Apr 4 (Day 94) - First time in New Orleans, calico cat genetics

This is my first trip to New Orleans. This was a non-birding area that I made special consideration to include on my route. I figured it would be a crime to make it this far and not visit this unique place. So far I have not been disappointed. Bourbon street was predictably full of people last night, and the local food I sampled was certainly up to my expectations. As a spicy food enthusiast, I am loving the culinary heat down here! Last night, I stayed in the Best Western Landmark French Quarter Hotel. It was situated perfectly for my nocturnal wanderings last night, and they provided a stellar and geographically appropriate start to my day when this came out of the waffle maker.

Fleur de lis waffle!

I had the waffle hat trick (3) this morning.

I spent the morning wandering around the French Quarter on foot. I wanted to take a few pictures and relax for a few hours. My plan was to enjoy the morning before the rain settled in later in the afternoon. As it turns out, that rain came only briefly around midday. The afternoon was pleasant for the most part, and so I spent some time taking in a few additional sights en route to my destination for tonight. I am staying right near City Park in north-central New Orleans. My Warmshowers host and avid cyclist, Peter, informed me that this park was designed by the same Frederick Law Olmstead who designed Central Park in New York! He is an urban planner and bicycle activist here in New Orleans so he know a lot about this sort of stuff. It is nice to have the energy to properly interact with my host tonight. I was not in a condition to do this last night.

I did take a quick turn through the park late this afternoon, but it was very quiet. I also had the fully loaded bike and was unable to bird off the main roads. Tomorrow I will leave the bike at home and do all my morning birding on foot. Hopefully there will be at least a few migrants put down by the overnight rain. I mapped out ~11 miles that I did today, but rounded up to 15 since I spent a lot of time just snaking around the French Quarter.

 Enjoying Bourbon Street this morning. 

The standard bike shot

 Random place I saw this morning.

The dog really did it for me.

I was robbed of the front page by "Wrestlemania"

which will occur at the Superdome on Sunday.

Jackson Square - I managed to get a clean

shot without any people in it!

Bike. Street poles are always a problem since they can break up an image.

Here, I hid it against the door to make the shot serviceable.

Fleur de lis (not on a waffle)

A sleepy female calico cat - Notice painting of Jackson Sq!

Since I do not have any birds for you from today, I will tack on another "science lesson" similar to the refractive index discussion from the other day. The cat above is a calico cat. A calico cat is a special type of tortoiseshell cat, and tortoiseshell cats are always female. Many people know this, but fewer know the reason why. Tortoiseshell cats can trace their characteristic coats to an epigenetic phenomenon known as X-inactivation. Every one of us, males and females, has 23 pairs of chromosomes: 22 pairs of autosomes and 1 pair of sex-determining chromosomes. Females have 2 "X" chromosomes, and males have 1 X and 1 "Y". This creates a bit of a problem as females have two copies of each gene on the X chromosome to males' one. To combat this discrepancy in gene dosage, females inactivate one of their X chromosomes. In short, they crumple it up and stash the inactive chromosome (a 'Barr Body') in a corner of the nucleus of the cell. The decision of which X chromosome to crumple up is completely random. This inactivation event takes place very early in embryonic development, and the pattern of inactivation is inherited by all the cellular descendants of the cell in which the inactivation event originally took place. 

This phenomenon occurs exactly the same in female humans and female cats. The last column below is the tortoiseshell cat scenario; This female cat carries one chromosome with the orange allele (XB), and one chromosome with the black allele (Xb). You can see that males cats ONLY EVER have one possible color (orange or black) since they only have 1 X chromosome. The inactive chromosome (Barr Body) in females is drawn as the U-shaped thingy in the diagram below.

To generate an actual calico cat with white fur as well is a bit more genetically complicated, but the basic idea is that there is another gene that can override either the orange or black allele to give the cat patches of white as well. We'll leave that for another day......