Hello Philly!

Hello there, fellow animal-lovers!
ZooGirl here, with a long-awaited update.

It has been quite a while since I have posted but I am finally back. After receiving a job offer to work at oldest zoo in the country, the Philadelphia Zoo, I have spent the last few weeks packing, moving, house-hunting, and unpacking. It has been quite a crazy month but things have finally settled down.

I have finished my orientation needed in order to start at the Philly Zoo and will be starting working there very soon. In the meantime, I have been working very hard to get my zoo sites all back on board, especially my YouTube channel.

I will be updating more in the future on my blog, Youtube channel, and twitter accounts. At this point, YouTube has gotten most of my attention. I have posted several videos since moving so please feel free to check them out. It is greatly appreciated!

More will follow in the future, I promise this time!

In the mean time, stay wild!

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Musically-Inclined AND Pretty Bird?

Anyone who knows me knows that of all the living creatures in the world, birds have always held a special place in my animal heart. I am fascinated with their behavior, their physiology, and the mindblowing degrees of observable evolution they have undergone as a group. Of course, all living existence changes over generations both in genotype and phenotype. However, I am constantly amazed at how strongly the variation in birds can be seen on a large scale.

Tanagers form a subgroup of Passerines, or songbirds, found in the tropic regions of the Americas that is well-known for their typically beautiful plumage and non-migratory patterns. There are about 280 species, however, the tanager taxonomy is highly debated.

It was always a very popular anecdote (especially for birds) in my zoology classes when discussing evolution that most animals experience “trade-offs.” To put it simply, when individuals with a specific trait reproduce more than individuals without it, that trait will become more prevalent over time. For example, let’s imagine that one species of bird has blue males and brown males. If blue males have better mating opportunity and give rise to more offspring than the brown males, we would expect to see a higher population of blue birds over many generations. Selection pressure on the large amount of blue birds would then give rise to small variations between them. Let’s say in this population of blue males, there is one that also has a large crest of feathers on his head. Perhaps, he experiences more mating opportunities than blue males with small crests. Once again, over a long period of time, we would expect to see increases in crest height simply because he is having more progeny compared to his bald bird brethren.

As you can imagine, any living creature has limited resources biologically. It would seem that if a male bird has spent more energy on a cellular level producing blue pigments and growing a crest, some other trait would have to take the hit. If cells are using more resources to maintain fancy feathers, that is less energy that could be spent on say, regulating body temperature or digesting diet efficiently, for example. Maybe this bird will compensate by spending more time foraging to intake more food and energy. As a result, however, there is less time to spend pursuing mates or building nests. As you can see, it would make perfect sense that there are advantages and disadvantages to how an individual’s energy is spent.

This theory makes so much sense and has always been an important basic Darwinian principle drilled to me in school so it was no surprise that an article titled “Maybe Birds Can Have It All: Dazzling Colors and Pretty Songs” posted on Science Daily a few days ago ruffled my feathers. How could a bird develop decorate plumage and complex songs to attract mates? I imagined that a bird growing a showy tail would be physically unable to form intricate vocalizations as well. In fact, Darwin’s early work conceptualized into what was eventually coined the “Transfer Hypothesis.” This theory basically states that if two sexual traits in an individual incur a biological cost to express, they will have a inverse correlation. In other words, if one trait is expressed more, the other trait should be expressed less. Although it initially did not seem possible to me, it appears that birds very well can have both.

The study showcased in the article was completed by the Department of Biology at San Diego State University and looks closely at 9 variables of plumage and 20 variables of song composition in various subfamilies of tanagers to observe any evidence of correlation between them. Plumage was quantified by analyzing patterns in coloring, UV reflection, and dichromatism while song complexity was measured by arrangements of song duration, continuity, syllables, and overall repertoire size.

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While it appears overwhelming at first, this visualization shows one clear-cut trend: there appears to be no trends at all. In some families, it appears that plumage and song are positively or negatively correlated while in others, they appear to be completely exclusive of each other. Instead of a significant pattern in one direction or another, there is instead a broad level of independent evolution of sexual traits.

What I find fascinating is that several studies have been done in the past comparing these sexual traits in birds with different results.

  •  A 2002 study found the predicted negative correlation in finches.
  • However, a 1990 study on warblers and a different 2013 study on tanagers showed positive correlation between elaborate feathers and certain song patterns.
  • Better yet, this 2009 study found no correlation between the traits in trogons.

It is obvious that there is an almost immeasurable amount of possibilities. There are often differences between methods of studies. There are also vast variations between groups of birds, especially in tanagers which make up 10% of the world’s songbirds. Perhaps, habitat variation is more involved in sexual evolution than anticipated. Maybe predator prevalence would affect the priority of growing fancy feathers or singing tedious tunes. Of course, we can’t forget that while feathers and vocalizations serve to attract potential mates, they also aid in other conspecific communication like defining territory and in communal species.

As more and more studies are performed on sexual selection, it just becomes clearer just how complex evolutionary theory is in process… and that is just what evolution is, a theory. It is difficult to say if we will ever truly understand the intricate forces that drive nature to change. However, it is clear that studies like this one will only push us to keep searching for answers and continue our exploration of life on Earth.

 

 

Jumping the Shark

“Jumping the Shark” is a simple expression used to describe the moment that the quality and appeal of something once great and loved has started to decline. It originated in television, particular from an episode from “Happy Days,” when Fonzie water-skiied over a shark. Yes, you heard that right. “Jumping the shark” is usually the defining moment in a series when you know it has hit its low point. Think Cousin Oliver on The Brady Bunch or Scrappy Doo joining the Mystery Gang.

