Learning more about the mysterious Galapagos Martin

November 5, 2018

By David Anchundia, ornithologist with the Charles Darwin Foundation.

The Galapagos Martin

The population size and health status of the Galapagos Martin is currently unknown.

As an ornithologist and a lover of all things Galapagos, my focus is to conserve and protect the unique birds of these Islands. My current goals include getting to know one of the most mysterious and elusive birds of the Archipelago, the Galapagos Martin. This bird, endemic to Galapagos, is closely related to the Purple Martin. The Galapagos Martin has never been studied. We don’t know how many individuals exist in the Archipelago and if they are threatened. It’s a difficult species to study as it is rarely seen and, when it is, it is usually found on hard-to-reach sea cliffs and hilltops.

In July 2017, with the support of Galapagos Conservancy, I was able to search for and count Galapagos Martins on the shore and sea cliffs throughout much of the Archipelago during the blue-footed booby census. We only managed to see about 30 individuals and identify three potential breeding sites. I could not estimate population size with this technique, but the discovery of the breeding sites was vital to furthering our understanding of these elusive birds.

Galapagos Martin nest in cliffs

Galapagos Martins nest in crevices in cliffs making them hard to study.

Since 2015, we have been searching for Galapagos Martin nests to determine whether the invasive parasitic fly Philornis downsi attacks its chicks, as they do to other landbirds in Galapagos. They feed on the blood of nestlings, which often results in death. Galapagos Martin nests are located on high sea cliffs; checking them is dangerous due to loose rocks and big waves that make for hazardous navigation.

In 2017, we received reports from naturalist guides about one nest with two chicks at Tagus Cove on western Isabela. When I visited the site, the nest was active, but it was only accessible from the tip of the boat during very high tide. Conditions were unsafe, so I had to leave without examining the nest in detail. On my return visit, the nest was empty, but nest material remained. With the help of park rangers skillfully driving the boat to avoid hitting the rocks, I was able to collect the nest material. Unfortunately, I found empty fly pupae that looked very similar to Philornis downsi pupae.

In May 2018, we received another report from naturalist guides that there was an active nest with two large chicks at the same site. I was able to travel on the National Geographic Endeavour two weeks later but found the nest empty. I did manage to collect the nest and found 21 fly pupae, which we placed in a container with cotton and water. The flies emerged two days later — and we now know Philornis does attack the Galapagos Martin.

Galapagos Martin house

Martin houses have been set up on Isabela and on Santa Cruz Island to study breeding behavior.

We don’t know how great an impact the fly has on the Martin, but given the incredibly destructive impact Philornis has on other landbird species it will be important to investigate this further. Natural nests are almost impossible to locate, so I decided to get creative — I built a Martin house following models used for Purple Martins. After an adrenalin-filled boat ride on the roughest seas I have ever experienced, park rangers and I set up a Martin house near the existing bird colony at Tagus Cove in July of 2018. It has six compartments and a Martin decoy sits outside to welcome other birds. We hope the birds will be attracted to the house and begin to nest there. If the house works, I will do an extended trip to Tagus Cove to collect the first data on brood care and the impact of Philornis. I hope to catch the birds, band and measure them, take blood samples, and conduct a general health check. We will also employ techniques to track them more efficiently throughout the Archipelago.

Galapagos Martin house at Tagus Cove

The Martin house at Tagus Cove on the west coast Isabela.

With this encouraging start, we hope to uncover the mystery of the Galapagos Martin.
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David Anchundia, CDF ornithologistNative Ecuadorian David Anchundia has been working as a researcher on the Landbird Conservation Project at the Charles Darwin Foundation since 2015. He completed his Master’s degree with Dave Anderson of Wake Forest University on Blue-Footed Boobies. David first started working in Galapagos in 2008 and is passionate about finding ways to ensure the long-term protection of the unique birds of the Galapagos.

All photos © David Anchundia, CDF.

 

 

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