Friday, May 9, 2025

THE GREAT HORNED OWL

Bubo virginianus, a large-size owl can be up to 25 inches in length, has a wing span of up to three feet wide; with females being somewhat larger than males (Wikipedia, 2025). It has widely spaced ear tuffs, and its body feathers are mottled brown above, lighter below.

Two views of the same Great Horned Owl observed in northern Los Angeles County, Southern California.

It is native to the Americas, from 68 degrees latitude north to 54 degrees south): including North America [but not north of the high Arctic tree line], Central America, and to the Straits of Magellan in Chile in South America. It can live in forests, wetlands (including marshes and mangroves), deserts, and urban areas. It prefers scrub areas, woodlands, deserts, canyons, and bottomlands. The northern population may migrate south during winter months. And this owl can live at elevations from sea level to 11,000 feet in elevation. It can live in hollow trees, caves, rock ledges, abandoned nests of other birds, or even man-made structures.


They live to be about 28 years old in the wild and up to 50 years in captivity. 


They can fly as fast as up to 40 mph. They have giant cat-like eyes that do not move but can see in shades of black, gray, and white. Some have limited color vision. Females are larger than males, but males have a deeper sounding hoot. They can hoot all night to solidify their pair bonding (they general mate for life). They are most active at dawn and dusk. They can carry up to 10 pounds of weight.


The can attack any medium-sized mammal. Their talons can exert great pressure, enough to severe the spine of their prey. 


Their call is: "hoo, hoo-hoo, hoooo-ho"; the male’s pitch is higher than that of the female. 


Active at dawn and dusk + night; they sleep during the day. Thus, they are rarely seen; and also because of their excellent camouflage.


They live for 20 to 30 years.


GEOLOGIC RANGE OF OWLS: Their earliest geologic occurrence (a few bones) of owls, is a single species of Ogygoptynix, of late Paleocene (Mayr, 2002). A few bones of Eocene owls are also uncommon. Barn Owl dates back to the Miocene (25-20 million years ago (Wikipedia).


GEOLOGIC RANGE OF THE GREAT HORNED OWL: Fossil bones of late Pleistocene Bubo virgianus have been found at Rancho La Brea Tar Pits in southern California (Madan et al. 2019).  


ACKNOWLEDGMENT:

The owl shown here was seen and photographed by my youngest daughter, in the morning during mid-April, in northern Los Angeles County, southern California. Sightings at that time of day one are rare!                                          


REFERENCES CITED


Madan and two others. 2019. Stasis in the smaller owls from Rancho La Brea during the last glacial-interglacial climate change. Palaeontolgia Electronic 22.3.70, pp. 1-12.


Mayr, G. 2002.A  owl from the Paleocene of Walbeck, Germany. Mitt. Mus. Nat.kd. Berl. Geowiss 5, pp. 283-288. (pdf available online for free). 


North America Wildlife---Reader’s Digest.


Wikipedia. 2025.

Sunday, May 4, 2025

WHITE-CROWNED SPARROW, NORTHERN LOS ANGELES COUNTY, CALIFORNIA

Lately, I ventured into observing and recording a diverse range of aquatic birds living in northern Los Angeles County, southern California (see one of my recent blogs), but I held off researching terrestrial birds. Yet, the latter are a treasure right before my eyes. So, stay tuned to my blog! Who knows what species of animal or plant will turn up next! 


Having diverse flower gardens, in both front and back yards of my home, has made them “bird havens.” Plus, we have a sturdy hedge in the front yard, and a tall brick wall in the back yard. These provide some protection against wandering predators. Such a yard stands out in glaring contrast to most other homes in my neighborhood. Mostly, they are usually nothing more than the standard grassy yard ± a few shrubs and/or a few flowers.


I could no longer ignore some small birds that regularly visit, early every morning, the garden in my front yard. These birds are Zonotrichia leucophrys (Foster, J.R., 1772). This species, which is also known as the “white crowned sparrow” (Burton, 1999), “caught my attention” because of its striking head pattern of black and white stripes.


