For the last year I have been walking around Las Vegas every day with my camera for exercise and to avoid going mental. Over that time period I have accumulated a collection of lizard photos which I thought would make a nice post. Even though there are lots of little lizards in the Mohave desert (more than 20 species), even in the urban landscape of Las Vegas, most photos are fortuitous since they are so quick and usually small. Lizards and iguanas both belong to the reptile group of vertebrates. The Squamata, or the scaled reptiles, are the largest recent order of reptiles, comprising all lizards and snakes. Iguanas are actually a type of lizard. Therefore, they are not very different from lizards in many aspects. However, they are different from most lizard species in several ways including their colors and the foods they eat. Many lizard species are insectivorous. They like eating insects such as cockroaches, crickets, ants, and beetles. Many lizard species are also omnivorous; they eat just about everything including insects, carrion, small tetrapods, spiders, fruits, and vegetables. Iguanas tend to be herbivores. Of the many species of swifts and spiny lizards, 22 species, some with several subspecies, occur in the United States. Others are found southward through Mexico to northern Panama. In the United States, the lizards of this group are found from southern New York, southern South Dakota and northern Washington in the north, to South Florida, the Gulf States and the Mexican border. Several of the fence lizards (which, because of their rapid movements, are colloquially referred to as “swifts”) are familiar backyard species. Others, among them the bunchgrass lizards and Yarrow’s spiny lizard, are denizens of remote montane fastnesses. Like many other lizards, spiny lizards exhibit metachromatism, which is color change as a function of temperature. When it is cooler, colors are much darker than when the temperature is high. Darker colors increase the amount of heat absorbed from the sun and lighter colors reflect solar radiation.
This is the final post in my series on photosynthesis in Mohave desert plants. While green leaves are commonly considered as the primary sources of photosynthesis, higher plants can potentially use almost all vegetative and reproductive structures to perform carbon fixation. Chlorophyll-containing bark and wood tissue, most fruit, root and fertile flower organs typically perform an effective internal CO2 recycling using the respiratory released CO2. Photosynthetic stems have positive effects on the carbon economy of plants through two main mechanisms. Photosynthetic stems can either assimilate atmospheric CO2 and contribute to the net carbon gain of the plant through the process of stem net photosynthesis, or decrease respiratory losses by recycling CO2 previously respired by roots and stems through the process of stem recycling photosynthesis.Plants with green stems are categorized by one of three types of stem photosynthesis syndromes. Retamoids include leafless or almost leafless woody plants that have stomata in the stem epidermis allowing for gas exchange with the atmosphere (Schaedle 1975). Another type of photosynthetic stems are the succulent pachycauls or the sarcocaulescent group, which has large-sized stems with translucent exfoliating bark, a large amount of parenchymatous tissue that serves as a water reservoir, and non-succulent, drought-deciduous leaves (Franco-Vizcaino et al.1990). An example of this would be the Boojum Tree (Fouquieria columnaris) and the related Ocotillo (Fouquieria splendens) as both lack stomata and recycle respiratory released CO2 to survive during drought. Another type of photosynthetic stem is found in cactus, which take up carbon dioxide at night with stoma using CAM photosynthesis. The inadequacy of the current state of knowledge for describing or understanding the diversity of structure, function, and ecological significance of photosynthetic stems suggest areas for further research. The diversity of taxonomic types, and classes of photosynthetic stems, results in a large diversity of structural characteristics. In this post, I have simply chosen interesting examples without resolving these difficulties. I have also decided to throw caution to the wind and use lots of technical jargon.
