Wild Nature Institute Partners with Como Park Zoo for Giraffe Science

Wild Nature Institute is excited about a new partnership with Como Park Zoo to help us with giraffe science. Jill Erzar, scientist and giraffe-keeper at the zoo, spent two weeks with us in Tanzania, using our giraffe identification photographs to estimate heights of individuals over time. These data provide us with growth rates as well as an index of animals' ages. With this information we can study whether growth rates vary in different parts of our study area, and we can determine at what age juveniles disperse from the herd in which they were born.

Jill and Monica measuring giraffe necks from photographs to estimate height.

We employ a technique called photogrammetry, which means using photographs to measure distances. Here we measure the number of pixels in the giraffe's neck and then use an algorithm to calculate height, and then use height as an index for age. The two photographs below are from the same individual in June 2014 and again September 2015.

Young female from June 2014.

The same female in September 2015.

With Jill's help we measured giraffe necks from 1,800 photographs!

We also visited our study area in Tarangire National Park where Wild Nature Institute has been monitoring demography and social relationships of more than 3,100 individual giraffes over 8 years. Happily we saw a lot of our 'study animal' as well as many of the other spectacular animals that share the savanna with giraffes.

Thank you so much, Jill, and we look forward to a long and fruitful working relationship.