red-crowned Parrot
Red-crowned Parrot
The photo above shows the darker eye of a young bird. There are orange feathers coming in the crown above the eye that point to Red-crowned, even though the cere is a bit dark and the eyering color is ambiguous. And the red comes down all the way to the base of the upper mandible clear down to the gape. There's no problem with this bird being a Red-crowned Parrot, and no reason to invoke the hybrid hypothesis.

Now that I know to listen for the upslurred or downslurred whistles, I'll feel better about identifying birds as they fly over, or are perched high in a palm against overcast coastal morning skies.

Interestingly, many birders do not pay much attention to introduced or escaped birds. After all, only wild, free-flying birds are "countable" by the major birding organizations. Escaped cage birds are not countable, and populations that escape and breed are only considered "established" if they have been present for many years (10-20 years) and their population is not dependent upon continued releases in order to maintain itself. On the other hand, birders can't keep ignoring the growing populations of feral birds in California, Texas, and Florida--they are "real" birds eating food and competing for resources whether or not they are "countable" on a birder's list.

Still, there's more information on identification of parrots on the local parrot cage bird website than in the birding field guides. That doesn't seem right, either.

Sunday, June 19, 2016

Some days I just can't get my head screwed on straight

Wait. Is that? Yes, yes it is.

Great Blue Heron with a unique perspective on life.
If you don't want to bend your neck down to look at the ground, you can always twist your neck around and look up at the ground.

Unscrewed.
The nearby heron in the background seems unimpressed and uninterested.

Stately Great Blue Heron.
These photos came from the bait docks in San Diego Bay. The bait tanks hold live small fish for the fishermen to use as bait. Hundreds of cormorants and herons hang out on these docks hoping to catch a snack.

I'm really sorry I didn't react quickly enough to get a picture of a Black-crowned Night-Heron that was all splay-legged out on the dock with it's head down inside a hole in the boards!

Thursday, June 16, 2016

Birding Site Guide: Dixon Lake

Dixon Lake is a city park in Escondido. It has fishing, boat rentals, and camping on the southwest corner. It is popular on holidays and summer weekends. Usually, though, it is rather quiet and not overly crowded. It is adjacent to Daley Ranch with its many miles of additional hiking trails through chaparral.

Map of San Diego area with Dixon Lake

Getting there: Exit 1-15 on El Norte Parkway in Escondido and head east 3.1 miles. After a large sweeping right hand curve turn left onto La Honda Drive (the sign for the lake is small and easily overlooked). After 1.3 miles you have arrived at the park entrance. Map navigation: near 2256 La Honda Dr., Escondido, CA 92027. Parking/vehicle entry: $5 weekends. Free for age 60+; Free on weekdays. Park free across the street in the Daley Ranch dirt parking area and walk in. No pets. No alcohol. No glass containers. Gate opens at 6:00 a.m. Web site.

Dixon Lake map

Where to bird: The entry to the park off La Honda Drive is marked (A) on the map. If you have arrived on the weekend and don't want to pay the vehicle entry fee, park in the Daley Ranch Dirt Parking Lot. There are several options (outlined below) for birding, and one could take about 5-6 hours to explore the whole lake area.

Entry Picnic Areas: The picnic area immediately at the entrance (still A) has many trees and lots of birds, including migrants, in spring. There is an upper and lower (Jack Creek) picnic area. Some of the birds found here are American Robins, Dark-eyed Juncos, and Mountain Chickadees--all at elevations a bit lower than typical. Hermit Thrushes are regular in migration. A walk through the picnic area and around the ball fields is sure to reveal some good birds.

Picnic area at Dixon Lake
Picnic area at Dixon Lake
Ball field at Dixon Lake
Ball field at Dixon Lake
Jack Creek Trail: Down below the ball fields and main picnic area is the Jack Creek picnic area. It is more hidden, and is quite birdy. Acorn Woodpeckers, Nuttall's Woodpeckers, Western Bluebirds, House Wrens, and Lesser Goldfinches are common. From A down to C is the Jack Creek Trail. It is actually a "loop trail" following both sides of the creek. It follows a steep riparian ravine down to a little reed-edged cove of the lake. It's a bit hard to find, but it's there! Jo's Morning Walk checked out this trail in spring 2016. Click this link for her photos.

