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Accurately estimating hippopotamus (Hippopotamus amphibius) numbers is difficult due to their aggressive nature, amphibious lifestyle, and habit of diving and surfacing. Traditionally, hippos are counted using aerial surveys and land/boat surveys. We compared estimates of numbers of hippos in a lagoon in the Okavango Delta, counted from land to counts from video taken from a DJI Phantom 4TM drone, testing for effectiveness at three heights (40 m, 80 m, and 120 m) and four times of day (early morning, late morning, early afternoon, and late afternoon).

We counted waterbirds along a fixed route in the panhandle of the Okavango River in Mahango Game Reserve in the dry season during two seven-year periods (1991–1997 and 2000–2006). Palearctic migrants represented by 11 species in 1991–1997 and nine species in 2000–2006 together composed only a small percentage of all birds recorded in both periods. The two most numerous foraging guilds were birds foraging in shallow water and those foraging in deep water. The former guild was more numerous in 2000–2006, while the latter guild was more numerous in 1991–1997.

This article continues the series on trends in Namibian waterbird populations and summarises count data for herons and egrets for the period 1977 to December 2008. For each species the Red Data Book (RDB) status, both global and Namibian, is given, the population trend as per Wetlands International, the number of times the species was counted, the number of times it has passed the 1% population criterion, the maximum count and the sites where it has passed the 1% population criterion.

Namibia was blessed with extraordinary rains in most parts of the country early in 2011 and this is evident in the results of the summer wetland bird counts. Access to many of the count sites was difficult due to the wet conditions. In fact, the count at Lake Oponono had to be abandoned because of the muddy conditions. Rain interrupted many counts and even at Sandwich Harbour the counters had to endure about two hours of pouring rain before continuing with the count. Oddly enough, Tsutsab Vlei, near Tsintsabis in northern Namibia, was bone dry when the counts were done.

This article continues the series on trends in Namibian waterbird populations and summarises count data for herons and egrets for the period 1977 to December 2008. For each species the Red Data Book (RDB) status, both global and Namibian, is given, the population trend as per Wetlands International, the number of times the species was counted, the number of times it has passed the 1% population criterion, the maximum count and the sites where it has passed the 1% population criterion.

This is the last article in a series describing the results of regular wetland bird counts in Namibia. This paper looks at eight coastal sites, including two of Namibia's four Ramsar sites i.e. Sandwich Harbour and Walvis Bay. Unfortunately data for Namibia's other coastal Ramsar site, the Orange River Mouth, is incomplete and hence it has not been included in this analysis. (Larger scale replications of the graphs in this article are attached to the end of this edition).

The third article in the series on trends in Namibian waterbird populations summarises count data for cormorants and darter for the period 1977 to December 2008. For each species the Red Data Book (RDB) status, both global and Namibian, is given, the population trend as per Wetlands International, the number of times the species was counted, the number of times it has passed the 1% population criterion, the maximum count and the sites where it has passed the 1% population criterion.

The fifth article in the series on trends in Namibian waterbird populations summarises count data for storks and ibises for the period 1977 to December 2008. For each species the Red Data Book (RDB) status, both global and Namibian, is given, the population trend as per Wetlands International, the number of times the species was counted, the number of times it has passed the 1% population criterion, the maximum count and the sites where it has passed the 1% population criterion.