If Flowers Could Hear…Oh, Wait! They Can?

by Carlos de la Rosa
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Walking around Catalina’s interior these last few weeks has been a hugely enjoyable trip into the world of flowers, insects, pollination, and life in a Mediterranean climate island. There are millions of flowers popping out of the ground. Some trees, such as the fragrant feltleaf ceanothus (Ceanothus arboreus), one of three species of Ceanothus on the Island, buzz with insects visiting the tiny flowers that bloom in large bunches that cover the entire tree. Their sweet scent is intoxicating to bees and humans. Insects also visit the spectacular big yellow flowers of the giant coreopsis (Leptosyne gigantea) and the stunning pink blooms of the Santa Catalina Island bush mallow (Malacothamnus fasciculatus var. catalinensis). It is all part of a great circle of life, where plants and insects collaborate in their endless quest to reproduce, obtain food, and build the next generation.

Flowers spread their genes (encased in those minute, dust-like particles produced by the flower’s male parts and called pollen) through various means. The white and purple Island shooting stars (Primula clevelandii var. insularis), for example, produce pollen that needs the buzzing of insects, particularly bumblebees, to be released. The bees literally shake up the flowers with their buzzing wings, and this releases the pollen. This pollen then gets attached to the insects or flies into the wind, eventually finding its way to the stigma or female parts of other flowers, closing the circle of fertilization. These flowers also have interesting structures and colors, which are clearly attractive to insects.

The colors of flowers are actually more vibrant than what our human eyes can see. Many insects, for example, can see into the infrared area of the light spectrum. In this range, other colors and patterns on the flowers appear, which guide the insects towards the center of the flowers where they can find their rewards (nectar and pollen). Some flowers are also shaped in such a way that they can reflect the heat from the sun towards the center of the flower, like a parabolic shape, or sonar or satellite dish shape. Some insects hide inside flowers that close at night, taking advantage of this warm shelter.

But here is where the story gets really weird. What if some flowers could actually “hear” or sense the sounds made by the beating wings of insects and increase their nectar production to attract more insects? Yeah, this sounds incredible, I know. But in recently published research this is precisely what is happening. Researchers from the University of Tel Aviv, in Israel, have documented the phenomenon on one species of plant whose flowers seem to be able to detect the sound of insects and increase their nectar production within minutes. Doing experiments with the beach evening primrose (Oenothera drummondii), which grows wild in the southeastern United States, they documented the yellow parabolic-shaped flowers responding to the sound frequencies and recordings of bee wings berating to produce some 20% more nectar than when exposed to other wavelengths of sound. The parabolic shape of some flowers has also been documented in the rainforests, where some flowers use this shape to attract pollinating bats by reflecting back the ultrasounds produced by the bats as they hunt and look for nectar.

Looking around at the Island’s flora, we can see many species that have shapes similar to those shown by the primrose. And many insects including bees, bumblebees, flies of all sizes and colors, wasps, butterflies and moths, beetles, and more, visit them throughout the summer. Could any of the flowers can also “hear” and reward their pollinators? Looks to me like a fertile area of new research!

In a future article, we’ll talk about the importance of insects to the health of both, natural and man-made (agricultural) ecosystems. No matter how annoying people may find them, without insects—bees in particular—our agricultural systems would literally collapse, and the natural splendor of a wildflower show like the one we are witnessing this year on the hills of our beloved Island would come to an end. Our lives are made more precious because of all these creatures, great and small. Learning about fascinating and astounding features such as the ones being discovered right now only makes us appreciate more the value that nature and wilderness have in our lives.

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Want to learn more about this phenomenon?
Check out the links below!

The original article on the subject of plant responses to pollinator sound can be found and downloaded at this link: https://www.biorxiv.org/content/10.1101/507319v1

And here is an article on the subject in Spanish. Y aquí un artículo sobre el tema een español: aquí

What’s Up With Those Giant Mosquitoes?!

by Carlos de la Rosa
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They are all over Avalon. Actually, they are all over the Island! Giant mosquito-like creatures, flying clumsily into our houses, bouncing against the ceiling, gathering around the lights, landing on our carts. They look like the great-white-sharks of mosquitoes, gigantic, scary-looking. People call them “mosquito-eaters” so they can’t be all bad, can they?

As a matter of fact, pretty much everything you hear about these harmless creatures is wrong. They are NOT mosquitoes. They don’t eat mosquitoes either. They don’t bite. As a matter of fact, they don’t eat a lot, if anything. Maybe A bit of nectar from a flower.

These scary-looking Hulk-like insects are called crane flies (because of their crane-like, long legs). They are a relative of mosquitoes (belonging to the Order diptera, or two-winged flies), but belong to a different family, the Tipulidae.

Crane flies are completely harmless. They live only for a few days as adults. As larvae, they live in wet areas, streams, ponds, and even in the moist soil, feeding of decaying organic matter. As adults, their sole responsibility is to find a mate and procreate. Some species visit flowers (see the pollen on the head of the crane-fly in one of the photos), sipping a bit of nectar and helping pollinate them.

The nature of Catalina Island is fascinating and full of mysteries and stories. We will be sharing more of these stories in upcoming essays and a book.

