Hoiho Education
Science
Individual identification of yellow-eyed penguins / hoiho
Yellow-eyed penguins / hoiho do not have any natural markings that allow researchers and conservation managers to tell individuals apart. Instead birds are “marked” with transponders to help us recognise individuals.
Transponders
A transponder is a tiny microchip embedded in glass (similar to those used to identify your dog). Transponders allow long-term data information to be gathered about the birds.
Flipper bands
Using banded birds, Richdale established much of the basic population biology and behaviour knowledge of the species. A valuable research programme which continues to band birds has existed at Boulder Beach, Otago Peninsula for more than 30 years.
Using a transponder wand to identify yellow-eyed penguin
Monitoring of yellow-eyed penguins
To manage the yellow-eyed penguin population effectively and enable scientists to conduct good research, comprehensive data needs to be collected.
Nests are counted to give an indication of overall population trends. These nests are then monitored through the breeding season. Observing the number of eggs laid and whether these chicks survived to fledge, helps us to determine breeding success.
Because birds are marked we can keep track of them, work out who is breeding with who and determine which birds get injured or die. This tells us about the survival rate of hoiho.
Data gathered from individually marked penguins will continue to be added to the Department of Conservation’s yellow-eyed penguin database, and will enhance the Trust’s understanding of hoiho populations and their dynamics, including issues such as recruitment.
Science at the Trust
In February 2016, the Yellow-eyed Penguin Trust was externally resourced to employ its own Conservation Science Advisor, a new role that will help us advance the aims of the organisation.
Based both at the Trust and Otago Museum, the Conservation Science Advisor will identify, stimulate, broker and analyse research that investigates the marine environment, and factors affecting the productivity and sustainability of hoiho. This role focuses on using research to inform the decisions of the Trust to deliver optimal species management.
It was timely that funding allowed for the appointment of this position given the serious concerns for hoiho and the low breeding numbers over the past few seasons.
The Trust is delighted to announce that funding was secured from Otago Regional Council (70%) and the balance from Otago Museum, for a three-year term.
Threat management and recovery plan for yellow-eyed penguin / hoiho
The Hoiho Threat Management and Recovery Plan is mandated under the Conservation and Fisheries Acts and includes representatives from Ngāi Tahu, Yellow-eyed Penguin Trust, DOC and Fisheries New Zealand as partners in the provision of guidance and advice.
This approach provides a reasonable range of perspectives across non-governmental organisations, iwi and agencies to ensure the best outcomes for hoiho recovery. However, the group recognises the many other parties working in hoiho recovery and will ensure their input in the interim and longer-term plans.
See here for more information about this process.
Stable isotope analysis
Stable isotope analysis can be conducted on feather, bone, muscle or blood samples from penguins. We look at the ratio of carbon and nitrogen in these samples – nitrogen indicates the trophic level that the penguins feed at (i.e. how far up the food chain) and carbon helps to determine the primary source responsible for energy flow in an ecosystem.
By comparing historical and modern hoiho feathers from both the sub-Antarctic and mainland New Zealand for the we can work out whether there have been any changes in the ecosystem which reflects in what the penguins are/were eating.
Multibeam echosounder surveys
Multibeam echosounders (MBES) can be used to create high resolution bathymetry and geo-referenced images of the seabed. Trials have been conducted with the University of Otago (Surveying and Marine Science departments) off Otago Peninsula over the seabed where penguin foraging has been observed.
The aims of the trials are to test the MBES as a tool for investigating the benthic environment used by penguins, to examine what seabed features make important foraging areas (e.g. substrate type, depth) and examine any evidence for human impacts on the seabed (e.g. disturbance from fisheries, dredging).
Long-term we hope to map important benthic habitat off the Otago and Southland coast, highlighting specific habitat types. The data can then be used to examine the extent that human impacts overlap with penguin foraging habitats, and highlight areas requiring marine protection.
GPS data loggers
We know little about the habits of yellow-eyed penguins at sea. With the aid of satellite technology, studying penguin behaviour at sea using mini GPS logging devices attached to individual birds has opened a new window of opportunity.
The devices are attached to their backs using adhesive cloth tape, which allows for easy detachment without causing damage to the penguin’s feathers. Loggers can record the penguins’ dive depths at given intervals as well as their geographical position after each dive.
By studying the foraging behaviour of hoiho at different locations, we may shed light on where they feed, the depths that they dive to and how consistent these are for individuals and colonies over time. This will allow us to examine when and where penguins overlap with human activities and shed light on how we can better protect them.
Smart nest boxes
The Trust has established an ongoing working relationship with the Otago Polytechnic to develop new ways of monitoring hoiho. Students are currently working on ‘smart’ nest boxes which will be able to remotely collect data on which bird has accessed the nest, their weight and how often the parents guard the nest for before changing over.
Collecting fine-scale data about individual birds and nests will enable us to answer questions about how long foraging trips are, how much each parent invests in raising their chicks, the birds (adult and chick) weights throughout the season.
In the future there is potential to expand this work and add other sensors, for example, temperature loggers.