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50001 <br />c5 <br />•a <br />z <br />4000 <br />as <br />as <br />Toa 20001 <br />0 -i <br />• <br />• <br />.4 Tre4c.ti rlitN r <br />2000 <br />2005 <br />Year <br />2010 <br />2015 <br />Figure 5. State -space model estimates of palila abundance from 1998 through 2018. Points are <br />estimates from DISTANCE models, the line shows the median estimate from the Bayesian posterior <br />distribution of abundance, and the shaded area shows the 95% credible interval of abundance <br />posteriors. <br />CONCLUSIONS <br />The 2018 palila population was estimated at 778-1,420 birds (point estimate of 1,051). There was very <br />strong evidence that the palita population declined after 1998, with the greatest decline occurring after <br />2003. The average rate of decline during 1998-2018 was 168 birds per year, resulting in a 76% decline in <br />the population over the 20 -year period. <br />Trends assessment shows very strong evidence that the pallia population is in decline. The most <br />optimistic interpretation shows only an 8% chance of it being stable or increasing. Despite the 2017 <br />survey having almost twice the survey effort in the core area (825 vs. 419 survey visits) the width of the <br />bootstrap uncertainty interval for the two years was almost the same (636 vs 642). <br />MANAGEMENT IMPLICATIONS <br />The palila population has been in decline since 1998. The 2018 abundance estimate is the lowest <br />published since regular surveys began in 1998, although Johnson et al. (2006) attempted to correlate <br />historical survey methods with modern techniques, and suggests it may have been lower during the <br />mid -1980's. A naive projection of the decline since 2009 would predict the population will half the <br />current abundance in 10 years and become extinct in another 20. <br />14 <br />