The Boulders Beach African Penguin Colony was established in 1982 by a breeding pair of penguins who settled near Capetown, South Africa after fleeing when a larger colony was devastated. Today there are currently 28 African penguin colonies, only four of these occurring on the African mainland. These colonies run along the coast, from Algoa Bay in South Africa to Namibia’s Penguin Islands. Despite the huge distances between these colonies, it is not uncommon for young penguins to visit, and occasionally resettle, at a different colony from which they hatched. African penguins are clearly resilient animals. They have evolved the behavioral mechanisms to move their entire population to deal with changes in the abundance of food. Despite their wide range and versatile juveniles, African penguin numbers are declining fast – so fast that it is believed they will be extinct within 10 years. Today there are fewer than 21 000 pairs of African penguins left in the wild – 100 years ago there were single colonies that had over a million, like Yzerfontein’s Dassen Island. Dassen Island is, unfortunately, not a unique case. The total breeding population across both South Africa and Namibia fell to a historic low of about 20,850 pairs in 2019. Quite simply, our common seafoods – sardines, anchovies and pilchards – are the products directly linked to the decline in penguin numbers. You may have been unaware, but sardines/pilchards have recently been added to the WWF SASSI Orange List – a seafood you should avoid. These ratings do not only mean that the fish itself is at risk, but also that the practices used to catch it are harmful to other species. I would go a step further in saying seafood of any kind should only be consumed if it is sustainably farmed. Bottom trawling destroys far more ocean habitat than any other fishing practice. In this common fishing method, large weighted nets are dragged across the ocean floor, clear-cutting a swath of habitat in their wake. Some of these scars will take centuries to heal, if ever.
Dragonflies and their relatives are an ancient group. Meganisoptera is an extinct order of very large to gigantic insects, occasionally called Griffinflies. The largest known Griffinfly and/or insect of all time was a predator resembling a dragonfly but was only distantly related to them. Its name is Meganeuropsis, and it ruled the skies before pterosaurs, birds and bats had even evolved. The oldest fossils are of the Protodonata from the 325 Mya Upper Carboniferous of Europe, a group that included the largest insect that ever lived, Meganeuropsis permiana from the Early Permian (300–250 Mya). Meganeuropsis permiana was described in 1939 from Elmo, Kansas. It was one of the largest known insects that ever lived, with a reconstructed wing length of 330 millimetres (13 in), an estimated wingspan of up to 28 inches (710 mm), and a body length from head to tail of almost 430 millimetres (17 in). Nevada designated the Vivid Dancer Damselfly (Argia vivida) as the official state insect in 2009. Sadly, I have no photos of the state insect but Nevada has many eco-zones and the Henderson Bird Viewing Preserve has quite a number of equally beautiful species.
Butterflies have been held in reverence and high esteem for millennia, enshrined by the ancient Greeks in the mythical love affair between Cupid/Eros and Psyche the butterfly goddess. According to Greek mythology, Psyche was a beautiful maiden who fell in love with Eros/Cupid. Cupid’s mother, Aphrodite, was jealous of Psyche’s beauty and tried to keep the lovers apart. Eventually, however, Aphrodite realized that Cupid and Psyche were destined to be together and so Zeus made Psyche immortal. Psyche is also the Greek word for “soul” and “butterfly.” Although the original Greek story has been lost to history, the mythology of Cupid and Psyche was preserved in the book Metamorphoses written in the 2nd century CE by Platonicus. The Greek story of Eros and Psyche is known from at least the 4th century BCE and was a popular subject in Greek and Roman art. The word for butterfly in formal Greek is psyche, thought to be the soul of the dead. Ancient Greeks also named the butterfly scolex (“worm”), while the chrysalis – which is the next stage of metamorphosis from a caterpillar – was called nekydallon, meaning “the shell of the dead”. The metamorphosis of the butterfly inspired many to use butterflies as a symbol of the soul’s exit from the body. Thus, the myth of Psyche concomitantly signifies soul and butterfly. It has come to mean the story of the soul coupled with divine Eros, but which must nevertheless endure tribulations before achieving immortality. Psyche, a mortal woman, was released from death by Zeus, the father of the gods, who took pity on her and granted her immortality. Psyche’s mythological imagery in ancient art is represented with butterfly wings, amply depicted in pottery as well. Freed from death, the body of the soul could fly freely, soaring, departing from the shackles of the chrysalis. I thought this lovely Greek story would be the perfect introduction to a review of beautiful butterflies.
