1. Evolution: Big Bawls, Small Balls
John L. Fitzpatrick, Stefan Lüpold 
Current Biology 
Volume 25, Issue 22, Pages R1084-R1086 (November 2015)
DOI: /j.cub
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2. Figure 1 A howler monkey in the Brazilian Amazon.
A male Spix’s red-handed howler monkey (Alouatta discolor) with clearly visible testes descending a tree in the south-eastern Amazon in Brazil. A recent study [5] sheds light on the evolutionary link between male investment in testes and vocalizations in howler monkeys. (Photo: Charles Cruze, Wikimedia Commons.)
Current Biology  , R1084-R1086DOI: ( /j.cub )
Copyright © 2015 Elsevier Ltd Terms and Conditions