Killer Whales (Orcinus orca) evoke fearsome images in the minds of most people.  As apex predators, they have spread to most marine environments.  Further, separate killer whale populations have developed preferred local diets.  While these different populations may have some overlapping territory, they don’t mingle and they don’t inter-breed. 

Here is a brief summary of the primary killer whale populations.  They fall into three categories based on their social structure.  

      • Whales in the Resident group include males and females that tend to stay within their birth group.   They have a tight social structure.  They prefer to eat fish and squid.
      • Whales in the Transient or Bigg’s group roam along the coast.  They do not maintain a strong tie to their birth group.  They hunt marine mammals. 
      • Offshore whales are found out in deep water.  They feast on schooling fish.

Recently, studies in killer whales revealed that the females of this dominant species experience menopause.  Did you know that only humans and a few whale species go through this (difficult and uncomfortable, IMHO) phase of life?  

When menopause was discovered in the Resident group, the research team hypothesized that the social closeness of the Resident group triggered the end of reproduction in older females.  Perhaps it would not occur in the Bigg’s group.  However, despite the loose social structure, menopause happened.  So, it’s back to the drawing board.  No one knows for sure why menopause is a physical reality.  

To read more about this, check out this link:  https://onlinelibrary.wiley.com/doi/10.1002/ece3.7756

Orcas Image by djmboxsterman from Pixabay

Also reported in the news is the discovery of a new species of lizard found in central Peru.  Announced on the Pensoft blog, this is a new species of wood lizard and the male’s appearance is striking.   

Pictures can be seen here:  http://blog.pensoft.net/2021/09/01/new-beautiful-dragon-like-species-of-lizard-discovered-in-the-tropical-andes/

The researchers involved in this discovery needed to conduct their field study at night over seven years to formally describe their prized species.   That’s dedication!  Congratulations to all.

Summer months usually portend a dip in research paper publications.  Despite a reduction in volume, there doesn’t seem to be a lack of intriguing findings.  Here is a sample from the recent announcements.

Spectacled Bear
Spectacled Bear Image by Jake Heckey from Pixabay

News from Peru about the Spectacled Bear (Tremarctos ornatus) appears to be promising.  A team of researchers from Gothenburg University in Sweden, Martin Luther University Halle-Wittenberg in Germany, and Stony Brook University studied the population of this endangered species.  Using facial recognition tools, they determined that the population of these incredibly shy bears may be larger than originally estimated.  Good news, indeed.

The report then introduced a second surprise.  While conducting their fieldwork, some of the team spotted the first “golden” bear.  This bear’s fur was blonde, in contrast to the typically black fur of the spectacled bear.  The golden bear has been dubbed Paddington Bear, based on its resemblance to the children’s book character.  

You can see a picture of the golden bear here:  https://pressemitteilungen.pr.uni-halle.de/index.php?modus=pmanzeige&pm_id=5278

To learn more about the spectacled bear population research, check out this paper: https://bioone.org/journals/ursus/volume-2021/issue-32e12/URSUS-D-20-00005.3/An-Andean-bear-population-hotspot-in-Northern-Peru/10.2192/URSUS-D-20-00005.3.short

Remember seeing (or having) an ant farm when you were young?  Those ants tunneled into the medium to create and connect their chambers.  

Scientists from four international universities have taken their fascination with ant farms to a whole new level.  The team wanted to understand how the ants knew where to dig and what areas to leave alone.  The researchers compared the ants’ method to playing the game Jenga.   

Ants
Ants Image © Carmen Craig | Dreamstime.com

If you haven’t played, the idea is to remove a block from a precarious stack of wood without causing the entire structure to fall.  Experienced players know to test various blocks to see if they are loose and therefore not load-bearing before removing them.  

The team hypothesized that the ants were doing something similar with the soil they were choosing to move.  Keep in mind that these ant structures can extend many feet down and you will begin to realize that they are an engineering marvel. 

Researchers discovered some ant-building principles.  First, ants like to build in straight lines.  That makes sense since it is the shortest distance between two points.  Next, they prefer to dig at the steepest angle possible and still maintain the stability of loose material, also known as the angle of repose.   

Finally, the ants’ progress takes advantage of force chains.  Wiki describes force chains as “…a set of particles within a compressed granular material that are held together and jammed into place by a network of mutual compressive forces.”  In other words, the ants have an understanding of the physics of their surroundings and the dynamics of their building material.   

