Title

Variation in dugong fecundity

Objectives

1. To document spatial and temporal variation in dugong calving rates in an attempt to generate hypotheses to explain the patterns observed.
2. To determine whether the proportion of calves observed on aerial surveys is consistent with current understanding of dugong population dynamics.

Relevance

Calving rates are a measure of fecundity, one of the major parameters used in population models to determine sustainable harvest rates. Data from carcass studies indicate that there is considerable variation in dugong fecundity but the reasons for this are poorly understood.

Feasibility

Data on dugongs are available from two sources at James Cook University:

1. Carcass studies based in Townsville, Torres Strait and Numbulwar (Northern Territory)
2. Calf counts on aerial surveys

Methodology

This would be a desktop study to study the data listed above:

1. To document spatial and temporal variation in dugongs calving rates to generate hypotheses to explain the patterns observed and to document the impact of the fluctuations in fecundity on population change using established population models, and
2. To determine whether the proportion of calves observed on aerial surveys is consistent with current understanding of dugong population dynamics given the data on the relative amounts of time spent at the surface by cows with calves and unaccompanied adults obtained for the project entitled `Improving estimates of absolute abundance of dugongs'.

Approximate cost

$5000

Time required

Two months