Variation in the weight of the adrenal, pituitary and thyroid gland of the white-footed mouse,Peromyscus maniculatus

✍ Scribed by McKeever, Sturgis

• Publisher: Wiley (John Wiley & Sons)
• Year: 1964
• Tongue: English
• Weight: 841 KB
• Volume: 114
• Category: Article
• ISSN: 0002-9106
• DOI: 10.1002/aja.1001140102

✦ Synopsis

The white-footed mouse is a ubiquitous animal in coniferous forests of northern California. Studies of this species afforded an opportunity to examine its adrenal, thyroid and pituitary glands in relation to weight, sex, reproductive condition and age of the animals. The relationship of adrenal size to population density was explored in view of the conclusion of Christian ('59) that a behavioral-endocrine feed-back system regulates growth of populations through stimulation of pituitaryadrenocortical activity. Social competition associated with high populations is assumed to produce enlargement of the adrenal cortex through a degree of stress proportional to population size (Christian, '55). Stress, a condition which increases the metabolic demands of the whole body or of some of its organs, causes a discharge of adrenalin, which in turn causes the pituitary to release ACTH; in addition, stress may act upon the hypothalamus, which may in turn stimulate increased production of ACTH by the pituitary (Hall, '59).

Studies were made on animals collected in either ponderosa pine (Pinus ponderosa) or mixed red fir (Abies magnifica) and white fir ( A . concolor) forests on the east slope of the Sierras, Lassen County, California from January, 1958 through December, 1961. The climate of the area is characterized by severe winters with heavy snowfall, and moderately hot summers, during which there is little or no precipitation from late March to October.

Methods

Most animals were collected in snap traps. Traps were set in census lines consisting of 60-100 stations, with stations at 50-foot intervals. The first 60 stations