Chaparral Nature Trail: This trail starts near the entry across the road from the picnic area at G on the map. The first part of the trail goes through some brushy trees in a wet ravine sure to have migrant warblers, vireos, grosbeaks, sparrows, flycatchers, and other birds. Heavy chaparral attracts many birds such as Wrentit, California Thrasher, Spotted Towhee, California Towhee, Bewick's Wren. This is a good area to find Rufous-crowned Sparrows, Black-chinned Sparrows, and Ash-throated Flycatchers in spring and summer. Joining the resident Anna's Hummingbirds you may find summer Black-chinned Hummingbirds and Costa's Hummingbirds. The trail goes straight east for a half mile (F) where it meets up with trails to Daley Ranch or switchbacks down to the lake, or leads back to the entrance following old roads on the north shore.

North Shore Hike: If you want to hike along the northern lake shore, there is a trail from C to E to F. The area around the dam is fenced off. Either walk back again or hike the rather steep switchbacks uphill to F and then back to the entry via a trail back to the rough roads or the Chaparral Trail (F to G). More below. It is about 2.4 miles to loop around from A-C-D-E-F-G-A.

North Shore Drive: A poorly maintained road, once paved, now full of potholes leads to 2 parking areas (C and D) with trails down to the lake and docks. If you don't want to hike the entire north shore, drive to the easternmost parking lot (D) and walk down into the Whisker Bay part of the lake (E). This is a quieter part of the lake and you may find marsh birds such as Common Gallinules, Marsh Wrens, and Black-crowned Night-Herons.

Dixon Lake Ranger Station: From the entrance you may drive to the right on the south side of the lake and stop at two small parking lots before getting to the larger parking lot at the Ranger Station (B). The lawns and trees around the ranger station are good for migrants in April. This is a good spot to scope out the lake for ducks: Mallards Gadwall, Ring-necked Ducks, Lesser Scaup, and Ruddy Ducks are the most common. You may find grebes of several species in winter. You may even find a few American White Pelicans. The trees will have tanagers, grosbeaks, and orioles in spring and summer, and Great-tailed Grackles will be obnoxious throughout the year.

Dixon Lake Trail: If you want to hike along the trail from the entry, past the Ranger Station and near the dam (A-B-dam, out-and-back) it is 2.1 miles. The dam itself is off limits and fenced.

Camping: The camping area (H) lies beyond the Ranger Station on the south side of the lake and is closed to non-campers. Camping spaces are up on the steep dry hills. Better birding in similar habitat is on the north side of the lake, so no need to be tempted to bird the camping areas unless you are actually camping.

Scenic view of Dixon Lake
View of Dixon Lake from the first parking lot on way to Ranger Station.
Scenic view of Dixon Lake
View across Dixon Lake of the Ranger Station area.

Check out the San Diego Birding Pages Dixon Lake site guide by Mary Beth Stowe (perhaps written before 2008).

Monday, June 13, 2016

Highland Valley Road, Escondido, Coast to Crest Trail Again

In April I wrote a little Site Guide to the San Dieguito River Park--Coast to Crest Trail. I visited again at the end of May. This time I only walked the trail from the Old Coach Trail Parking Lot. This is east of I-15 (Pomerado Rd exit) on Highland Valley Rd about 2.4 miles. [Enter 13982 Highland Valley Rd, Escondido, California into your GPS navigation app to get close.]

The parking lot is in the middle of a palm tree nursery. The riparian area is across the road, but the water--via irrigation--is in the nursery. Thus, many birds are along both sides of the road flying back-and-forth.

The trail from the parking lot leads northeast along the edge of the nursery, then crosses Highland Valley Road. The trail goes right and left (see sign, below). I first turn left (toward Mule Hill) and follow the trail across a low walkway and enter the riparian (the only place the trail really does so). Just check the birds in this section, and when you reach the dry grass with no birds, go back and take the trail to the right (toward Raptor Ridge) this time.