Drama on the Flowers

by Carlos de la Rosa
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Ant holds bee by leg. Gotcha! The ant is holding this flying bee by the leg. If lucky, the bee will get away. This bee has already lost part of a leg to a previous similar encounter.

The bright yellow flowers of the goldenbush (Isocoma menziesii) nod in a gentle afternoon breeze. It is late fall on Catalina Island and the splash of color catches your eye. Up close, a whole production is unfolding. Numerous bees hover over the expanse of flowers, a butterfly awkwardly scuttles off to visit the delicate flowers of the narrow-leaf milkweed (Aesclepias fascicularis), a fly struggles to extract itself from a spider’s web, and ants are swarming on the flowers and running up and down the stems of the plants. What else is going on? Several dramas unfold every day in and among the flowers of Catalina’s plants. These interactions between plants, insects, and animals illustrate a number of ecological concepts in quite dramatic and interesting ways. It’s the true theater of life, filled with danger, heroes and villains, sex and death, a struggle to survive, natural selection at work, a battle of tiny jaws and claws repeated endlessly day and night.

The first concept one can explore is that the more complex the flower, the more likely it is that it evolved specifically for a species or group of insects for pollination. And, the insects more than likely have developed characteristics that maximize the benefits from these specific plants. This joint evolution, a form of an “arms race for reproduction,” is known as co-evolution. Many plants reproduce sexually by producing male and female “gametes” in the form of pollen and eggs that when joined will form the seeds for the next generation. Sexually reproducing plants use flowers in the production and packaging of these gametes and many of these flowers use insects as the means to transport their gametes to other flowers. A pollen-laden insect is a great reproduction messenger, bringing the pollen from flower to flower ensuring that a plant will not self-pollinate, something that for some plants is not a good thing

Ladybug eating an aphid. Ladybugs are fierce predators of aphids, the yellow insects sucking sap from the stem of this plant. Both, the larva and the adult of the ladybug feed on aphids. Lunch time for ladybugs. Aphids multiply very fast and can eventually harm the plant they are feeding on. Ladybugs eat the aphids, but often not fast enough!

These plants have evolved in ways that attract and reward their insect visitors, particularly those that get involved in the transport of pollen to other flowers. The sweet and often not-so sweet collection of scents produced by flowers act as attractants to a variety of insects and birds, like hummingbirds. Some smells are quite disagreeable to us humans, like the smell of rotting meat produced by some flowers of certain succulent plants. Why would a plant smell like rotten meat? To attract flies, of course! And flies get fooled and walk around the flower looking for the piece of decomposing flesh and in the process pick up a lot of pollen that they take to the next flower. A cruel deception, you may think, but it must work for both the flower and the fly, because it keeps happening and evolving and it is fairly common in nature.

 

Bee with pollinia drinking nectar. Bees, such as honey bees and other species, visit flowers not only to drink their nectar, but also to collect pollen, which they use as food back in their nests for their growing larvae. This bee drinking nectar from a milkweed flower also has accidentally collected the flower’s pollinia, or pollen sacs, which can be seen as yellow structures attached to the bee’s legs.The bee will carry these sacks to the next flowers it visits.

Color is also an important attractant, although insects and even birds see color differently than us. Many insects, for example, can see into the infrared region of the color spectrum, something we can’t detect with our naked eyes. So a flower that to us looks uniformly yellow can appear very different to an insect, with contrasting patches, lines, “landing zones” and other features that we can only see when using ultraviolet light and a camera that can see UV. And then there is the reward: nectar. The word nectar encompasses a suite of sugars (mostly sucrose, fructose and glucose) produced by specialized glands called nectaries. Most of the nectaries are found in flowers, although they can also be found on leaves, pedicels of leaves and other locations on plants. Nectar is an important source of energy for insects such as bees, butterflies, wasps and ants, as well as birds like hummingbirds and many species of bats.

We now have the ingredients for an all-out war. With a smörgåsbord of scents and colors and the sweet loot of nectar, a broad assembly of pollinators and opportunist, predators and potential prey will gather around the colorful battlefield. Where there is nectar, there are nectar-feeders, and where these are, there is likely to be a predator around. This is the next piece in the complex web of life. Spiders, ants, praying mantises, wasps and other creatures, including lizards and frogs, hang around flowers because of the abundance of potential prey. Some, like Argentine ants, attack insects visiting the flowers either to catch and kill them or to defend other plant-associated resources, such as aphids, from which they obtain benefits (the so-called honey-dew aphids exude for the ants). And often there will be competition for the nectar, doled out in small quantities by the flowers.

