Question about heart rate in relation to life span

[Auburngirl05]

I have read that while certain animals (elephants, turtles, etc) live much long lives in terms of years as compared to other animals (rodents, etc), their lifespans are fairly equal in terms of number of heartbeats, with the smaller animals running on faster metabolisms “using up” their ultimate “allotment” of heartbeats faster than the larger animals with slower metabolisms. All of this makes perfect sense to me.

My main question is this: I thought that birds have relatively fast metabolisms, with rapid heartbeats. If this is true, though, how do certain types of birds, like the large breeds of parrots and macaws, often live for well over 50 years? How does their metabolic rate compare to that of a small mammal, and if it is similar, why do they not follow the pattern of heart rate being inversely proportional to lifespan?

The only thing I could come up with is that maybe you can only make comparisons within classification (mammals, birds, reptiles, etc), for example elephants live longer than dogs which live longer than mice and macaws live longer than sea gulls which life longer than sparrows, etc etc. So I guess the second part of my question is if the heart rate theory is all inclusive in the animal kingdom or if it is relative to each separate classification.

I’m sorry if this is a dumb question, it’s not for a school assignment or anything, just my own curiosity/confusion.

[Irken_Link]

I think this might be true Examples: shrews live a short life,while the tortise lives a long life

[pi_of_9]

But parrots (Umbrella Cockatoo and African Grey Congo) can live from 80-100 years.

 

Electrocardiographic Reference Values for Macaws (Ara species) and Cockatoos (Cacatua species)

Issn: 1082-6742 Journal: Journal of Avian Medicine and Surgery Volume: 15 Issue: 1 Pages: 17-22

Authors: OGLESBEE, BARBARA L., HAMLIN, ROBERT L., KLINGAMAN, HEATHER, CIANCIOLA, JANINE, HARTMAN, STEPHEN P.

 

Electrocardiograms (ECGs) were recorded from 41 healthy macaws (Ara species) and 31 healthy cockatoos (Cacatua species). All birds were anesthetized via face mask with isoflurane anesthesia. Standard bipolar (I, II, III) and augmented unipolar (aVR, aVL, aVF, V10) leads were recorded with birds in dorsal recumbency using a direct-writing oscillograph. Heart rates for macaws and cockatoos ranged from 231 to 571 beats per minute.

 

Pretty amazing as to how they can maintain that rate for so many years.

[Auburngirl05]

 

Pretty amazing as to how they can maintain that rate for so many years.

I know, that's what confuses me about the whole thing...I haven't done much reading on ornithology, but bird biomechanics seem like a fascinating subject.

[swansont]

It's called Kleiber's Law.

 

Basically it goes as C * M^3/4, where M is mass and C is a constant that is different for different types of animals. It seems to work for metabolism, heart rate, and lifespan. Lung surface area and encephalization quotient follow the same relationship, but all these things are inter-related, so scaling the same way shouldn't be too surprising.

 

So birds would have a different constant than mammals which would be different from amphibians.