Archive for November, 2011

Comparative Anatomy:Head and Neck

Saturday, November 26th, 2011

There are so many inter­est­ing com­po­nents to a bird that I can devote an entire post to just the head and neck.

The brain is very dif­fer­ent than mam­malian brains. There are homo­lo­gus struc­tures but over­all appear­ance is very different.

Birds have rele­tively large optic lobes and rel­a­tively small olfac­tory lobes which may reflect the rel­a­tive  impor­tance of vision and rel­a­tively poor sense of smell in some birds. http://people.eku.edu/ritchisong/birdbrain.html

Birds eyes have incred­i­ble vari­abil­ity in size, loca­tion and spe­cific func­tion depend­ing on the type of bird. For exam­ple. Owls are preda­tors and need good depth per­cep­tion so they have eyes in the front of their head like humans. This allows for stereo­scopic vision and bet­ter depth per­cep­tion. Birds that could be con­sid­ered prey species such as par­rots and passer­ines have eyes on the sides of their head. This improves periph­eral vision so they can watch for preda­tors. For great arti­cle on avian eye anatomy and how this affects vision for dif­fer­ent species, please see: http://www.birdsnways.com/wisdom/ww31eii.htm

Lets move on to bird beaks/bills. The beak is a more com­plex struc­ture than peo­ple real­ize. The beak has the outer ker­atin layer that is the aspect that we see.This layer is sim­i­lar to our fin­ger nails. Under this is a layer of con­nec­tive tis­sue, blood ves­sels and nerves and then bone. There is the upper beak with an under­ly­ing max­il­lary bone and a lower beak with an under­ly­ing mandibu­lar bone. As a vet, I have seen my share of beak avul­sions. This means that due to some trauma, the upper beak or or lower beak (or both) have been torn off. It is some­times hard for peo­ple to under­stand why this doesnt grow back since they know they have seen the beak tip grow when bro­ken. The rea­son is that the tip of the beak is the end of the karatin layer and the ker­atin layer is regen­er­a­tive. As long as the base of the ker­atin layer near the cere (fleshy aspect near the nos­trils) has not been dam­aged, the outer sur­face of beak will grow out (just like your fin­ger­nails). How­ever, once there is bone involve­ment, there is per­ma­nent dam­age and then this is a more seri­ous situation.

Other inter­est­ing anatomy facts on birds: They have a cleft palate –an open­ing called choana–that con­nects to their sinuses and nos­trils. There tra­chea is made of com­plete car­ti­lage­nous rings so the tra­chea does not eas­ily col­lapse. They do not have an epiglot­tis to cover the glottis–opening to the tra­chea. Unfor­tu­nately this makes inhala­tion of seeds a true con­cern. Bird tongues have a bone to aid their move­ment and manip­u­la­tion of food. They have a less devel­oped sense of taste than humans but they have addi­tional touch recepters. Birds do have ears but they do not have pin­nae or those outer flaps of ears that we asso­ciate ears. The ears are hid­den by the feath­ers on the side of their heads.

Wow, I can keep going on bird anatomy but it is quite exhausting…so I think I will stop here for now. I think next week will have to be a small mam­mal blog week just for some­thing dif­fer­ent  :)

Happy Thanksgiving

Friday, November 25th, 2011

I am cur­rently in  the process writ­ing my post on com­par­a­tive anatomy part 2. How­ever I thought I would write a quick hol­i­day post today and get back to the other one next week.

I hope every­one had a great thankg­siv­ing. Mine was quite enjoy­able. It was very quiet, just my hus­band and son–and the oven. I ended up cook­ing a ban­quet of food. For­tu­nately my hus­band took care of the turkey on the BBQ-rotisserie style so that freed the kitchen for all of the sides and desserts. By 1:30, it was all ready and we had a Thanks­giv­ing lunch. It was yummy and we all suc­cumbed to tryp­to­phan coma and had a good nap in the late after­noon. In fact, my tod­dler slept from 3 pm to after 6 pm when I finally woke him up. So things I am thank­ful for:

Of course my fam­ily and friends who have always sup­ported me in every­thing I do. My hus­band has allowed me to make huge deci­sions in my life that has improved my qual­ity of life and has sup­ported me every step. My son is a con­stant reminder of what is truly impor­tant. I can just look at him and stop wor­ry­ing about the lit­tle things. My par­ents, in-laws, sib­lings, extended fam­ily is a won­der­ful net­work that helps ground me and remind me of the big­ger picture.

