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Knowledge of a population’s abundance is of primary importance for conservation management. However, robust estimates of abundance are often difficult to obtain, especially for cetaceans which spend most of their lives submerged. Cetacean abundance is commonly estimated using aerial or vessel-based line transect surveys and distance sampling methods. During 2012–2014, the first line transect surveys to estimate cetacean abundance were conducted in Namibian waters.

Robust abundance estimates of wild animal populations are needed to inform management policies and are often obtained through mark–recapture (MR) studies. Visual methods are commonly used, which limits data collection to daylight hours and good weather conditions. Passive acoustic monitoring offers an alternative, particularly if acoustic cues are naturally produced and individually distinctive. Here we investigate the potential of using individually distinctive signature whistles in a MR framework and evaluate different components of study design.

Knowledge of the occurrence and distribution of cetaceans is particularly important for conservation and management, but is still limited within Namibian waters. We collated 3211 cetacean records from the Namibian Exclusive Economic Zone (EEZ) for the period 2008 to 2016 and applied the principle of minimum cross entropy (MinxEnt) to predict habitat suitability. MinxEnt is a generalised form of maximum entropy modelling that allows incorporation of additional information such as sampling bias.

The coastal population of common bottlenose dolphins Tursiops truncatus found in Namibia is regionally isolated and unique. This population faces several potential anthropogenic threats, especially in Walvis Bay, including boat-based tourism, a commercial harbour undergoing expansion, and aquaculture for oysters and mussels. Between 2008 and 2012, 238 boat-based surveys were conducted, resulting in 170 encounters with bottlenose dolphins. Overall, group sizes varied from 1 to 45 individuals (mean 10.7).

A total of 250,786 Cape Cormorants, of which 16,038 were individuals on nests in 349 colonies, and 15,831 Cape Fur Seals were counted during a complete aerial photographic census of the island of Tigres and part of the adjacent coast in Angola in March 2017. Such a concentration of birds and seals and the large number of breeding Cape Cormorants highlights the need to protect Tigres and its rich surrounding waters. Keywords: aerial census, Arctocephalus pusillus pusillus, Baía dos Tigres, Cape cormorant, Cape fur seal, Phalacrocorax capensis.

Many long-distance migrating shorebird (i.e., sandpipers, plovers, flamingos, oystercatchers) populations are declining. Although regular shorebird monitoring programs exist worldwide, most estimates of shorebird population trends and sizes are poor or nonexistent. We built a state-space model to estimate shorebird population trends. Compared with more commonly used methods of trend estimation, state-space models are more mechanistic, allow for the separation of observation and state process, and can easily accommodate multivariate time series and nonlinear trends.

Summary of the 2015 Summer Wetland Bird Counts in Namibia.

The following is a summary of waterbird count data for selected species in Namibia, covering the period 1977 to December 2008.

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).