Sorry if this question has been answered elsewhere - I couldn’t find it anywhere.
Can Motus be used to monitor terrestrial mammals? In areas with good tower coverage (e.g., southern Ontario), it would be appealing to get sporadic hits of tagged mammals as they travel across the landscape. Much cheaper and less intrusive than collars, albeit providing less thorough data. But I don’t know if it’s possible.
The potential problems I anticipate are:
Habitat interference. Whereas birds/bats fly in the clear sky, terrestrial mammals can travel through forests and other areas with structures that could block transmission. So signal would be intermittent, but that’s ok if we’re just looking for lucky sporadic pings.
Shorter sightlines on ground than air. The radius of detection around towers should be lower for terrestrial animals since they’re down on the ground instead of in the air with our round earth. But if we even get sporadic pings from towers when mammals happen to come nearby that’s ok.
Tag permanence. Mammals will scratch at tags to remove them. There might be ways to attach them in a robust way to the ear tags we already attach. e.g., maybe we could encase the tag in protective transparent epoxy attached to the ear tag - would transparent epoxy inhibit the tag’s signal?
Does anyone have experience trying Motus with terrestrial mammals (especially large mammals like black bears)?
Thank you for any advice.
Jay Fitzsimmons
Ontario Ministry of Natural Resources and Forestry
In short, absolutely, yes. Any Motus-compatible tag can be modified into a form factor appropriate for a terrestrial mammal, from ear-tag, to collar, to backpack harness, etc. You’re right that the detection probability will be lower as the animal gets lower to the ground, but there are definitely cases where the range of the animal and the density of the network could warrant its use. There have been several projects in the US where multiple mammal species were tagged with Motus-compatible radio tags manufactured into a collar form-factor to look at predator/prey relationships. In the cases I’m aware of, the researchers were not using the Motus network per se, but the same equipment (including a finer-scale node network), but the tags were detectable from the Motus network had the researcher registered them, and presumably if the animals ventured far enough they would also get picked up by other Motus stations in their path. A nice example of species-base variation in detection was exemplified in some of the bat work at MPG Ranch (William Blake could chime in from his experience there) where they found that the bats were not getting picked up by the more long-range surveillance stations they had established on ridges (great for high-flying migrant birds)…so they placed smaller stations in lower riparian areas and increased their bat detection exponentially…so it’s likely to benefit mammal researchers to think about how augmenting the Motus network in a mammal-specific way could increase the usability of the technology for a broader range of species.
It’s worth noting also that the recent Southeast (US) Motus expansion, funded by a competitive state wildlife grant, includes a project on tracking Bog Turtles, further demonstrating the evolution of Motus’s usefulness across a broader range of species.
Cheers,
David
David A. La Puma, PhD (He/Him) • Vice President, Global Market Development
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I unfortunately do not have an answer for you, Jay, so I apologize for
butting into your conversation. I work with both turtles and bats and would
like to contact the people David mentioned to discuss their projects. I
placed nanotags on bats last year and didn't get the number of detections I
was hoping to achieve. I think I might be having the same issue that was
mentioned. I also study turtles and would really enjoy implementing a
project that would allow for passive monitoring as we have a small crew.