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The first flight to begin an elephant survey covering parts of Angola, Botswana, Namibia,Zambia and Zimbabwe took off from a dirt strip in Zimbabwe on 22 August 2022. The survey area, known as the Kavango-Zambezi Transfrontier Conservation Area (KAZA TFCA), hosts over half of Africa's savanna elephants, which underlines the importance of the survey.

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.

An overview of elephant conservation and management in Namibia.

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.

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.

Recently introduced unmarked spatial capture–recapture (SCR), spatial mark–resight (SMR), and 2-flank spatial partial identity models (SPIMs) extend the domain of SCR to populations or observation systems that do not always allow for individual identity to be determined with certainty. For example, some species do not have natural marks that can reliably produce individual identities from photographs, and some methods of observation produce partial identity samples as is the case with remote cameras that sometimes produce single-flank photographs.

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).

Aerial surveys of the centra] and eastern areas of the Etosha National Park were undertaken during September 1968, April 1969 and February 1970, primarily to establish the efficacy of an aeroplane in counting the larger mammals in the Park and to obtain some idea of the numbers and distribution of the various populations. Previous census methods such as road strip counts and waterhole counts were found inaccurate, unreliable and often impractical in Etosha.