The Srebarna lake, near the Danube River, Bulgaria, is a key site for biodiversity, specifically for ornithofauna. Thus, it has been designated as a managed nature reserve, a biosphere reserve, a Ramsar site, an Important Bird Area and Natura 2000 sites. Srebarna (and recently Persina Island) hosts the only breeding colonies of the Dalmatian pelican (Pelecanus crispus) in Bulgaria, assessed as critically endangered in the Bulgarian Red Data Book (2015). In April 2019, through a remote-controlled video surveillance system, we captured for the first time depredation of eggs of Dalmatian pelican by raccoon dogs (Nyctereutes procyonoides). As a result of regular Raccoon dog raids (up to three individuals simultaneously), about 25 nesting pelican pairs (approximately 30% of the Bulgarian breeding population) were disturbed and left the breeding grounds looking for new nesting places. These observations show that even few individuals of an invasive species such as the Raccoon dog can have a strong negative impact on concentrations of an endangered species; this necessitates taking proactive measures to control and even remove this species.