Feeds:
Posts
Comments

Archive for the ‘Science’ Category

A few years ago, I wrote a post called Lizards, Ticks, and Lyme. It explained how Western Fence Lizards (Sceloporus occidentalis) have a blood protein that kills the bacteria that causes Lyme Disease, and this is one of the major explanations of why Lyme Disease is so much less common in the Western USA.

Well, new research (see references at the end) has added a really intriguing facet to the Tick-Lizard-Lyme story. This new research focuses on the southeastern USA. The southeast is another area where Lyme Disease rates are very low. But why? The southeastern USA has populations of Black-legged Ticks (members of the genus: Ixodes), which are the ticks that can carry Lyme Disease. The region has the mammal species such as deer and mice that act as reservoirs for Lyme Disease. People in the southwest get bitten by ticks, just like other parts of the country. So why is Lye Disease so much more common in the northeastern USA than the southeastern?

Well, once again, it looks like we can thank lizards. Skinks are a group of smooth-scaled rather lovely looking lizards and they are one of the preferred hosts for ticks in the southeastern USA. In the northeastern USA mice are the much more common host to ticks. And this sets up a roadblock for Lyme Disease in the southeast because skinks have been shown to be really bad transmitters of Lyme Disease. Mice, on the other hand, have been shown to be very effective transmitters of Lyme Disease.

A Southeastern Five-lined Skink (Photo credit: Animal Spot)

It is not yet known if the stinks blood contains proteins that actually kill the Lyme Disease-causing bacteria, or it there is something else about skinks that reduces transmission rates, but this difference in host does help to explain why Lyme Disease rates are so much lower in the southeastern USA as compared to the northeastern USA.

So, fence lizards and skinks both contribute to reducing Lyme Disease in the areas where these lizards are found. Pretty fascinating stuff! I am very much looking forward to learning more about this subject as more research is done. Do other lizard species also reduce the occurrences of Lyme Disease? Does skink blood kill the bacteria that causes Lyme Disease? What is the blood protein that the fence lizards produce that kills the bacteria, and can it be synthesized? So many questions!

I hope you follow this story, and are as intrigued by it as I am. I will certainly write more as more is discovered.

Here are some sources for further reading: a Science News article, and an SF Gate article.

Read Full Post »

Have you ever seen a v-shaped flock of geese fly overhead and wondered, why do they do that? In this video I share some information explaining this interesting behavior. I also talk about the other species that also fly in v-shaped flocks, and dispel an oft repeated myth.

If you enjoy the videos I am creating, two ways to stay informed would be to subscribe to the A Birding Naturalist channel and/or become a follower of this blog.

Eurasian Cranes (Grus grus) flying a v-formation (Photo courtesy of Wikipedia)

Read Full Post »

So, 2020 has been quite a year. Dominated by the ongoing COVID-19 pandemic, this year has been a hard one by just about any standard, and COVID-19 was not the only major environmental issue of the year by any means. Here is an article on some of the major environmental news stories of 2020. These stories highlight some major challenges and disasters that took place in 2020, but also some of the tremendous accomplishments that have occurred this year, not the least of which was the inspiring work done to understand and respond to the same COVID-19 virus. This work resulted in a triumph of medical science with multiple vaccines being developed in record time and beginning to be distributed and administered around the world as I am writing this!

In case you are looking for some reading material, and because I am book lover, here are two lists of some of the top nature/science/environment/conservation books published in 2020. The first is an article from Mongabay.com on 11 interesting books that have been published this year. The second is the top voted books from goodreads.com. These two lists will definitely impact my 2021 TBR (to be read) list.

And 2021 holds huge possibilities! Here is an article on some of the frontiers of science in 2021 that will be the type of research that expands our understanding of the universe, this planet, and the living creatures upon it including ourselves.

Happy New Year! Thank you for being a part of ABirdingNaturalist! Your support and time are tremendously appreciated.

Will 2021 be a good year for the environment? Here are our top 10  predictions - Environmental Defence

Read Full Post »

A few years ago I wrote a post on niche partitioning among herons and egrets. That post was inspired by watching several species of herons and egrets foraging for food along Putah Creek near Davis, CA, and the resource they were partitioning into niches was food.

Recently, as part of my work at the Sacramento-San Joaquin Delta Conservancy, I encountered another example of niche partitioning by herons and egrets. This time, the resource these birds are partitioning into niches is nesting trees.

One of the grants that I manage at the Delta Conservancy is at the Cosumnes River Preserve and it includes and grove of large Valley Oak trees that many herons, egrets, and cormorants use as a rookery (a rookery is a colony of breeding animals, generally birds). One way that the various species have evolved to utilize the same trees, and yet avoid directly competing with each other, is for each species to utilize a different part of each tree to nest in.