This species is just one of the very diverse group of western sparrows, which are native to North America and also widespread from Alaska through California, Baja California, and northern Mexico; but not along the eastern seaboard of the United States. This species is a common bird in southern California (Los Angeles area), Oregon, and Washington. For more details, go to https://www.allaboutbirds.org/guide/White-crowned_Sparrow/overview 


The west-coast population of this species of sparrow is stable and not threatened. This small bird (5.5 to 7 inches in length) is very active and does not stay in one spot for very long at all! It is difficult to get a photo of it. A small group (about 10 individuals) usually visits my garden every morning (March) and at the same time. They stay for only about a few minutes, quickly searching the ground for seeds, especially those shed by the adjacent borage plants (see one of my earlier posts about this plant). These small birds hop and flutter about so quickly that it is very difficult to take a photograph that is not blurred. I finally realized that I should just take a rapid succession of images and hope for the best. That worked OK, but the images are somewhat blurred when enlarged. Nevertheless, these images (as shown here) clearly show that the population of this bird that visits my garden is characterized by having has a central white stripe down the center of the head. These sparrows apparently migrated away by early April, and they have been replaced, in a much less way, by a few occasional but different sparrows with brown heads.


Also, if you are interested in seeing other photos of this species, I recommend the internet site, available (for free), at https://ebird.org > species > wchspa 



Fig. 1. A white-crowned sparrow in the garden in the front yard of my home.




Fig. 2. A white-crowned sparrow next to a borage plant in the same garden.



References:


Burton, R. 1999. The Audubon Backyard Birdwatcher. 329 pp.


ebird.org


7.fs1.hubspotusercontent-na1.net 


https://www.allaboutbirds.org/guide/White-crowned_Sparrow/overview


Monday, April 28, 2025

AN UNUSUAL INSECT: THE HOVER FLY, IN SOUTHERN CALIFORNIA

AN UNUSUAL INSECT: THE HOVER FLY, IN SOUTHERN CALIFORNIA

Recently, I came across a most unusual looking bee-like/wasp-like insect on a plant in northern Los Angeles County, southern California. It is a moderately large insect with a broad body and two big and long, transparent wings. I had never seen a bee like this one! It reminded me of a wasp with its vivid yellow-and-black markings, yet it lacked the narrow waist” of a wasp. After consulting my few books about insects, I was batting zero.” None of the books even mentioned anything like what I found, let alone, figured it! Then, I turned to my computer and started looking for information about bee-like insects. Very soon, I came across hover flies” [improperly also known as hover bees”]. These insects, which are broader and much flatter than bees and wasps, hover over flowers (especially yellow or white flowers, e.g., sunflowers, Gazania, Iris, etc) in search of aphids. Hover flies are up to 2.5 inches long, with brightly colored yellow stripes on their abdomen. They have relatively short antennae with only a few segments. They also have one set of long, transparent wings. Not only do hover bees eat pests, they are great pollinators. Also, hoverflies do not make nests.


The hover fly I found belongs to genus Eupeodes = the western aphid-eater. This hoverfly occurs from California to Washington, most of British Columbia [western Canada], as well as Texas, Colorado, Wyoming, and Montana. Hover bees can tolerate cool weather. These insects are harmless; they mimic wasps in order to protect themselves from  predators.

Shown above is a female? hover fly (Eupeodes sp.), dorsal view, 2.3 inches long) found April, 2025, on a boysenberry leaf in garden in Santa Clarita, northern Los Angeles County, southern California. 


Hover-fly males look different than females. The large eyes of the males meet in the middle (forming a continuous black area), whereas the eyes of the females are separated The specimen in the above photograph looks like the eyes are somewhat separated..

Hover flies occur from March to November. They have no nests  


Their classification is:


Kingdom Animalia

Phylum Arthropoa

Class Insecta

Order Diptera

Family Syrphidae

Genus Eupeodes

Species E. fumipennis


Fossil Record: As would be expected for an insect, hoverflies are poorly represented in the fossil record. The earliest known occurrence is in a lacustrine (lake) deposit of Oligocene age in France (Nidergas et al., 2018). According to this publication, it is possible that the geologic record of hoverlies is as old as the Late Cretaceous (in Siberia). 


Sources of Data:


https://www.inaturalist.org.taxa  This site has MANY (hundreds) photos of hover bees.


https://explorer.natureserve.org


Nidergas, V. and three others. 2018. The first pipizine hoverfly from the Oligocene of Cereste, France. Acta Paleontologica 63(6):539-548. [pdf is free and readily available].


