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Conservation Measures
Measuring the Impact of Island Conservation

To ensure that island restoration efforts are successful and imperiled species are being protected, Island Conservation employs a Conservation Measures Program by monitoring, measuring and mapping targeted species and their habitats. Scientifically documenting the response of island species and ecosystems also enables us to adjust and improve island restoration strategies and tools. 

Complete island recovery after the removal of invasive species can take as long as 30 to 40 years. To monitor recovery, Island Conservation uses short-term measures (1-5 years post removal) that are indicative of longer-term change. Examples of these measures include quantifying the calling activity of seabirds returning to breed on Rat Island, Alaska, and counting the number of native plant seedlings on Palmyra Atoll, both of which we expect to respond quickly following restoration of these islands.
 
How we measure impact
 
We use standardized methods ranging from using satellite imagery to map vegetation change, using artificial habitat to count threatened reptiles, and trained experts to identify bird nests and measure breeding success. We evaluate islands before and after the removal of invasive species and where possible, we compare restoration efforts to control islands where no invasive vertebrates are being removed, or where they have never been present, to provide a yardstick for recovery expectations.
 
Who we work with
 
Island Conservation contracts with the University of California at Santa Cruz Coastal Conservation Action Lab to implement monitoring on specific islands, such as Rat Island in Alaska and Palmyra Atoll in the Line Islands. We also engage directly with partners that are undertaking monitoring, such as PRBO Conservation Science in California’s Farallon islands and the Charles Darwin Foundation in the Galapagos.
 
Conservation Measures in action

DESECHEO ISLAND, PUERTO RICO Before we began removing invasive species from Desecheo Island in 2008, we started counting Higo Chumbo (Harrisia portoricensis) plants, a rare and threatened cactus. To date, since the removal of majority of invasive species, 33 new cactus plants have been discovered in island-wide field surveys, compared to only nine reported in 2003.
 
RAT ISLAND, ALASKA Rats, an invasive, non-native species on this Aleutian Island, had invaded what came to be known as Rat Island several decades ago. The rat found easy prey in the island’s abundance of birds, including the Song Sparrow, a small songbird. Not surprisingly no records of this species were collected during surveys in the presence of rats. Following the removal of rats from the island in 2008, this charming bird was identified first time during 2010 bird counts, potentially indicating a return of this species to Rat Island. Additionally, In June-August 2011, biologists recorded Leach's Storm-petrels calling on the islandThe presence of these birds and their behavior is strong evidence that the island is quickly recovering. 
Songmeters on Desecheo Island, Puerto Rico. These lightweight and unobtrusive tools can be deploywed for months at a time, providing a cost-effective way to indentify changes in bird calling activity over time.


Featured Species
How three people helped protect an important population of the "Titi" in just four short weeks.

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