New list of American bird species

Posted on July 1, 2020 by petrel41

This is a video about a turquoise-browed motmot in Costa Rica.

From the American Ornithological Society Publications Office:

Goodbye northwestern crow, hello Mexican duck

Updates to the official list of North and Central American bird species

June 30, 2020

The latest supplement to the American Ornithological Society’s Checklist of North and Middle American Birds, published in The Auk: Ornithological Advances, includes several major updates to the organization of the continent’s bird species, including the addition of the Mexican Duck and the removal of the Northwestern Crow. The official authority on the names and classification of the region’s birds, the checklist is consulted by birdwatchers and professional scientists alike and has been published since 1886.

The Northwestern Crow has long been considered a close cousin of the more familiar and widespread American Crow, with a range limited to the Pacific Northwest. However, a recent study on the genetics of the two species prompted AOS’s North American Classification Committee to conclude that the two species are actually one and the same. “People have speculated that the Northwestern Crow and the American Crow should be lumped for a long time, so this won’t be a surprise to a lot of people,” says the U.S. Geological Survey’s Terry Chesser, chair of the committee. “Northwestern Crows were originally described based on size, being smaller than the American Crow, and behavior, but over the years the people who’ve looked at specimens or observed birds in the field have mostly come to the conclusion that the differences are inconsistent. Now the genomic data have indicated that this is really variation within a species, rather than two distinct species.”

However, birdwatchers disappointed to lose the Northwestern Crow from their life lists can take solace in the addition of a new species to the official checklist: the Mexican Duck. “The checklist recognized Mexican Duck until 1973, when it was lumped with Mallard,” says Chesser. “But the Mexican Duck is part of a whole complex of Mallard-like species, including Mottled Duck, American Black Duck, and Hawaiian Duck, and all of those are considered distinct species except for, until recently, the Mexican Duck. Now genomic data have been published on the complex and on the Mexican Duck and Mallard in particular, and they show that gene flow between them is limited, which was enough to convince the committee to vote for the split.”

Additional changes introduced in this year’s checklist supplement include a massive reorganization of a group of Central American hummingbirds known as the emeralds — adding nine genera, deleting six others, and transferring seven additional species between already-recognized genera — as well as an update to the criteria for adding introduced, non-native species to the list that raises the bar for introduced species to officially be considered established.

Black-throated blue warbler migration, new research

Posted on February 21, 2020 by petrel41

This 2017 video says about itself:

Black-throated blue Warbler

Although fairly common in northeastern North America (Appalachians) in deciduous and mixed undergrowth it was a challenge to film. The male as shown here singing is clean cut with blue, black, and white. Its black throat, cheeks and sides contrast with the white underparts. It has a blue-gray back and a bold white patch on its dark wings.

The female and Immature is more drab. They have brownish-olive upperparts with buffy underparts. There is a white eyebrow stripe and a small whitish wing patch.

From the American Ornithological Society Publications Office:

Fifty years of data show new changes in bird migration

February 20, 2020

A growing body of research shows that birds’ spring migration has been getting earlier and earlier in recent decades. New research from The Auk: Ornithological Advances on Black-throated Blue Warblers, a common songbird that migrates from Canada and the eastern U.S. to Central America and back every year, uses fifty years of bird-banding data to add another piece to the puzzle, showing that little-studied fall migration patterns have been shifting over time as well.

Loyola Marymount University’s Kristen Covino and her colleagues used data housed at the USGS Bird Banding Laboratory on migrating Black-throated Blue Warblers between 1965 and 2015. Across the United States, researchers working with this program safely capture migrating birds, collect data on them, and fit them with metal leg bands with unique codes that allow them to be identified if they’re captured again. Analyzing almost 150,000 individual records, Covino and her colleagues found that the timing of the birds’ spring migration has advanced over the last fifty years, with early migrants passing through banding sites approximately one day earlier each decade. Crucially, their data also covered fall migration, which has been less well-studied, and found that while the timing of the peak of fall migration hasn’t changed, fall migration takes longer today than it did fifty years ago.

The North American Bird Banding Program is one of the most expansive historical datasets on migratory birds, including records for over 38 million songbirds banded since 1960. “My coauthor Sara Morris and I were already working together on another paper on Blackpoll Warblers using data we’d requested from banding stations across North America. We wanted to take a similar large-scale approach for this study, but we wanted to demonstrate that we could do this approach with data that is completely available from the Bird Banding Lab,” says Covino. “We selected Black-throated Blue Warblers because it’s relatively straightforward to determine their age and sex, which means that the data this species generates are both accurate and powerful.”