CalTech has a reader-friendly overview here:  https://www.caltech.edu/about/news/the-science-of-underground-kingdoms

If you want to get into the scientific details of this fascinating 3-D modeling, check out the PNAS paper here: https://www.pnas.org/content/118/36/e2102267118

Nature’s complexity must be infinite.  It’s certainly unpredictable. I am in awe of the nature lessons I learn every week.   

This time, let’s explore some of the latest information about animal cooperation behaviors that were once thought to only be the purview of humans.  Here are a couple of examples.

Giraffe Family
Giraffe Family Image by Savannah Morgan from Pixabay

Most folks are aware of the family, community relationships, and cooperative behaviors of elephants.  You may also recognize similar behaviors among some species of whales.  Now, researchers have discovered that giraffes (Giraffa camelopardalis), once thought to experience only casual relationships, actually have strong family-centric behaviors.  Most interesting is the role of the post-reproductive females, also known as the post-menopausal non-mothers. The unexpected finding revealed that these older giraffes are essential to help raise the young that are born within their matrilineal line.   

This behavior doesn’t surprise me. However, it seems to be big news in the scientific community.  I’ll bet if research teams did closer observations of deer behavior, similar family and helper dynamics would be identified.  I’m sure I’ve witnessed this intergenerational support among those deer that share our land. 

To learn more about giraffe social behavior — https://onlinelibrary.wiley.com/doi/10.1111/mam.12268

 

When you think about bees, do you picture a busy hive, active with hundreds of buzzing worker bees?  I do.  I was surprised to learn that social bees such as honeybees (Apis spp.) or bumblebees (Bombus spp.) make up less than 10 percent of all bee species worldwide.  The remaining 90 percent are comprised of solitary bees.  

Female solitary bees prepare their nests in cracks and crevices, often in the ground.  I’ve seen these nests. You probably have as well. Although, I didn’t realize that this was the behavior of most bee species.  

Sweat Bee
Sweat Bee/Solitary Bee Image by Gwen M from Pixabay

Seemingly in contradiction to their single lifestyle, some solitary species do aggregate their living quarters.  As an analogy, these bees have a studio in an apartment complex.  Compare that to the commune living of honeybees and bumblebees.

Just because they are solitary bees doesn’t mean that they can’t help each other.  Like the giraffes, females of certain solitary bee species will cooperate in nest building and offspring-rearing.  Apparently, bees can have strong communities and still respect individuality.  

There is so much to learn.

A comprehensive resource about Solitary Bees is Bryan N. Danforth’s book, The Solitary Bees: Biology, Evolution, Conservation.

We all know that mature forests are essential for many species to thrive, and even for some to survive.   Recently, however, a team from the University of Connecticut explored the impact on bats of young forests that emerge from areas that had been logged.  

Taking a cue from similar research previously conducted with birds, the team wanted to learn if there was a similar response in bats.   In birds, once they have fledged from the nest and before migrating, they tend to seek canopy gaps.  These gaps allow more sunlight which stimulates additional vegetative growth and attracts more insects.  The birds then have a greater food supply and consequently grow more quickly. 

Little Brown Bat
Image by Bernell MacDonald from Pixabay

Bats do have a related response to opportunities presented by these canopy gaps. The team discovered that within 24 hours of the logging, bats increase their activities in the young forest.  As the vegetation continues to grow in height, the bats decrease their foraging.  

This initially struck me as counterintuitive but now I understand the logic.   Both old growth and new growth play a vital role in the lives of different species.  We need them all. 

To read the original press release, check it out here:  https://today.uconn.edu/2021/07/young-forests-are-preferred-summer-vacation-destinations-for-bats/#

I may be the last person to learn these things, but just in case I’m not, I thought I would share them with you.

  • Did you know that some jellyfish species are found in freshwater?  I always thought that they were strictly saltwater creatures.  These freshwater types are known as medusas (Craspedacusta sowerbyi).  They seem to appear sporadically in blooms so they aren’t always there to observe.  

Some scientists speculate that they are airlifted from their point of origin which is believe to be the Yantzee River and “deposited” by birds in lakes and streams.  However, no one has ever seen a jellyfish attached to a duck, for example.  You may think that this is a geographically isolated phenomenon but these jellyfish have been found in locations as distant as Australia, Chile, and in my home state of Maine. 

