Archive | Natural history RSS feed for this section

Creation Turtle

15 Jan

Wiley, the Midget Coyote, and She took a break in their routine to hike in Closed Canyon along the Rio Grande del Norte.

“Wow! This is a neat place!”

“Yup. Canyons, like many land forms, are like books. When you open a book in the middle and read the two flanking pages, you might wonder just how the story led there and where it goes. You might thumb through previous pages, or perhaps those leading to the end. Unless you read all the pages, you are left with pieces of narrative, dialogue and pictures that lie in wait for the whole story. That is what canyons are.

Canyons are slices in the upper layers of the planet we live on. Yet these levels we see were once buried deep in the earth’s crust, flowed from places  far away, or crashed into by other layers and heaving them up. As in Santa Elena Canyon,  there may be bumpy levels of stone made of accumulated bodies of minute sea animals. Or, as in Closed Canyon, they might be hard sleek cliffs of what was once flowing molten rock.

In essence, Wiley, canyons are open books, their steep cliffs pages of time and accumulated activity, far far greater than we can imagine. Layers of differential stone and rock, colors and form, tell us pieces of stories, events long before mammals and humans walked the surface. Remains of living entities that precede us may lie in wait to provide a dialogue enriching the story. Canyons talk to you if you listen.”

Wiley stood still. “Well, I hear things, but not sure what canyons talk like. Do they growl like me? Yip? Grunt like Josephine? This is like my Home where I was a pup.  Sort of.”

“The canyon is a bit different than those you remember, aren’t they?”

“Yup. This one is only big enough for two of us coyotes to run in side-by-side.”

“It’s called a slot canyon, Wiley.”

“Hey, remember I am ‘Coyote‘!”

Sigh. “Yes, Wiley; you are that, too.” She and Wiley sat on a big boulder.

Wiley took a deep breath and then……. “Okay, so this is my turn to tell a story. They say…..  Are  you writing this down? I can’t hear talking pages, you know.”

“I am writing your story, Wiley.  I will read aloud the talking pages to you so you can hear them.”

“Okay. So.

They say this is the way it was, long ago. When Sky  Woman fell from Sky World and down towards the Great Water world, Turtle saved her. He swam underneath her and she fell on his back.

When she did, Turtle’s feet pushed mud up underneath him so they would both not drown. The mountains, valleys and oceans formed underneath them. Where his claws dug into the mud, water flowed and they grew into rivers. So the world grew from Turtle’s back, the mud underneath him, and Sky Woman’s songs.

Some of those claw marks in the mud lost their water. Some are narrow, like this here, and some are wider, like those where I grew up. Yet, when waters fall from Sky World and call on Turtle and Sky Woman below, that water will run through these gashes in the mud that is now rock. They look and search for Turtle and Sky Woman. And they take pieces of the rock mud with them when they go. That is how they remember how this world was created.

That was how it happened, they say. A long time ago.”

“That was a good nature story, Wiley.”

“What is this ‘nature’ ? What do you mean?”

“It is many things. It is the water in the well that was there before any of us came to be. It is also the bucket into which we put things, or ‘the’ things we call ‘Nature’. And it is a leaky  bucket.”

“What do you put in the bucket?”

“We put in things we meet: lions, thunder, wind, water, rocks,  you. Some people see only a bucket with one thing and call it ‘Nature’. Or they see only certain things in the bucket that they call ‘Nature’. Or things that have already been called ‘Nature’. ”

“But how did all those things get in the well?”

“Ah, well, that depends on who you ask, or who is looking. Some of us humans believe that things have been in there long before we could see them, and probably many things that we can’t see or even know about. Yet.

Many of these things were not created in the human mind, or in any living thing’s mind. They just ‘are’. Or ‘are not’. ”

Wiley said, “I don’t know about this ‘Nature’ thing. I only know I have to find food to eat. If I don’t, I may starve, maybe even die. Or I might become food for something else. Is that in the well, too?”

“Well, that is more an interaction with other things in the well. That tends to be put into the bucket, too, sometimes. Just as sometimes that tends to leak out,” She replied.