Wikipedia

Monday, April 21, 2025

THE SUNFLOWER: MOST EVERYONE RECOGNIZES IT, BUT FEW KNOW ITS GEOLOGIC HISTORY

The evolutionary history of sunflowers dates back to middle Eocene time, about 48 million years ago. That is when the former supercontinent Gondwanaland “broke apart,” forming South America, Australia, Africa, India, and Antarctica. The sunflower evolved in an ancient subtropical environment, most likely in northwest Patagonia, South America. The earliest fossils of sunflowers are extremely rare, especially considering that they are of two complete fossil flowers, with some associated pollen grains (Barreda, 2010).

Sunflowers were probably first domesticated in Mexico. Early Spanish explorers carried seeds from American plants to Europe (Wikipedia, 2025).


The classification of the sunflower is:

Kingdom Plantae

Order Asterales

Family Asteraceae (= the daisy family)

Genus Helianthus 

Species H. annuus


The tallest record of a sunflower is 9.17 m (30 feet an one inch) (guinnessworldrecord.com). Interestingly, young sunflowers track the sun, thus they exhibit heliotropism) in odrer to maximize sunlight absorption for photosynthesis.


Sunflowers usually die each year, but they can reseed themselves and grow back. These flowers are referred to as “annuals.” Their species name indicates this fact. The sunflower illustrated below was, indeed, an annual that grew during a rather mild winter this past year in southern California. Other sunflower plants, however, are perennial and will return from their roots each year.


Sunflowers can be a color other than the usual bright yellow. They can be blue, purple, red, reddish, orange, or even very light-yellow. These cultivated variations are referred to as “cultivares” of the color (e.g., red, orange) (Wikipedia, 2025).


Each sunflower blossom is a composite flower. The outer part of the sunflower has large so-called petals, but more properly referred to as “ray flowers,” which are sterile. The black ring/disk (= the “flowerhead” or pseudanthium), at/near the center the plant consists, however, of numerous tiny “disk flowers,” also known as florets (Figures 3, 4, and 5, below). These are true, fertile tiny flowers that contain pollen  (https://www.ndsu.edu/pubweb/chi).


Note: There can be considerable and "mind-blogging," genetic variation in the details of features of the black ring/disks and their flowers, even when they are part of the same sunflower plant (i.e., emanating from the same stem). The variation includes such features like the thickness of the ring/disk, the width of the band of florets, the shape of some florets, the color of the florets (some are yellow but some can be blue), etc. The details are far beyond the scope of a blog.


Sunflower seeds develop in association with the “disk flower,” after they have visited by flying insects. These seeds are a popular snack food, and they are harvested each year, after the sunflower plant has been pollinated by flying insects. There are two types of commercial sunflower seeds (small, all-black seeds, used for sunflower oil; and the larger non-oil seeds that are black and white “striped” and used in food (sunflowernsa.com.) (Figure 6). The non-oil seeds are the official state flower of the state of Kansas, in the United States.


References cited:


Barreda, V.D. 2010. Fossils of the daisy family. Science, v. 329, no. 5999. Online access to this journal requires a subscription.\


guinnessworldrecord.com


https://www. ndsu.edu/pubweb/chi)


sunflowernsa.com


Wikipedia. 2025.


                    FIGURES FOR THE TEXT GIVEN ABOVE


Fig. 1. A field of sunflowers (photo courtesy of Lindsey T. Groves, Collections Manager of Mollusks at the Los Angeles Natural History Museum).



Fig. 2. A home grown-sunflower plant (in my backyard) with the flower at the top not yet open. When this photo was taken, the plant was 5 feet tall. It eventually stopped growing at 6 feet tall. That was when the bulb at the top of the plant opened up and a yellow flower appeared.



Fig. 3. Same plant as shown previously. The bulb at the top is about ready to open up.



Fig. 4. An open bulb at the top of a sunflower immediately adjacent to the plant shown in the previous two photographs. The long, yellow petals surrounding the “black” central disk are called “ray flowers,” whereas the tiny yellow “dots” [in a ring that encircles the central-black] disk are the true, fertile individual flowers, commonly referred to as “disk flowers” or “florets.” The tiny yellow “dots” contain yellow pollen. The center of the central disk is black, without any florets or other recognizable structures.




