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A recent article in Evolutionary Applications by LaSharr et al. reports on trends in the size of horns of bighorn sheep (Ovis canadensis) throughout much of the species' range. The article concludes that there are "... stable or increasing trends in horn growth over nearly 3 decades in the majority of hunt areas throughout the western U.S. and Canada." However, the article equates nonsignificance of predominantly negative trends in the areas with the most selective harvest as evidence for the null hypothesis of no trends and also fails to consider well‐known and serious biases in the use of data collected in size‐regulated hunts. By applying meta‐analysis to the estimates reported by LaSharr et al., we show that there has been a pervasive overall trend of declining horn sizes in Alberta, where the combination of horn size‐based legality, combined with unrestricted hunter numbers are understood to generate the greatest selective pressures. Given the nature of the biases in the underlying data, the magnitudes of the trends resulting from our re‐analysis of LaSharr et al.'s (Evolutionary Applications, 2019, 12, 1823) trend estimates are probably underestimated. [ABSTRACT FROM AUTHOR]

ABSTRACT Long-term data (1974-2011) from harvested bighorn rams ( Ovis canadensis) in Alberta, Canada, suggested a reduction in horn size and in the proportion of trophy rams in the provincial population over time. Age at harvest increased over time, suggesting slower horn growth. Rams that experienced favorable environmental conditions early in life had rapid horn growth and were harvested at a younger age than rams with slower horn growth. Guided nonresident hunters did not harvest larger rams than residents, suggesting that few large rams were available. Resident hunter success declined in recent years. Despite an apparently stable population, successive cohorts produced a decreasing harvest of trophy rams. We suggest that unrestricted harvest based on a threshold horn size led to a decline in the availability of trophy rams. That decline is partly an inevitable consequence of selective hunting that removes larger rams. Although our analysis does not establish that evolution of smaller horns caused the observed decline in both horn size and harvest of trophy rams, we suggest that intensive trophy hunting may have artificially selected for a decrease in horn growth rate. © 2013 The Wildlife Society. [ABSTRACT FROM AUTHOR]