Although the researchers emphasize that their findings can’t be explicitly linked to climate change without incorporating climate or environmental data, they believe similar methods could be useful for tracking the effects of climate change on birds. “The protraction of fall migration means that the season is getting longer overall, but it could also mean that the breeding season may be shifting, ending earlier for some individuals but later for others. To determine what this means in the context of breeding season shifts in timing, additional studies that incorporate both arrival on the breeding grounds and, importantly, departure from them are needed,” says Covino. “More studies of these patterns of fall migration timing and, even more so, both spring and fall migration timing across years are needed to gain the complete picture of how species are changing migration timing.”

Central America critical for migrating birds

Posted on September 14, 2019 by petrel41

This January 2015 video says about itself:

US Bird Count Shows Climate Change Affecting Migration Patterns

Thousands of birdwatchers in the United States, Canada, Latin America and the Caribbean were out in force from mid-December to the beginning of January (December 14-January 5) counting birds. They took part in the 115th “Christmas Bird Count”, sponsored by the National Audubon Society, a U.S. bird conservation organization. Data collected from the annual event is helping scientists understand how environmental changes affect birds. VOA’s Deborah Block joined a group of birdwatchers in the wetlands at Mount Vernon, Virginia -the famous home of the first U.S. president, George Washington.

From Oxford University Press USA:

Conservation of a Central American region is critical for migrating birds

September 12, 2019

Many of North America’s migratory birds are declining, but the mysteries about when and how birds migrate must to be solved to effectively protect them. A new paper in The Auk: Ornithological Advances, published by Oxford University Press, identifies a previously overlooked area that is critical for conservation: the region between southern Mexico and Guatemala where songbirds fuel up for a grueling flight across the Gulf of Mexico.

Migration is a dangerous time for birds, especially during flights over large bodies of water. Many birds migrate directly across the Gulf of Mexico, requiring over 600 miles of sustained flight. The details of how the survivors manage this feat of endurance have been murky, especially for species like warblers, whose small size prevented researchers from tracking their full migration routes until recently.

Researchers used light-weight geolocators to identify migration strategies for the vulnerable and declining Golden-winged Warbler, finding 80% of individuals spent a week in southern Mexico and Guatemala to feed and build up reserves for the flight over the Gulf of Mexico in spring migration. The importance of this stopover region was previously unknown for this species, and it needs conservation given the rapid conversion of natural habitats to pasture and farmland.

While most Golden-winged Warblers stopped in this region, not all did. Some that overwintered in northern Central America were able to make the trans-Gulf flight directly from their overwintering grounds without the stopover. “This is an important finding,” says Dr. Ruth Bennett of the Smithsonian Migratory Bird Center, “because birds that migrated directly across the Gulf were able to shave a week off their total migration time. These birds may experience a selective advantage in the spring.” That is because male Golden-winged Warblers race north in spring migration to establish breeding territories. Results from the study suggest the spring period requires more energy and poses a greater risk of predation and starvation, while fall migration allows for more flexibility to minimize energy costs and avoid risks.

“The variation we describe in migration routes and stopovers is encouraging,” says Bennett. “Variation helps buffer a population from local changes in environmental conditions.” Now that authors have identified where and when Golden-winged Warblers prepare for migration, they can start identifying the habitats that best allow birds to fuel up and successfully cross the Gulf of Mexico. This study provides a critical piece of the larger puzzle about where, when, and how to best protect the declining Golden-winged Warbler and other North American migratory birds.

A study published today in the journal Science reveals that since 1970, bird populations in the United States and Canada have declined by 29 percent, or almost 3 billion birds, signaling a widespread ecological crisis. The results show tremendous losses across diverse groups of birds and habitats — from iconic songsters such as meadowlarks to long-distance migrants such as swallows and backyard birds including sparrows: here.

Central American leaf frogs, new discovery

Posted on August 5, 2019 by petrel41

This 5 August 2019 video from England says about itself:

He Spent His Career Studying a Frog. Then He Discovered Its True Identity. | Short Film Showcase

Andrew Gray, Curator of Herpetology at Manchester Museum spent his career studying the Splendid leaf frog. However, when a supposed new species arrived from Central America, he made a shocking discovery. Using the original specimen of the Splendid leaf frog—first collected in 1902—as a comparison, Gray noticed several unique distinctions between the latest arrivals and those he had been studying. These were, in fact, the Splendid leaf frog and the frogs Gray had been studying were the new species.

