In group-oriented applications for wireless networks, reliable multicast strategies are important in order to efficiently distribute data, e.g. in Wireless Mesh Networks (WMNs) and Mobile Ad-hoc NETworks (MANETs). To ensure that developed protocols and systems will operate as expected when deployed in the wild, a good understanding of several factors such as packet loss characteristics is necessary. In this paper the correlation of erasures in a cluster of receiving mobile devices is measured and analyzed. In the considered scenario, a source node broadcasts packets to a cluster of receivers located relatively far away. To ensure that the obtained data can easily be applied in analysis, we introduce the textit{cluster erasure transition matrix}. We then analyze a simple broadcast and cooperative scheme, and show that the assumption of independent packet erasures unfairly favors the cooperative scheme according to the obtained measurements.