Hunting ban should not be an option to conserve animal diversity because a ban increased poaching incidences hence the hunting of species that could be conserved when none vulnerable species were allowed to be hunted.
This is a complex question and the answer depends on your study system !
Apart from your own answer, there is also the case when we (human) extirpated natural predators and we now have overabundance of prey that reduce vegetal diversity.
Ban on hunting cannot assure conservation of animal diversity. God has created all other creatures for the benefits of human being. Hunting is human instinct and man cannot be made work against his instinct. For the conservation of animal diversity, there is a need to sensitize the hunters about the importance and ecological role of the wildlife species. Also the need for awareness raising about the sustainable use of natural resources. Our efforts to stop hunting or forbidding the hunters forcefully cannot be fruitful unless we convince the hunters and masses about the importance of biodiversity.
Definitely not. We have experience where certain protected species are absent from protected areas (i.e. National Park) and present in the neighbouring hunting ground. Protection of certain species directly removes them from the hunting list, and CIC removes trophies so they are not of interest any more. Also, I agree with Shimane, poaching is the main problem, not hunting (hunting is regulated by several instances).
A hunting ban is only one of several options that can be used to conserve animals. In some instances, a ban can be vital (e.g. if there are very few individuals left in the case of critically endangered species). However, in others, it may be inappropriate or indeed counter-productive (e.g. if an outright ban on hunting had been put into effect for wolves in Yellowstone NP, then the farming community surrounding the park would never have come on board with the reintroduction - instead farmers have the right to hunt and shoot wolves if they are attacking their herd). Waseem is partially correct in his response by saying that hunters need to be educated on the role of their prey in ecology - hunters can be important elements of habitat management through culling of excess populations. However, hunting must be controlled - indiscriminate killing (poaching) has no place in conservation strategies.
This is wide problem - because very important is area character. When the area is biodiversity hot spot, with predators like bears, wolfes and the nature processes are preserved, then hunting is not needed. Poaching is widespread together with hunting and hunters are also very often poachers - slovak situation...But in farmland or in area without large carnivores, there hunters can be useful to reduce population of herbivores.
Back to the answer - hunting ban could be very useful for nature conservation in some cases. Problem is especially ilegal shooting. On other site - one example on positive effect hunting activity - higher game density in some places, which support predators like birds of prey - eagles, hawks and falcons. But there is opportunity for human - predator conflict.
You must think about it. Important are: location, experiences with hunters in this area, ilegal activities in region, nature diversity, culture and support from government and local people.
In Europe, hunting was and is normal because the carrying capacity of the land has been calculated, so hunting is, effectively, culling. In Asia, on one hand there is a large human population, malnutrition and limited natural landscape and on the other hand, a market for wildlife products. Here, hunting can conceivably cause damage, if it is unregulated. In Africa, there is much the same problem although pressure on land is not so acute. North America has regulated hunting, while South America is again largely unregulated. India has enforced a ban on hunting since 1972, but I have not seen any studies that suggest that wild life populations have improved since then. Instead, in parts of the Himalaya, agriculture has come to a standstill because of the combined menace of rhesus macaques and wild boar, whose population exploded in the absence of large cats, human hunting and the large resource base that forays into agricultural land opened up for them.
To my mind, hunting on a permit system is sensible, provided the expertise is there to judge when culling is necessary. Without that expertise, and with a corrupt regime, certain species can easily be exterminated with official connivance.
I think hunting ban can help threatened species conservation, as for wolf in Italy. See for example the introduction of this paper: http://rcin.org.pl/Content/12566/BI002_2613_Cz-40-2_Acta-T40-Suppl3-101-110_o.pdf
There's no such thing as a more valuable species. Over populated species might be hunted. Does that put humans on the list? I generally don't approve of hunting and support bans. I think poaching is a problem whether hunting is legal or not. I'd like to see the jungle meat markets shut down and wiped out. In the US many of the top predators were hunted to near extinction. There's lots of resistance to reintroduction and conservation of them. I work with a farmer who had tried raising sheep. He had no shepard and no dogs. The coyotes chased his sheep up to the hilltops where they didn't eat. Now the coyotes are his best friends in controlling rodents.