Saturday, February 15, 2025

FRESHWATER MIGRATORY BIRDS SEEN RECENTLY IN NORTHERN LOS ANGELES COUNTY, SOUTHERN CALIFORNIA

In late 2025 and early 2026 (i.e. the fall and early winter seasons), I and my oldest daughter, observed the following southward-migratory freshwater birds in two bodies located in northern Los Angeles County, southern California. One of these areas is in a community called Bridgeport (elevation 1165 feet) in, a master-planned community, with water canals next to homesites. The other area is the southern-tip of Castaic Lake (elevation 1151 feet), a large reservoir. Bridgeport is 6 miles (via straight line-bird flight) due southeast of Castaic Lake.


Note: This was our first bird-watching experience. Who knew how interesting birds can be. 


IMAGES OF OBSERVED BIRDS AND COMMENTS

Canada Goose

Branta canadensis

   white area on cheek; dark neck, back, and tail; white belly, body

   length 22-40 inches; weighs up to 18 pounds


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Snow Goose

Chen caerulescens 

   white body, black wing tips (white phase); dark body, white head and neck (blue phase)

   body length 24-30 inches


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Mallard Duck

Anas platyrhynchos

   male: head and neck glossy green, with white rim

   female: brown  overall, webbed feet

   commonest duck in the world (America, Europe, & Asia)

   body length 16-24 inches



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American Coot (the birds, not “old paleontologists”)

Fulica americana  [“fulica” is the Latin word for coot]

   dark, ducklike

   white bill and white-frontal shield, reddish eyes

   grayish-white toes (lobed rather than webbed), green legs

   body length 13 to 15 inches



As a coot swims, it typically “bods” it head. These birds often do short dives after they make a little jump first. The feet of coots are green and not webbed; instead, they have “flaps”/”lobes” on their long and stout toes. These unusual shaped feet aid in their excellent swimming and diving abilities. Coots cannot fly as well as a duck does, but, never-the-less, coots do a good job of flying taking a relatively long start (i.e., runway flapping).

   The fossil record of coots is sparse: from mid-Pleistocene to present day (Olson, 1974).


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Western Grebe

Aechmophorus occidentalis

Black cap, gray-black wings, white body

Body length 22 to 30 inches

Good divers

Body length 22 to 30 inches

(closely resembles the double-crested cormorant, see below)


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Double-Crested Cormorant

Phalacrorax auritus

Large, dark bird with orange on throat

They eat fish by diving (for relatively long times) for them

Flocks can be mistaken for Canada Geese

Length 2.5 to 3 feet

Good fliers, silent without any “honking”

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Great Egret

Casmerodius albus

White bird, neck long and thin (elegant birds)

Bill orange or yellow

Legs and feet black

These birds nest in trees.

Body length 36-42 inches


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Green Heron

Butorides striatus

Small size, brownish, red-brown neck, orange legs

Very sharp-pointed orange bill, orange legs

Body length 12-22 inches

This bird can stand motionless overlooking water and can dive.



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Birds seen at Bridgeport

based on several trips

Abundant sightings 

American Coots

Mallard Ducks

Canadian Geese

     

Fairly Common sightings

Egrets (white, tall)


Uncommon sightings

Double-Crested Cormorants


Very rare sightings:

Western Grebe

Green Heron


Birds seen at Southern End of Castaic Lake (Reservoir)

based on a single visit

Abundant sightings

Canadian Geese


Uncommon sighting

Western Grebe 

                               ADDITIONAL COMMENTS

 

In the last 25 years or so, the classification of birds, like all living organisms, has undergone significant revisions based on DNA studies, as well as via the re-evaluation of time-honored, physical and behavioral features. In this present blog post, I have incorporated the latest classification information available to me.

 

All birds are classified as Kingdom Animalia, Phylum Chordata, and Class Aves, and numerous orders, families, genera, and species. Currently, there are 23 recognized orders and 9,700 species of birds (Wikipedia, 2005).