Kinkajou on video

Posted on April 14, 2019 by petrel41

This 14 April 2019 video says about itself:

On this episode of Breaking Trail: Legacy Series, we take a look back at the time that Coyote encountered and fed one ferociously adorable KINKAJOU! How adorable do you think he is on a scale of 1-10?! We’re thinking a 10!

Kinkajous live in Central and South America.

Central American refugees from climate change, oppression

Posted on November 28, 2018 by petrel41

This 27 October 2018 video from the USA says about itself:

How a Climate Change-Fueled Drought & U.S.-Fed Violence Are Driving Thousands from Central America

President Trump is urging Mexico to deport the thousands of Central American migrants who are at or approaching the U.S. border in an attempt to seek asylum, days after U.S. border authorities fired tear gas into a crowd of asylum seekers as some tried to push their way through the heavily militarized border near San Diego.

Trump tweeted, “Mexico should move the flag waving Migrants, many of whom are stone cold criminals, back to their countries. Do it by plane, do it by bus, do it anyway you want, but they are NOT coming into the U.S.A. We will close the Border permanently if need be. Congress, fund the WALL!”

This comes just days before Andrés Manuel López Obrador is sworn in as Mexico’s new president. López Obrador’s incoming government has denied it made any deal with the Trump administration to force asylum seekers to remain in Mexico while their U.S. asylum claims are processed.

We speak with John Carlos Frey, Emmy Award-winning investigative reporter and PBS NewsHour special correspondent. He recently returned from reporting trips in Guatemala, Mexico City and Tijuana, where he was documenting the migrant caravan.

CHRISTIANS SLAM TEAR GASSING KIDS Some Christians denounced White House “cruelty” after Trump’s administration defended federal agents’ use of tear gas at the U.S.-Mexico border. Doctors told HuffPost that using tear gas on children can have serious physical and psychological health effects. However, Trump’s homeland security secretary issued a forceful defense of the gassing, saying migrants were “warned about the danger” of traveling to the border. [HuffPost]

Trump threatens to shoot refugees from Trump-backed right-wing dictatorships

Posted on November 4, 2018 by petrel41

This video from the USA says about itself:

Trump Threatens to Shoot Migrants Fleeing US-Fueled Violence and Instability

3 November 2018

While Donald Trump deploys troops to the Mexico border and orders them to shoot immigrants who throw rocks, many people in this migrant caravan in fact already fled US government-fueled violence in Central America. Eduardo García discusses impunity for Border Patrol killings and US-backed instability in Honduras and Guatemala.

Democratic candidates praise Trump’s attacks on immigrants as troops arrive at the border: here.

On the eve of the US midterm election, the Trump administration went to the US Supreme Court seeking authority to shut down the Deferred Action for Childhood Arrivals (DACA) program, under which some 800,000 young immigrants brought to the United States as children are allowed to work and go to school despite lacking legal status: here.

INTERNATIONAL U.S. REFUGEE OFFICES TO CLOSE The Trump administration plans to close the 23 international offices of U.S. Citizenship and Immigration Services, which facilitates services involving refugees, international adoptions and family reunification. [HuffPost]

Human Rights Watch (HRW) released a report on Wednesday titled “Deported to Danger: United States Deportation Policies Expose Salvadorans to Death and Abuse,” which found 138 cases of deported Salvadorans who were killed upon return to their country of birth between 2013 and 2019: here.

886 American snake species, new research

Posted on November 24, 2017 by petrel41

This 2013 video says about itself:

Our encounter with the South American Aquatic Coral Snake, also known as “Micrurus Ssrinamensis” in the Madidi Jungle National Park, Amazon Basin, Bolivia.

Don’t always go with the red to yellow, kill a fellow / red to black friend of Jack rhyme. That is true only for snakes found in North America, in South America Coral Snakes can have different patterns.

The Coral native to this region can be identified by the pattern of a black triad surrounding two yellow bands with red separating each triad. Also the bands should go all around the body.

The Aquatic Coral Snake (Micrurus surinamensis) is found throughout the Amazon including the Guianas, Brazil, Bolivia, Suriname. It is also called the coral “venenosa” in Bolivia, and the “boichumbeguacu” in Brazil. This species is one of the most famous South American coral snakes, and one of the biggest too (80 to 100 cm).

The Surinamensis is a very good swimmer, and spends most of its life in slow-moving bodies of water that have dense vegetation.