Trail sign
From this sign I go left a few hundred feet, then I come back and walk about a mile to the right.
Some day I would like to walk all the way to the Raptor Ridge Viewpoint. However, it is a comfortable mile to a eucalyptus grove. That's where I've turned back on two visits now. The out-and-back walk, watching birds and taking photos, took me 2 hours this last visit. This grove has nesting Western Kingbirds and Bullock's Orioles. But that's jumping to the end of the story.

First you start right in the parking lot and walk NE along the edge of the palm tree nursery. Birds in the nursery include summering Pacific-slope Flycatchers, Blue Grosbeaks, Hooded Orioles, and many more.

Blue Grosbeak
Blue Grosbeak. Highland Valley Road, Escondido, California. May 30, 2016. Greg Gillson.
Blue Grosbeak

Cross the road (carefully--you can activate a flashing light at the crossing to warn traffic, but that guarantees nothing, as you know). Then you enter a wide riparian area. This has perhaps the most birds of the route, just across the street from the palm tree nursery. Yellow Warblers, Common Yellowthroats, Black-headed Grosbeaks, House Wrens, Bell's Vireos, and Yellow-breasted Chats are summer breeders. Year-long residents include Mourning Doves, Common Ground-Doves, Song Sparrows, Bewick's Wrens, Downy Woodpeckers, Nuttall's Woodpeckers, American Kestrels, Red-shouldered Hawks and more. It really helps to know your bird songs and calls, as the habitat is quite thick, and one is reminded to stay on the trails.

Downy Woodpecker
Downy Woodpecker.
Common Ground-Dove
Common Ground-Dove.
Yellow-breasted Chat
Yellow-breasted Chat.
Red-shouldered Hawk
Red-shouldered Hawk.
After the first quarter mile the trail the trail pulls away from the willow tangle and hugs the bottom of the dry rocky hill.


You still have wetland birds on the left (Yellow Warbler, Black-headed Grosbeak), but chaparral birds on the right (California Towhee). As you cross under the high-tension power lines listen for Rock Wrens and Canyon Wrens on the cliffs above.

Blue-gray Gnatcatcher
Blue-gray Gnatcatcher
As you walk along the drier parts of the trail there are a few scattered live-oaks and you pick up Ash-throated Flycatchers, Phainopeplas, and Greater Roadrunners.

Greater Roadrunner
Greater Roadrunner
A tiny little butterfly--a Lupine Blue.
This is a nice flat wide dirt trail. You share it with bicyclists and joggers, but it is not crowded. And there's lots of birds here--those that frequent both riparian and chaparral habitats.

Friday, June 10, 2016

It's just not a pelagic trip without albatrosses

Here is my trip report for the May 21, 2016 pelagic trip from San Diego. This was a 12 hour trip. Usually this trip is aboard Grande, but it is in dry dock for annual maintenance. So about 35 of us birders were aboard Ocean Odyssey. Due to the change and having to move the boat, we got a late start.

Ocean Odyssey
Ocean Odyssey backing into the dock to pick us up.
Before even boarding we were being watched by this Black-crowned Night-Heron in another boat's rigging.

Black-crowned Night-Heron
Black-crowned Night-Heron.
Overhead flew Caspian and Elegant Terns.

Caspian Tern
Caspian Tern
Another common bird in the marina, and throughout the rest of the day--even far offshore, was Brown Pelican.

Brown Pelican
Brown Pelican
As we made our way down the bay toward the ocean, we were accompanied by Western Gulls, and one Heermann's Gull.

Heermann's Gull
Heermann's Gull
Soon we reached the mouth of San Diego Bay and passed by Point Loma and entered the ocean.

Point Loma Lighthouse
New Point Loma Lighthouse
We check all the buoys for roosting Brown Boobies. Instead, we found a couple of California Sea Lions. We found boobies later.