And so we go back to the goldenbush flowers of the introduction. Argentine ants (Linepithema humile) have claimed the territory for themselves. They are nectar hogs, not the sharing kind of creature. Any bee that approaches a flower will get rushed and attacked as an intruder. Argentine ants are not native to Catalina Island. Originally, they come from northern Argentina, Uruguay, Paraguay, Bolivia and southern Brazil and have become invasive in the US, displacing many native ants. Our native bees are not used to the Argentine ant’s aggressive behavior. The bees land on the flowers and as they begin to sip the nectar, the ants confront them and injuries occur. I photographed several of these interactions, finding a number of bees with missing legs or segments of legs that had fallen prey to the bellicose ants. And if losing a limb or two wasn’t bad enough, their nectar-gathering time gets also severely reduced. A bee that would normally spend a 10 or 20 seconds exploring the flower head and sipping the nectar can only spend a second or two before getting mugged by the ants. This reduces not only its fitness and ability to forage efficiently, but also reduces the fitness of the goldenbush because the bees can’t get enough pollen on them to go to the next flowers.

Argentine ants attack bee. A swarm of Argentine ants on a wooly sunflower will prevent insects from landing and drinking the flower’s nectar. Some may even lose their lives to the ants. Here, a sweat bee lands on the wooly sunflower to collect nectar. The ants make their move and start swarming towards the bee. The attack is swift and efficient. The bee has precious few seconds before an ant gets a hold of it, which could lead to harm or even death.

We can only wonder what the long-term effects of these changes in the relationships between ants, bees and flowers will bring. Invasive species, a topic for a separate essay will be explored in more detail another time. Suffice to say that Catalina is a fertile ground for active evolution and natural selection, some prompted by the effects of human activities, others by the global changes we are experiencing in climate. It is an evolving story and we could use more researchers to help us understand what beneficial role we could play in this ongoing drama.

 

Milkweed bug on milkweed. A milkweed bug, bright in its warning colors that say “Don’t eat me! I taste really, really bad!” doesn’t drink the nectar of the narrow-leaved milkweed flowers but pierces the stems of the plan with its sucking mouthparts and drinks the sap, probably the main reason why it tastes so bad!

From Seed to Shining Seed

by Carlos de la Rosa
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The whole process of sexual reproduction in flowering plants is fascinating and deserving of its own article. However, I want to focus here on that part of the plant’s life cycle that develops in what we know as “seeds.” I have always been fascinated by the extraordinary variation shown in seeds, from the gigantic sea coconut or coco de mer seed (Lodoicea maldivica), an endemic palm found on the islands of Praslin and Curieuse in the Seychelles, which can weigh close to 40 lbs., to the minute and dust-like seeds of many orchids in the tropical rainforests of South America, weighing 1/35 millionth of an ounce.

Flowering plants reproduce by producing blooms that eventually turn into fruits that contain seeds. All seeds contain a tiny embryo. These baby plants are usually surrounded by nutritive tissues that help them grow once they sprout. From each seed, a small root emerges, ready to tap into the soil and begin to absorb nutrients for the growing plant. The seeds found on Catalina are beautiful, strange, diverse and wonderfully adapted to the various conditions and opportunities for plants on the Island. Some are dispersed by wind, others by water, and yet others by animals; a few are dispersed by their own devices. Some seeds are quite large, like oak acorns, and some so tiny they look like coarse sand. But all of them are part of the balance of nature on our incredible Island.

This flowering specimen of giant coreopsis (Coreopsis gigantea) shows its spring leaves and yellow daisy-like flowers. The seeds of the giant coreopsis are hardy and germinate readily.

Each plant species has its own set of adaptations for making their seeds germinate successfully. Some enter a dormant period that can last for years, waiting for the right set of conditions, like temperature, humidity or light, to tell it when to germinate. Others, like some of our fire-following plants, need a trigger, like the heat from a fire or the smoke generated with it, to start the germination process. Through experimentation, native plant experts in California discovered that the seeds of certain chaparral habitat plants like chamise (Adenostoma fasciculatum), felt-leafed ceanothus (Ceanothus arboreus) and white sage (Salvia apiana) among others can break seed dormancy and be incited to germinate upon exposure to liquid smoke. Yes, that same stuff you put on BBQ meats to make them taste as if you cooked them outdoors on a wood fire! This has been published in the scientific literature, and it is widely used in the horticultural industry and in native plant nurseries, including our own on the Island. And the reason for this phenomenon is that liquid smoke (there are several brands out there) is actually produced by distilling and liquefying smoke produced in burn chambers with selected wood chips and sawdust. Many of the chemicals that the seeds encounter in the wild after a fire are concentrated and present in this food additive. This fire in a bottle was a significant breakthrough for horticulturists and ecologists focused on native plant restoration of degraded habitats.

A toyon (Heteromeles arbutifolia) in flower is an amazing sight, with its bright red fruits visible from a huge distance. Toyon seeds are encased in capsules, packed in fours or fives inside the fruits. Each capsule has usually two small brown seeds.

Native plant seeds on the Island range in size from large, like oak acorns, wild cucumber, and Catalina cherry, to tiny, like those of the bush mallow, shooting stars, silver lotus, and the minute ocean spray. Some of our seeds are also uniquely shaped, like the long and hairy Catalina Island mahogany, with its curly fox tails that help it be dispersed by the wind, and the odd-looking and sticky seeds of the beautiful Crossosoma. Looking at the native seeds under magnification tells stories of dispersal, hardiness, adaptations to survive cold and fire, drought, and floods. The seeds carry the essence of the next generation, and their survival is the most important thing for the plant.

