BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: birds

Birds Can Teach Us More Than Just Flying

Birds are known for their mostly beautiful, sometimes annoying songs, as well as their super flight abilities, but now, those shouldn’t be the only things they are known for. Scientists have observed the method small birds use to make their nests, as a guide to constructing cellulose gels in a nontoxic way. Scientists use a freeze-thaw process to make the cellulose. This process is modeled after how swift birds (not named after Taylor Swift) spit on the twigs in their nests to hold them together, but also to help connections form between the twigs. Cellulose gel is just a hydrated version of cellulose. Cellulose is the most abundant organic compound on earth. It is a chain of glucose that is different from starches because the glucose is in its beta form. It forms long chains that can build cell walls. It is a major constituent of paper and cotton. Most organisms can not digest cellulose, but inside of us, it acts as soluble fiber that stimulates the digestive tract to secrete mucus to help move feces along.

Cellulose is also a very useful material when it comes to making hydrogels, something that is used in a variety of things in the medical field ranging from contact lenses to wound care. Unfortunately, the process of creating hydrogels is not only difficult but can also be toxic. Normally, you would have to break down the cellulose and then get it to make the crosslink or structure of interest. This process often required the use of toxic, unstable, and/or difficult-to-handle solvents. Knowing how swift birds make their nests, The researchers added a water-soluble cellulose called carboxymethyl cellulose (CMC) to an acid solution and dissolved the CMC. After that, they added powdered cellulose fiber to the solution and put it through four rounds of freezing and thawing. This process generated cellulose gel. Repeatedly freezing and thawing the solution causes the cellulose to compact and intertwine itself into the sticky network. The researchers also did those processes with bamboo fibers and it was a success. This implies that this bird-like freeze-thaw process could be useful with other lignin and cellulose-containing fibers. The cellulose gels are robust, stable at room temperature, and can be tuned to degrade on a schedule, meaning that they’d be very helpful with drug delivery.

Do you think there’s anything else in nature that might hold the key to solving human challenges?

What are some other examples of humans learning from nature?

Little swift, Apus affinis, at Kruger National Park, South Africa, crop

Are Rats Really Interacting With Reef Fish???

A new study has found that the presence of invasive rats on tropical islands is affecting the territorial behavior of fish on surrounding coral reefs. The rats, which arrived on the islands as stowaways on ships in the 1700s, change the behavior of jewel damselfish, a herbivorous species of tropical reef fish that “farm” algae in the branches of corals.Microspathodon chrysurus

The study, which was led by scientists from Lancaster University in the UK and involving researchers from Lakehead University in Canada, was published in Nature Ecology and Evolution and compared five rat-infested and five rat-free islands in a remote archipelago in the Indian Ocean. The rats disrupt an important nutrient cycle by attacking and eating small resident seabirds and their eggs, leading to a drop-off of nutrients in the seas surrounding rat-infested islands. This results in a lower nutrient content of seaweed for herbivorous fish, such as the damselfish. The damselfish around rat-infested islands behave less aggressively and need to have larger territories due to the lower nutrient content of the algae.

Seabirds travel out into the open ocean to feed and return to nest on islands. The seabirds then deposit nutrients, through their droppings, onto the islands, and many of these nutrients are subsequently washed into the seas, fertilizing the surrounding coral reef ecosystems. On islands with invasive rats, the rodent populations decimate the seabirds, leading to seabird densities that are up to 720 times smaller on rat-infested islands. This results in much less nitrogen flowing onto the coral reefs around these islands.

Seabirds LC0141

Around islands with intact seabird populations, the farming damselfish aggressively defend their small patch, typically less than half a square meter, of the reef to protect their food source – turf algae. However, the scientists observed that farming damselfish on reefs adjacent to rat-infested islands were much more likely to have larger territories and were five times more likely to behave less aggressively than those who lived on reefs adjacent to islands without rats. The damselfish around rat-infested islands need to have larger territories because the algae around rat-infested islands is less nutrient-rich due to the missing seabird-derived nutrients.

NSW seabed 1

This behavior change in the damselfish could potentially have wider implications for the spread of different species of coral, the distribution of other reef fish, and the resilience of damselfish over generations due to changes in hereditary traits. Changes in behavior are often the first response of animals to environmental change and can scale up to affect how and when species can live alongside one another. This study is the first to show that invasive rats can change the behavior of coral reef fish in this way and highlights the importance of understanding and managing the impacts of invasive species on ecosystems.

Students in our AP Biology class are likely to be familiar with these concepts of nutrient cycling and the importance of nutrients in supporting the growth and productivity of an ecosystem. The study highlights how the nutrient cycle on coral reefs is disrupted by the presence of invasive rats, leading to a drop-off in nutrients in the surrounding seas and a lower nutrient content of seaweed for herbivorous fish. This can have consequences for the growth and productivity of the coral reefs and the overall health of the ecosystem.

Do Birds Think Like Us?