California Sea Lion
California Sea Lion
The San Diego Bay faces south. We continue about 5 more miles in that direction, heading to the Mexican border. We trailed gulls, terns, and pelicans.

Brown Pelican
Brown Pelican, adult (left) and immature (right)
Brown Pelican
Brown Pelican
Soon we reached the border with Mexico and turned westward. From here the Coronado Islands, I mean, Islas Coronados, offshore 9 miles from Tijuana, were also only about 9 miles away to our south.

Islas Coronado
Islas Coronados
We picked up our first Northern Fulmar in this section. They were in heavy molt and can be flightless this time of year. Remembering that fulmars are more aggressively attracted to human food than gulls (if you can believe that) it occurred to me that I had been up since 4 am and hadn't had anything to eat. So I ordered a huge breakfast burrito from the galley. Pelagic birding trips from San Diego are the only ones I know of that regularly bring a cook!

Northern Fulmar
Northern Fulmar
We also picked up our first Scripps's Murrelets. Spring is the best time for this species in San Diego County. Soon we reached the south end of the Nine Mile Bank and turned northward to follow it.

Scripps's Murrelet
Scripps's Murrelet
There were many small flocks of Sooty Shearwaters throughout the day.

Sooty Shearwater
Sooty Shearwater
As we left the north end of Nine Mile Bank and headed northwest across the San Diego Trough, we spied a mixed flock of birds that included a Brown Booby.

Brown Booby
Brown Pelican (left), Western Gull (center), Brown Booby (right)
Both Sooty Shearwaters and Pink-footed Shearwaters were in heavy molt. The lack of normal wing surface made them flap more than typically, with less gliding. It also gave them odd wing and tail shapes and odd exposed wing patches normally covered by feathers.

Sooty Shearwater and Pink-footed Shearwater
Sooty Shearwater (left) and Pink-footed Shearwater (right)
Pelagic birding boat trip
A relaxed moment
Ahead we spotted the tall blow of one of the great whales. We headed toward the animal on the surface. As we neared it dove. We decided to wait around 10 minutes or so for it to resurface. When it did, we got great views (as previously posted here).

Blue Whale spout
Blue Whale
Blue Whale fluke
Blue Whale
As we waited for the whale to resurface and get those photos above, a Black-footed Albatross came in, curious to see what we were doing. I organized and attended over 175 pelagic trips from Oregon from 1994 to 2014. Albatrosses were always the draw and crowd-pleaser. Somehow, a pelagic trip just isn't the same without the friendly albatrosses. They are much rarer in San Diego County waters, but spring--especially May--is the time to see them.

Black-footed Albatross
Black-footed Albatross. No white on rump or vent, and no flight feather molt, so probably only 1 year old.
The albatross circled once and landed in the stern for the popcorn chum we were throwing out continuously on this trip. I had one person in the past express disappointment that albatrosses came in to popcorn and cheese puffs like a city park goose. Somehow it spoiled the regal majesty of the bird in his eyes. I guess he had never read Loye Miller's 1940 description of the Black-footed Albatross as a "feathered pig" when it came time to choose food to eat, but a 'gentleman in table manners.'

Black-footed Albatross
Black-footed Albatrosses
As we reached waters at the edge of the Thirty Mile Bank we had more flocks of Black Storm-Petrels. Waters were a little roughed up, but we glimpsed a few smaller storm-petrels, of which we were able to identify a couple as Ashy Storm-Petrels and a couple as Leach's Storm-Petrels (a county-first for me!). My attempts at photographing the storm-petrels were unsuccessful. Most were out-of-focus. Over the years I have taken thousands of photos of beautiful waves with out-of-focus birds flying in front. Therefor, I find it most successful to take a picture of the water under where I think the bird is flying, as odd as it sounds. The camera wants to focus as far back as it can on all those ripples, not the little bird in the frame. Here's my "best" storm-petrel shot for the day...

Black Storm-Petrel
Camera-shy Black Storm-Petrel darting behind a wave.
After we turned around and headed back southeast to travel back across the "less birdy" (but not totally birdless) San Diego Trough, I decided to take a break, eat lunch, and re-hydrate myself. The galley was open and the cook made me a huge burger. Unlike most people, pelagic trips make me hungry!