Wiley paused, then asked, “So, is Nature only those things that we see, touch, smell, taste, hear, and….?”

“Yes and no. It is all those things. We put all those things we encounter matching our world into a container. But Nature also does things on its own – with no containers. It did so long before we arrived with our buckets and it will continue to do so long after we are done with our looking and investigating and leaves it alone. Because it is a only word in our language. And a very leaky bucket.

Shall we continue on our hike?”

“Yeah. But can we leave the bucket behind for now?

I’m going to teach you how to stalk. You need to learn how if  you are going to hunt rabbits like I do. First you have to get low to the ground. Then move slowly and quiet, so the rabbit won’t know you are there. Hide behind a rock or tree, or slide along side this canyon side. See those rabbits up there? I’m watching your back.”

 

“Those aren’t rabbits, Wiley. Those are people.”

“So! You can pretend they are rabbits! That way you can practice for when you do see a real rabbit.”

“Okay, Wiley. Can I get up now?”

“It sure took them a long time to crawl around that deep pool of water. I’m getting thirsty……”

“We’ll just sit here and watch them. Here, have some water from my bottle.”

“Good, ’cause I don’t think I could get out of that pool. I wonder if Turtle is in there……”

(Original story written by this author in 2011 and published in issue of ‘Alpine Daily News,’ Alpine, Texas, 2013)

Flying High

6 Nov

Last night on the way back from town, I observed and drove along with a flock of ~250-300 sandhill cranes returning to the refuge from foraging north of here. (Couldn’t do an accurate flight count and drive at the same time.)

Observing the flight dynamics of this group was really quite interesting. Unlike Canada geese that typically form several dynamic ‘V’ patterns, this flock of cranes did not. Except for the front ‘V’ with a very truncated side ‘arm’ of five individual cranes, the rest of the flock was one long linear flock stretching for a few miles.

Typically with geese the front leading bird of the ‘V’ formation frequently changes, trading places with nearby individuals. This seems logical because energy is then conserved among the leading birds. Not so with this flock. The leading crane never left its position as lead and never ‘coasted’ in flight, aka never altering or ceasing wing-flap flight. I was impressed, but also suspected it was very energy consumptive. Additionally, the five cranes forming the truncated arm behind the leader never changed positions and also never faltered in consistent wing activity.

The cranes following in line behind the leader, on the other hand, often coasted with short periods of folding wings alongside their bodies. Whether this was to rest (energy conservation) or to retain their position in the long line, I cannot be sure. I did notice that some individuals did change positions when some birds slowed or fell slightly out of line. Consequently, the line was truly maintained as one long linear fight pattern! I also wondered how many of these birds were immature cranes who aren’t yet as strong as the older adults, or if they haven’t yet mastered the ‘protocol’ of flying in large flocks. I watched one crane fly under and ahead of five other cranes in front of its former position and fill in a gap in the line. It reminded me of how blackbirds and other flock songbirds change positions while roosting on utility lines, with some hop-scotching to keep a tight and consistent line formation.

I was fascinated by the flock and flying dynamics of these several hundred sandhill cranes! Very different from the geese. Although my original intent was just to monitor where this flock landed, I was treated to an entirely different perspective of flock flying dynamics.

Because questions of daily roosting versus feeding movements and populations of sandhill cranes arose during a meeting between state and federal managers this week, I thought watching where this flock was destined might be interesting. Only a small percentage of the total flock (~24) landed on the small ‘crane ponds’ (small shallow water impoundments just north of the main refuge where cranes often roost). I expected a higher sub-set of this flock to land there. I briefly watched these birds try to locate the members of their family units for roosting overnight, then I drove ahead to monitor the remainder of the flock.

As the larger sub-set of birds approached the center of the refuge where two large impoundments are shallowly flooded for roosting and feeding, the linearity of the flock dissolved as smaller flocks formed and dispersed. Approximately 50% of the flock settled on these impoundments, and the other 50% flew east to roost on the sandbars of the Rio Grande River.

