 The authors also pointed out that because the last sighting before 1662 was in 1638, the dodo was probably already quite rare by the 1660s, and thus a disputed report from 1674 by an escaped slave cannot be dismissed out of hand.Although the IUCN lists the Rodrigues solitaire as going extinct by 1778, the species probably became extinct some time between the 1730s and 1760s; the exact date is unknown.Its disappearance coincided with the tortoise trade between 1730 and 1750, when traders burnt off vegetation, hunted solitaires, and released cats and pigs that preyed on eggs and chicks.