Last summer, the Discovery Channel released what they initially called a documentary to kick off their famous annual “Shark Week.” The feature was called “Megalodon: The Monster Shark Lives” and showcased a 55-foot-long species of shark believed to have been extinct for over a million years. As you may have guessed from the title, however, this was not just a simple educational special designed to teach its audience about prehistoric sharks. By using the present tense of “lives,” viewers are instantly drawn to think Discovery is putting out a program that will present hard evidence that Megalodon may very well still be roaming the planet’s waters. After all, the majority of the ocean has yet to be explored. Isn’t it quite possible?

Well, after watching the program and looking at some of the “evidence” they presented, it is obvious that this was not a serious scientific effort which is disappointing to say the least. I would encourage anyone with a practical and objective perspective to check it out and decide for themselves. I also would like to acknowledge that while it was initially advertised as a “documentary,” they have more recently referred to it as a “docufiction.” It is very similar to Discovery’s previous special, “Mermaids: The Body Found,” which led viewers to believe strong evidence had been found about aquatic apes or “mermaids.” Both features display very brief and vague disclaimers about its legitimacy on a scientific basis. “Megalodon: The Monster Shark Lives” presents three of them:

“None of the institutions or agencies that appear in the film are affiliated with it in any way, nor have approved its contents.”

“Though certain events and characters in this film have been dramatized, sightings of ‘Submarine’ continue to this day.”

“Megalodon was a real shark. Legends of giant sharks persist all over the world. There is still debate about what they may be.”

Despite these brief warnings, many viewers took the program as fact. By using mock footage and actors, Discovery led its audience to believe that they had spoken with experts and gathered photo and video evidence. Well, let me clarify. They did present plenty of photos during their amazing Shark Week debut that, by the way, had the highest numbers of viewers of any Shark Week episode during its 26-year history. Here are a couple of the photos:

George Mombiot blog on sharks : Whale carcasss on beach  George Mombiot blog on sharks : German submarine and shark

 

 

 

 

 

 

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I really don’t have much to say other than that both of these photos are simply ridiculous. Aside from the fact that no half-eaten whale has ever showed up in Hawaii, that u-boats weren’t around the coast of South Africa in 1942, and that the older image is a cut from a video with the sepia, the swastika and most importantly, the shark, doctored in, Discovery gives no sound evidence whatsoever that Megalodon may still be alive. Is it possible? Most definitely. Let’s not forget when fishermen in Africa caught a live Coelacanth in 1938 when experts believed it had gone extinct 400 million years ago. There is no doubt in my mind that there are prehistoric species roaming the earth today. Megalodon may be one of them.

As I have always been a fanatic for sharks and the like, it’s hard to narrow down what is more upsetting to me… the fact that they did not give me sufficient proof that Megalodon is out there or that Discovery Channel, a network I count on to deliver captivating zoological programming with the factual background to support it, completely “jumped the shark.”

I could be bold in saying this but it appears to me that Discovery Channel has tried especially hard this year to cash in on the fascination we have in sharks and has gone so far as to jeopardize their reputation as one of the greatest non-fiction networks on television to do it. Besides, Shark Week is always one of their most popular TV events and they have always done an exquisite job showcasing their ability to effectively hunt and kill its prey. As long as we are in awe of one of the ocean’s greatest marvels and demand to see it, there is bound to be a steady supply of it.

The disappointing thing is that Megalodon definitely existed at one time or another. Discovery Channel had an amazing opportunity and the resources to showcase the largest shark the world has ever known to open up their hugely popular Shark Week. While fossil records of Megalodon are rare and not very complete due to the cartilaginous skeleton of sharks and its relatives, there is enough real evidence out there to fill a 2-hour special that would have still intrigued loyal viewers, including myself.

Why not talk about the skeletal reconstructions that experts have used to try to depict Megalodon? They are incredible. To support the the estimated 5 rows of 275 teeth total, a massive and extremely robust jaw would be needed, spanning 6-8 feet across and able to crush an automobile in one bite, something that dinosaurs couldn’t even accomplish. They could have also talked about evolutionary trends and discuss the theories as to why many of the animals in today’s world are smaller versions of past species. Today’s sharks aren’t 60 feet long. How are animals becoming smaller and more efficient at surviving? Sharks are also very clever and strategic hunters. This documentary could have been such a chance to talk about how Megalodon is thought to have target its prey by attacking its bony structures, something that modern sharks by contrast, intentionally avoid. Most importantly, it could have focused on what would have caused it to go exist if it had, as well as what miraculous circumstances it would have had to endure to survive this long unnoticed if it is still on this earth. Any of that subject matter would have produced a program that better represented what Discovery Channel is acknowledged as and respected for: a network staffed by educated and resourceful experts with the goal to bring the amazing examples of science and nature to people who otherwise may never see them.

At least it would have better served their mission statement.


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While I suppose the phrase “highest quality” is very open to interpretation and not necessarily synonymous with “factually accurate”, the term, “enlighten” is reatively static. In all fairness, Discovery’s opening to Shark Week 2013 was definitely entertaining to a lot of people and engaged quite a dialogue on the internet. However, it is did not leave anyone more educated or enlightened (as you put it) about Carcharodon megalodon.

In conclusion, it is undoubtedly an enormous fascination we have… larger-than-life predators that dominated the world long ago in a way that we never had the chance to see… the idea that they still may be on this earth just waiting for us to find them and learn all of their biological secrets and marvels… I get it. It is a big part of why I got into Zoology in the first place. As I said before, I encourage you to watch it for yourself before making a judgment. I only ask that you go into it with an open mind and never rely on just one source for your facts.