Contrary to popular belief, a bird’s brain is indeed intelligent. Pigeons are able to identify the painting of Picasso and Monet, with training and ravens are able to identify themselves in a mirror. For a long time, it was believed that bird brains are not complex, however, according to an article from Scientific American, recently it has been discovered that bird brains have many similarities to the brains of mammals. 

The neocortex is the outer layer of the brain that allows cognition and creativity, in mammals. Although the brains of birds hold a different shape, new research can compare their structure to the neocortex in mammals. It is found that the layout of the brain is similar to humans, explaining their advanced behavior and abilities. Originally, it was believed that avian brains were a  group of neurons located in a region known as DVR, and an individual nucleus called the wulst, whereas mammal brains consist of six layers with columns of neurons that transfer information horizontally and vertically. These clusters of neurons, each contained a nucleus which ultimately allows for the production of proteins in the cell. However, In a study done by, senior author Onur Güntürkün, a neuroscientist at Ruhr University Bochum in Germany, along with his colleagues they discovered that, ”in both pigeons and barn owls, these brain regions are constructed much like our neocortex, with both layerlike and columnar organization—and with both horizontal and vertical circuitry” (Stetka). This research rejects the once accepted understanding of avian brains. Additionally, “We can now claim that this layered, corticallike organization is indeed a feature of the whole sensory forebrain in most, if not all, birds,” says Martin Stacho, co-lead author of the study and Güntürkün’s colleague at Ruhr University Bochum. Ultimately, it is confirmed that the DVR of avion brains is related to the cortex of mammal brain, thus explaining many of birds unique abilities. Although this theory was suggested by Harvey Karten in the 60s, it was not supported, but new this research credits Kartens hypothesis

This new discovery raises more questions of the possibility of sensory consciousness in avian brains and ancient animal brain evolution. The latest common ancestor of birds and mammals are reptiles, from 320 million years ago, and its brain is believed, “it wasn’t like the neocortex or the DVR. It was probably something in between that, in mammals, developed a six-layered neocortex and, in birds, to the wulst and DVR”, said Martin Stacho.

 

With the current discoveries on bird brains, new possibilities are being researched and many scientist are realizing that our brains may hold more similarities to different animals than previously believed.

 

 

“Look! Up In The Sky! It’s a Bird! It’s a Plane! It’s…. A Blue-Throated Hillstar!

A decade ago, most scientists and bird-watchers believed that there were between 9,000 and 10,000 species of birds on the planet. A new study in 2016, however, led by the American Museum of Natural History, doubled that estimate, suggesting that there are 18,000 bird species in the world. One big step in the discovery of these unknown bird species was announced just several weeks ago, with the finding of a new species of hummingbird in Ecuador. Named Oreotrochilus cyanolaemus, or blue-throated hillstar, the species was discovered in the Andes by a multinational team of ornithologists from Ecuador, Venezuela, Denmark and Sweden. Dr. Francisco Sornoza-Molina of the Instituto Nacional de Biodiversida in Quito, Ecuador, and his colleagues first photographed the hillstar during fieldwork in the Ecuadorian highlands back in April of 2017; they would return later that spring to verify the finding.

File:Lampornis clemenciae.jpg

Hummingbird that resembles the blue-throated hillstar | Taken by Sheri L. Williamson

The blue-throated hillstar is approximately 13 centimeters in length and has a slightly curved beak, which it uses to reach the flowers of the chuquiragua, an Ecuadorian plant known as the “flower of the Andes” or “flower of true love” that is used to brew tea. It has a rich, deep-blue neck and greenish-blue head and body feathers.

Ecuador is rich in biodiversity, containing 132 hummingbird species out of the more than 300 in the world, but that doesn’t make the discovery any less surprising. Hummingbird expert and researcher at the University of New Mexico, Dr. Christopher Witt,  commented, “The hillstar hummingbirds occur in the most rugged, isolated, and inaccessible parts of the Andes, where they roost in caves, forage on the ground, and spend half their lives in hypothermic torpor, so the discovery of a new species in this group is incredibly exciting.” With estimates on the number of individuals of blue-throated hillstars varying between 250 and 750, ornithologists agree that the species is in danger of extinction, with its high-altitude habitat between the provinces of Loja and El Oro near the Pacific Ocean threatened by gold-mining, fire, and grazing. Commenting on the life-threatening conditions facing the blue-throated hillstar, Dr. Sornoza-Molina of the research team said, “Complete support from national and international conservation agencies is needed in order to save this species. The action plan for the conservation of this bird is creating a network of protected areas along its geographic range.”

Single father birds taking care of their babies

 Researchers at University of Bath, studied six different populations of plovers located across Africa, Asia and Latin America. The three populations of plover birds had a balance in the sex ratio of males to females and shared parenting of their offspring. The scientists found that in populations when there were more males than females, or vice versa, the parenting roles shifted leaving the males to look after the chicks.

