Influence of Diet on Basal Metabolism
Background.—With respect to Ḣb, McNab (1986a:1) maintains that "the influence of climate is confounded with the influence of food habits," and that departures from the Kleiber (1961) "norm" are best correlated with diet. Although this does appear to be the case for diet specialists, the analysis is not so clear-cut for omnivorous species (McNab, 1986a). His analysis also indicates that an animal's "behavior" (i.e., whether it is terrestrial, arboreal, subterranean, aquatic, etc.), secondarily modifies the influence of food habits on Ḣb. For example, terrestrial frugivores have Ḣb's that are very near predicted values, whereas arboreal frugivores have rates that are much lower than predicted (McNab, 1986a).
Table 9.—Food habits of some Procyonids. References for foods were as follows: Potos flavus, Procyon cancrivorus, and Nasua nasua taken from Bisbal (1986); Nasua narica taken from Kaufmann (1962:182-198); Bassariscus astutus taken from Martin et al. (1951), Taylor (1954), Wood (1954), Toweill and Teer (1977), and Trapp (1978); Procyon lotor taken from Hamilton (1936), Stuewer (1943:218-220), Stains (1956:39-51), and Greenwood (1981). Symbols represent either qualitative (#) or quantitative (+, †) assessments of feeding habits: # indicates that the animal was observed eating the food; + and † represent volume and frequency, respectively, of food utilization. No attempt was made to account for seasonal variation in the use of these foods.
| + | <20% by volume when found. | † | 1%-19% frequency of occurrence. |
| ++ | >20% by volume when found. | †† | 20%-50% frequency of occurrence. |
| ††† | >50% frequency of occurrence. | ||
| Food | Potos flavus | Procyon cancrivorus | Nasua nasua | Nasua narica | Bassariscus | Procyon lotor | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mammalia | + | † | # | ++ | ††† | ++ | †† | |||||
| Aves | ++ | † | + | †† | ||||||||
| Birds' eggs | ††† | |||||||||||
| Reptilia | + | † | + | ††† | # | + | † | + | † | |||
| Amphibia | + | † | + | † | ||||||||
| Pices | ++ | †† | ++ | †† | ||||||||
| Insecta | ++ | † | + | ††† | ++ | ††† | # | + | †† | ++ | †† | |
| Arachnida | ++ | ††† | # | + | † | + | † | |||||
| Chilopoda | ++ | ††† | ||||||||||
| Diplopoda | # | + | † | |||||||||
| Crustacea | ++ | ††† | # | ++ | ††† | |||||||
| Mollusca | + | †† | # | + | †† | |||||||
| Annelida | # | + | † | |||||||||
| Nuts | ++ | †† | ||||||||||
| Grains | ++ | †† | ||||||||||
| Buds | + | † | ||||||||||
| Fruit | ++ | ††† | ++ | # | †† | ++ | ††† | |||||
| Leaves | + | † | ||||||||||
| Grass | + | † | ||||||||||