Fig. 5. Close-up of another open-bulb at the top of another sunflower near the one shown in the previous figure. Diameter of the entire “black disk” 4.5 cm, with a ring of very tiny, five-rayed yellow “disk flowers (florets).” These florets have yellow pollen attached to them, and the pollen falls off, easily just by being touched with a finger (or by the encounter with a bee crawling around over the disk).



Fig. 6. Honey bees feeding on the pollen a sunflower (photo courtesy of Lindsey T. Groves, Collections Manager of Mollusks at the Los Angeles Natural History Museum).


Fig. 7. Non-oil sunflower seeds (the biggest ones are approximately 0.5 inches long). The seeds grow only within the centrally located, black-disk area.

Monday, April 14, 2025

Iris Flowers: Beauty With a Geologic History

The word “iris” is a Greek word pertaining to rainbows, because the flowers of this flower have many colors. “Iris” aptly describes also the various colors of the human eye. There is an iris in the eyes of most mammals and birds. The iris controls the diameter size of the pupil, which is the black dot = the eye’s aperture. It is also interesting to note that the very distinctive, three prominent petals of Iris flowers stand for “faith, wisdom, and valor.” As a final note, it is interesting that these flowers grow on very long stems.

The iris plant had its beginnings during a warm-climate time of middle Late Cretaceous time, about 80 million years ago. It possibly originated in what is now Turkey or Syria. The cultivation of Iris began with the early Egyptians.


It was introduced in the 1600s to North America via European settlers. Iris plants are hearty and require low maintenance (well-drained soil, appropriate amount of sunlight, etc.). They do well in many climates. Today, there are now between 200 and 300 species. Most are readily affordable from nurseries and have been by called by some gardeners as “a poor-mans’ orchid.” They grow from blubs and bloom in early spring to early summer. They have even bloomed as early as early February in sunny southern California.


Iris plants belong to family Iridacea and genus Iris.


The irises figured below are classified Iris x hollandica (a hybrid commonly known as the “Dutch Iris.”). The “Dutch Iris developed from species native to Portugal, Spain, and North Africa. Iris flowers can be any color (blue, purple, yellow, white, red—or any combination thereof). They nearly always have minor patches of another color (i.e., commonly yellow). Thus, white ones are not all white. Irises grow back each year because they are perennials. Nevertheless, some gardeners treat them as annuals (die off after a year), discarding the old plant and planting fresh bulbs each years.


Irises are toxic to cats and dogs, but the highest concentration of toxins is in the underground rhizomes of these plants.



Figure 1. Long-stemmed blue and yellow Iris, width of a single flower 5 inches.


Figure 2. From the cluster of flowers in previous image is a close-up view of a single Iris flower, width 5 inches. 



Figure 3. Close-up view of a white Iris flower, width 5 inches (as well as a partial view of an adjacent flower).



Figure 4. Close-up view of a lavender, white, and yellow Iris flower, width 5.5 inches (as well as a partial view of an adjacent flower. 



Figure 5. Close-up view of a blue and white Iris flower, width 4.5 inches. Note: this flower was photographed in an early version of my family’s garden, in  2014. 


References Consulted


Waters, T. 2016. The evolution of irises. A blog article.


World of irises. [A blog of the American Iris Society]. https://the american iris society.blogspot.com/2016/the-evolution-of-irises.html 


Another informative blog about Iris is: https://funny how flowers do that.co.uk


Tuesday, April 8, 2025

TWO “TONNIDS” OF SEASHELL

These seashells belong to Tonnidae, a small family of shallow-marine gastropods that live today in tropical habitats, in both shallow and relatively deep waters. These animals have medium size to some rather large shells that are sub-spherical with a low spire and a very large, enveloping last whorl having an aperture (= “opening”) that accommodates their very large "foot," which is used for crawling around and for digging. Tonnid shells are rather thin and fragile. The family name of these gastropods is derived from their having a shell shape resembling wine casks (a.k.a “tuns.”).


Tonnids are carnivores that live semi-faunally (at or near the ocean-floor) in soft-substrates, in both shallow and relatively deep ocean waters. During the day, these animals burrow into the sandy bottoms. At night, they emerge and feed on crustaceans, sea cucumbers (they eat them whole!), and bivalves. Some of the larger tonnid species also capture fish by using their expandable proboscis (mouth area) to also swallow them whole.


