Indexing Capromys pilorides (Say, 1822) (Cuban Hutia) Population Abundance for Conservation and Management

Richard M. Engeman; Desley A. Whisson; Bryan M. Kluever

Indexing Capromys pilorides (Say, 1822) (Cuban Hutia) Population Abundance for Conservation and Management

Richard M. Engeman¹, Desley A. Whisson², and Bryan M. Kluever³^,*

¹United States Department of Agriculture, Wildlife Services, National Wildlife Research Center, 4101 LaPorte Avenue, Fort Collins, CO 80521, USA [Retired]. ²Deakin University, Geelong, Australia, School of Life and Environmental Sciences, 221 Burwood Highway, Burwood, Victoria, Australia. ³United States Department of Agriculture, Wildlife Services National Wildlife Research Center, Florida Field Station, 2820 East University Avenue, Gainesville, FL 326414, USA. *Corresponding author.

Caribbean Naturalist, No. 100 (2024)

Published 8 November 2024

Abstract
We applied 2 disparate observation procedures for indexing Capromys pilorides (Cuban Hutia) populations at Guantanamo Bay, Cuba. We used data from both observation methods in a well-established population-indexing paradigm. One observation method was based on measuring the proportion of mass removed by Hutia from same-sized chew blocks, and the other was based on the proportion of tracking tiles covered by Hutia tracks. We selected for testing 3 sites with different management histories that were expected to follow a gradient of population densities. We deployed chew blocks and tracking tiles to intercept Hutia activity along their distinctive trails and made observations at each of the 2 types of stations for 2 consecutive days. We calculated the mean proportion of chew block removed and mean proportion of tiles tracked per station each day for each site. The index for each measurement was the mean of the daily means. Both the proportion of chew block removed and the proportion of tile with tracks provided index values in line with expectations for relative population abundances among the sites based on management histories. In addition, these 2 very different observation methods had a high degree of agreement, with a correlation of 0.99 among daily observational means. The criteria for validating population abundance indexing methods in the absence of known populations were satisfied. Treating the data as binary responses (presence or absence) instead of continuous proportional measures greatly reduced the sensitivity and accuracy of inferences.

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