Blue tits in paradise
February 25, 2009
If it wasn’t enough that these birds get to live on the beautiful island of Corsica, female blue tits actually incorporate fresh and fragrant flowers into their nests. Well, plant matter, actually. Everything from lavender to mint, anything that’s rich in volatile compounds. In other words, anything that smells.
A study published in the March issue of Animal Behaviour investigated the effects of this behavior by adding additional plant matter to established blue tit nests. Interestingly, the addition of aromatic plants increased the average chick mass in broods in experimentally enlarged broods. That is, where additional chicks were added to increase competition for food, these plants seemed to aid chick growth. Furthermore, chicks raised in nests with additional plant matter had increased haematocrit levels. Haematocrit is important for the aerobic capacity of the birds and is closely related to survival. Finally, the aromatic plants had a positive effect on chick feather development in one year of the two-year study.
While these benefits did not translate into a higher body mass at the time the chicks left the nest, the researchers speculate that these aromatic plants may benefit the birds’ immune systems. Another possibility is that the plants are an advertisement of female quality. By adding these aromatic materials to her nest, a female may entice males to invest more in his offspring being raised there, which would increase the fitness of the chicks.
While this study did not find any change in paternal feeding behavior as a result of the additional plant material, more research is clearly needed to evaluate either of the above hypotheses. Indeed, why do these bird mothers spend so much time and energy decorating their nests?
Notes:
Lazy bacteria
February 19, 2009
Evolutionists have long argued that all organisms, from bugs to birds, are inherently selfish. If presented with an opportunity to escape responsibility without suffering retribution, most (if not all) organisms will do so. Bacteria are no exception. Many strains of bacteria require the cooperation of the entire group to communicate efficiently for the purposes of reproduction or toxicity within a host.
Such an environment is ripe for cheaters, individuals who do not participate in the costly communication but who benefit from all the work the rest of the group is doing. Indeed, cheating bacteria have been identified in many different bacterial strains and have been the focus of much theoretical work on the evolution of social behavior. But recently, scientists have proposed a practical application for these selfish bacteria…treating disease.
Amazing animals
February 16, 2009
Ingenuity. Creativity. Resourcefulness. These qualities, exemplified by MacGyver but possessed to some degree by everyone, were once believed to uniquely human. But more and more evidence is accruing that demonstrates such higher cognitive abilities in other animals, such as non-human primates, cetaceans, and even birds.
I went to a symposium at the AAAS conference in Chicago last weekend that got me thinking about all of these things. Professor Alex Kacelik of the University of Oxford gave a talk about tool use in Caledonian crows. These birds are amazing! Here’s a short video of one using a piece of wire to form a hook in order to remove a bucket of food from a small tube. During his talk, Kacelik also described several other examples when the crow would exhibited incredible awareness and intelligence. For example, one crow retrieved the food with the hook and then flew away to a perch to eat it. It soon realized it still needed the hook to extract the food from the bucket and flew all the way back to where it had left the wire hook, demonstrating not only clever problem-solving skills, but an impressive memory as well. Another crow withdrew the bucket from a well, ate the food, and then replaced it several times, presumably in hopes that it would be refilled!
The examples of intelligent behavior in nonhuman primates are less astonishing perhaps, but impressive nonetheless. In this same symposium, Professor Tetsuro Matsuzawa of Kyoto University spoke about his number studies in chimpanzees. After teaching young chimps to count from one to nine by touching the numerals on a screen, he decided to test their memory. He would flash the nine numerals on the screen for just a fraction of a second, then cover them with white squares. Amazingly, the chimps were still able to touch all nine numerals in the right order a staggering 80 percent of the time! Matsuzawa then decided to give humans a shot at it. With the same short interval to view and remember the numerals’ locations, adult humans performed at a mere 40 percent accuracy, about half as good as the young chimps.
These are just a couple of examples of the remarkable intellectual capacity of animals. I share them with you first and foremost because I have always been fascinated by studies of animal cognition. But also, as humans it is our natural tendency to look for what sets us apart from the rest of the animal kingdom. While our uniquely human qualities are to be treasured for sure, I urge you to embrace the similarities that we share with animals as well. The sooner we are able to find a likeness between ourselves and the other creatures of the worlds, the easier it will be to retrace the steps of our past, to learn from the animals who we once were and perhaps who we are to become.
For more on the crow studies, click here.
For more on the chimp study:
Unhappy birthday?
February 11, 2009
Tomorrow marks the 200th birthday of Charles Darwin, father of evolutionary biology and inspiration to scientists worldwide. While others before him had similar speculations about the change of species over time, it was Darwin who boldly put forth a cohesive theory of evolution: descent with modification. Slowly, we are realizing that our acceptance of the once radical idea takes a similar path: each generation builds on the beliefs of those that came before while trying to incorporate the new knowledge amassed during its reign. And the process may be just as slow as the natural evolution of species. Now, 150 years after the formal introduction of evolutionary theory, a majority of U.S. adults (55%) still do not think that humans evolved from another species, according to a nationwide Harris Poll of 1,000 Americans. To Glenn Branch, deputy director of the National Center for Science Education in Oakland, Calif, this is not a cause for celebration.
A gift from man?
February 8, 2009
A recent genetic analysis published in the Feb. 5 issues of Science Express revealed that the black coat color found in some North American and European gray wolf populations may have a domestic origin. Researchers believe that the dominant gene for dark coat most likely arose as a result of artificial selection on domesticated dog breeds. Interbreeding between the common pets and the less-tame wolves then introduced the trait to these wild populations. Finally, scientists speculate, the diminishing snow-covered habitat set the stage for the selection and spread of the darker coloration. If their theory is true, this would be the first example of a human-selected trait becoming an adaptation when reintroduced to nature.
Energy drink explosion
February 4, 2009
The introduction of Red Bull to Austria in 1987 marked the birth of the energy drink era. When it hit U.S. shelves just 10 years later, the energy drink market exploded, now bringing in over $6 billion each year. But the question is: are they safe?
Check out my recent article on energy drinks in the Indiana Daily Student…