New Mexico state biologists survey populations of waterfowl on the river via aerial surveillance once a month. This refuge conducts feeding surveys every week. We are discussing now whether to incorporate ground roosting surveys for geese and cranes once or twice/month to add to the total data on use of the resources and land in the mid-Rio Grande Valley, especially since most of the cranes now present here are flying north to feed during the day at state-managed refuges (~38 and ~60 miles north of here).

Estimating the light geese roosting population would be easier than that of the cranes because the former typically take flight in one large massive flock. Cranes, on the other hand, usually depart from their overnight roosting places in small family units of 2-4. However, cranes congregate in overnight roosting  flocks at only a few locations on the refuge. Counters posted at each of these locations can easily count the family units and obtain total numbers as they take flight. It might take longer, but it might also be more enjoyable.

dsc09839

Feeding sandhill cranes at Bosque del Apache NWR

Climate and species are a-changin’

8 Oct

This summer was a perfect example of environmental changes. In the northern states, some waterfowl species never migrated south last fall, and this spring’s surveys revealed that some birds migrated north earlier than normal. Conversely, milkweed (Asclepias spp.) emerged one to two weeks early and migrating monarch butterflies arrived two to three weeks late in all the northeastern states. Areas in a few northeastern states were stricken with a historic “100-year or more drought.” On the other hand, many areas in the semi-arid southwest experienced historical devastating floods.

Is this a fluke? Or is this the new norm? Perhaps somewhere in the middle, but more likely these weather and climatic changes are the ‘new normal.’  The events and data support that assessment.*

How do living organisms respond?

Published studies by biologists have been documenting the impact of climate change on the environment, especially species that are adapting and not adapting. We can learn about impacts on organisms  by examining changes in cyclic and seasonal natural phenomena of plants and animals in relation to climate. These seasonal changes and cycles are known as phenology. Noting the times of year that specific plants bloom, or when birds migrate are two examples. Comparing the phenology of many species over a period of time can reveal informative clues on how changes in climate may affect them. Many studies along this model of investigation demonstrate that the living environment is indeed impacted.

United Kingdom researcher Stephen Thackeray(1) and his colleagues analyzed the phenology of a wide range of species. They used 10,003 phenological data sets to determine if and how much species’ phenology have changed over a minimum of 20 years. The analysis revealed that phenology has shifted in unequal rates in different species groups. Thus, climate change leads to disruptions of the phenological match between species, which often impacts ecological relationships.

Another question the researchers asked was how sensitive events in their life cycles are to the two most common variables in climatic change: temperature and precipitation. Both variables have changed in an uneven process over the flow of seasons. How does this impact species relationships? Some periods of the year have warmed faster than others, which may affect two interrelated species with equal temperature sensitivities but at different times. This could shift their phenological events at different rates and cause a mismatch in their relationship.

For example, milkweed plants emerging and flowering much earlier than normal resulted in sub-optimal conditions for the late-arriving monarch butterflies to use the plants for breeding. Additionally, the persistent hot and humid weather in the northeast could impact monarch larva (caterpillar) by either accelerating or arresting development.

trophic-pyramid

Trophic levels

The study authors also discovered a difference of sensitivity to temperature variations at different positions of the food chain (referred to as trophic levels). Species at different levels did not differ in the time of year at which they were sensitive to annual variations in temperature. But they did vary in how sensitive they were.

 

Species in higher levels of the food chain (the secondary consumers) are less sensitive to temperature changes than species at the bottom (the producers and primary consumers). These species are twice as sensitive to temperature changes than upper level species. Secondary consumers are also less sensitive to precipitation variations.

The authors then combined the species sensitivities with a future climate scenarios. They forecast that primary consumers -birds, insects, small mammals, etc- will shift the timing of their phenological events by twice as much as will species at other levels of the food chain. One reason their response varies is because species at different tropic levels respond differently to exactly the same temperature cue. Species respond differently to temperature during various times of the year.

The above example of the milkweed and monarch butterfly mismatch could impact the breeding success and thus population numbers of the butterflies. Both species have different physiological mechanisms that determine their phenological events and use different cues to determine their timing. Although these cues will be correlated to some extent, the cue used by the consumer -in this example, the monarch butterfly- is less reliable than that of the the plant they rely on. This cue unreliability in the consumers may mean that they will evolve with less temperature sensitive phenology than those species at the trophic level they rely on.

