Biology ETDs

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The present study was undertaken to investigate the food habits in two species of kangaroo rats, Dipodomys ordi Woodhouse and Dipodomys merriami Mearns, by comparing the seeds that they store in their cheek pouches. Since both species of kangaroo rat occur sympatrically at many places in the Southwest, Gennaro (1966) has concluded that interspecific competition with D. ordi might serve to limit the northern distribution of D. merriami in the Rio Grande Valley of New Mexico. The nature of this interspecific relationship was investigated through a comparison of the seeds of both species.

Investigations have revealed that there is a definite difference in the diameter and the weight of seeds eaten by D. ordi and D. merriami. The greatest mean diameter of 68% of the seeds selected by D. merriami fall between 0.06 and 0.10 cm and 65% of the seeds selected by D. ordi fall between 0.11 and 0.15 cm. Sixty-nine percent of the seeds selected by D. merriami occur between 0.1 and 0.5 mgm; 65% of the seeds selected by D. ordi range between 0.6 and 1.0 mgm. Studies have also indicated a definite seasonal variation in the seed species eaten by these two rodents. Salsola kalii appears to be an important seed species eaten by both D. ordi and D. merriami, while Prosopis juliflora and Opuntia sp. appear to be seeds of additional importance in the diet of D. merriami.



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Department Name

UNM Biology Department

First Committee Member (Chair)

James Smith Findley

Second Committee Member

Clifford Smeed Crawford

Third Committee Member

William Clarence Martin

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Biology Commons