• Recordings of chorus howls reveal the presence of wolf pups in wolf populations

    May 18, 2016

    The study, in which the University of Oviedo has taken part, offers a useful tool to analyze the reproductive status of wolf populations.

    Foto de José Larrosa

    Wolves produce vocalizations known as chorus howls. These sounds may reveal the presence of pups during the breeding period so they are useful to determine the reproductive status of wolf populations. The acoustic structure of this chorus is, however, very complex, so determining the presence of pups through their howls is even difficult for expert observers.

    A study conducted by the Mixed Unit for Research in Biodiversity and the Department of Mathematics, both from the University of Oviedo, The Cavanilles Institute for Biodiversity and Evolutionary Biology, of the University of Valencia, and the Firm ARENA S.L. has evaluated the usefulness of the analysis of the recordings of the chorus howls to identify the presence of pups. The work has been published in the journal PLOS ONE.

    The research published in ‘PLOS ONE' has been able to predict successfully the presence of pups in 94% of cases analyzed.

    Vicente Palacios, of the Cavanilles Institute for Biodiversity and Evolutionary Biology explains that to come to these conclusions they analyzed 110 chorus howls produced by Iberian wolves of a known group, including the presence or absence of pups. The study revealed that the distribution of acoustic energy of the chorus showed higher frequencies when the pups participate. Thus, creating mathematical models, experts have successfully predicted the presence of pups in a chorus howl in 94% of the cases analyzed.

    Researcher José V. López-Bao, of the Mixed Unit for Research in Biodiversity of the University of Oviedo, adds that the quantitative analysis of the chorus howl is an objective and accurate method, easy to implement and independent from the observer. "All these advantages are especially relevant when monitoring large wolf populations or when there are many observers involved", he says. In fact, this methodology has recently been implemented for the monitoring of wolf populations in the National Park of Picos de Europa, autonomous community of Galicia and also in the national estimation of wolf packs performed in the period 2012-2014, promoted and coordinated by the Ministry of Agriculture, Food and Environment.


    • Decoding Group Vocalizations: The Acoustic Energy Distribution of Chorus Howls Is Useful to Determine Wolf Reproduction. PLOS ONE. 4 de mayo de 2016.
    • Vicente Palacios, José Vicente López-Bao, Luis Llaneza, Carlos Fernández, Enrique Font.

    Front picture: transferred by researcher Juan Carlos Blanco.