Ecologist Marcel Visser (at Netherlands Institute of Ecology) calls attention to moving from conventional two-species interaction research to a more holistic approach: investigating the effects of climatic change on the entire food-web. In a review(2) of the Thackeray, et al. study, Visser additionally proposes that impacts by phenological mismatches could be buffered by other mechanisms in their ecosystems.

To help us understand the consequences of phenological mismatches and thereby form predictions, he proposes questions that should be considered in studying changes in climate changes and relationships:

How are the strengths of the links in a food web affected by phenological mismatches? What happens if the phenology of species at one trophic level shifts more than that of species at another? Does this lead to the loss of some links and the formation of others? Does this destabilize the web? Such analyses would be a stepping stone from studying the phenological shifts of species to understanding the effects of
climate change on ecosystem function.(2)

dscn2300-m

Stink bug preys on larva.

An example for a holistic ecosystem approach is field observations (my own and in the literature) that have suggested that as prolonged temperatures increase, depredation and parasitism of monarch larvae and adults increase. Is this a function of differences in phenology of  monarchs and its predators, or changes in all vegetation and species interactions (a complex of one or more phenological overlapping and mismatches)  in the habitat? Do temperature mismatches in other members of the monarch habitat increase risk or rates of depredation?

One research team suggested that migration of monarch butterflies may have evolved as an adaptation to decrease depredation and parasitism in their breeding habitats. If monarch adults were to delay or ignore cues to migrate because of changing climate, how would that impact their overall population?

Adding to the complexity, climate sensitivity in species is not fixed. Phenological mismatches can lead to selection on the timing of phenological events. Resilience to environmental challenges can alter phenology, but over time can also result in genetic changes to sensitivity, thereby fixing phenological changes. Conventional theory on temperature range sensitivity of monarch adults and larvae states that it quite narrow. However, some observations(3) of their coping mechanisms with prolonged high temperatures in the Pacific Northwest sub-population questions if this sensitivity range is more flexible than conventional thought, or if this could be a developing adaptation.

Some researchers are already investigating genetic changes accompanying phenological adaptations to climate change (e.g. genetic alterations in melanin associated with plumage and physiology in European owls that have adapted to changing ecosystems). Such complex studies must be conducted to forecast the impacts of climate change and phenological responses and ecosystem function.

Research by Thackeray, Visser, and other colleagues demonstrates that long-time series of data are essential for such investigations. They also applaud and encourage professional and citizen scientists to continue collecting and submitting observations to add to the data pool. As Visser commented, “The additional advantage is that observing phenological shifts in, sometimes literally, your own backyard drives the message of global climate change home.”


(1) Thackeray, SJ, et al. “Phenological sensitivity to climate across taxa and trophic levels”. Nature 535, 241–245 (14 July 2016)
(2) Visser, ME. “Interactions of climate change and species”. Nature 535, 236–237 (14 July 2016)
(3) Anecdotal observations by Dr. David James, Washington State University entomologist, in central Washington and myself at Malheur National Wildlife Refuge, eastern Oregon.

* The main difference between weather and climate is time. Weather is the atmospheric local events over a short period of time.  Climate is an average of the weather over much longer time in a region or globally. Sure, we can agree that weather and climate is cyclic, with highs and lows historically up and down. Also, a few episodic variances from the average can be expected.  But climate does not vary as greatly as weather. The trends clearly demonstrate that climate is changing. Modern paleoclimate technologies can now add to the 70-year human records of climatic changes, both which confirm that climate change is a reality. Those changes have accelerated, more than any other equal span of time in historical evidence.

Wings of mimicry

17 Sep

dscn1812-m

The early rising sun greeted us with a visitor in the damp grass one morning of a camping trip near New York’s Thousand Islands. As sunlight glistened on the blanketing dew, this large winged visitor rested on the grass waiting for moisture to evaporate off its wings and the sun to warm its body. It reminded me of another large moth, the luna moth (Actia luna), that I knew well during my life in the Maine woods.

