Editing Amazon river dolphin (section)

===Communication===
Like other [[dolphin]]s, river dolphins use whistling tones to communicate. The issuance of these sounds is related to the time they return to the surface before diving, suggesting a link to food. Acoustic analysis revealed that the vocalisations are different in structure from the typical whistles of other species of dolphins.<ref>{{cite journal|first1=Jeffrey|last1=Podos|first2=MF|last2=Vera da Silva|first3=R.|last3=Marcos Rossi-Santos|year=2002|title=Vocalizations of Amazon River Dolphins: Insights into the Evolutionary Origins of delphinid Whistles|journal=Ethology|volume=108|issue=7|pages=601–612|doi=10.1046/j.1439-0310.2002.00800.x}}<!--|access-date=22 November 2015--></ref>

Male Amazon river dolphins have been observed to exhibit an unusual aerial [[urination]] behavior, predominantly in social contexts involving other males. During these events, a urinating male positions itself upside down, ejecting a urine stream into the air, while a receiving male actively seeks the stream with its [[Rostrum (anatomy)|rostrum]], possibly detecting chemical signals through specialized bristles. Researchers speculate that this behavior likely serves a social or communicative function beyond waste elimination, potentially facilitating [[Semiochemical|chemical communication]] in a species with limited olfactory capabilities.<ref>{{Cite journal |last1=Araújo-Wang |first1=Claryana |last2=Cantor |first2=Mauricio |last3=Wang |first3=John Y. |date=2025-02-01 |title=Aerial urination suggests undescribed sensory modality and social function in river dolphins |url=https://www.sciencedirect.com/science/article/abs/pii/S0376635725000117 |journal=Behavioural Processes |volume=225 |pages=105149 |doi=10.1016/j.beproc.2025.105149 |pmid=39864636 |issn=0376-6357}}</ref>