Medusa Freshwater Jelly
Image by Rostislav Stefanek at Dreamstime.com
  • Because I never thought about it, I assumed that humans were the longest living mammals on the planet.  That is incorrect.  Bowhead whales (Balaena mysticetus) live to an average age of 200 years if we don’t kill them first.  That’s still a brief lifespan compared to the Greenland shark (Somniosus microcephalus) which lives for 300 to 500 years.  This is the longest living vertebrate animal, beating out the Galapagos Giant Tortoise (Chelonoidis niger complex) and Orange Roughy (Hoplostethus atlanticus), both of which live for up to 250 years.

    Greenland Shark
    Image by Planetfelicity at Dreamstime.com
  • And while we are exploring some aquatic novelties, there is an 18-foot shark called the Megamouth Shark (Megachasma pelagios) that has been spotted only about 100 times, ever.  Despite its enormous mouth, this shark has tiny teeth.  It is a filter-feeder, eating only plankton and jellyfish.  

Consequently, stories that the shark was discovered when it swallowed a US Navy ship anchor in 1976, may be an exaggeration.  More likely, the shark became entangled in the anchor’s cabling. 

Another unique feature of this deepwater shark is its silvery-white upper lip. At one time, scientists wondered if it was bioluminescent in order to lure its prey.  Research conducted in 2020 uncovered that it was merely highly reflective.  This is an interesting adaptation, nonetheless.

Sources:

More about freshwater jellyfish — https://esajournals.onlinelibrary.wiley.com/doi/10.1002/fee.2343

More about freshwater jellyfish in Maine — https://www.maine.gov/dep/water/lakes/jelly.html

More about the age of various animals — https://safarisafricana.com/animals-that-live-longest/

For more information about the Megamouth — watch NatGeo’s World’s Weirdest, Season 5 Episode 3

Study about the bioluminescence study of megamouth —https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0242196

Have you ever wondered if you are creating a dependency by putting out birdseed?  I have. Well, worry no more. There’s good news.

Researchers at Oregon State University studied the winter feeding behavior of black-

Black-capped chickadee
Image by GeorgeB2 from Pixabay

capped chickadees (Poecile atricapillus).   Chickadees were chosen because they are small but they are frequent feeders.  This is because they have high daily energy requirements.  

To conduct the study, the team used a group of birds whose feathers had been clipped. These were the experimental group while non-clipped birds became a control group.  Then the birds were fitted with radio frequency identification (RFID) tags for tracking purposes.  

Feeders were offered to all the birds. Foraging in a natural environment was also an option. Then feeders were removed but foraging remained available.  Both groups did well.  There were sufficient environmental sources like seeds, berries, and small invertebrates even for the clipped birds.  The clipped birds were not reliant upon the supplemental food.  

It appears that feeders were just another dining option!

To read more about the study, here is the press release:  https://today.oregonstate.edu/news/don’t-worry-birds-won’t-become-dependent-you-feeding-them-osu-study-suggests

And here is the published study:  https://onlinelibrary.wiley.com/doi/epdf/10.1111/jav.02782

@ForAnimEcolLab

 

In other news, a team of researchers in Wisconsin quantified the reduction of deer–vehicle collisions (DVCs) as a result of restoring the local wolf population.  In Wisconsin, where the study occurred, the wolves’ presence reduced DVCs by an incredible 24%.  Interestingly, the reduction is mostly due to the deers’ behavioral change in response to wolves rather than through a deer population decline from wolf predation. 

This should give wolf detractors something to think about…the upside may be worth the risks.

To read more about their research, check out the PNAS article here:  https://www.pnas.org/content/118/22/e2023251118

 

Finally, there is a report about how an elephants’ personality plays a role in their problem-solving abilities and approaches.  I’m pretty sure I saw one of the participating elephants solving a puzzle on the television show, The Zoo, on Animal Planet.  The research team worked with 15 Asian elephants and three African savanna elephants at the San Diego Zoo, the Smithsonian’s National Zoological Park, and the Oklahoma City Zoo.

Asian Elephant
Image by Marcel Langthim from Pixabay

The elephants solved puzzles in exchange for a treat (a marshmallow, I believe).  They were asked to solve the problem three times.  Most solved them faster at each turn. The elephants also displayed a variety of measurable traits such as level of activity, affection, aggressiveness, defiance, excitability, mischievousness, shyness, and sociability.  Each of these may reflect components of their personality. 

The findings showed that traits such as aggressiveness and activity were important predictors of their overall problem-solving ability.  On the other hand, the personality traits did not predict the elephant’s ability to learn and subsequently solve the problems or do them faster. 

