Research done has showed a similar correlation between Body mass and BMR in birds and mammals, as wells as a similar correlation between Body Mass-specific BMR and Body mass in the two. Since there is a similar relations between birds and mammals, it can be assumed that there will be the same relationship between reptiles (non-avian) and birds (avian reptiles).

Data was taken on Birds and non-avian reptiles regarding their body mass, basal metabolic rate, and body mass-specific basal metabolic rate.

Both birds and reptiles (non-avian) had a correlation value between .75 and 1 regarding BMR vs. Body mass, however when comparing Body mass-specific BMR to Body mass birds had a correlation value between .75 and 1 but reptiles had a correlation value outside this range.

When looking at a vertebrate phylogeny tree, both reptiles and birds separate from other species under the branch reptilia. From there, they part under different classes: reptilians (non-avian) and aves. Being that they came from the same ancestors, they have some similarities such as being vertebrates and having scales instead of skin. As both species continued to evolve, there became differences between the two. Aves (birds) evolved to have feathers on top of their scales making the lighter making flight possible. The main difference between the two is that reptiles are exothermic, meaning that they regulate body heat through the outside environment (the sun). Where as, Birds (Aves) are endothermic and can regulate their own body temperature.

Both mammals and Birds are endothermic resulting in a similar correlation between BMR and body mass, and mass specific BMR and body mass. Since reptiles share an ancestor with birds, do they have a similar correlation or will it be different since they are exothermic?

Do reptiles (non-avian) and Birds (Avian reptiles) have similar correlations between BMR and body mass as well as body mass-specific BMR and Body mass?

It is assumed that the correlation values between birds and reptiles will both be between .75 and 1, showing a similar correlation regardless of being exothermic or endothermic.

Using data provided by the University of Michigan and extracted from Quaardvark, different data analysis and statistical techniques will be ran in order to compare metabolic rates in reptiles and birds.

The independent variable is the data for BMR, body mass, and mass-specific BMR for birds and reptiles. The dependent variable will be the correlation values for the statistical tests.

Data is extracted from Quaardvark and transfered to excel for further analysis and statistical data

After starting a new search query in Quaardvark, search Aves for the animal group then for the report go under physical description and create three reports for Mass, Basal metabolic rate, and mass with basal metabolic rate (mass-specific BMR). Download all reports and transfer data into an excel sheet. Repeat on a separate query for reptiles. After all data is in excel, create 4 different scatter plots (Body mass vs. BMR for birds and reptiles, and Body mass vs. mass-specific BMR for birds and reptiles) including a line of best fit and regression value.

The regression values found in the body mass vs. BMR graphs for both birds and reptiles are between .75 and 1 showing strong positive correlation. The regression value for Body mass vs. mass-specific BMR in birds is between .75 and 1 showing a strong correlation, however the regression value for Body Mass vs. Mass-Specific BMR in reptiles is between .25 and .5 showing a weak correlation.

The correlation values were within the predicted limits for Body Mass vs. BMR in both birds and reptiles, but only the value for Body mass vs. mass-specific BMR in birds was in this range. The value for Body Mass vs. mass-specific BMR in reptiles was drastically lower than the predicted values. This shows that when comparing body mass and BMR being exothermic or endothermic doesn't change the correlation, but when comparing body mass and mass specific reptiles (exothermic) have a lower correlation rate that that of birds (endothermic).

The result shown for both reptile and bird body mass vs. BMR supports the 3/4-Power scaling rule as presented by Farrell-Gray and Gotelli (2005). The regression correlation for both was in the 3/4 range (.75 to 1).

While supporting other research that compares body mass and BMR, animals have a correlation value between .75 and 1 showing a similarity regardless of how they regulate their body temperature. When comparing body mass to mass-specific BMR, the correlation differs when comparing endothermic animals (birds) to exothermic animals (reptiles). Since the endothermic animals have a strong positive correlation and exothermic animals have a weak correlation, the could be advantages to both depending on the specific environment. This could possible be one of the reasons for the evolutionary advancement of being able to regulate body temperature either internally or externally.

Hulbet AJ., Else PL. 2004. Basal Metabolic Rate: History, Composition, Regulation, and Usefulness. Physiological and Biochemical Zoology: Ecological and Evolutionary Approaches 77(6):869-876 Glazier DS. 2008. Effects of Metabolic Level on the Body Size Scaling of Metabolic Rate in Birds and Mammals. Proceedings: Biological Sciences 275(1641):1405-1410. Speakman JR. 2005. Body size, energy metabolism and lifespan. Journal of Experimental Biology 208:1717-1730. Farrell-Gray CC., Gotelli NJ. 2005 Allometric Exponents Support a 3/4-Power Scaling Law. Ecology 86(8):2083-2087