As varied as they are in shape and size, they are also diverse in other characteristics, such as viability. A seed is not viable forever under natural conditions. It will come to a point where if it doesn’t germinate, the germ or embryo it contains will die. For some species, like the oaks, this can happen very quickly. Acorns are usually viable only for a few months. If they don’t germinate right away, they will dry, rot, or most likely get eaten by the plentiful wildlife that depends on acorns for its sustenance. This is one of the reasons oaks produce such a tremendous number of seeds. Odds are that some of them will make it to germination and survive the seedling and small plant years. But there are other species, like the fire-followers or fire-adapted ones mentioned above, that will enter a period of dormancy and wait for the conditions to become ideal. For the fire species, this can be years. And then, there are other species that under the right conditions (low humidity, cold temperatures and lack of predators or diseases) can live for decades and even centuries. Seeds from the narrow-leafed campion, Syllene stenophylla, a species of flowering plant found in Siberia, were recovered from frozen rodent burrows and carbon-dated to 30,000 years of age. Scientists were able to germinate these seeds and grow full plants from them! There are several species of this genus in southern California. Same stories have been reported using seeds from archaeological excavations dating back to two thousand years. These conditions of low humidity and temperature can be replicated and provide an environment for the storage of many seeds from our native plants. The Ackerman Native Plant Nursery in Middle Ranch does just this, and it has millions of seeds stored in a walk-in refrigerator, cataloged and tested regularly, ready to be put to use in the Conservancy’s restoration projects.

The Catalina Island mahogany (Cerocarpus traskiae) is an endemic species of special importance to the Island. These spiky structures are the seed “tails” starting to grow. The seeds of the Catalina Island mahogany have a unique structure that looks like a little hairy tail and it helps the seed to disperse.

Seeds and the fruit capsules that contain them use a variety of strategies to move around. Some plants have fruits that literally explode when ripe, sending the seeds flying through the air some distance away. Others are transported by water, using floods and streams as means for dispersal or have extensions and adaptations to be dispersed by the wind.

Some fruit capsules have hooks or barbs that get attached to passing animals (or unwary hikers) and get transported long distances by these means. Many fruits are edible and attractive to wildlife and are swallowed whole by birds and mammals. These seeds have to have tough coatings to survive the trip through the acidic guts of animals and come out the other end viable. In fact, some seeds actually need to go through an animal’s gut to germinate. One good thing is that these seeds, scarified by the acids from the digestive tract of its transporter, get deposited in a convenient “pool of nutrients” (yes, I mean poop) once they leave the gut of the disperser. In fact, every species on the island has its own unique form of dispersal, germination, and characteristics, making the study and exploration of seeds an intellectually rewarding endeavor.

The flowers of several species of Eriogonum (like our St. Catherine’s lace) change colors when maturing, from white or light pink to russet. The seeds of Eriogunum are very small and pointed.

My Life in My Bookshelves

by Carlos de la Rosa
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Surrounded by books. Author C. de la Rosa and some of the libraries and books mentioned in the article.

It started early, in Venezuela, when my mother purchased a small nature encyclopedia for the home, which she kept neatly in a large wooden cabinet on the living room of our apartment. The 14-volume set explored topics such as rainforests, rivers and lakes, the Earth, deserts, and more. Illustrated with not-so-vibrant but still fantastic color photos, these books took me many places in my imagination and increased my early knowledge about the world. I kept them in my library for many years, until I recently gave them away to a friend for her kids. My own library started early as well, in my early teens. Among my first favorites (besides a few comic books that were too expensive to buy regularly) were inexpensive issues of classic literature books that had illustrations interspersed between the text pages, something like a comic book within the actual book. I would read through the illustrated version first and then go into the text, comparing the full story with the abbreviated comic book version. This way I was introduced to Gulliver’s Travels by Jonathan Swift; The Lost World, Sherlock Holmes, and (the terrifying) The Hound of the Baskervilles, by Arthur Conan Doyle; Ivanhoe by Sir Walter Scott; the anonymous classic Poem of Mio Cid; and many more.

When I was 14 years old, I discovered the Círculo de Lectores (Circle of Readers), a literary club in Venezuela that would edit their own, less expensive editions of classic books and novels and made them available to their members. I was the youngest subscriber to the Club and spent just about every penny I got (my allowance and whatever I scrounged from small jobs) on these books. The Club introduced me to “the big ones” such as Tolstoy’s War and Peace; Dostoevsky‘s The Brothers Karamazov and Crime and Punishment; Hugo’s Les Misérables; and Dumas’ The Count of Monte Cristo among many others. I delved into the Spanish royal dynasties in a series of 12 amazing books, traveled to the center of the Earth and to space with Jules Verne, took a crack at Cervantes’ Don Quixote (I couldn’t finish that one, a very challenging book), and enjoyed Stevenson’s Treasure Island. Among my most favorite ones were Defoe’s Robinson Crusoe; Twain’s Adventures of Huckleberry Finn; and Wyss’ The Swiss Family Robinson, books that left an indelible mark in my desire to explore nature and the world. I also got scared out of my wits with Wilde’s The Picture of Dorian Grey and Stoker’s Dracula. There were many more, of course, all beautifully translated to Spanish and available at a significant discount.