Coral Snakes are usually red with black bands bordered by white (or yellow) at intervals, yet not all Coral Snakes are tricolor. The eyes of the venomous tricolor Corals are very small, in contrast with the larger eyes of the nonpoisonous tricolor false corals. Coral snakes are generally not very aggressive snakes, but it would, however, be very dangerous to step on one inadvertently, especially with bare feet.

The venom of all coral snakes is strongly neurotoxic, it affects the nervous system and can cause respiratory paralysis and suffocation. These venoms are among the most potent found in snakes, yet the venom yield per animal is less than that of most vipers or pit vipers. In Mexico Coral Snakes are known as the “20-minute snakes,” for the victim is supposed to be dead 20 minutes after being bitten by one. Corals being burrowing snakes though, few accidents are actually caused by them.

From the Senckenberg Research Institute and Natural History Museum in Germany:

150 years of snake collections: Data bank proves rich snake diversity in the neotropics

November 24, 2017

An international team made up of scientists from Brazil, Australia, USA, Ecuador, Germany and Sweden has published the results of an extensive database constructed for snakes of the American tropics. This database is made up of museum collections from the past 150 years and demonstrates that some Neotropical regions, such as the Cerrado in central Brazil, contain a disproportionately high diversity. Furthermore, some other diverse regions are disproportionally under sampled, such as the Amazon. For the first time all factors, such as distribution patterns, collection records and frequency of occurrence are recorded from a total of 147,515 contributions to 886 snake species. Thus, the database covers 74 per cent of all snake species from 27 countries. The database, which has been so far unique in this form, will serve as a solid basis for conservation concepts, to biodiversity and evolution models in the future, as well as to design research agendas. The study was recently published in the journal “Global Ecology and Biogeography”.

About 10,500 species of reptiles (animals such as lizards and snakes) are found around the world and about 150 to 200 new species are also discovered every year. Snakes make up about 34 percent of this group of animals. “We assume that there are still many snake species that we still do not know. However, the identification of areas poorly-sampled, where probably new species can be found, must come from data and mapping of the known species” explains leading author Dr. Thaís Guedes from the University of Gothenburg and adds: “We realize that the very rich Amazonian area is, for example, one of the least explored areas.

Most of the area is of high inaccessibility, the low investments in local research sum to relative shortage of experts to explore this huge area explain this result. Besides that, the centers of research, as scientific collections, are limited to the geographic area of major cities and universities.”

The international group of scientists have collected data about snake collections of the Neotropics — South and Central America, the West Indies and the southern part of Mexico and Florida — to record the diversity of snake species, their distribution, as well as their threats. The result is a unique database with 147,515 entries for 886 snake species from 12 families. Senior author of the study Alexandre Antonelli from the University of Gothenburg is pleased: “We have published one of the largest and most detailed surveys on the distribution of snakes — one of the most species-rich reptile groups in the world! What an achievement!”

The huge dataset is the result of a merger of a public database, which was examined by experts in the course of this study and the collection data of various international taxonomists.

Another of the study’s authors, Dr. Martin Jansen from the Senckenberg Research Institute in Frankfurt, says: “The review by taxonomic experts has greatly enhanced the data. One could say that the data bank now has a kind of quality mark, something like ‘taxonomically verified’. This is very important, as biodiversity models often lack this in-deepth taxonomic expertise.”

The results from this most comprehensive and novel database also highlight the necessity to better sample, explore, and protect areas of high diversity, as well as rare species. “Our database provides the ideal basis, and it can now be used by other scientists (without taxonomic expertise) as a solid basis for subsequent models, for example, on evolutionary patterns or climate change effects”, explains Guedes.

Biologists are studying the mechanics of snake movement to understand exactly how they can propel themselves forward like a train through a tunnel: here.

Amazon farmers discovered the secret of domesticating wild rice 4,000 years ago

Jewel scarab beetles look like gold, why?

Posted on June 19, 2017 by petrel41

This video says about itself:

Jewel Scarab in Costa Rica -Chrysina

4 February 2014

Here is a video of a lovely creature I came across during a rain forest exploration. I love insects and this one really took the cake. It’s body was was a like a mirror that reflected all the colors around it.

From the University of Exeter in England:

Secret of why jewel scarab beetles look like pure gold, explained by physicists

‘All that glitters is not gold,’ finds research program into way jewel beetles reflect light

June 15, 2017

The secrets of why Central American jewel scarab beetles look like they are made from pure gold, has been uncovered by physicists at the University of Exeter.