More fun puzzles and more treats will be needed to get to these answers. Now, don’t you think maybe the elephants are playing the researchers?  My dear departed dog would have gone to any length to get another treat.  Just saying. 

You can read more about the study here:  http://www.uwyo.edu/uw/news/2021/06/uw-researchers-elephants-solve-problems-with-personality.html

And you can see a video here, if you haven’t found the episode on Animal Planet.  This one features Chandra, the elephant mastering a water-based problem:  https://youtu.be/Pq882T6KMQ0

@lisapbarrett  @AnimalSmarts    @UWyonews

Noise created by humans often disrupts normal animal or bird behaviors.  Just consider the consequences of human noise pollution. Disrupting ocean life is but one example.  Sadly, the negative outcomes are well documented in whales, dolphins, and other sea creatures.

A team from California Polytechnic State University and Boise State University wanted to understand the role of naturally occurring soundscapes on the behavior of other animals.

This team, led by ecologist Dylan Gomes, tested a hypothesis that natural sounds influence where bats and birds live and forage. Bats and birds were chosen because they are sound-dependent for critical behaviors such as communication, navigation, and hunting.

To test their hypothesis, the team created rushing whitewater sounds where gentle

Stream in Pioneer Mountains
Photo by Robert Crum on Dreamtimes

streams typically flow. They chose 60 study sites within the remote Pioneer Mountains of Idaho and set up the equipment.  Then they generated the noise, varying loudness and audio frequency.  

The results showed that both volume and pitch (frequency) impacted the bats’ and birds’ ability to go about their duties.  Pitch is important because it may mask or overlap with birdsong, as an example.  Consequently, subsequent increases in either decibel (for volume) or kilohertz (for pitch) caused both species to decrease their foraging behavior.  Some bats and birds even move away from the study sites.  The violent rushing river sounds appear to have been too distracting to continue life as usual.

Birds that stayed in the area were less efficient foragers. They harvested fewer insects.  In comparison, some bats were a bit more adaptable and made adjustments. They shifted from listening for their prey to using echolocation.  Despite this shift in behavior, foraging success still suffered.

More studies are warranted but if these species are this sensitive to natural sounds perhaps we have underestimated the impact of our noise-generating activities. 

For another example of naturally occurring noise impacts on a species, check out this earlier post about the waterfalls and the frogs.  https://comfortmewithnature.com/nature-in-the-news-unexpected-nature/

Sources:

Article at Cal Poly site – https://calpolynews.calpoly.edu/news_releases/2021/May/birdsbats

 Research paper about this research – https://www.nature.com/articles/s41467-021-22390-y

 

@CalPoly   @BoiseState  

Each year we have the privilege of sharing our yard with the resident groundhog (Marmota monax), which is also known as a woodchuck.  From previous years, I thought I knew a lot about this rodent’s daily activities. Then I saw it do something different which prompted me to explore its behavior. 

My earlier observations suggested that she was an herbivore.  She grazes frantically through our flower garden.  However today I’m somewhat certain that she was eating insects.  She wasn’t chowing down on greens but she was nibbling on the sides of the leaves.  It looks like she’s capturing insects.  She also dug down into the dirt, perhaps seeking grubs. 

Are groundhogs carnivores?  What else is unexpected about these critters?

Here’s what I found out:

  • First, they are a member of the squirrel species.
  • They stand up not necessarily to warm themselves in the sun but to survey the surrounding lands.
  • Groundhogs occupy the same territory each year.  Males’ territories are about 3x the size of females.  
  • Their two upper incisor teeth grow about 1/16 of an inch each week.  
  • They greet each other with a version of an Eskimo kiss, that is, nose to nose. 
  • Gestation occurs in just 32 days followed by a birth in April to mid-May. Then, there is a six-week weaning period before we get to see a litter of four to six kits.  Even though they can be disruptive, I can’t wait to see the kits!
  • In the fall, the young ones move off to tear up someone else’s garden find their own territories.
  • A groundhog’s average life span is between three and six years.  

Given how long we’ve had a groundhog living under the hedges, ours perhaps exceeded the average life span.  Otherwise, this is an example of a burrow system that has sheltered several generations. 

We are one, big happy, multi-species family!

Sources:

Some facts – https://blogs.scientificamerican.com/thoughtful-animal/7-things-you-didnt-know-about-groundhogs/

Still more – https://www.esf.edu/aec/adks/mammals/woodchuck.htm

Bears are without a doubt the dominant predators of their ecosystem.  Other carnivores such as coyotes and bobcats frequently share those locations.  Gray foxes are on that list too but further down the pecking order.  There is a lot of competition around. 