My awe­some career–I am so fur­tu­nate to have become a vet­eri­nar­ian and an avian/exotic one at that…life time goal has been ful­filled and I can appre­ci­ate it.

My cur­rent employ­ers at Car­ing Hands Ani­mal Hos­pi­tal. So sup­port­ive and smart. Com­pas­sion­ate in every­thing they do. I truly can appre­ci­ate the oppor­tu­nity they have given me.

My cats and their uncon­di­tional love, hair­balls and all.

My clients who have will­ing­ingly fol­lowed me to my new loca­tion and allowed me to con­tinue to bond with their pets.

My country–with all of the free­doms it pro­vides. We have the right to freely express our­selves in peace­ful ways, we have the right to dis­agree or agree with the gov­erne­ment, and we have the right to pur­sue life lib­erty and happiness.

I hope every­one has a great week­end, does not get top­pled over by crowds at the black fri­day sales and has plenty of left overs for the next few days.

Comparative Anatomy

Friday, November 18th, 2011

I was try­ing to decide what to write about next and I started to think about what make birds unique. There are many inter­est­ing anatom­i­cal dif­fer­ences and sim­i­lar­i­ties to mam­mals that most peo­ple don’t real­ize. Adap­ta­tions in anatomy allow birds to fly, migrate hun­dreds of miles, stay warm or cool in harsh envi­ron­ments, digest food that oth­ers may not be able to eat, talk and mimic like no other ani­mal, and the list goes on.
So here are some inter­est­ing anatom­i­cal facts:

  • Many birds have become asym­met­ri­cal to make them lighter and more effi­cient. For exam­ple, mam­mals have two jugu­lar veins that allow blood to flow from the head back to the heart and they are about the same size on both sides of the neck. Most birds have a larger ves­sel on one side of the neck than the other–often it is the right side that has a more promi­nent vein. Many female birds also have a  sin­gle oviduct or repro­duc­tive struc­ture with one ovary. This is usu­ally found on the left side of the body. Males do have two tes­ti­cles though.
  • Wings are amaz­ing struc­tures. Just like front leg/arms on a mam­mal, they have a humerus, radius and ulna (although the ulna is larger of the two bones in the bird which is oppo­site of humans), and a wrist joint and fin­gers or dig­its. Most of the wrist bones and bones that would be a hand are fused (carpals and metar­cara­pals) and they  have three digits–the alu­lar digit is sim­i­lar to the mam­malian thumb.

homology: homologies of the forelimb among vertebrates

  • Birds have air­sacs through­out their bod­ies. Imag­ine bal­loons that fill up with air, then the air passes to the lungs, then to another air sac, then back to the lung–thus allow­ing air to pass twice through the lungs for more effi­cient fil­ter­ing of oxy­gen. The air­sacs also extend from the body into the the wings and legs (humeri and femurs) and this allows these bones to be hol­low and lighter than those found in other animals.

http://www.mytoos.com/airsacs.html

 

 

 

 

 

 

  • Birds do have ribs and they have a keel. Any­one who has eaten a bird or prepped a meal has seen the large breast plate that is under the “white meat” or breast mus­cle. It is this bone and these mus­cles that allow the bird to expand the chest to breath. Birds do not have a diaphragm and thus all of their organs are in one cham­ber with no divi­sion. This is why it is so impor­tant to restrain a bird prop­erly. If you hold a bird two tight around the body and chest, they will not be able to breath.
  • Birds have two parts to their stom­achs. A sim­ple stom­ach called the proven­tricu­lus which has gas­tric juices and flu­ids for enzy­matic break­down of food. They also have a giz­zard or a ven­tricu­lus. This is a mus­cu­lar struc­ture that acts as a grind­ing organ to break down harder foods and seeds. Many peo­ple of pet birds assume they need to pro­vide grit (tiny peb­bles) daily for the birds so that the giz­zard can use this to help grind down hard foods. Pet birds do not need a daily dose of grit. In fact they need lit­tle if any to help with nor­mal grind­ing func­tion of the giz­zard. In fact, too much grit can lead to obstruction.

These are just a few of many dif­fer­ences.  After get­ting this far, I fig­ured I should post on this and then make addi­tional posts for more fun facts…otherwise I can just keep going and never it it on my page. So stay tuned…

 

 

Pigeons Revisited

Saturday, November 12th, 2011

I have pre­vi­ously blogged about pigeons and dis­cussed some great resources that can be found out there. Today, I will explore there his­tory a lit­tle further.

