🧵: new work out in @AmOrnith! We used #cameratrapping to monitor Roseate Tern nests in 9 colonies in the Virgin Islands. We wanted to know how nest survival & predation risk changed w colony traits, since Caribbean Roseates move nesting islands yearly. https://academic.oup.com/condor/advance-article/doi/10.1093/ornithapp/duaa069/6131368?guestAccessKey=879105a6-1e1d-4d56-bf32-b93db921b58d
Colony characteristics influence nest survival of Caribbean Roseate Terns

Abstract. Determining how site characteristics influence reproductive success can help guide conservation planning for declining wildlife populations. For colon

https://academic.oup.com/condor/advance-article/doi/10.1093/ornithapp/duaa069/6131368?guestAccessKey=879105a6-1e1d-4d56-bf32-b93db921b58d
These colony sites are really different in terms of veg, other seabirds present, human disturbance, & predator presence. Colony sizes are also variable, from 5-700 breeding pairs! More birds at a nest site may = more protection from predators, but also more competition for fish.
These colony sites are really different in terms of veg, other seabirds present, human disturbance, & predator presence. Colony sizes are also variable, from 5-700 breeding pairs! More birds at a nest site may = more protection from predators, but also more competition for fish.
These colony sites are really different in terms of veg, other seabirds present, human disturbance, & predator presence. Colony sizes are also variable, from 5-700 breeding pairs! More birds at a nest site may = more protection from predators, but also more competition for fish.
These colony sites are really different in terms of veg, other seabirds present, human disturbance, & predator presence. Colony sizes are also variable, from 5-700 breeding pairs! More birds at a nest site may = more protection from predators, but also more competition for fish.
These colony sites are really different in terms of veg, other seabirds present, human disturbance, & predator presence. Colony sizes are also variable, from 5-700 breeding pairs! More birds at a nest site may = more protection from predators, but also more competition for fish.
On these islands, Roseate Tern nests are really variable too, ranging from isolated individuals to dense groups, & from exposed to totally concealed nests. How does all this variation influence egg & chick survival?! And is high nest predation contributing to population declines?
On these islands, Roseate Tern nests are really variable too, ranging from isolated individuals to dense groups, & from exposed to totally concealed nests. How does all this variation influence egg & chick survival?! And is high nest predation contributing to population declines?
On these islands, Roseate Tern nests are really variable too, ranging from isolated individuals to dense groups, & from exposed to totally concealed nests. How does all this variation influence egg & chick survival?! And is high nest predation contributing to population declines?
On these islands, Roseate Tern nests are really variable too, ranging from isolated individuals to dense groups, & from exposed to totally concealed nests. How does all this variation influence egg & chick survival?! And is high nest predation contributing to population declines?
On these islands, Roseate Tern nests are really variable too, ranging from isolated individuals to dense groups, & from exposed to totally concealed nests. How does all this variation influence egg & chick survival?! And is high nest predation contributing to population declines?
We found that nest predation was high & the primary cause of nest failure. Potential predators varied by colony site & included Red-tailed Hawks, but invasive brown rats were main nest predators, followed by (surprisingly!) a Great Egret, then Laughing Gulls.
We found that nest predation was high & the primary cause of nest failure. Potential predators varied by colony site & included Red-tailed Hawks, but invasive brown rats were main nest predators, followed by (surprisingly!) a Great Egret, then Laughing Gulls.
We found that nest predation was high & the primary cause of nest failure. Potential predators varied by colony site & included Red-tailed Hawks, but invasive brown rats were main nest predators, followed by (surprisingly!) a Great Egret, then Laughing Gulls.
We found that nest predation was high & the primary cause of nest failure. Potential predators varied by colony site & included Red-tailed Hawks, but invasive brown rats were main nest predators, followed by (surprisingly!) a Great Egret, then Laughing Gulls.
We found that nest predation was high & the primary cause of nest failure. Potential predators varied by colony site & included Red-tailed Hawks, but invasive brown rats were main nest predators, followed by (surprisingly!) a Great Egret, then Laughing Gulls.
Overall, Roseate Tern nest survival was low over the 2 years of our study: only 46% of nests produced a chick that survived >4 days. This is compared to other regions like the NW Atlantic, where nests average >1 chick annually, & could be why the VI population is declining.
Unexpectedly, the only colony trait that influenced both Roseate Tern nest survival & predation risk was SIZE. More birds = greater nest success, lower predation. Is this because of cooperative defense? More individuals congregating at higher quality sites? Unclear!
What this does tell us is that in tropical regions, management efforts are best directed towards enhancing colony size & protecting larger colonies. It also tells us that as tropical Roseate Tern populations decline, nest survival will likely go down as colonies get smaller.
A great outcome was learning that #cameratrapping is effective for monitoring nests! Caribbean Roseate Terns are understudied in part bc it’s so hard to reach islands & terns can abandon colonies w researcher presence. Cameras = minimal disturbance & only 2 visits to colonies!
A great outcome was learning that #cameratrapping is effective for monitoring nests! Caribbean Roseate Terns are understudied in part bc it’s so hard to reach islands & terns can abandon colonies w researcher presence. Cameras = minimal disturbance & only 2 visits to colonies!
A great outcome was learning that #cameratrapping is effective for monitoring nests! Caribbean Roseate Terns are understudied in part bc it’s so hard to reach islands & terns can abandon colonies w researcher presence. Cameras = minimal disturbance & only 2 visits to colonies!
A great outcome was learning that #cameratrapping is effective for monitoring nests! Caribbean Roseate Terns are understudied in part bc it’s so hard to reach islands & terns can abandon colonies w researcher presence. Cameras = minimal disturbance & only 2 visits to colonies!
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