[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Packing in the bats
Possible reasons why flyers might have high species packing: ability
exploit steep or vertical surfaces; mobility - ability to use scattered
Good call; those could definitely have an impact.
It is probably worth mentioning, however, that not all flyers tend
towards high species packing. Small-bodied, short-range taxa have a
strong tendency to produce heterogenous, species-rich clades with high
species packing. Larger and/or wider ranging species produce the
opposite, however. Both "modes" persist over time, but probably for
slightly different reasons: Long-distance flyers with wide geographic
ranges are robust to local pertubations. Many seabirds and raptors, as
well as several pterosaur lineages, have both long durations in the
fossil record, and I suspect that this is a result of have large
ranges. By contrast, species like passerines and vespertilionid bats
probably have higher turnover rates, but they more than make up for it
with a higher speciation rate. In essence, at a higher clade level,
both types of lineages persist for long periods of time, but the
wide-rangers have a few morphs over a large area, while short-rangers
are dominated by heterogenous distributions (many morphs, each with a
small range, that altogether cover a wide area).
The difference in average home range, as well as emergent
extinction/speciation rates probably have an impact on species packing.
That's my best hypothesis at the moment, in any case.