Professor Tamás Székely, Professor of Biodiversity at the Milner Centre for Evolution at the University of Bath said: “When there are more males in the population, the females have more opportunities to find partners and so they are more likely to leave the family and mate with multiple partners in the breeding season, leaving their male partner to look after the chicks.”

According to the researchers, it is harder for male plovers  to get another partner. Therefore, they are more likely to stay monogamous and be the primary parent and invest time in raising their offspring. Influencing mate availability, the adult sex ratio can change social behaviour with divorce, infidelity, and parental antagonism due to being more common in sex-biased populations.

The study, published in Nature Communications, took data collected over 10 years from six wild shorebird populations that were closely related but displayed different parental strategies.

Dr Luke Eberhart-Phillips said: “We found that the chicks had a 50:50 sex ratio at hatching in all these species, and that the skewed adult sex ratios were caused by a difference in survival of male and female juveniles, although it’s still unclear why this happens.

“Our study highlights the knock-on effects that differences in survival rates between the sexes can have on population dynamics and social behaviour.”

The researchers continue to investigate how sex ratio and population affects social behavior.

What is that? Oh, it is the first ever hybrid bird species from the Amazon!!

According to the Science Daily article, A team of researchers from Scarborough revealed ,through a series of tests, a golden crowned manikin. This bird was first discovered in Brazil in 1957 ,but not seen until 2002.

“While hybrid plant species are very common, hybrid species among vertebrates are exceedingly rare,” says Associate Professor Jason Weir, senior author of the research.

A hybrid species forms when two parental species mate to produce a hybrid population, which then causes the birds to stop being able to freely interbreed with the parental species

The teams gathered genetic and feather samples over two trips to Brazil. They sequenced a large portion of the golden-crowned manakin’s genome including 16,000 different genetic markers. This led to the finding that 20 percent of its genome came from the snowy-crowned, and about 80 per cent came from the opal-crowned. In addition to that, the researchers used coalescent modelling to figure out at what point the golden-crowned split off from its parental species.

“The golden-crowned manakin ended up with an intermediate keratin structure that does a poor job of making either the brilliant white or the reflective iridescence of the parental species,” says Weir.

In its early existence, The golden-crowned manakin likely had duller white or grey feathers due to its keratin structure ,but eventually grew into yellow feathers to attract females. This led to unique color of the species.

“Without geographic isolation, it’s very likely this would never have happened because you don’t see the hybrids evolving as separate species in other areas where both parental species meet.”

 

 

 

Birds and Migration: More Than Just the “V-Formation”

birds

For as long as we can remember, we have known that many species of birds migrate south during the winter, in a “V-formation.” Recent studies by ecophysiologist Steven Portugal have suggested that the classic formation helps birds to conserve the most energy possible. His investigation involved researching the Northern Bald Ibis, a bird that was extinct in Europe for around 400 years. Johannes Fritz has been working tirelessly to bring the Northern Bald Ibis out of extinction, by pioneering an human-led migration throughout Europe, for the past 12 years. (To discover more about these birds, and their emergence from extinction in Europe, check out this site.)

Through his studies, Steven Portugal has identified that his hypothesis was correct; the “V-Formation” does, in-fact, help a flock of birds conserve the most energy as well as “the birds’ formation fitted the theoretical predictions of aerodynamics.” The birds synchronize their flapping when they experience turbulence. He also found that the birds break their arrangement to those of “less-optimal positions.” This includes, birds going one-behind-the-other, and changing their wing-flapping patterns. This is all believed to prevent downwash, which is “the downward deflection of of an airflow,” as defined by the dictionary.

Thanks to the work done by Steven Portugal, Johannes Fritz and their respective teams, we have come much closer to discovering “the why” in bird-behavioral patterns, namely their flock formation during migration.

Hawks to the Rescue, or…

Do you have a bird problem? If you do, you can use a 4000 year old technique to get rid of it. The technique is falconry. In a recent article, Nricco Iseppi explained how he brought his talents to Water Garden office park in Santa Monica, California.

Photo by Tobyotter

Two hawks, known as Mowgli and Melvin, are brought to the Water Garden three times a week and put on “pest control.” The Water Garden had a pest problem, specifically with seagulls. The idea is that the trained hawks would fly around the office park and when they see a seagull, they would scare it away. When the day is over, Mr. Iseppi would blow a whistle and the hawks would return to him.

I see seagulls all the time, but I never really consider them “pests.” Sure they fly around and usually stay with other seagulls but I don’t really see why people would want to get rid of them. We learn in biology about the food chain. If one part of that chain is disrupted, then the whole system will fail. What this article fails to mention is how this idea of falconry affects the surrounding environments.

Falconry has become very popular on the west coast. From San Diego to Seattle, birds of prey are being used to control other species’ populations. If this technique becomes too popular, what will happen to the species that is pushed out of the original environment? For example, if we look at New York City with all of the pigeons and have another bird come in to keep them all out, what will happen to the pigeon population?

Falconry is great for the short term, but where are all of the birds going to move to?

 

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