Penguin work on Robben Island

Kate Robinson and Richard Sherley are two members of the ADU who work on the Robben Island African Penguin colony. Different kind of work is carried out but we can quote two main protocols that require a lot of work and involvement: 

- Logger positioning on African penguins in order to learn more   about penguins' movements once at sea (1)

- Chick measurements for the chick growth study (2)

Pictures from Elsa Bussière and Craig Harding

(1) Logger positioning on African penguins

The logger is a small device positioned on penguins' back. Light and hydrodynamic, its discomfort and disturbance have to be minimal.

First step: Logger calibration

The logger is getting prepared to go to sea. Kate Robinson chooses the settings and makes sure that the connection with satellites is working.

Second step: Find an appropriate nest. Chicks must not be too young cause we try avoid any kind of disturbance while they are fragile. But they must not be too old as well. Indeed, the adults might not stay in the nest anymore and it becomes really complicated to retrieve the logger. Once we found a good nest, we mark one of the adult with some coloration (which is totally harmless) and monitor the nest for a couple of days to make sure that the parents switch well and regularly, therefore the chances to retrieve the logger are high.  

Marked penguin with pink on the neck

Third step: Prepare all the equipments before interacting with birds. 

Step 4: Catch one of the adult. Adult penguins with chicks are brave and face the intrusive visitor, ready to bite anytime. To minimize disturbance, the capture must be calm and quick, and therefore done by an experienced person like Kate who learnt how to appraoch penguins with Antje. 

It is really important to make sure that during the positioning, chicks remain in the nest. 

Once caught, the penguin is given to the field assistant who will have to hold it immobile for approximately 15 minutes, while Kate positions the logger. 

Elsa bussière, field assistant, taking over from Kate to hold the penguin

Step 5: The penguin holder takes some time to have place comfortably cause then the bird will have to remain immobile. The penguin's head is covered with a clothe, it thus calms down. A pattern is positioned on the penguin's back to define the area where Kate will work on, which is the area where the logger will be applicated. 

Application of the red pattern

Step 6: Slowly, Kate will lift feathers rows and slip under pieces of sellotape. 

Then, a few drops of glue are scattered on the feathers.

Step 7: Applicate the logger and start turning down the tips of the sellotape around the device. 

The sellotape helps keep the logger waterproof.

Step 8: Remove the pattern around the logger.

Step 9: Add more sellotape and glue along the edges to prevent water from getting between the sellotape layers. 

Step 10: Sprinkle sand on the device to prevent the glue to come on the chicks' feathers once the adult back into the nest. 

Done! The penguin is ready to go!

Step 11: Put the penguin back into the nest making sure that the chicks do not run away. 

See you in two days! 

Hopefully, this penguin will go to sea and come back in two or three days. Then, the same procedure is repeated and the logger removed. Some measurements are done :

- bill length

- bill width

- mass

The data from the logger will then be downlaoded and analysed. 

This procedure is never repeated more than once on the same penguin.

(2) Chick measurements

By measuring penguin chicks weekly, we can hope to define an index that would correlate size and age. This index would help assess penguin's age thanks to the measurements or, if we know the age, assess teh chick's condition. 

Generally, penguins lay two eggs that would give two chicks. 

First step: Catch the chicks

Once between the legs, the chick feels safer and stops figthing. Nevertheless, never trust a penguin and watch out your fingers.

Second step: Mark the two chicks with two different colors 

This color mark will enable us to recognise them in a week time. Besides, when they will get bigger, they might move within a few meters around the nest and then it would become difficult to know which ones are those that have been monitored. 

Third step: Measurements

- skull length

- flipper length

- mass

The penguin is in the bag!

Step 4: Release the chicks and make sure they do not leave the nest

Richard, release this chick!

In order to minimize disturbance, nests that are chosen for the chick growth study are always different nests from those chosen for the logger study.