Now showing items 1-15 of 15

  • Cetacean abundance and distribution in European Atlantic shelf waters to inform conservation and management 

    Hammond, Philip Steven; Macleod, Kelly; Berggren, Per; Borchers, David Louis; Burt, M Louise; Cañadas, Ana; Desportes, Genevieve; Donovan, Greg P; Gilles, Anita; Gillespie, Douglas Michael; Gordon, Jonathan Charles David; Hiby, Lex; Kuklik, Iwona; Leaper, Russell; Lehnert, Kristina; Leopold, Mardik; Lovell, Philip; Øien, Nils; Paxton, Charles G. M.; Ridoux, Vincent; Rogan, Emer; Samarra, Filipa Isabel Pereira; Scheidat, Meike; Sequeira, Marina; Siebert, Ursula; Skov, Henrik; Swift, Rene James; Tasker, Mark; Teilmann, Jonas; Van Canneyt, Olivier; Vázquez, José Antonio (2013-08) - Journal article
    The European Union (EU) Habitats Directive requires Member States to monitor and maintain at favourable conservation status those species identified to be in need of protection, including all cetaceans. In July 2005 we ...
  • Distance sampling detection functions : 2D or not 2D? 

    Borchers, David Louis; Cox, Martin James (2017-06-15) - Journal article
    Conventional distance sampling (CDS) methods assume that animals are uniformly distributed in the vicinity of lines or points. But when animals move in response to observers before detection, or when lines or points are ...
  • Double-observer line transect methods : levels of independence 

    Buckland, Stephen Terrence; Laake, Jeffrey L.; Borchers, David Louis (2010-03) - Journal article
    Double-observer line transect methods are becoming increasingly widespread, especially for the estimation of marine mammal abundance from aerial and shipboard surveys when detection of animals on the line is uncertain. The ...
  • Double-observer line transect surveys with Markov-modulated Poisson process models for overdispersed animal availability 

    Borchers, David Louis; Langrock, Roland (2015-12) - Journal article
    We develop maximum likelihood methods for line transect surveys in which animals go undetected at distance zero, either because they are stochastically unavailable while within view or because they are missed when they are ...
  • The effect of sea-ice loss on beluga whales (Delphinapterus leucas) in West Greenland 

    Heide-Jørgensen, M. P.; Laidre, K. L.; Borchers, David Louis; Marques, Tiago A.; Stern, H.; Simon, M. (2010) - Journal article
    An aerial survey was conducted to estimate the abundance of belugas (Delphinapterus leucas) on their wintering ground in West Greenland in March–April 2006 and 2008. The survey was conducted as a double platform aerial ...
  • An efficient acoustic density estimation method with human detectors applied to gibbons in Cambodia 

    Kidney, Darren; Rawson, Benjamin M.; Borchers, David Louis; Stevenson, Ben; Marques, Tiago A.; Thomas, Len (2016-05-19) - Journal article
    Some animal species are hard to see but easy to hear. Standard visual methods for estimating population density for such species are often ineffective or inefficient, but methods based on passive acoustics show more promise. ...
  • Flexible density surface estimation for spatially explicit capture-recapture surveys 

    Borchers, David Louis; Kidney, Darren (University of St Andrews, 2014-07-01) - Report
    1. Existing spatially explicit capture-recapture (SECR) software does not have the ability to fit flexible nonparametric models of animal density. 2. We describe and implement in the R package secrgam, a flexible method ...
  • Large scale surveys for cetaceans : line transect assumptions, reliability of abundance estimates and improving survey efficiency – A response to MacLeod 

    Hammond, Philip Steven; Gillespie, Douglas Michael; Lovell, Philip; Samarra, Filipa Isabel Pereira; Swift, Rene James; Macleod, Kelly; Tasker, Mark L; Berggren, Per; Borchers, David Louis; Burt, M Louise; Paxton, Charles G. M.; Canadas, Ana; Desportes, Genevieve; Donovan, Greg P; Gilles, Anita; Lehnert, Kristina; Siebert, Ursula; Gordon, Jonathan Charles David; Leaper, Russell; Leopold, Mardik; Scheidat, Meike; Oien, Nils; Ridoux, Vincent; Rogan, Emer; Skov, Henrik; Teilmann, Jonas; Van Canneyt, Olivier; Vazquez, Jose Antonio (2014-02) - Journal item
  • Model-based distance sampling 

    Buckland, Stephen Terrence; Oedekoven, Cornelia Sabrina; Borchers, David Louis (2016-03) - Journal article
    Conventional distance sampling adopts a mixed approach, using model-based methods for the detection process, and design-based methods to estimate animal abundance in the study region, given estimated probabilities of ...
  • Occurrence, distribution and abundance of cetaceans in Onslow Bay, North Carolina, USA 

    Read, Andrew, J.; Barco, S.; Bell, J.; Borchers, David Louis; Burt, M Louise; Cummings, E.W.; Dunn, J.; Fougeres, J.; Hazen, L.; Williams-Hodge, L.E.; Laura, A-M.; McAlarney, R.J.; Nilsson, P.; Pabst, D.A.; Paxton, Charles G. M.; Schneider, S.Z.; Urian, Kim; Waples, D.M.; McLellan, W.A. (2014) - Journal article
    In this paper the occurrence, distribution and abundance of cetaceans in offshore waters of Onslow Bay, North Carolina, USA is described. Between June 2007 and June 2010 monthly aerial and shipboard line-transect surveys ...
  • Open population maximum likelihood spatial capture-recapture 

    Glennie, Richard; Borchers, David Louis; Murchie, Matthew; Harmsen, Bart; Foster, Rebecca (2017-09-04) - Journal article
    Open population capture-recapture models are widely used to estimate population demographics and abundance over time. Bayesian methods exist to incorporate open population modelling with spatial capture-recapture, allowing ...
  • Point process models for spatio-temporal distance sampling data from a large-scale survey of blue whales 

    Yuan, Y.; Bachl, F. E.; Lindgren, F.; Borchers, David Louis; Illian, J. B.; Buckland, S. T.; Rue, H.; Gerrodette, T. (2017-12) - Journal article
    Distance sampling is a widely used method for estimating wildlife population abundance. The fact that conventional distance sampling methods are partly design-based constrains the spatial resolution at which animal density ...
  • A spatially explicit capture-recapture estimator for single-catch traps 

    Distiller, Greg; Borchers, David Louis (2015-11) - Journal article
    1. Single-catch traps are frequently used in live-trapping studies of small mammals. Thus far a likelihood for single-catch traps has proven elusive and usually the likelihood for multi-catch traps is used for spatially ...
  • Using hidden Markov models to deal with availability bias on line transect surveys 

    Borchers, David Louis; Zucchini, Walter; Heide-Jørgensen, M.P.; Cañadas, A.; Langrock, Roland (2013) - Journal article
    We develop estimators for line transect surveys of animals that are stochastically unavailable for detection while within detection range. The detection process is formulated as a hidden Markov model with a binary ...
  • Workshop on new developments in cetacean survey methods 

    Borchers, David Louis; Thomas, Len; Buckland, Stephen Terrence; Skaug, Hans; Barlow, Jay (University of St Andrews, 2011) - Report
    This report contains the slides from a workshop on New Developments in Cetacean Survey Methods held on 27th November 2011 at the 19th Biennial Conference on the Biology of Marine Mammals, Tampa, Florida. Review talks were ...