Walia Special Edition on the Bale Mountains (2011) - Zoologische ...

long-term study areas. However, total counts of focal packs are only useful for calculating absolute
population size if all packs in the Bale massif are monitored and pack demographics are reliably
determined for each pack, both of which require a substantial investment of resources and are
difficult (if not impossible) to achieve. The tremendous quantity and quality of monitoring data
collected by the EWCP on focal packs over many years has made it possible to follow meaningful
trends in group size, pack territories and reproductive success. While variation in monitoring effort
across packs, study sites, and years makes estimating total population size a challenge, extrapolation
of these data have provided a means of assessing population trends up to present.
As a complementary approach, an index of abundance from the Web Valley and Sanetti
Plateau transects has been applied successfully to estimate wolf trends in high density wolf areas
(Marino et al. 2006). However, the index was deemed less accurate at estimating wolf abundance in
low-density areas (Marino et al. 2006)
Monitoring Long-term Genetic Diversity
Genetic diversity is deemed necessary for population persistence because it allows the evolutionary
adaptability of populations to natural or human-induced environmental changes (Allendorf and
Leary 1986; Gilpin and Soulé 1986; Lande and Barrowclough 1987) and counters the negative
effects of inbreeding on fitness (Lande 1988; Falconer 1989; Frankham 1995; Amos and Balmford
2001). Thus, one of the EWCP’s conservation goals is to maintain 90% of the species’ genetic
variation over 200 years - the recommended target for the genetic minimum viable population
(MVP) (Ralls and Ballou 1986; Soulé et al. 1986).
From 2002 to 2005, a study was undertaken to examine the current level and distribution
of genetic variation in the Bale wolf population (Randall et al. 2010). A total of 156 Ethiopian
wolves present in the population during this period were sampled and genotyped at 17 polymorphic
microsatellite markers. Within subpopulations, allelic richness ranged from 4.2 to 4.3 (with 4 to 12
alleles per locus) and expected heterozygosity (H ) ranged from 0.584 to 0.607. A similar analysis
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of genetic variation is currently being completed for other populations across the species’ range
(Gottelli et al., unpublished data). These data provide a baseline from which changes in genetic
diversity can be monitored.
Genetic methods can also be used for monitoring population size and demography; and noninvasive
genetic sampling is a particularly useful tool that can be applied to species that are either
too rare or elusive to observe, or where the threatened status of a population precludes or deters
capture and handling of animals (Kohn and Wayne 1997).
Indeed, individual identification of wolves using genetic methods has been possible in both
the Bale population (Randall et al. 2007; Randall et al. 2010) and smaller populations in North
Ethiopia (Asmyhr et al. unpublished data, Gottelli et al. unpublished data). However, low quality or
quantity DNA obtained from faecal or hair samples are more prone to erroneous genotyping which
have undesirable consequences for analyses using genetic data (for example, genotyping errors
<strong>Walia</strong>-<strong>Special</strong> <strong>Edition</strong> on the Bale Mountains 35