And there were the Venezuelan and Latin American classics as well, such as Marquez’s A Hundred Years of Solitude and Love in the Times of Cholera; Gallegos’ Doña Bárbara and Canaima. I laugh hysterically to this day with Amor y Humor (Love and Humor) by the fantastic humorist Aquiles Nazoa. My bookshelves filled up in my little bedroom. Book piles accumulated in the closet, on the floor, desk, and under the bed. I was happy.

As I finished high school, my book preferences expanded to other Latin American authors, such as Jorge Luis Borges, Alejo Carpentier, Pablo Neruda, Carlos Fuentes, Gabriel García Márquez, and Mario Vargas Llosa. Later, while in college (still in Venezuela), Isabel Allende, Julio Cortázar, Laura Esquivel, and Paulo Coelho joined the list of authors I loved and read. My library overflowed my room and spilled over into the living room.

At this time of my life, in college studying mechanical engineering and later biology, my shelves swelled and struggled with the weight of textbooks and journals. One late night, while sitting in the living room with my best friend who was spending the night with me in my tiny room, we heard a frightening crash sound coming from the bedroom that shook the floor of the apartment. We ran to the bedroom to witness that the entire wall of bookshelves had ripped out of its wall moorings and collapsed down on the bed and the mattress I had set on the floor for my friend. We would have certainly been harmed—if not killed—by the hundreds of pounds of wood and paper that crashed to the floor.

I decided to go to the US to complete my university studies. I left my beautiful library behind, taking with me a duffel bag with my clothes and personal items and a heavy cardboard box with a handle made out of rope filled with books. Packing this box with a selection of books I wanted to take to the US with me was one of the most painful things I had to do to prepare for this trip.

Once in the US, I discovered bookstores like I had never seen in Venezuela, especially used bookstores, where I could rebuild my left-behind library at a significant discount and find treasures I had never imagined I could have. I realized you could get information on anything you wanted (this was way before the Internet) because someone already had written a book about it. My $400/month scholarship (with which I had to pay food and rent) was stretched thin by the irresistible drive to acquire and read more books. At this time of my life, my bookshelves filled up with non-fiction: books on biology, ecology, building construction, gardening, animals, dictionaries and thesauruses (I was learning a new language and reading for the first time whole books in English that were not textbooks or translations). I amassed collections of books on arts and techniques, special topics such as insects in amber, gigantic books on artists such as Frida Kahlo and Salvador Dalí (among several others), books about photography and drawing, human anatomy and physiology, classics such as an entire collection of Charles Darwin and Russell Wallace books, and selections from authors such as Stephen Jay Gould (I read every single book and article he wrote, and he was incredibly prolific!). I immersed myself in the writings of authors that help me evolve my career as a conservationist and an ecologist, such as Thoreau’s Walden; Carson’s Silent Spring; Leopold’s A Sand County Almanac; several Edward Abbey books such as Desert Solitaire; Goodall’s My Life with the Chimpanzees, In the Shadow of Men, Reason for Hope, and others; Fossey’s Gorillas in the Mist; Galdikas’ Reflections of Eden; Matthiessen’s The Snow Leopard and others; London’s The Call of the Wild; Mowat’s Never Cry Wolf; Schaller’s The Last Panda; Stoney Douglas’ The Everglades: River of Grass; Dawkins’ The Extended Phenotype and others; all of E.O. Wilson’s many books starting with Sociobiology; Dan Janzen’s Costa Rican Natural History; and Quammen’s The Song of the Dodo among the best known. My library grew exponentially, reaching numbers into the thousands. I also started writing at that time, so the collection expanded to include books about writing of all kinds, novels, period books, historical novels, humor, crime, science fiction, biography, natural history, and more.

Every move to another city, to a new job—including two US-Costa Rica-US moves—made me reconsider what to keep and what to give away. Many of my books carried with them faint but particular strains of mold acquired in the dry forest or rainforest of Costa Rica, in Pennsylvania, West Virginia, Florida, or California. Some of these books make me sneeze when I open them. They have traveled with me for thousands of miles, faithful and dear companions. I have lost hundreds of books to mold, termites, and flooding — all losses that were profoundly and painfully felt. I have also given away hundreds of books, to my kids, to friends, to students, and to children I see my books as my closest friends, important shapers of my intellect and personality, an integral part of my life and my history. Some of the books I mentioned above are still with me; sweet reminders of my early forays into reading and writing. They are hunks of paper and ink that collected the thoughts, dreams, adventures, aspirations, techniques, and brilliance of people I never met—and some I actually have met in person—but have always admired, people who took the time and the pain to write down and publish their thoughts to enrich my life so much.

I have traveled and worked around the world, and traveling is a great way to learn and to expand your mind. But books have played a significant and essential part of this education. The books I read became the foundations of my life’s philosophies and the lessons I taught my children. My children are bibliophiles as well, all of whom grew up surrounded by books instead of TV. The books I have written and the ones I’ll write will be my legacy to them, my way to go on living after the earthly vessel gives up. I can’t think a better way to have spent my life than reading, writing, learning, and teaching and putting all that knowledge to the benefit of people and the planet.