Great Blue Herons typically nest on the very tops of the crowns of trees, Great Egrets typically nest only in the upper one-third of the canopy, Snowy Egrets typically nest in the middle one-third of the canopy, and Black-crowned Night-Herons prefer to nest in the lower one-third of the canopy (see the image below).

Niche partitioning of nesting locations within a tree by heron and egret species

I think this stratifying of nesting locations is amazing! Species have evolved to fill so many different niches, and so many niches can be divided into finer and finer gradations. I wonder if there is really any limit to how many species can evolve, and how complex an ecosystem can develop, in a give location.

Read Full Post »

Audubon's Yellow-rumped Warbler 01

An adult male Audubon’s Yellow-rumped Warbler

In my December article for Berkeley Hills Living, Montclair Living, and Piedmont Living magazines, I decided to focus on the Yellow-rumped Warbler and the idea that this one species may be split into several. Take a look!

2019.12 BerkeleyHillsLiving_Final2019

 

Read Full Post »

Phoebes 02

A Black Phoebe

I have been writing a monthly article for a set of three neighbor magazines for the past couple of years now. These magazines are distributed to a handful of east bay neighborhoods. I have shared one or two of the articles in previous posts, and am thinking of doing so more regularly, so here is the article on Phoebes that I wrote for the November issue of Berkeley Hills Living, Monclair Living, and Piedmont Living magazines.

Berkeley Hills Living – November 2019 Issue

Phoebes 01

A Say’s Phoebe

Read Full Post »

Rich Stallcup Bird-a-thon 2019 logoPoint Blue Conservation Science has a blog called Science for a Blue Planet that highlights the great work done by this organization. The blog post reporting on the 2019 Bird-a-thon features the Drake’s Beach Sanderlings!  It is really wonderful to get this kind of acknowledgement, and exciting that the Sanderlings might be the high species total winner this year!

Read Full Post »

Rich Stallcup Bird-a-thon 2019 logo

What a day! What a day! What a day! The Drakes’ Beach Sanderlings participated again in the Rich Stallcup Bird-a-thon on October 5th. The Drake’s Beach Sanderlings, which is Point Blue Conservation Science’s longest running youth bird-a-thon team, was a bird finding machine! Thanks to our amazing donors, our team raised over $2,500 this year! To each of our sponsors, thank you so much for your support!

IMG_20191005_122800

The 2019 Drake’s Beach Sanderlings birding on Drake’s Beach (from left to right: Susie, Max L., Oscar, Max B., Eddie, Connor, Lucas, and Aaron)

As usual, our day began very early. At 5:15am, and in the 39°F chill of the pre-dawn morning, we met at the Bear Valley Visitor Center. The sky was spectacularly clear which made for beautiful star-gazing but did not bode well for finding migrants later in the day. As soon as we got out of our cars, we realized we were surrounded by Great Horned Owls, and after a bit of listening, we added Spotted Owl to our list for the day! A good start!

The team stopped by Olema Marsh which irrupted in a cacophony of Virginia Rails as soon as we clapped for them! We then sped off to Five Brooks Pond where we tried to find more owls while it was still dark. As dawn approached, we were treated to a terrific mixed flock of Bushtits, both species of Kinglet, and lots and lots of Townsends Warblers. We then drove past Bolinas Lagoon and birded Stinson Beach.

Leaving Stinson Beach we broke into the Oreos and headed for the Outer Point! It was still early, and a quick overview of the species list showed that we had already found over 100 species by the time we reached the Outer Point! This put us ahead of schedule on both time and species.

Confirming our concerns from the morning, the clear skies the night before resulted in there being no vagrant birds anywhere on the Outer Point, though there were tons of Red-breasted Nuthatches. It was somewhat frustrating to find no unusual birds at Chimney Rock or Drake’s Beach, but we did not get too attached to birding the area and left to head east. We did stop at an overlook near Chimney Rock to find Black Oystercatchers and got to watch a pod of Humpbacked Whales feeding off the coast.

IMG_20191005_115137.jpg

Drake’s Beach Sanderlings team members Max L., Oscar, Max B., and Connor searching for Black Oystercatchers near Chimney Rock.

The team then started zig-zagging across the east half of the county picking up more bird species all along the way. We certainly had some ups and downs. We made some targeted stops for particular species that mostly worked in our favor. The ponds at the Las Gallinas Water Treatment Plant were the emptiest I have ever seen them, but a quick change of course to the Hamilton Wetlands was gangbusters! As usual, we ended at our customary final stop at an east San Rafael marsh where the Ridgeway’s Rails were calling before we even got out of the car!

