SU0014056 - Laserfiche WebLink

Home Browse Search

7/27/2021 IPaC:Explore Location resources Each green bar represents the bird's relative probability of presence in the 10km grid cell(s)your project overlaps during a particular week of the year. (A year is represented as 12 4-week months.)A taller bar indicates a higher probability of species presence. The survey effort (see below) can be used to establish a level of confidence in the presence score. One can have higher confidence in the presence score if the corresponding survey effort is also high. How is the probability of presence score calculated?The calculation is done in three steps: 1. The probability of presence for each week is calculated as the number of survey events in the week where the species was detected divided by the total number of survey events for that week. For example, if in week 12 there were 20 survey events and the Spotted Towhee was found in 5 of them, the probability of presence of the Spotted Towhee in week 12 is 0.25. 2. To properly present the pattern of presence across the year, the relative probability of presence is calculated. This is the probability of presence divided by the maximum probability of presence across all weeks. For example, imagine the probability of presence in week 20 for the Spotted Towhee is 0.05, and that the probability of presence at week 12 (0.25) is the maximum of any week of the year. The relative probability of presence on week 12 is 0.25/0.25 = 1; at week 20 it is 0.05/0.25 = 0.2. 3. The relative probability of presence calculated in the previous step undergoes a statistical conversion so that all possible values fall between 0 and 10, inclusive. This is the probability of presence score. To see a bar's probability of presence score, simply hover your mouse cursor over the bar. Breeding Season ( ) Yellow bars denote a very liberal estimate of the time-frame inside which the bird breeds across its entire range. If there are no yellow bars shown for a bird, it does not breed in your project area. Survey Effort (1) - Vertical black lines superimposed on probability of presence bars indicate the number of surveys performed for that species in the 10km grid cell(s)your project area overlaps. The number of surveys is expressed as a range, for example, 33 to 64 surveys. To see a bar's survey effort range, simply hover your mouse cursor over the bar. No Data (—) A week is marked as having no data if there were no survey events for that week. Survey Timeframe Surveys from only the last 10 years are used in order to ensure delivery of currently relevant information. The exception to this is areas off the Atlantic coast, where bird returns are based on all years of available data, since data in these areas is currently much more sparse. probability of presence breeding season I survey effort —no data SPECIES JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC https://ecos.f\vs.gov/ipac/location/AWS2S6WTNFFRXHIS26KF2RKQQY/resources 7/13