“I just want to count them! Considerations when choosing a deer population monitoring method”

Abstract

Effective management of any population involves decisions based on the levels of abundance at particular points in time. Hence the choice of an appropriate method to estimate abundance is critical. Deer are not native to Australia and are a declared pest in some states where their numbers must be controlled in environmentally sensitive areas. The aim of this research was to help Australian land managers choose between widely used methods to count deer. We compared population estimates or indices from: distance sampling, aerial surveys, spotlight counts, and faecal pellet counts. For each we estimated the labour input, cost, and precision. The coefficient of variation varied with method and time of year from 8.7 to 36.6%. Total labour input per sampling event varied from 11 to 136 h. Total costs of vehicles and equipment per sampling event varied from AU$913 to $2966. Overall, the spotlight method performed the best at our study site when comparing labour input, total cost and precision. However, choice of the most precise, cost effective method will be site specific and rely on information collected from a pilot study, We provide recommendations to help land managers choose between possible methods in various circumstances.

A systematic review of the impacts and management of introduced deer (family Cervidae) in Australia

“…For example, monitoring protocols have been developed that use faecal pellet counts (Parks Victoria 2005;Forsyth 2006) and camera trapping to index the relative abundances of deer (Davis 2014;Davis et al 2015a), and studies have compared the efficacy of spotlight counts, distance sampling and aerial surveys (Amos et al 2014a;Baillie 2014) to index or estimate deer abundances (S3). Bennett and Coulson (2008) developed a method to measure the impacts of sambar on vegetation using differential exclosures, although the application of this design to smaller deer species has not been tested.…”

Noninvasive genetic spatial capture‐recapture for estimating deer population abundance

“…Of central importance are accurate estimates of deer abundance. At present, none of the methods available to estimate deer abundance are effective in all vegetation types (Amos et al , Hagen et al ).…”

Precision and reliability of indirect population assessments for the Caspian red deerCervus elaphus maral

“…Mean Pepin et al (2004Pepin et al ( , 2008Pepin et al ( , 2009, Carranza et al (1991) they are difficult to apply in places where this species is rare or less habituated to human presence (Tsaparis et al 2009), and in hardly accessible rugged landscapes (Singh and Milner-Gulland 2011). Dung counts are often applied as an alternative method to count deer species (Alves et al 2013, Amos et al 2014. In this study, we successfully estimated population size and density of red deer in Golestan from dung counts (Table 3).…”