Over the course of the day, the team moved incredibly efficiently. When a site was not producing the species we were hoping for, we quickly made decisions to abandon those stops and to go look elsewhere. The knowledge of all the team members came together to produce a cornucopia of species even though we did not find a single species that would be considered noteworthy for Marin County. The list we ended up with included 162 species as a group, and 2 more that were only seen by a single team member and so don’t quite count! The full list is on the next page. We all had an amazing day. We enjoyed every bird, ate a lot of cookies, and shared a lot of stories and knowledge. All the things that make the Sanderlings great!

I want to thank all those who supported this team. The Drake’s Beach Sanderlings is a very special group that I am honored to lead, and passionate to see continue. With the support of our sponsors, we all help promote bird conservation and climate science, and also something more. We help to show the role that young people can play. Bringing in funding in an event like this reminds the world, and the birding community in particular, that dedicated young birders can and do make significant contributions to the cause of protecting our world. I hope that all our sponsors return next year to support us again, and all those who did not sponsor us this year will consider joining the cause next year. I can’t wait!

Read Full Post »

How much is a Kirkland’s Warbler worth?

What is the monetary value of a California Condor?

Once of the significant changes that is being made by the current presidential administration to the US Endangered Species Act (ESA) is to take the economic considerations of a project or a impacted species into account. This will mean that if a particular project could generate a lot of money, it might be able to move ahead even if it destroyed an endangered species. Also, if measures to save a particular species are expensive, they may be ignored in favor of a profitable project.

This is a terrible change.

Protecting a species should be undertaken simply for its own right. If that is expensive, so be it. If it is difficult, so be it. If it is unprofitable, so be it!

Economic considerations have no place in deciding which species to save and whether or not some species to go extinct. Period.

If economic considerations do become part of the endangered species conservation decision making process, we will all have to answer the two questions that I began this post with. Many industries will be working hard to put dollar amounts on species, and to make sure those values are as low as possible.

Here is a short video from Beau and the Fifth Column, a youtube content creator I like, on the subject.

Let’s talk about the Endangered Species Act, Chickens, and Painters….

And here is a link to written testimony by Dr. Jane Goodall to the U.S. House of Representatives on the value and importance of the Endangered Species Act.

Dr. Jane Goodall to the U.S. House of Representatives

One result of adding economic considerations into conservation decisions will be more extent species. And this during an ongoing extinction crisis.

 

 

 

 

Read Full Post »

In 1982, the year I was born, there were only 22 California Condors alive in the world. Those 22 birds were all that remained of a population that once spanned the western US, and bits of Canada and Mexico. The Condor population plummeted as a result of lead poisoning, hunting, habitat loss and pollution.

California Condor 01

Geographic range of the California Condor in the 1880s

By 1987, the world population of California Condors was 27 birds. Since the causes of the California Condor decline were distinctly human activities, it only seemed appropriate for humans to step up and attempt to fix what they had broken. To that end, the 27 birds were captured and taken into a captive breeding program run by the U.S. Fish and Wildlife Service. The goal of that captive breeding program was to first raise Condors and establish multiple captive breeding populations, and then to establish multiple wild populations. It was an ambitious plan.

Over the last 37 years, the program has overcome countless challenges from figuring out how to hatch condor eggs, to how to raise babies that will grow into wild adults, to teaching those young adults to find food. California Condors are not fast breeders. A pair will only lay one egg each year, and they sometimes skip years. The young birds take several years to grow and gain full independence, and will begin to breed after about five years. It has taken extensive amounts of money and time, but success after success have become realities.

California Condor 03

An adult California Condor

A small number of captive breeding populations were established in zoos raptor breeding facilities. In 1992, Condors began to be released into the wild. Additional releases established small populations in California, Arizona, Utah, and Mexico.

Now a new milestone has been reached. In March of this year, the 1000th California Condor chick has hatched since 1987 when the captive breeding population was initiated. This brings the living population to around 500 individuals, since numerous chicks, juveniles, and adults have died in the last 37 years. The 1000th chick hatched in the wild to a pair of Condors living in Zion National Park in Utah.

A population of 500 individuals is still not big enough to be out of danger of extinction, and as such are still protected by the U.S. Endangered Species Act. But it is certainly a wonderful accomplishment, and the 1000th chick born is also a occasion to be celebrated. Hopefully, the California Condor population will continue to grow, and the amazing birds, the largest in North America, with their 9 foot wingspans will be circling 15,000 feet over our heads in greater numbers and across greater areas as the next 37 years unfold.

California Condor 02

 

Read Full Post »

Older Posts »