Recently, a group of University of New Hampshire researchers lead by Dr. Remington Moll published a study taking a deeper look at the hierarchy of these carnivores.   What they found was that gray foxes, which are the smallest of this group, stayed close to areas where there were black bears.  Consequently, coyotes stayed away.   However, when winter rolled in and the bears were hibernating, the coyotes were three times more likely to move into that territory.  The gray foxes in response vacated the area.  As a result, the researchers dubbed the seasonal protective presence of black bears as the “bear shield” benefiting the foxes.

Researchers conclude that mortal fear drove the behaviors of both the prey and the predators. Coyotes gave wide berth to the bears.  Foxes gave wide berth to everyone.  When the bears weren’t around, coyotes become top dogs, so to speak.   

These behaviors are believed to be instinctual.  Even though this study was done near Lake Tahoe where black bears were nearly extinct a few decades ago, it is likely to be the common response in any area where black bears, gray foxes, and coyotes co-exist.

To read more about this study, check out this link:  https://www.unh.edu/unhtoday/news/release/2021/06/03/unh-research-black-bears-may-play-important-role-protecting-gray-fox

 

And while we are talking about research from the University of New Hampshire (which happens to be my alma mater)…

Another team of researchers, also under the direction of Dr. Moll, discovered the longest recorded distance roamed by an adult male white-tailed deer. He covered close to 200 miles, in just over three weeks.  He crossed a major river seven times, a railroad, an interstate highway, and eight state highways.

The distance was remarkable, but there were other notable features about this trek.  First, this was an adult buck.  Juvenile males do wander for breeding purposes but adult males tend to have an established range.   The buck also traveled quickly and at night, both of which are unusual.  Deer frequently shelter in the forest overnight. 

This did occur during hunting season, but there is no apparent correlation to a pursuit. 

Maybe this buck, who originated in Missouri, just wanted to see the rest of the state?

You can read the original press release here:  https://www.unh.edu/unhtoday/news/release/2021/06/08/buck-stops-where-unh-research-records-longest-ever-deer-distance

@UofNH  @UNHNews

Following animal trails can be an excellent way to learn about wildlife.    Today’s stories may further expand your thinking about the value of these trails. 

Did you know that sponges are aquatic animals, not plants?  They are defined as primitive because they have few specialized cells andSponges they don’t have any organs.  Their porous bodies are made from collagen.  Water and nutrients circulate through them, so until now, people assumed that they do not move.  That assumption is wrong. 

A team from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research discovered sponge trails on the seafloor in a deep section of an Arctic sea.   The sponges are actively moving, albeit extremely slowly.  These trails are not the result of currents pushing the sponges around because there aren’t any at the depth of this finding.

Using a towed underwater camera dropped from an icebreaker, the team captured images.  These were then used to create 3D models of the sea bottom.  Surprisingly, 69% of the images had trails, many of which led to living sponges.  

The discovery prompts many additional questions.  Why do they move?  How do they move?  These are among the most basic details yet critical to determine what is going on.  Hopefully, more will be known soon.

The paper was published in Current Biology on April 21, 2021.  Go here for the summary or to access the full paper:  https://www.cell.com/current-biology/fulltext/S0960-9822(21)00353-5?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982221003535%3Fshowall%3Dtrue

If there are multiple paths to get from point A to point B, how do you choose which one you will take?  Time constraints, your intentions once you arrive at point B, and even your energy level can influence your decisions.  Your cognitive abilities allow you to parse through the various options.  

Now, a study of the path choices of 164 wild primate groups in 36 countries is providing new insight into the primates’ evolutionary cognitive development.  Decision-making processes in the wild are likely to be different than those conducted in a designed experimental scenario.  New insights surely will emerge.

The foci of the studies included travel path decisions for food acquisition, avoidance of predators, and locating shelter, as examples.   Cognitive functions tested include spatial reasoning, short-term memory, and learning. While the report did not provide results or conclusions based on the data, the research design and data were interesting on their own.

One of the major benefits of this data collection is the willingness of the team to share the data with other researchers who are interested to use it for additional studies.  Though not specifically stated, I wonder if the data may also be useful information to help support and establish more connected corridors for wildlife so that they may be able to travel more safely and further ensure their survival.

You can read the full study here at :  https://www.cell.com/iscience/fulltext/S2589-0042(21)00311-4?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2589004221003114%3Fshowall%3Dtrue