The ornate beetles, which have a brilliant metallic gold colour, are highly valued by collectors. But until now the reasons behind their golden iridescent hue, have not been fully understood.

University of Exeter physicists specialising in colour and light have done experiments exploring the origin of the scarab beetles’ striking metallic golden appearance, showing that the golden beetles have a unique ‘optical signature’. The structure of the beetle and its armour uniquely manipulates the way the light is reflected so that it looks like pure gold.

Their results are published in the Journal of the Royal Society Interface.

Professor Pete Vukusic, a physicist specialising in light and colour, led the research which involved experiments and advanced modelling. He found that the golden appearance is due to the high reflectiveness of the beetles’ exoskeleton, which also manipulates a property of the light called its polarisation: the orientation of the reflected light wave‘s oscillations.

The scientists mapped the optical signature of the beetle’s Chrysina resplendens‘ colour, and found it was unusually ‘optically-ambidextrous’, meaning that it reflects both left-handed and right-handed circularly-polarised light.

Professor Vukusic said: “The brilliant golden colour and distinctive polarised reflection from the scarab beetle Chrysina resplendens sets it completely apart from the hundreds of thousands of other beautiful and brightly coloured animals and plants across the natural world. Its exoskeleton has a bright, golden appearance that reflects both right-handed and left-handed circularly-polarised light simultaneously. This characteristic of Chrysina resplendens appears to be an exceptional and wonderfully specialised characteristic in currently known animals and plants. It will serve as a valuable platform from which bio-inspired optical technologies can spring.”

The golden jewel beetle is prized by collectors because of its resemblance to the precious metal.

Other scarab beetles, valued by ancient cultures such as the Egyptians for use as amulets which were sometimes wrapped in the bandages of mummies, are a jewel-like green and blue colours. The vast majority of brightly-coloured beetles tend to be green and do not reflect polarised light. These beetles, in comparison to the brilliant golden colour of Chrysina resplendens, lack much more specialised aspects of their exoskeleton’s finely detailed structure.

Dr. Ewan Finlayson, research fellow on the project, said: “We were drawn to the study of this jewel scarab not only by its striking metallic golden appearance, but also by its ability to control a less obvious property of the reflected light: the polarisation. We have learned that there is great subtlety and detail to be found in these optical ‘signatures’ and in the elaborate natural structures that generate them.”

The golden jewel scarab beetle Chrysina resplendens, mainly found in the Americas, has evolved an exoskeleton that contains intricate nano-structures that are responsible for its appearance.

The spacing of the repeating layers of the nano-structures is found to vary over a specific range through the exoskeleton — a key property that causes the simultaneous reflection of a range of visible colours. It is this fact that explains the very bright reflection as well as the golden hue.

The nano-structured exoskeleton is composed of natural materials including chitin and various proteins. In addition to their brilliant reflectiveness, these structures are remarkable in the way they manipulate the way polarised light is reflected.

Their nanostructures produce circularly-polarised light, where the orientation of the light’s oscillations rotate as the light travels. The two possible directions of rotation are referred to as left handed and right handed.

The experiments build on the work of an early American scientist called Michelson who, in 1911, looked at the polarised reflection from many different Chrysina beetles, and on the work of Anthony Neville (then at Bristol University) in 1971, who began looking more closely at Chrysina resplendens.

There are around 100 species of Chrysina jewel scarab, which are found exclusively in the New World, mostly in Mexico and Central America. The species Chrysina resplendens is found in Panama and Costa Rica. Chrysina scarabs typically live in mountain forests. The larvae feed on rotting logs of various tree species, while the adults feed on foliage. The larval form lasts for several months to a year, and pupation takes a month or two. After the adult emerges it lives for about a further three months, although this span probably varies between species.

One explanation for the highly-reflective appearance of the beetle exoskeleton is crypsis: the ability of the animal to blend in to its surroundings.

Dr Martin Stevens, Associate Professor of Sensory and Evolutionary Ecology at the University of Exeter and an expert in animal vision, colour change and camouflage, said: “It is not absolutely clear why these beetles are a bright golden colour, but one option is that it somehow works in camouflage under some light conditions. The shiny golden colour could also change how the beetle is seen as it moves, potentially dazzling a would-be predator. There are many species which are iridescent but jewel beetles are one of the most charismatic and brightly coloured, and their colour might be used in mating. However, it is not clear how other beetles see the gold colour and reflected light. Many small mammals would not be able to distinguish the golden colour from reds, greens, and yellows, but a predatory bird would likely be able to see these colours well.”