It's likely this shrinking habitat caused an increase in competition for food and territory between individuals of the species, and perhaps as a result of this, the solitaire evolved a club-like bone growth on the end of each wing. It used this against other solitaires in territorial boxing matches. These would have been quite a sight, as the males stood almost a metre tall and weighed 28kg while the females were sandy coloured and were half that size.
Leguat described how the birds used their short wings to make a loud rattling sound that could be heard "two hundred paces off". He also described the bone on their wing which grew larger at the end, forming a mass under the feathers "as big as a musket ball". This was used as a club-like weapon, and along with their beak, was "the chief defence of this bird".
"They never lay but one egg, which is much bigger than that of a goose. The male and female both cover it in their turns, and the young is not hatch'd till at seven weeks' end: All the while they are sitting upon it, or are bringing up their young one, which is not able to provide itself in several months."
Monogamy and shared parental care are common in other pigeons we see today, including close living relatives of the solitaire, the nicobar pigeon and crowned pigeons. Like these pigeons, the solitaire likely fed their chicks "pigeon milk', a nutrient rich soup produced in the walls of the throat pouch of the parent birds. Two parents are able to produce more food, and so a larger chick, increasing their competitive advantage against other birds in the fight for territory.
Parts of the behaviour of the solitaire described by Leguat, including the aggression, can be seen in the crowned pigeons, which will hit anything that approaches them on the nest with small bone spurs on their wing-wrists, but in the solitaire, with its evolutionary cauldron of the shrinking island of Rodrigues, these adaptations were pushed to an extreme.
http://www.bbc.com/news/science-environment-42057143
No comments:
Post a Comment
Due to a small but consistent influx of spam, comments will now be checked before publishing. Only egregious spam/illegal/racist crap will be disapproved, everything else will be published.