Editing Population viability analysis (section)

==Examples==
The endangered [[Fender's blue butterfly]] (''Icaricia icarioides'') was recently assessed with a goal of providing additional information to the [[United States Fish and Wildlife Service]], which was developing a recovery plan for the species. The PVA concluded that the species was more at risk of extinction than previously thought and identified key sites where recovery efforts should be focused. The PVA also indicated that because the butterfly populations fluctuate widely from year to year, to prevent the populations from going extinct the minimum annual population growth rate must be kept much higher than at levels typically considered acceptable for other species.<ref>{{cite journal|last=Schultz|first=Cheryl B.|author2=Hammond, Paul C.|title=Using Population Viability Analysis to Develop Recovery Criteria for Endangered Insects: Case Study of the Fender's Blue Butterfly|journal=Conservation Biology|date=October 2003|volume=17|issue=5|pages=1372–1385|doi=10.1046/j.1523-1739.2003.02141.x|s2cid=59046296 }}</ref>

Following a recent outbreak of canine distemper virus, a PVA was performed for the critically endangered [[island fox]] (''Urocyon littoralis'') of [[Santa Catalina Island, California]]. The Santa Catalina island fox population is uniquely composed of two subpopulations that are separated by an [[isthmus]], with the eastern subpopulation at greater risk of extinction than the western subpopulation. PVA was conducted with the goals of 1) evaluating the island fox’s extinction risk, 2) estimating the island fox’s sensitivity to catastrophic events, and 3) evaluating recent recovery efforts which include release of captive-bred foxes and transport of wild juvenile foxes from the west to the east side. Results of the PVA concluded that the island fox is still at significant risk of extinction, and is highly susceptible to catastrophes that occur more than once every 20 years. Furthermore, extinction risks and future population sizes on both sides of the island were significantly dependent on the number of foxes released and transported each year.<ref>{{cite journal|last=Kohlmann|first=Stephan G.|author2=Schmidt, Gregory A. |author3=Garcelon, David K. |title=A population viability analysis for the Island Fox on Santa Catalina Island, California|journal=Ecological Modelling|date=April 2005|volume=183|issue=1|pages=77–94|doi=10.1016/j.ecolmodel.2004.07.022}}</ref>

PVAs in combination with [[sensitivity analysis]] can also be used to identify which vital rates has the relative greatest effect on population growth and other measures of population viability. For example, a study by Manlik ''et al.'' (2016) forecast the viability of two [[bottlenose dolphin]] populations in Western Australia and identified reproduction as having the greatest influence on the forecast of these populations. One of the two populations was forecast to be stable, whereas the other population was forecast to decline, if it isolated from other populations and low reproductive rates persist. The difference in viability between the two studies was primarily due to differences in reproduction and not survival. The study also showed that temporal variation in reproduction had a greater effect on population growth than temporal variation in survival.<ref name="Manlik et al. 2016">{{cite journal |author1=Manlik O. |author2=McDonald J.A. |author3=Mann J. |author4=Raudino H.C. |author5=Bejder L. |author6=Kruetzen M. |author7=Connor R.C. |author8=Heithaus M.R. |author9=Lacy R.C. |author10=Sherwin W.B. | title=The relative importance of reproduction and survival for the conservation of two dolphin populations| journal=Ecology and Evolution |volume=6 |issue=11 |pages=3496–3512 | year=2016 | doi=10.1002/ece3.2130|pmid=28725349 |pmc=5513288 }}</ref>