Specimens wey people collect long before modern genetic tools fit still answer new questions. Smithsonian October 14 release describe research into frog decline for Brazil Boracéia Biological Station. Researchers use museum collections investigate events wey happen decades before present-day fieldwork.
Dem sample more than 370 preserved animals from 17 species, comparing collections from before and after the decline for late 1970s. Earlier specimens show no evidence of chytrid fungus for the tests, while more than half of specimens from 1980s test positive.
That timing support fungus as important explanation for local losses. E no mean every old frog decline across Brazil get the same cause. Researchers explicitly limit their conclusions to this site. Environmental conditions fit also contribute, so one finding no automatically explain every place.
Different species show different patterns. Some wey remain plenty carry infection, while those wey decline sharply show no detected infection for surviving collection. Authors suggest differences in tolerance and whether collectors find animal before e die fit help explain this apparent contradiction. Na explanation to investigate, no be direct record of every death.
Modern field visits find 12 out of the 17 species for historical collection. Failure to find the other five alone no prove extinction. E identify gap wey need more observation, and show why present-day surveys and old specimens suppose be interpreted together with proper care.
The broader contribution na method for investigating old ecological puzzles. Museums preserve evidence wey fit answer questions collectors never imagine. Careful comparison across time fit strengthen explanation without pretending say surviving collection record every animal, every infection or every cause behind changes for the forest.