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While recent technological developments have considerably improved the efficacy of such approaches , for example , using remote - sensing devices such as audio - or camera - traps or even remote drones ( Koh & Wich 2012 ) , there has been a growing realization of the power of molecular methods that identify mammals based on trace evidence .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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