Using the online source: worldbirdnames.org, I tried my best to classify, using modern thinking, the freshwater birds (fowl) observed during the field work for this blog post


TAXONOMIC GROUPS OF THE OBSERVED BIRDS (ALL OF WHICH ARE ILLUSTRATED ABOVE):

 

PALEOGNATHAE

 ---Gallonaseres 

         Anseriformes (includes many water fowl)

                     Canadian goose

                     Snow goose

                     Mallard duck

 ---Neoaves

          Gruiformes 

                      American Coot

          Podicipediformes

                      Western Grebe

          Suliformes

                     Double-Crested Cormorant

          Pelecaniformes

                     Green Heron

                     Snowy Heron (Great Heron)


Credit:

A friend of my oldest daughter was very helpful in identifying some of the above-mentioned birds.


References Cited: 


North American Wildlife. 1982. Reader's Digest. Pleastantville, New York. 559 pp. 


Olson, S.L. 1974. The Pleistocene rails of North America. Museum of Natural History.


Reid, G. K. and three others. 1967. Pond life. Golden Press, New York, 160 pp.


Sprunt, A. and H. S. Zim. A guide to North American species and their habits. A Golden Nature Guide, Golden Press, New York. 160 pp.


Wikipedia, 2025. 


worldbirdnames.org


Tuesday, February 11, 2025

COMPARISON OF TWO CLASSIC” CASSID GASTROPOD SPECIES

Cassid gastropods are memorable for their medium-sized, sturdy, and pretty shells. As shown below, some of them can have a detailed carved image (i.e., cameo) on the back of their shell, and some of cameos are expensive collector's items.


The shell terms length and width, which are used herein, were defined by Groves and Squires, 2023. Length = greatest distance between anterior and posterior termini. Width = greatest distance between lateral margins.


Phylum Mollusca 

Class Gastropoda

Order Littorinimorpha

Family Cassidae

Genus Cypraecassis

     This genus has a geologic range from the Miocene to present day.


Two views (front and back) of Cypraecassis rufa, length 3 inches [= 7.25 cm], width 1 ¾ inches [= 4.7 cm], from southern Africa. This specimen has, most likely, some bleaching of its shell's color by sunlight before being collected.


    A cameo (hand carving) on the back of a specimen of Cypraecassis rufa.  Intricate cameos were most commonly made before the 1900's.

    __________




    Two views (front and back) of Cypraecassis testiculus, length 4 inches [= 9.75 cm], width 2.5 inches [= 6.5 cm], locality unknown but undoubtedly from tropical shallow-marine water. Although this species is similar to the previous species, C. rufa shown above, there are important differences other than size and coloration (study the illustrations presented here, and you will soon detect these differences. Just a few examples of these are the following: lack of spiral bands on the top of C. testiculus, fewer and coarser ribs” on the aperture (opening to the interior) of C. testiculus, and so on. The more you carefully compare the two shells, the more differences you will find---welcome to the fascinating world of identification of mollusk shells and how species differ in subtle but important ways.

    REFERENCES:


    https://www.sealifebase.se/summary/Cypraecassis-rufa.html  


    Groves, L.T. and R.L. Squires. 2023. Revision of northeast Pacific Paleogene cypraeoidean gastropods including recognition of three new species: implications for paleobiogeographic and distribution for faunal turnover. PaleoBios 40(10):1–52. (pdf free and very easy to acquire).

    Wednesday, February 5, 2025

    TINY TEETH OF AN EXTINCT LATE CRETACEOUS MAMMAL

    Multituberculates represent an extinct order of rodent-like mammals (mouse-sized to beaver size) that lived from the Middle Jurassic to late Eocene time. They had their evolutionary peak during Late Cretaceous and Paleocene time. There are about 200 known species (Wikipedia, 2024).

    Typical early multituberculate animal (rat-size). Image modified (by the author) from a figure in Savage and Long (1986).

    Typical skull of an early multituberculate.

    Two views (left side = first image) and (right side = second image) of the same tooth (4 mm wide, 3 mm tall, and 1 mm in thickness) of the multituberculate Mesechua? from the Upper Cretaceous Bug Creek “anthills” locality in Montana. This tooth is a lower jawbone (mandible) premolar cheek tooth cheek anterior to larger molars.


