INTRAINDIVIDUAL AND INTERINDIVIDUAL VARIATION IN FLANK GLAND SECRETIONS OF FREE-RANGING SHREWS CROCIDURA-RUSSULA

Individual differences in Rank gland secretions were examined among ma les of the monogamous shrew Crocidura russula during the breeding and nonbreeding seasons. Gas chromatography was used to measure intra- and interindividual variation of flank gland secretions of free-ranging s hrews from different populations. The number of compounds detected by gas chromatographic analyses was correlated with body mass, flank glan d size, and the presence of blood parasites in individual shrews. Very few compounds were detected from the Bank gland area of juvenile male s. After they reached sexual maturity, however, the number of compound s detected from the Rank gland secretions increased significantly. At the beginning of the reproductive season 48 different compounds were d etected from male flank gland secretions. In the middle of the breedin g season 70 compounds were detected, while only 11 compounds were dete cted during the nonbreeding season. Few compounds were common to all m ales. There were more volatile compounds in the Bank gland secretions of males in the beginning of the breeding season than later in the bre eding season. Males from the same population had fewer differences in the elution profile of compounds than males from different populations indicating that individuals from a distinct population have similar e lution profiles of compounds and that each population has its own type of elution profile. No correlations were found between the number of compounds detected by gas chromatography for each male and the male's body mass or flank gland size. Blood parasites (trypanosomes, Trypanos oma crocidurae) were found in only three of 30 males investigated.