Since we are com­ing off of Veteran’s Day (thank you all of our ser­vice men and women) I think it is appro­pri­ate to men­tion some of the pigeons that have served our coun­try. This is no joke. Cher Ami was a WWI mes­sen­ger pigeon that helped save lives–specifically mem­bers of New York’s 77th Divi­sion of US Army. Dur­ing a bat­tle in France, the bat­tal­ion was sep­a­rated from allied forces and sur­rounded by the enemy. The allies started fir­ing and did not know that their own troops were in the fray. The bat­tal­ion sent out mes­sen­ger pigeons to get word to the allies to stop shoot­ing. After two pigeons were shot down, the third and last pigeon (Cher Ami) was sent out. Despite being shot in the breast and hav­ing a leg shot off, he was able to fly the mes­sage to the Allies and the shoot­ing stopped. See the full story http://www.birds.cornell.edu/pigeonwatch/resources/pigeons-in-history
or learn more and see Cher Ami’s pre­served body at the Smith­son­ian Insti­tute National Museum of Amer­i­can History.

Pigeons were domesi­cated over 5000 years ago and was intro­duced from Europe to North Amer­ica in the 1600’s.  Pigeons have been used for food, as pets, bred for show­ing and rac­ing, and used to send messeges such as Cher Ami.

 Bokhara trum­peter pigeon

Pigeons can be kept in coops and allowed to fly freely and expected to return home. They are able to nav­i­gate their way back home by sens­ing the earth’s mag­netic field.

So what is the dif­fer­ence between pigeons and doves? not much. Pigeons and doves belong to the fam­ily Columbidae and the order columb­i­forme. What we con­sider pigeons seen in most urban set­tings are also called rock doves and are a species of doves (Columba livia).

 Vic­to­ria crowned pigeon! Isn’t it beautiful?

So now you know why I love pigeons. If you are look­ing for more pic­tures, books and resources of these amaz­ing birds, please refer back to my blog from July 2011.

Conures

Friday, November 11th, 2011

There are many dif­fer­ent types of conures and the term conure includes mul­ti­ple gen­era. Here are a few of the more pop­u­lar conures kept as pets:

Sun Conure: Aratinga sol­sti­tialis
These birds orig­i­nate from Guyana, south­east­ern Venezuela, and north­east­ern Brazil. They live in open forests, palm groves and savan­nahs. They tend to live in huge flocks on trees with ripen­ing fruit. Any­one who owns a sun conure will agree that they are very loud and can be destruc­tive to wood. They are also beau­ti­ful and vibrant and can form a close bond with their human.

Jen­day Conure: Aranti­nga jen­daya
Orig­i­nated from North­east­ern Brazil and live in for­est clear­ings and among coconut palms. These are also very loud birds that can be destruc­tive. These birds are highly intel­li­gent and very play­ful. They are closely related to and look sim­i­lar to the sun conure.

Nan­day conure: nan­dayus nen­day
Nan­day conures are from south­east­ern Bolivia, south­ern Matto Grosso, Paraguay, and north­ern Argentina. These birds live in savan­nahs, forests, palm groves and agri­cul­tural land. In the wild, they eat food from grain fields,rice fields and fruit plan­ta­tions, sun­flower and corn fields and will some­times live with quaker (monk) par­rots. These conures are also noisy and can be destruc­tive but are again affec­tion­ate and intelligent.

Maroon bel­lied conure: Pyrrhura frontalis
These conures are found in south­east­ern Brazil, Uruguay, Par­guay and north­ern Argentina. They live in forests, organge plan­ta­tions and corn fields. Flocks are usu­ally 10–40 birds.  Maroon bel­lied conures eat plants, blos­soms and insects and lar­vae. These conures tend to be qui­eter in nature then other conures but are still very intel­li­gent and social.

There are many other conures that are beau­ti­ful and fas­ci­nat­ing. Con­sider read­ing about green cheek conures, blue crowned conures, golden conures, crim­son bel­lied conures, blue throated conures, red fronted, His­panolan, Cuban, golden capped, red masked.…the list goes on.

Once again, most facts were pro­vided by the Ency­clo­pe­dia of Para­keets by Kurt Kolar & Karl Heinz Spitzer 1990 and pic­tures were stolen bor­rowed from the world wide web.

Next up: pigeons: beau­ti­ful birds with an amaz­ing his­tory or sky rats and dirty birds, you decide.