Summary: Now that you know what MOTUS is and what it does, let’s talk about how is helps Arizona birds. Join Cheryl and Kiersten to find out how MOTUS is helping some Arizona birds. For our hearing-impaired listeners, a transcript of this podcast follows the show notes on Podbean. Show Notes: “Desert Deliverance”, by Margo Rosenbaum, Audubon Magazine Fall 2023, pg 18-19 “Home Away From Home”, by Daniel Grossman, Audubon Magazine Fall 2022, pg 30-35 “The Mysterious Decline of the American Kestrel,” by Jillian Mock, Audubon Magazine Spring 2023, pg 20-27 “Keeping Up with the Grosbeaks,” by Zoe Grueskin, Audubon Magazine Winter 2023, pg 15 Transcript Cheryl-Intro: Recently, we posted a podcast about MOTUS. What it is-radio tracking system-more towers being placed in Arizona, one possibly at the Gilbert Riparian Water Ranch. I wanted to revisit this because I found actual research studies using MOTUS that has an impact on Arizona birds. It is exciting to see the impacts of this new technology and how it is advancing research in bird studies. Keirsten: Purple Martins If you have lived on the east coast or in the mid-west of U.S. you have seen Purple Martins, and the colonial-style bird houses that they like to nest in. A little back story about this bird, Purple Martins are insectivorous (insect eaters) which has made them vulnerable to the pesticides we use on our yards. So, their numbers were really in decline here in the U.S. until citizen science got involved. People who enjoyed seeing the birds and understood their importance to local insect control started placing the correct nest boxes these birds like. These citizen scientists monitored the boxes, eliminated pesticide use on their properties, kept cats indoors etc. Over time the populations of Purple Martins bounced back in the Untied States. So why are we talking about them…because their numbers are still in decline, and scientists don’t really know why. Purple Martins have been studied extensively In North America; scientific knowledge tapers off when they fly south. Just where do they go, Wat routes they take, and what critical habitat lies Along the way remain largely a mystery. The marathon journeys these birds undertake every year compounds the risk to their survival. Arizona has its own sub-species of Purple Martins that prefer to nest in Saguaro cacti in the southern part of our state. Arizona’s Purple Martins spend the winter where? They take a similar marathon journey as those who summer east of the Mississippi River. Cheryl: Get to the point-Brazil. Just off a slice of land sitting mid-stream in Brazil’s Rio Negro, is an island locally known as Ilha do Comaru, every year this island is submerged in March and only the tree tops poke above the surface. There in those treetops are Purple Martins. Now, Motus helped to locate this tiny island of 12 acres (slightly larger than Yankee Stadium). How you ask? Back in the U.S., scientists with the help of volunteers tagged nesting Purple Martins (adults and fledglings) with radio tags that will ping a receiver, that by chance was placed near this island. Scientists looked at the MOTUS network tracking and thought huh? Where is that? It turns out that MOTUS revealed to scientists a space that is host to a concentration of roughly 250,000 birds between February and April, it’s one of the largest Purple Martin roost ever discovered. Its significance isn’t just its size, however, but also the pivotal role the roost may play in the bird’s long-distance migration. Comaru could be the staging ground, or launch pad, for many of the 9.3 million Purple Martins that funnel through from South to North America. Scientists are tagging Purple Martins on this tiny island, so they can trace birds coming and going to see where these birds’ journey to breed. Some head to Arizona, and some head towards the east coast of the U.S. This is important to Arizona Purple Martins because our sub-species like to nest in Saguaros that are 40 ft high. It is easier for everyone if the tagging is done on this tiny island. Scientists are excited to trace the movements of these birds to figure out what they’re eating and analyze whether they’ve been contaminated by pesticides and other pollutants, we can learn something about how they’re doing in Brazil. Scientists feel that by taking a closer look at the birds onto this small isle, they hope to glean insights that can help secure the future of the entire species, and any discoveries they make will help uncover what’s behind the decline of other songbirds, especially other aerial insectivores. Keirsten: The American Kestrel Arizona hosts the American Kestrel all year long. It just moves within the state. This bird is on the decline here due to loss of habitat, pesticide use, and the ...