The moth found on the wet grass that morning was a polyphemus moth (Antheraea polyphemus). Both moths are of the Giant Silkmoth family (Saturniidae). With a wingspan of up to six inches or more, the polyphemus moth is about the same size as a luna moth. These two species are the largest moths in continental America and may be found from Canada to northern Mexico.

dscn1816-s

Male polyphemus moth (antenna are larger than female’s)

Polyphemus moths are generalists, which means they do not require a specific species of plant for the larvae to develop and survive. Females lay flat brown eggs on many species of decidous trees: elm, birch, willow, maple, beech, locust and a variety of Prunus species (cherry, plum, peach, etc). Like many Lepidoptera, polyphemus larvae develop through five stages and molts (instar). Unlike monarch butterflies, of which the instars are very similar in coloration, these moths have slightly different coloration with each instar. The fifth and final instar is an average of four inches long and a bright green color with silver spots on its sides. A caterpillar can devour about 86,000 times its weight from emergence to full development in two months.

From the photos of the adult moth below one can see hair-like body scales, small head and mouth parts, and the eye spots on the wings. Because of their small mouth parts, adults do not eat and only live for a week or less, during which their entire purpose is to avoid depredation and reproduce.

Mimicry

Mimicry throughout the animal kingdom is an example of natural selection in evolution. Ranging from mammals to tiny insects, mimicry may increase survival of individuals in their environment. Or it may reduce survival in another environment.

Lepidoptera are fascinating examples of how mimicry enables survival. One tactic is to mimic another insect that may be undesirable prey. Another tactic is the patterns and structures on butterfly and moth wings that mimic a component of their environment to hide from depredation. These tactics may be adaptive defense mechanisms (or artifacts of other patterns of coloration) in response to threats. Our polyphemus moth will serve as an example of mimicry as a defense mechanism.

Distraction Pattern

Like many saturniids the polyphemus moth has large ‘eye spots’ on its hind wings. These wing eye spots are translucent ‘windows’ which may be surrounded by bright colors. The pair of eye spots on the polyphemus hind wing are bordered by bright colors and, with the entire wing pattern, may resemble eyes of a predator. These are distraction patterns, which is a form of mimicry. They may resemble eyes of a different animal and confuse or deceive potential predators.

Wing eye spots can be a form of self-mimicry and a distraction pattern: to draw a predator’s attention away from the most vulnerable body parts or to appear as an inedible or dangerous animal. When threatened, adult polyphemus moths flash their  wings exposing the large hind wing eye spots to distract, startle, or scare off potential predators.

dscn1814-m

The centers of the eye spots lack scales, so they are transparent.

Another example of distraction pattern in mimicry is camouflage which helps avoid detection by predators. Eye spots and wing color patterns on adult polyphemus can serve as blending camouflage (color matching) and pattern camouflage (pattern matching) in their environment.

Unrelated to mimicry, these eye spots may also play a role in mate attraction, but this has not been conclusively confirmed.

dscn1811-sMimicry is also exhibited by the polyphemus caterpillars. They can be protected from predators by their cryptic green coloration (another example of what kind of distraction pattern?). When threatened the caterpillars often raise the front part of the body up in a threatening pose. If attacked, the caterpillars make a clicking noise with the mandibles.  This clicking is associated with a distasteful fluid exuded by the caterpillars which can cause regurgitation by the attacker. Some animals (squirrels, birds, other insects) are deterred by the ingestion and regurgitation and the clicking may serve as a warning.

Mimicry and names

Since one of my interests is the etymology of animal binomial names (simply put, the naming of things), mimicry also plays a part in this moth’s name.

The four silkmoth species in the New World (the Americas) were assigned to either Telea or Metosamia genus. The polyphemus silkmoth in the Americas was first described and named by Dutch naturalist Pieter Cramer in 1776 as Telea polyphemus. Jacob Hübner, a German entomologist (1761-1826), assigned the Old World (endemic to Asia and Europe) silkmoths to the genus Antheraea in 1819.  In 1952, American entomologist Charles Duncan Michener (1918-2015) systematically categorized the Telea and Metosamia in with Antheraea classification. All the silkmoths are now in one genus classification.