Sooty Shearwater
Sooty Shearwater
Most birds on the return trip were the same. But the lighting and the return with the wind and waves made spotting Cassin's Auklets ahead much easier and we saw scores. Most flushed several hundred feet in front of the boat, so photos were out of the question. In fact, for those who had never seen them before, they really still haven't had a good look. We did get a close look at a few Red-necked Phalaropes on a tidal rip.

Red-necked Phalarope
Red-necked Phalarope
We encountered more flocks of Sooty Shearwaters. We tried and tried to find some rarity hidden within, but no.

Sooty Shearwater
Sooty Shearwaters
Because we didn't get Grande this day, this was a new skipper and crew to bird watching. They did a pretty good job. But sometimes they put the birds on the wrong side of the boat so we were looking into the sun at them. And sometimes they didn't come up stealthily on an arc, but pointed the boat directly at the birds, causing this (below), instead of good photo opportunities. The rough water splashing against the side of the boat didn't help allay the birds' fears either.

Sooty Shearwater
Sooty Shearwaters taking flight
Finally, at the south end of the Nine Mile Bank, we turned due east, and a cry of "Jaeger!" went up that quickly changed to "Skua!" I was a bit slow to remember that I had a 10 pound camera around my neck for the past 10 hours, so I was a bit late getting this shot off. It's sufficient for documentation purposes, I guess. Late May is about the earliest you can expect a skua off the West Coast. This is primarily a fall bird that peaks (in this case meaning more than one individual) in early October and is immediately not seen after that. It is rather rare in San Diego waters, even so. My second first-county-record of the trip.

South Polar Skua
South Polar Skua
Finally I got a decent shot of a shearwater.

Pink-footed Shearwater
Pink-footed Shearwater
This next photo was more an experiment to see if I could anything in focus on flying murrelets. These didn't take off until the boat was quite close, so that helped. The camera focused on the water, but the bright sun aided in keeping a high shutter speed so the wings weren't a blur. The "sweet spot" (settings where I get the most good pictures) on my camera/lens combination is f7.1 and ISO400. So I always shoot aperture priority with these settings and let the shutter speed vary with the light. The left hand bird is back a ways toward those in-focus waves behind. So the right hand bird is a bit soft in focus. If you don't blow up the photo too large it looks pretty good.

Scripps's Murrelet
Scripps's Murrelets. White underwings and even white chins visible for ID confirmation.
Well, we're just about back, only another hour to go. I saw 7 Brown Boobies in this trip segment. One white-headed adult male approached closely. None of the photos were really good. So I present an artistic mood photo below (that just means it isn't very close).

Brown Booby Islas Coronados
A Brown Booby soars off toward the Coronado Island, a few miles away in Mexico, where there is a breeding colony.
I had basically tired out by this point. I was still looking for new birds but not counting anymore after we reached a mile offshore. We entered the bay and then slowly motored past the bait docks. They were crowded with cormorants and herons.

Bait dock buddies
Bait dock buddies. Snowy Egret and California Sea Lion.
San Diego
San Diego skyline and waterline.
Selected seabird trip totals (my sightings only, not entire boat):
Black Storm-Petrel: 316
Brown Booby: 10
Scripps's Murrelet: 19
Elegant Tern: 755
South Polar Skua: 1
Black-footed Albatross: 1
Cassin's Auklet: 35
Sooty Shearwater: 593
Pink-footed Shearwater: 31
Northern Fulmar: 4
Ashy Storm-Petrel: 1
Leach's Storm-Petrel: 2

Apparently, the only species seen by others that I missed was that 2 people saw a Fork-tailed Storm-Petrel (fairly rare here) for a second or two (literally) before it disappeared behind a wave, never to reappear. On the other hand, I was one of less than half the boat that identified the Ashy and Leach's Storm-Petrels. In this case my experience with shape and flight style helps in picking out birds from a flock that are just a bit different.