Author’s roll-call. All of the authors mentioned in this article. Images from Encyclopedia of Britannica, Wikipedia, and on-line archives.

Sticks and Shields: How to Hide in Plain Sight

by Carlos de la Rosa
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I got the message late on a Monday evening. I had been living in Catalina for less than four months, and already felt a bit overwhelmed by the complexity of the Island. I felt especially challenged by the Island’s amazing biology which I had started to experience by hiking its trails through canyons and valleys filled with species new to me. I had already begun the exciting but long road to learning this flora and fauna and felt energized about the prospect of cataloging, photographing, protecting, and learning about them.

In the e-mail, one of my new Island friends said “Could you identify this creature for me? It appeared in my patio and I had never seen one of them before.” Attached to the e-mail was a slightly over-exposed photograph of a walkingstick or stick insect. Nothing to write home about, I thought. Walkingsticks are fairly common, right? Wrong! When I looked at it closer and started my little research on the Internet and our wildlife file cabinets, I started to find the hidden stories. This was my first foray into the world of Catalina’s endemic insects, a few species that over the last century or so, have been found to live and thrive on the Island and nowhere else in the world.

The scarcely two-inch long stick insect happened to be one of these species. The Catalina walkingstick, known by its mouthful of a scientific name as Pseudosermyle catalinae, has been collected only a few times, not just because it is rare, but because it is very hard to see! They look uncannily like the little branches and twigs of the plants they sit on. It is only when they take a hike away from their host plants that they temporarily lose their camouflage and become visible to us. Our particular species was described and named for the first time in 1981 and, since then, only occasionally seen and collected by entomologists and Island naturalists. It lives its quiet life largely unnoticed by predators and naturalists. It belongs to the order Phasmatodea, the “phantom or ghost insects” because it literally disappears among the sticks and leaves that they normally rest upon.

 

Catalina’s walkingstick species, Pseudosermyle catalinae, shows a classic green coloration.

The walkingstick walk is a great example of a behavior that enhances its appearance. While immobile, the walkingstick looks like a little twig, sticking out like any other dry twig on a plant. Its long antennae are either held close to the body or extended out, very much like the thinner end of a “stick.” The deception is perfect. When it needs to move, it does so with slow, measured steps, balancing its body back and forth at each step, much like what you would see the wind do with a twig that’s about to fall from the tree. A slow pendulous movement, pulsing and natural. Again, the trick works well and the walkingstick remains unnoticed under its cloak of invisibility, even to the trained eye of a bug biologist. Feeding on leaves, the Catalina walkingstick lives a quiet, barely perceptible life among the Island’s native plants.

The Catalina shield-backed katydid, Neduba propsti, is so rare that for many years all we had were a couple of photos of preserved specimens. This was the first live individual, a male, that we had seen.

More robust and visible, although almost equally private, is another one of Catalina’s unique insects, the Catalina shield-backed katydid (Neduba propsti). Also known as Propst shield-backed katydid, it was named in honor of the Catalina Island Conservancy’s second President, Douglas Propst, who lived a large portion of his life in the Island he loved so much. It is a great honor to have an animal or a plant named after you, a little bit of immortality that endures beyond our short, busy lives. That is, until some other biologist reviews the taxonomy and changes the name to something else. It happens, but not that often.

Anyway, this katydid’s main distinguishing characteristic is a strong, knobby plate on its back that looks much like a shield, thus its given name and that protects its short wings. But, a brown katydid? Most katydids are green in color, which helps them blend well in their surroundings. In Catalina, green is not the color of choice for a terrestrial insect, largely because most of the Island is a palette of brown shades and tones, at least for most of the year. So, it pays for an insect to be inconspicuous and blend with its environment, and the shield-backed katydid does this admirably well. There are a couple of related species and subspecies of Neduba in other Channel Islands, all seemingly confined to each island, and all equally secretive in their life styles. To see photographs and additional information about our unique species, please visit the following website: https://entnemdept.ifas.ufl.edu/walker/buzz/149a.htm. Pay attention to the male’s song. It is so subtle that only young people can hear it. Older adults have lost the capacity to hear these superfine sounds. I know, I tried to listen to one in a terrarium and couldn’t hear it, while two younger naturalists could hear it clearly.

From the top (dorsal view), the shield-back katydid shows clearly the shield that gives it its name

This other species of walkingstick, Pseudosermyle stramineus, photographed by Joyce Gross, is a close relative of the Catalina species. The specimen pictured is a male.

The world of Catalina’s endemic insects is a world still to be explored. There are several other insects already determined to be unique to the Island, like four species of scarab beetles, two butterflies and a yet-to-be-named species of Jerusalem cricket. But knowing now what I know about the Island, the history of the entomological explorations and the diversity of habitats across this isolated bit of land, I can confidently say that we have barely scratched the surface. There are more Catalina’s endemic insects out there, hiding in the littler of the ironwoods, in the slowly drying pools after the scarce rains, under the kelp that wash ashore on its beaches, and in the patches of oak forests deep in the canyons, waiting to be discovered, studied, described and their secrets unfolded. For a biologist like me, Catalina is not just a great place to live, but a great place to explore, share and entice others to study and learn from it. It will be through this learning and research that the secrets of the Island will come to light, for all its residents and visitors to learn about and enjoy.

