Those newts carrying a malevolent parasite die off during their migrations, leaving only the newts with a mild strain of the parasite that return to the pond to mate... "Birds that fly each year from North to South America may be avoiding more than bad weather.
(Those newts; carrying; a malevolent parasite) (Birds; fly; T:each year; from North; to South America) (Those newts carrying a malevolent parasite; die off; T:during their migrations) (Birds; may be avoiding; more than bad weather) (Those newts carrying a malevolent parasite; leaving; only the newts with a mild strain of the parasite) (the parasite; return; to the pond; to mate)
Those newts Birds Those newts carrying a malevolent parasite Birds Those newts carrying a malevolent parasite the parasite
carrying fly die off may be avoiding leaving return
a malevolent parasite
T:each year from North to South America
T:during their migrations
more than bad weather
only the newts with a mild strain of the parasite
to the pond to mate