The Modern Latin genus name Antheraea likely derives from the Greek anthēros, meaning brightly colored, brilliant, or flowery.  The Lepidoptera Antheraea type species (the species on which the description of a genus is based on, and with which the genus name remains associated during any taxonomic revision) is the beautiful and vibrantly-colored tasar silkworm (Antheraea mylitta, formerly Phalaena mylitta), named and characterized in 1773 by English entomologist Dru Drury. Although not a silkworm like the tasar species, the polyphemus is colorful and has similar eye spots.

Cramer’s choice of the species name was based on Polyphemus, the giant cyclops from Greek mythology who had a single large, round eye in the middle of his forehead. Cramer may have been reminded of the name because of the large eye spots in the middle of the hind wings.

And the commonly used name ‘sphinx’ moth?  It could have arisen because of the behavior of threatened larvae. When they raise their heads and thoraxes up, the pose superficially resembles Egyptian sphinxes. Someone had imagination.

Of course, the family name Saturniidae  also peaked my curiosity.  The consensus is that it was based on the eye spots of some members of the family that contain concentric rings reminiscent of the planet Saturn. I’ll take that, too.

 

Nature in Photography

6 Feb

A week or so ago on FaceBook I was nominated by two friends to participate in the #challengeonnaturephotography meme. Although I rarely participate in these memes, the thought “Why not?” prompted me to give it a try. The protocol is to post a nature-themed photograph, include the hashtag, give kudos to the friend that nominated you, and then nominate another friend in the caption.

I played by the rules for three days. Then life got in the way (long days in the field), and I got lazy. I posted when I had time, dropped the official hashtag, the nominators, and ran out of FB friends to nominate. I keep my FB friends to a relatively small number (up to 50 now!), and friends who are into photography have already participated once or twice.

Now I submit a story with the photograph instead. Why? Because photography to me is a storytelling medium. Today’s photograph is a glimpse into the secret lives on the ‘little people’.

Nearly every day for three months last summer, I was privy to an entire world few of us see in depth and detail. I felt like a giant studying, learning, and enjoying a network of soil, water, plants, and insects……….at their level. Sometimes I was so giddy with childlike delight, I forgot who and what I was. And I was full of anger and intense sadness when part of this magical world was destroyed by humans. That, too, was a lesson I won’t forget.

Revealed below is a monarch butterfly larva and several cobalt blue beetles all ‘doing their thing’. They use milkweed as a common food source. Yet they tolerate each other. I have watched members of both species consume leaf material, side by side without conflict. Here, two beetles are copulating, undisturbed and unfettered. While the monarch voraciously chows down, preparing to form its chrysalis. This, however, is only one tiny window into the lives that live in the ecosystem in which I immersed myself.

Most nature photography depicts landscapes of empty agents and actors. Or portraits of animals, still and silent in pose like a person sitting for a photograph. To me this is an injustice to the inhabitants of the landscape as they live out their drama and narratives in those spaces. Few ‘nature’ photographs reveal the complex interrelationships within the landscapes and with their fellow animals. They fail to show the communities of life in places other than within our own human preconceptions and expectations. As if we strive to capture and show only a snapshot in time and space that suits what we want to see.

In addition to the beauty, the silence and solace depicted in landscape and wildlife portrait photography is a dynamic world of creatures living their lives just like we do. The drama, the beauty, the good and bad, birth and death, at every level; from micro to macro. There are stories out there that are not of our own.

And we can learn from them: About their lives, their interactions with each other and how we interact with them. We can even learn about ourselves.

Think about that the next time you are out in the natural world. Take time to observe before you press on that shutter release button. You never know what you might find.

image

Fifth instar monarch larva and cobalt blue beetles on showy milkweed.

Eyes in the Forests

12 Aug

  
If you look at the bark of an aspen tree, you will see wrinkles in time and eyes watching you.

%d bloggers like this: