Normalerweise besetzen auf kleineren Inseln verschiedene Anolisarten (sofern vorhanden) unterschiedliche ökologische Nischen (z.B. A. wattsi und A. bimaculatus). Wie sieht das bei den beiden Utilaarten aus? Wo ist welche der Arten dort zu finden? Haben beide Arten den gleichen Ursprung? Gibt`s dazu vielleicht auch Arbeiten?
Gruß
Horst
P.S.: Soll ich das mal ins DGHT-Forum setzen und/oder mal "Phelsuma" mal darauf ansetzen?
|
||||||||
wie ist das mit N. bicaorum und N. utilensis?Moderatoren: Horst, saumfinger, Timo
7 Beiträge • Seite 1 von 1
wie ist das mit N. bicaorum und N. utilensis?
Hi all,
Don't forget that bimaculatus and schwartzi are generalists under the anolis species. St Kitts for instance has 2 anolisspecies (the ones you mentioned). If you compare that to other isles that have two species you could get to a very interesting conclusion. One of them is big and the other one is small. These animals are mostly generalists that ocupy every ecological nische that isn't occupied by a competitor (for the smaller one that means it thrives in absense of the big one) and therefor the aren't very specialised their behavior. Anolis species that originate from places that have many competitors (for instance the greater antilian isles or the mainland species) are much more specialised tot their ecological nische and mostly only inhabit an specific area of their habitat to reduce the stress of competing species. I think since the anolis you mention are related they should have some sort of a natural barier between the species (that is a simple rule of thumb for allopatric speciation) or if they do live in contact with each other there must be a very strong form of disruptive selection that avoids interbreeding. greetings denny
Hallo Denny,
sind A. bimaculatus und A. wattsi richtige Generalisten? Ich dachte A. wattsi ist eine bodenorientierte Art während A. bimaculatus eine Baumbewohnende Art darstellt. Außerdem unterscheiden sich beide Arten sehr stark im Habitus und wohl auch im Beutespektrum. Und A. wattsi weicht wohl dort aus,wo A. bimaculatus auftaucht. Beide Arten haben aber den selben Ursprung. Weicht bei den Anolis (Norops) auf Utila auch eine Art der anderen aus? Haben beide Arten den selben Ursprung? In die Reptilia hab ich noch nicht reingesehen... Gruß Horst
Yes they are more or less generalists. They ocupy all ecological nishes that are pretty competition free. Because of a lack of competition there is no need to specialize as far as greater antillean species. I know for instance from L. Wijffels that A. bimaculatus is often found searching for food on the ground. A. schwartsi is food for A. bimaculatus so that is the reason the two species (well actually schwartsi) avoid contact. Simply said, if schwartsi (used to be a subspecies of wattsi) dares to enter the roam of a bimaculatus it is eaten. In places where the two species don't 'meet' each other they occupy all ecological nishes that have a relatively low competition. For that reason they are capable of living almost anywhere which makes them generalists. Bimaculatus prefers open places, schwartsi is found in forests but in absence of bimaculatus it also inhabits the open places. So schwartsi is the most generalist of them. But because of the lack of specific habitat use they are both seen as generalists. The difference in use of food resources has I think more to do with size than anything else. About Utila species, If they are closely related (I thought they where) they live in absence of each other because otherwise they would never have become different species (interbreeding shifts a species either one way or another producing 1 viable species. Species are formed because a natural barrier isolates them from there ancesters so they can evolve to a species. The animals therefor can inhabit the same habitat and nishe but most likely one is on the right side of the mountain while the other lives on the left side to put it very simple. They can coexist if they have evolved enough to rule out any sexual interaction between the species. To put it simple, one went over the mountain. became a species and went back over the mountain. Wel evolution is a very difficult thing you know. regards Denny
7 Beiträge • Seite 1 von 1
Zurück zu Alles rund um Anolis Wer ist online?Mitglieder in diesem Forum: Keine Mitglieder und 10 Gäste |
