scholarly journals Aerial Survey Intensity as a Determinant of Estimates of African Elephant Population Sizes and Trends

2009 ◽  
Vol 39 (2) ◽  
pp. 181-191 ◽  
Author(s):  
Sam M. Ferreira ◽  
Rudi J. van Aarde
1985 ◽  
Vol 12 (1) ◽  
pp. 57 ◽  
Author(s):  
LS Broome

Experimental aerial and ground censuses of waterbirds were conducted on three small, isolated bodies of water on the New England tablelands of New South Wales. The flying height at which sightability was optimized for the most common species was 30 m. Aerial and ground counts were significantly correlated for most species on the three watar bodies. Black swan, swamphen, coots, musk ducks and maned ducks were counted in equivalent or greater numbers from the air than from the ground on at least one water body. Other species were counted in lower numbers from the air than from the ground. A fairly high precision in the aerial-ground relationship for the most abundant species indicates that aerial survey can be a useful procedure for obtaining indices or estimates of the population sizes of these species. However, differences in sightability between species and between types of water body indicate that indices should be used and interpreted with caution. Other bird species from a variety of habitat types which are also amenable to aerial survey are discussed, and some recommendations for aerial surveys of birds are provided.


2009 ◽  
Vol 102 (7) ◽  
pp. 534-539
Author(s):  
Sarah Quebec Fuentes

How many elephants remain in Africa? For a variety of environmental reasons, monitoring the population of elephants in Africa is extremely important. When attempting to estimate the size of an elephant population in a certain area, a researcher must make several decisions. Should the count be conducted from the air or from the ground? Should the elephants in the entire area be counted or only those in a representative area? Should only the elephants themselves be counted, or should signs of their presence—such as dung, tracks, and feeding evidence—be considered as well? Over the past four decades, the approaches used to count elephants have become more statistically refined. This twopart article, to be continued in next month's issue, will explore the mathematics of some of the methods used to count elephants and will present related activities for the mathematics classroom. In this part, we will provide a brief but pertinent history of the African elephant and then present two different methods of counting elephants. This activity may be used as an entire unit or as an application of a particular concept and may be incorporated into several courses. Algebra and geometry students will be able to handle the necessary mathematics. Although this activity informally exposes students to several statistical concepts, a sophisticated understanding of statistics is not required to complete the first two scenarios. The mathematics for the third scenario is more advanced, however; thus, it could be used in higher-level classes such as statistics and calculus. The tasks involved in all three scenarios encourage students to make connections between mathematics and other disciplines and touch on the various implications of mathematical decisions.


PLoS ONE ◽  
2013 ◽  
Vol 8 (1) ◽  
pp. e53726 ◽  
Author(s):  
George Wittemyer ◽  
David Daballen ◽  
Iain Douglas-Hamilton

2021 ◽  
Vol 4 (4) ◽  
pp. 43-60
Author(s):  
Mahakata I. ◽  
Mapaure I.

This study aimed at examining local ranger-based knowledge and perceptions on explaining contributing factors to variations on elephant fluctuations seasonally and over a long period in Sengwa Wildlife Research Area following a massive decline of elephants by nearly 76% after the 2014 National Aerial Survey done in Sebungwe Region, Zimbabwe. Data were collected between 1st and 20th August 2020 using a purposive sampling approach administered to questionnaire to resident SWRA rangers (n = 25). Our results show that rangers considered a combination of factors that may have affected elephant fluctuations in SWRA including poaching, migration, settlement and impact of climate change. However, our results suggest that rangers had inadequate knowledge about elephant migration destinations. Moreover, mixed perceptions about the impact of trophy hunting, poaching and climate change-induced factors were recorded from the participants. The results contribute to a growing understanding of poaching, climate change, trophy hunting and human settlement on elephant behaviour. The study recommends improvement in elephant monitoring through investments in elephant collars and radio tracking to better understand elephant daily and seasonal dispersal movements.


2019 ◽  
Vol 24 (3) ◽  
pp. 225-251
Author(s):  
Naima Farah ◽  
John R. Boyce

AbstractIn response to the CITES ban on trade in elephant ivory, mammoth ivory began to be produced in post-Soviet Russia. We investigate how this substitute to elephant ivory has affected the poaching of elephants. We argue that the early success of the 1989 ivory ban at increasing the African elephant population was driven in part by increasing supply of mammoth ivory. The more recent increases in poaching appear to be driven by increasing demand and falling African institutional quality. We find that absent the 80 tonnes of Russian mammoth ivory exports per annum 2010–2012, elephant ivory prices would have doubled from their $ 100 per kilogram level and that the current poaching level of 34,000 elephants per year may have increased by as many as 55,000 elephants per year on a population of roughly half a million animals.


2008 ◽  
Vol 77 (1) ◽  
pp. 135-144 ◽  
Author(s):  
Simon Chamaillé-Jammes ◽  
Hervé Fritz ◽  
Marion Valeix ◽  
Felix Murindagomo ◽  
Jean. Clobert

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