Grove of Island Oaks by Carlos de la Rosa

The Butterfly and The Flower: Love is on the Wing

by Carlos de la Rosa
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The relationship between flowering plants and insects go back millions of years to the time when dinosaurs roamed and hunted in the forests and the plains, and mammals were rat-sized creatures shyly scampering in the undergrowth. Dinosaurs may have dominated the large food webs, but insects dominated the small-creature world. Flowering plants evolved quickly to take advantage of this abundant mobile “resource” that could transport their pollen from one flower to another.

The Avalon hairstreak (Strymon avalona) is a regular visitor to milkweed flowers. These flowers have adaptation to stick pollen packets on visitors for transportation to other flowers.

Insects relate to plants in different ways. The larvae and the adults of many insects eat the leaves, flowers, fruits and even the wood of many plants, and plants have responded by developing defenses against these assaults. They acquire bitter tastes, push poisons into their leaves, or exude sticky substances from their wounds.

The endemic Avalon hairstreak can be very subtle in its coloration, grayer and duller than its closer relatives. This female is laying eggs on a patch of flowers.

In some extreme cases, they have evolved into death traps for insects–even eating them, like the carnivorous Venus flytrap or the many species of pitcher plants. However, insects also help some plants in their reproduction, primarily by moving their pollen from one flower to the next. Between the arms race to protect its tissues from hungry insects and the symbiotic relationship of producing attractants (perfume and nectar) to bring insects to the flowers and use them to transport their pollen, the relationships between plants and insects evolved to become more and more complex and specialized.

Some plants have become absolute masters in attracting insects to their flowers. The scientific term for these is “entomophilous,” literally “insect-loving flowers.” And the insects, finding great rewards and predictability in their resources from these plants, have learned to be loyal and visit them in predictable ways. This form of co-evolution is the hallmark of some of the most remarkable plant-animal associations in nature.

On Catalina Island, the Avalon hairstreak (Strymon avalona) is an endemic species of butterfly that clearly found the right formula for surviving and thriving in this semi-arid environment. The butterfly lays its eggs within the flowers of the giant buckwheat (Eriogonum giganteum), a Channel Islands endemic species that is relatively common on rocky outcrops on the windward side of Catalina Island. The butterfly lays her eggs among the blooms while sipping the nectar from the flowers. The little caterpillars hatch in a few weeks and begin their long growth period, feeding on the tissues of the host plant. But the butterfly also visits other plants that produce nectar during the period the butterfly is active.

The Santa Catalina Island manzanita (Arcostaphylos catalinae) is one of our endemic shrubs. Its vessel-shaped flowers are delicate and, quite frankly, gorgeous.

All of these flowers provide the butterfly with a most valuable resource: the nectar that powers its flight. Fueled with this nectar, the Avalon hairstreak roams far and wide in search of the host plants that will feed its larvae. While it moves from flower to flower, the butterfly picks up pollen on its head, legs and mouthparts. This pollen gets transported to the next flower helping the plant carry out its reproduction.

The Santa Catalina Island manzanita (Arctostaphylos catalinae), an endemic species of shrub, has a very particular type of flower. The flowers look like little urns or miniature amphora with a narrow entrance, and this shape makes it hard for an insect to enter and get to the nectar and pollen. Some butterflies can reach the nectar with their long proboscis (the technical word for the butterfly’s mouthparts), but insects like bees, flies or wasps can’t get to the nectar so easily. However, manzanitas also can pollinate themselves. Their flowers have both male and female organs. The insects and hummingbirds that visit the flowers may actually help them self-pollinate by shaking them, loosening the pollen within.

Another plant common on Catalina Island, the chaparral mallow (Malacothamnus fasciculatus catalinensis), is a species thought by some to be endemic to Catalina and to some parts of the Santa Monica Mountains. The mallow also depends on a wide variety of insects to transport its pollen from flower to flower.

Where there are busy insects, there’s sure to be a waiting spider, like this endemic species of crab spider. Pollen has also rubbed on its body. They can change colors depending on the substrate they sit.

Blooming during the best part of the summer, the chaparral mallow is a seemingly inexhaustible source of nectar for hungry insects. And there’s no shortage of insects on Catalina! On a lazy afternoon at the peak of blooming of the Island bush mallow, you can see busy bees and lazy flies, tiny thrips and huge bumblebees, night-flying moths and day-loving butterflies. And where you find insects, you can also find the ubiquitous spiders. Some of them, like the crab spider, even change their colors to match the colors of the flowers on which they sit, camouflaging themselves against detection by potential prey as well as by predators. The mallow’s formula, like that of most insect-pollinated flowers, is a big hit in the insect world. Pollen, nectar, and perfume are the main ingredients of a healthy and long-lasting plant-insect marriage.

Next time you walk to the beach in the summer and see a blooming giant buckwheat hanging on the sunny rocks, or run into a gorgeous manzanita in full bloom, or see the unmistakable signature of little bluish/purple flowers of the bush mallow, stop for a few minutes and enjoy the parade of insects working their magic with their flower associates.