When reading a birding guide for a specific bird, talking to fellow birders or just researching an unknown bird, terminology comes up that can sometimes be confusing and/or unintelligible. Since I write extensively about birds, sometimes a simple definition of a term is not enough and adding it to the post makes the post unnecessarily long. This post is my solution to bird related anatomy and physiology definitions. Field marks are the distinctive stripes, spots, patterns, colors, and highlights that birds have in such abundance and variety. Birds developed these patterns for many reasons, but one way they use some of these markings is to recognize members of their own species. And bird watchers can use them for the same purpose. Generally speaking, there are two categories of field markings, anatomical/anthropomorphic and human clothing references. The comparison of human anatomy, emotions and characteristics is both familiar and time-honored dating at least as far back as the ancient Egyptians. Anthropomorphic comparisons are comforting, familiar and accurate in many instances. When corresponding anatomy is unclear or inaccurate, clothing analogies can sometimes provide more clarity. When all else fails, there are field markings specific to a specific family of birds.
Most of Costa Rica’s forests can be primarily classified into three groups; rainforests, cloud forests and topical dry forests. And while rainforests are the most common habitat, the cloud forests of Costa Rica are a magnificent sight to behold. Rainforests can be found in the southwest of the country as well as in the Atlantic lowlands, with towering trees and looping vines that create a magical wispy environment. Receiving a high annual rainfall, these dense forests are characterized by a wealth of plant and animal life. Rainforests are located at lower elevations, and as a result, they tend to be much warmer, especially during the dry season. Cloud forests, on the other hand, are usually located at much higher elevations, and are much cooler. This difference in temperature contributes to the mist and fog that is often visible in cloud forests, as the milder temperatures slow the evaporation process. However, despite being a little cooler than rainforests, cloud forests are very humid. Cloud forests generate water by capturing water from fog (surface clouds). Water condenses on the leaves and branches of cloud forest trees, epiphytes and lichen, drips to the forest floor, and enters streams. The tropical evergreen cloud forests on the slopes of the Cordillera de Talamanca in Costa Rica’s southern highlands is of vital importance both as a source of drinking and irrigation water to the main cities in the Valle Central and as a bastion of many endemic species. This is not meant to be a comprehensive survey of the plants in the cloud forest, concentrating instead on important and noteworthy plants in this ecosystem.
Situated among the mist-covered peaks of the Talamanca Mountains, Los Quetzales National Park was established in 2006. This park lies 47 miles southeast of San Jose, and you can easily reach this park from Manuel Antonio on the Pacific Ocean. From Jacó it’s about a two-hour trip. The entrance to the park is on Cerro de la Muerte, just before the turnoff for San Gerardo de Dota. Most of the park area is around the both side of the Savegre river that emerges in the Cerro de la Muerte and connects to the Pacific Ocean close to the Manuel Antonio National Park. it is surrounded by natural rainforest, breathtaking waterfalls, and beautiful canyons. This park includes not only rainforests but also cloud forests, formed by the collision of warm, moist Caribbean trade wind with the Talamanca mountain range which stretches from southwest of San José to beyond the border with Panama. When tiny droplets are deposited on surfaces before they collect together and fall as rain it’s called horizontal precipitation and in cloud forests it can be the main source of moisture. Peaks enveloped by trade wind-derived clouds can capture huge amounts of water when they are covered with tropical montane cloud forests. Their sponge-like epiphytes (mosses, ferns and bromeliads) massively increase the surface area for horizontal precipitation. Vibrantly colored, from the miniature to the gigantic, Los Quetzales flora is some of the most beautiful in the world. There seemingly endless tropical flower species and even orchids. Many can be found growing wild on the trunks of giant trees.
When I was in Costa Rica for a bird photography tour recently with Tropical Birding, I had an opportunity to visit Frog’s Heaven, a place that specializes in catching wild frogs for photography. The frogs are subsequently released back into the environment. These tiny frogs are getting harder to find, even in the optimized environments of the Frog’s Heaven preserve. Research suggests that even though amphibians are severely declining worldwide, there is no simple solution to halting or reversing these declines. Amphibians are good indicators of significant environmental changes. Amphibians, unlike people, breathe at least partly through their skin, which is constantly exposed to everything in their environment. Consequently, their bodies are much more sensitive to environmental factors such as disease, pollution, toxic chemicals, ultraviolet radiation, and habitat destruction. The worldwide occurrences of amphibian declines and deformities could be an early warning that some of our ecosystems, even seemingly pristine ones, are seriously out of balance. We were able to photograph a nice cross section of the different types of frogs which I thought I would present here.