Applied ML Systems · Capstone brief
DS-13 · Are the birds moving north?
Pick a species with dense occurrence records. Has the centroid or northern edge of its observed range shifted over the last thirty years — and how much of any apparent shift is just more people with phones?
GBIF species occurrence downloads needed a hand check when last checked. Confirm the current source before assigning this brief.
The question
Pick a species with dense occurrence records. Has the centroid or northern edge of its observed range shifted over the last thirty years — and how much of any apparent shift is just more people with phones?
Data
GBIF species occurrence downloads (https://www.gbif.org/). NOAA climate normals (https://www.ncei.noaa.gov/products/land-based-station/global-historical-climatology-network-daily).
Expected failure modes
Observation effort has exploded since smartphone apps arrived; raw occurrence counts measure observers, not organisms. Records cluster along roads and near cities. Taxonomic revisions split and merge species across the study period.
Done looks like
A range-shift estimate with an explicit effort correction, the correction method defended, and a sensitivity analysis showing how the conclusion changes under different corrections.
Five C's
CT: distinguishing signal from sampling. CR: constructing an effort proxy. CO: comparing species with a partner to see whether patterns are shared. CM: a figure that shows the correction's effect. CZ: climate evidence gets scrutinized adversarially — the work must survive it.
Mentor role
An ecologist, ornithologist, museum collections manager, or biostatistician reviews the effort correction at Checkpoint 1 and the sensitivity analysis at Checkpoint 2. School-supervised.
Rubric calibration
R1: one species, one measure of range. R2: taxonomic changes checked. R3: uncorrected trend as the baseline. R4: sensitivity across correction choices. R5: the corrected-vs-raw figure is the centerpiece. R6: states what confounders remain.
Two ways this goes wrong
(a) The student plots raw occurrences over time and discovers iNaturalist's launch date. (b) One effort correction is applied, produces the expected answer, and no alternative is tested.
Source moved or something unclear? Send feedback on this brief. Mentors are advisory; the school supervises. These briefs do not produce verified computer-science credit.