The classification (via Wikipideia) of tonnids is:

Kingdom Animalia

Phylum Mollusca

Class Gastropoda

Order Littorinimorpha

Superfamily Tonnoida

Family Tonnidae

Genus Tonna


Two representative large-sized examples are shown below:  


                                                                                     

                                                                 Tonna galea [a.k.a. “the giant tun) 


This species, whose thin shell is characterized by brown bands and yellow/brownish spots, lives in shallow, warm seas of the Caribbean, Atlantic, Mediterranean, and Indo-Pacific waters. It is also found in North Carolina, Argentina, Portugal, and Nambia. It prefers to live on offshore reefs, as well as bays and coves, on rock, sand, or shelly bottoms. Dimensions of illustrated shell: 17 cm, width 11.5 cm. [Note: this species is used as food by some humans].


                                                                                               

                                                              Tonna tesselata


This rather common species, whose thin shell is characterized by white bands with yellow/brownish spots, lives in shallow waters (e.g., offshore reefs, or bays and coves: on rocks in South Africa and the Western Pacific. Dimensions of illustrated shell: height 14 cm, width 12 cm.


Cited Referenences


Mollusca: The Southern Synthesis. Part B (of a two-volume set). Fauna of Australia Volume 5, Part B, CSIRO Publishing, Melourne, (see pp. 802-803). 

Wikipedia. 2025.

Friday, April 4, 2025

WESTERN POND TURTLE:MORE THAN MEETS THE EYE

This post concerns Actinemys pallida, the so-called “southwestern pond turtle” but does not include its northern relative, A. marmorata, which is confined to British Columbia, Washington, Oregon, and northern California.


Actinemys pallida is restricted to southern California and Baja, Mexico. It is a species that is vulnerable (i.e., threatened by human activities). This turtle species lives in both permanent and intermittent lakes and marshes, where it feeds on aquatic insects, crayfish, tadpoles, small fish, and small frogs. 


The classification of A. pallida is:


Kingdom Animalia

Phylum Chordata

Class Reptile

Order Testudines

Family Emydidae

Genus Actinmys

Species A. pallida 


Actinemys pallida shown here are about an estimated seven to eight inches long (with its head extended), and having  a dark-colored upper shell (carapace). This turtle is referred to as a “basking turtle,” because on sunny days, it leaves the freshwater source, crawls a short distance on the bank, and then basks in the sunlight. These turtles are hard to photograph without a telephoto lens. These animals are very shy and quickly dive into the water if they spot you. One has to stay a considerable distance away, so as not to "spook them." That is why some of my images do not have sharp focus.


The geologic record of the earliest known fresh-water turtles is very poorly known, with generalizations and speculations readily available online. The the most often-mentioned geologic time for the earliest fresh-water turtles is either the late Permian, Triassic, or the late Cretaceous. Amid all this confusion, it is pertinent to mention the recent discovery of fossil remains of soft-shelled turtles and pond turtles (as well as abundant alligator fossils, tapirs, brontotheres, etc.) in lower Eocene rocks on Elsmere Island, in Canada’s high-arctic area (see Eberle and Greenwood, 2012). These turtle fossils might well be one of the earliest confirmable geologic recordsof pond turtles.    



Figure 1. Actinmys pallida, oblique left-side view showing white band on cheek and yellow pastron (ventral side of carapace). Estimated length of entire animal: 7 inches.


Figure 2. A. pallida, oblique right-side view showing yellow ventral side of carapace. Estimated length of entire animal: 8 inches.




Figure 3. A. pallida, frontal view showing yellow ventral side of carapace, as well as yellow stripes on neck. Estimated width 4.5 inches.


REFERENCES CONSULTED


Ebele, J.J. and D.R. Greenwood. 2012. Life at the top of the greenhouse Eocene world-a review of the Eocene flora and vertebrate fauna from Canada’s High Arctic. Geological Society of America Bulletin, Jan/Feb 2012:124, no. 1/2, pp. 3-23. [This is not a free pdf].


Reid, K. and three others. 1967. Golden Nature Book “Pond Life”: A guide to common plants and animals of North American ponds and lakes. Western Publishing Co., New York, 160 pp.