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  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Mapping African buffalo distributions, in relation to livestock disease risk

    Buffalo Mapping Meeting

    7-8 June, Rome FAO, Canada Room

    Tim Robinson and Jennifer Siembieda

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Modelling densities of the African buffalo

    Adjustment for anthropogenic influence

    The buffalo-cattle interface

    Conclusions and next steps

    Overview

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Based on an approach developed for livestock mapping Gridded Livestock of the World (GLW) Wint and Robinson (2007); Prosser et al. (2011); van Boeckel et al. (2011)

    Assumptions that buffalo populations in protected areas occur at densities reflecting the

    suitability of the habitat to support buffalo

    that available statistics reflect the numbers reasonably closely that these habitat characteristics can be relatively well described by multi-

    temporal, Fourier processed, remotely-sensed environmental variables

    (vegetation indices, temperature variables, etc.),

    Buffalo distribution modelling

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Buffalo distribution modelling

    Buffalo data preparation Collect information on buffalo numbers in protected areas

    Suitability masking Mask unsuitable areas

    Calculate adjusted observed densities

    Sampling and stratification

    Define stratification methods for regressions Stratified random sampling of predictor variables for 25 bootstraps

    AIC stepwise regression analysis

    Log transform dependent variable Add quadratic terms for independent variables

    Stepwise regression, AIC variable selection

    Buffalo density predictions

    Apply regression coefficients to predictor variables Select best predictions (based on RMSE) from different strata Average the log buffalo density predictions for 25 bootstraps

    Model comparison and validation

    Compare to other buffalo maps Compute Standard Deviations over 25 bootstraps

    Compare predicted versus observed densities

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Buffalo data

    Figure 1. Distribution of protected areas (IUCN levels I-V) in Africa superimposed on the distributional extents of the four subspecies of buffalo (Syncerus caffer) on the continent

    (Source: IUCN 2010).

    Data collection

    FAO reps in 38 countries AU-IBAR wildlife focal points (n=35)

    South African National Parks (SanParks) Tanzania Wildlife Research Institute

    Rod East: African Antelope Database 1998. IUCN/SSC Antelope Specialist Group

    Data statistics

    n=121 vs. n=241Range of park areas: 72 to 64,257 km2

    Range of buffalo densities: 0.003 to 20.7 per km2

    Range of buffalo counts: 5 to 138,100Most populous: Selous National Park, Tanzania

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Buffalo dataAngola 1

    Botswana 2

    Burkina Faso 1

    Burundi 1

    Cameroon 1

    Central African Republic 9

    Chad 2

    Cote d'Ivoire 2

    Congo 2

    Ethiopia 3

    Ghana 2

    Guinea 1

    Kenya 14

    Malawi 6

    Mali 1

    Mozambique 5

    Namibia 5

    Senegal 1

    South Africa 9

    Sudan 1

    Uganda 9

    Tanzania 16

    Zambia 10

    Zimbabwe 17

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Predictor variables

    Locational longitude and latitude Anthropogenic

    Distance to roads Distance to city lights

    Demographic - human population Topographic slope and elevation Vegetation NDVI, EVI Temperature

    Land surface temperature Air temperature

    Water and moisture Vapour pressure deficit Distance to rivers Evapotranspiration

    General climatic - LGP

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Predictor variables

    MODIS satellite data, 2001-6 Fourier-processed imagery

    False colour composite

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Unsuitability masking and sampling

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Best result so far .

    Version 9b Reduced set of training data

    (n-121)

    200 points per 10,000 square kilometres

    Two stratification schemes Subspecies distribution Livestock production systems

    Unsuitable areas with mean annual NDVI < 0.2

    Data points in unsuitable areas ignored (not set to 0 density)

    Predicted buffalo density

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Best result so far .

    Predicted buffalo density

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Best result so far .

    Predicted buffalo density Standard Deviation of mean (n=25)

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Best result so far .

    Probabilistic model

    Predicted buffalo density Probabilistic Continuous Model (AMD)

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Adjusting for anthropogenic influence

    Based on the Human Footprint and the Last of the Wild (Sanderson et al. 2002)

    Assumptions: Buffalo occur outside

    protected areas where

    human influence is minimal

    Direct, linear relationship between human footprint and

    reduced habitat suitability

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Adjusting for anthropogenic influence

    Based on wilderness mapping Geographic proxies for Human

    Influence

    Summed to give a quantitative evaluation of HI on the lands

    surface

    Four types of data (9 datasets) as proxies for HI

    Each dataset was standardized from 0 (low HI) to 10 (high HI) to reflect

    their estimated contribution to HI.

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Adjusting for anthropogenic influence

    1. Population density higher human density leads to higher levels of influence on nature

    2. Land transformation 3. Accessibility of roads, major

    rivers and coastlines leads to extraction of resources, pollution and disruption of resources areas

    4. Electrical power infrastructure

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Human Footprint in protected areas

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Adjusting for anthropogenic influence

    0

    1

    0 10 20 30 40 50 60 70 80 90 100

    Ha

    bita

    t su

    ita

    bility

    Human Footprint

    0 = not suitable for buffalo

    1 = suitable for buffalo

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Adjusting for anthropogenic influence

    Predicted buffalo density Predicted density x HF

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Buffalo-cattle interface

    Where do cattle and buffalo potentially interact?

    Cattle distribution maps

    Links to specific production systems?

    Ruminant production systems

    Links to cattle movements Transhumance Trade-related movements

    Disease ecology and disease risk Combining risk factors

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Buffalo-cattle interface: Cattle densities

    Modelledcattle density

    Original maps produced for PAAT Information

    System

    Gridded Livestock of the World (2007)

    Recent developments Improvements to models

    and data (1 km)

    Monogastrics in Asia Ruminants in Africa

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Buffalo-cattle interface: Ruminant systems

    Land cover (GLC 2000)Ruminant Production

    Systems

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Buffalo-cattle interface: Ruminant systems

    Land cover (GLC 2000)Legend

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Buffalo-cattle interface: Ruminant systems

    Length of growing period Ruminant production systems

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Buffalo-cattle interface: Cattle movements

    Supply and use accounts Beef demand mapped against

    human distribution (GRUMP)

    Beef production mapped against cattle distribution (GLW)

    Difference = production surplus

    Beef production surplus (kg per Km2)

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Buffalo-cattle interface

    Predicted cattle density Predicted buffalo density x HF

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Buffalo-cattle interface

    Cattle-buffalo interface Ruminant production systems

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Buffalo-cattle interface

  • A Living from LivestockPro-Poor Livestock Policy Initiative

    Conclusions and next steps

    Buffalo data Park boundaries More detailed estimates of numbers Appropriate suitability masking

    Modelling approach Revisit the assumptions made Evaluate other statistical approaches Appropriate model stratification Distributional limits for sub-species

    Anthropogenic effects Improve on HF?

    Interaction with ag. landscape Incorporate pathogen information Disease ecology / nature of interaction

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