    Multituberculates are important fossils because they are found to have flourished on “both sides of the” famous K/T boundary [aka Cretaceous/Tertiary boundary]. These fossils help prove that small mammals did not go extinct at the end of the Cretaceous; instead, they survived and flourished for millions of years to come.


    Note: This blog benefited greatly from a single multituberculate tooth (see figure above). Such specimens are very rare for most fossil collectors. This tooth was kindly given to me by the late Father Jenkins who taught biology at Loyola Marymount College for many years. He was very interested in fossils, especially trilobites and early mammals. 


    References Consulted:


    Savage, R.J.G. and M.R. Long. 1986. Mammal evolution an illustrated guide. British Museum (Natural History). 259 pp.


    Wikipedia, 2024. Multituberculates.



    note: A post in the blog of The Fossil Forum.com was very useful in helping me in the generalized identification of the multituberculate tooth used in this blog.

    Saturday, February 1, 2025

    HOWLITE: A RARE (AND UNUSUAL) MINERAL

    Howlite is a rare mineral found in evaporate deposits at only a few places in the worldIt is a borate mineral: more specifically, it is a calcium-borosilicate-hydroxide mineral consisting of calcium, boron, silicon, oxygen, and hydrogen. 

    Howlite itself is not regarded as an "economically important mineral." It usually co-occurs, however, with the minerals colemanite and gypsum, both of which have considerable economic value. Polished pieces of howlite are sometimes sold as a substitute of the more valuable mineral turquoise, which howlite can resemble. 

    Howlite was first discovered in 1868 Nova Scotia by Henry How. It was named by James Dana, shortly thereafter. 


    WHAT DOES IT LOOK LIKE?

    Howlite is creamy white in color and can have gray-black streaks (veins). It typically occurs as gray nodules or masses that resemble a head of cabbage.” It is soft enough to carve and polish. The most common form of howlite is nodules. This mineral has a hardness of 3.5, and its common name (a misnomer!) is white turquoise.” 

    Figure 1. Three hand specimens that I collected from along the south side of the paved road next to the old-mine (see discussion, below). The scale is in centimeters. 


    CRONOLOGY OF THE MINE SITE NEAR JUST NORTH OF Los Angeles:


    1853: The map maker Lt. R.S. Williamson named Tick Canyon.”

    1905: Two prospectors found the deposit in Tick Canyon and staked a claim .

    1906: The prospectors sold their claim for $30,000.

    1908: The new owners of the claim began serious mining efforts, and the deposits became known as the "Sterling Borax Works." A large mill (see Fig. 2 below) was built, as well as 6 miles of narrow gauge track that would be used for a dinky train” to deliver the ore to an established Railroad siding, known as Lang Station. Eventually, a company town, with 160 workers, was established at Lang Station. At its heyday, the dinky train hauled 18,000 to 20,000 tons of ore. The howlite was regarded as slag or waste and dumped in the vicinity of the mill or a short distance down the canyon. To this day, pieces of this mineral can be found in the slag.

    1911: Borax Consolidated purchased the mine for 1.8 million dollars.

    1921: The mine was no longer profitable, and the equipment was shipped to a company-mining site in Nevada.

    1923: The company town at Lang Station became a ghost town.”

     

    The processed ore had to be transported several miles via another narrow gauge railway (wider gauge than the dinky one” mentioned earlier) to the south, to a regular railway siding, called Lang or Lang Station. There, a community of about 160 borax workers set up a company town” and lived there for a few years. Note: the narrow gauge train” that went to Lang Station had to be backed up, in order to return to the mine. There was no provision for it to turn around.”


    Figure 2. Newspaper clipping of the "Sterling Borax Works," as it appeared in 1917 (see Reynolds, 1983). The remains are now only some concrete  foundations.


    Figure 3. White-colored spoils (i.e., so-called waste deposits from any mine) in the immediate vicinity of canyon just south of the mill. Such spoils were also dumped short distance to the south of the site, along a road that is now a public road. Hoards of rock hounds have “picked over” the spoils for many years now.