Two bees compete for the nectar of the endemic Catalina Island bush mallow. In the process of getting their reward, they collect pollen all over their bodies, helping the flower cross-pollinate with other flowers.

The Fox and the Quail: A Tale of Two Catalina Endemic Species

by Carlos de la Rosa

It is about 8 p.m. on Catalina Island. I’m driving up Stage Road and my headlights land on a small, furry creature sitting by the side of the road between two eucalyptus trees. The first thing I see is a yellow, bright, single spot of light. The reflection comes from the end of a radio collar worn by the Catalina Island fox. The little fox calmly sits as I coast to a stop on the steep grade. It closes its eyes to the glaring lights and waits. I’m driving an electric car, a rather quiet vehicle, so there are no loud engine noises or exhaust fumes. As I stop the car, silence surrounds us.

The fox sits about 10 feet from the car, still a bit blinded by the lights, but seemingly unafraid. I take my camera out of the case from the back seat, slowly open the door, lean out, and take a few photos. Its ears turn to the slight noises coming from my camera, in tune with its surroundings and secure in its ability to confront any threat. It grew up surrounded by dangers, exploring and hunting among sharp cacti, learning to avoid deadly rattlesnakes, becoming surefooted in the loose rocks on the hillsides of its Island home. If all goes well, the little fox will live to the ripe old age of 9 or 10 years and produce several batches of pups. With an unconcerned swish of its tail, the fox stands up and slowly walks away over the edge of the road into the sheltering shadows.

Encounters with the Catalina Island fox are frequent in the interior, especially at dusk and during the night, but often in the middle of the day as well. I have seen them several times while hiking. In many cases, they didn’t seem concerned, but kept a respectful distance that seemed quite short to me, considering how endangered and susceptible they are to harm. Foxes evolved on their Island habitat for thousands of years, unexposed to many of the dangers they face today. Today they must deal with cars and trucks barreling down the Airport Road. Some diseases can decimate their populations. Water tanks, electric fences, guns, and dogs are among other present-day menaces.

At 3 to 4 pounds, the Island fox is a small version of the mainland gray fox that can weigh up to 15 pounds. Santa Catalina, Santa Cruz, San Clemente, Santa Rosa, San Nicolas, and San Miguel islands all have their own unique subspecies of fox, all small, all showing variations in their genes. On all of these islands, the fox is the top native terrestrial predator, a fierce little bundle of energy that chases after mice, quail, lizards, and insects but that also likes regular vegetarian meals as part of its diet. They eat the fruits of toyon, manzanita, prickly pear cactus, and saltbush, as well as other plants.

A different day. It is spring and, elsewhere on the interior of the Island, a different scene unfolds. A covey of quail quietly forages in the grassy vegetation along an old, seldom-used dirt road. Twisted oak tree branches reach in all directions, providing a broken canopy that lets light hit the ground in splotchy patterns. In the sunny patches, tiny miner’s lettuce plants intermix with scarlet pimpernel flowers, grass shoots, lichens, and mosses. I work my way slowly along the trail, unaware of the quail just ahead, photographing small flowers and the insects that visit them, often on my knees, face close to the ground. At one point, I start to stand up, brushing the dirt off my pants. A loud, explosive sound, like hundreds of pieces of wood running across a fence, knocks me off my feet and sets my heart to racing speed. I fall flat on my rear, startled. I see the flock take off low to the ground and alight about 100 feet ahead on the road.

After a few minutes, heart back to normal, I watch the quail continue to forage. I see a few males, sporting a beautiful black top-knot of feathers that bob when they walk. I start hearing different sounds too, like the repeated pips and calls of the males communicating with the females, the patter of tiny feet on the grass, the rustle of feet scratching the soil, beaks picking seeds, grasses, little flowers and insects and wings brushing against the vegetation. If I were a fox, I’d need to be very skilled and focused to be able to catch one. There is safety in numbers.

In April and May, quail mating season on the Island, the call of the males is eerie and melancholic, especially in the foggy silence of an interior morning. The repeated three-note call sounds something like “phee-phee-phuiii,” ending with a falling note, almost like the answer to a question. “I-am-heeere.” I’ve read that their nests are well hidden shallow depressions on the ground, under logs or dense clumps of grass, lined with plant materials where ten to twelve eggs are laid. The precocious chicks hatch from their tiny eggs and, within hours, are fully mobile. I’ve seen them cross dirt roads, two handsome parents followed by several little trails of dust crisscrossing in the dirt.

So here they are, two endemic species on Catalina Island, two species that depend on each other – one as a predator, the other one as prey – participating in the web of life. Both depend on healthy habitats full of insects, grasses, seeds, fruits, water and lack of disturbance.

The interior of Catalina Island is a place of wonder. It has served these and other species well for thousands of years, providing everything they need in food and shelter. As residents and visitors to the Island, as stewards and managers and as conservation-minded people, we honor this historical and evolutionary relationship and strive to help it continue. By restoring Island habitats and their populations, we become integral players in their sustained future.