    ___________


    1950s/1960s: Local geology departments brought many students to this area for field trips in order to comb” the spoil piles for minerals. Some schools (e.g., UCLA and Cal State Northridge = CSUN), however, brought their more advanced students to the mine-site area in order to do detailed geologic mapping of the faulted-synclinal structure in the area. Eventually, fences appeared and a few years ago, the land was posted as Private Property, Keep Out.” Now, if you want to collect legally, you have to collect south of the public highway.


    For those of you who have the interest, I highly recommend the very informative, online video, about this mine:


    https://scvtv.com/2007/07/01.philip-scorza-explores-the-sterling-borax-mine/


    Also very interesting is another online video: "Midnight run to fortune." [see SCV history.com]


    Written Reference Cited:


    Reynolds, Jerry. 1983. The Wreck of the Sterling.” Trip of the Week. Newhall Signal & Saugus Enterprise (a newspaper that is still being published). Friday, December 16, 1983. 

    [Note: Jerry Reynolds (died in 1996), who in my opinion was a suberb historian, always wrote reliable and accurate articles about Santa Clarita Valley.]

    Wednesday, January 22, 2025

    ONE VERY HEAVY CONCH SHELL

    Order Littorinimorpha

    Family Strombidae (the true conchs = gastropods)

    Genus Sinustrombus [formerly in genus Strombus and subgenus Tricornis].

    Species latissimus Linnaeus, 1758


    There are many hybrids (varieties) of this marine-gastropod species.



    Two views (apertural and abapertural) of a representative specimen (7 inches in length and 4.75 inches in width). The backside of this shell shows the effects of color bleaching by the sun. Also, notice the presence of many minute drill-holes in the shell; these are cause by sponges that lived on the "top" of the shell. This species lives in tropical waters (e.g., the Philippines, where people commonly use this gastropod as part of their diet). 


    For its size, the shell of this species is one of the heaviest that I have even handled!

    The solidness of its shell allows this species to live in extremely turbulent waters and/or has some formidable predators! 

    Thursday, January 16, 2025

    King Snake and Gopher Snake Examples from Southern California

    One of my previous blogs focuses on some rattlesnakes that I have encountered while doing geologic field work in southern California. This present blog focuses, however, on two non-venomous snakes that I encountered while I was walking along a little-used dirt road in Towsley Canyon, just south of Santa Clarita, in northern Los Angeles County, southern California. 


    The first of the two species I encountered is the:

     

    California King Snake

        Family Colubridae

        Genus Lampropeltis

        Species californiae


    I encountered this snake while it was on the dirt road. The snake was inert for awhile, but before I could get a measurement as to its length, the snake quickly sped off into the weeds. Typically, king snakes are 2.5 to 3.5 feet long. Their coloration is variable, ranging from black and white to black and yellow.


    On the same day, later in the afternoon while hiking on the same road (in the same general area of the previous snake I saw), I came across a "Pacific Gopher Snake:"


    Pacific Gopher Snake

      Family Colubridae

      Genus Pituophis

      Species P. catenifer 

      Subspecies catenifer


    This kind of snake is active during the day, thus it is one of the most commonly seen snakes. 


    The first photo shows the head and the typical two to three rows of spots on the sides of this gopher snake.



    The second photo shows how its body can be “kinked.”


    The third photo was taken just before the snake (now "unkinked") turned around and “took off” like a “rocket” for the nearby weeds. Just before it did, however, I was able to get a measurement of its length (about 90 cm) by placing, parallel to the snake, my "Jacob Staff" (= a common tool used by field geologists for measuring the thickness of rock layers; each red or white segment is 10 cm long). The Jacob Staff is also a great hiking “stick.” The head of the snake, which is on the left side of the photo, is obscured by rocks in the road. The posterior of the snake is obscured by vegetation on the side of the road.


    You never know what you might see when being in the field: that is one the alluring aspects of doing field work. By the way, I encountered both snakes near dwellings along a small stream. It is apparent that wherever a human builds a structure (especially near a stream), rodents will eventually find it to be good place to live. And, of course, snakes eat rodents.