Seasonal and habitat changes: How many of each kind of spider are present in your part of Australia at a particularly time depends not only on the season but also on such things as which country or district you are living in, whether you reside in forest, farmland or some other kind of environmental setting, and what weather conditions you have been experiencing lately. In general, it can be said that there are more adult spiders around during late spring to early autumn than for the colder months of the year because there are more insects around for them to feed on when the weather is warm. In addition, adult males of many species will only be found in summer and autumn because this is when the population of adult females will usually be greatest. Adult spiders will be hard to find during mid-winter unless they occupy a habitat that protects them from the adverse conditions of winter. Finally, you can expect to see plenty of immature spiders in autumn and in early spring and you will find more spiders in areas of high rainfall and fewer examples of most species during droughts. Changes due to human interventions: Although it is generally agreed that Australia still has more undescribed spider species than ones to which a scientific name has been assigned it is also true that some species have declining numbers, especially ones that have relatively limited ranges and especially in places where humans have greatly altered the natural environment. Clearing and exploitation of virgin lands by humans has put some spider species at risk and provided improved conditions of those spiders that have managed to adapt to places modified by human interventions. But perhaps a more generalised problem is severe adverse climatic events that are probably due to man-made global warming. Even in places where enterprises such as broad-acre farming have potentially improved the habitats of some spider species those spiders that have had their habitats destroyed by clearing of bushland, cultivation of soil and control of insect pests have inevitably gone into decline. This must surely get worse as Australia's human population increases. Spider classification changes: From a taxonomic (i.e. classification) point of view it is important for you to understand that at the present time the world's spider experts are very busy formally describing species that have not so far been assigned a scientific name but also reviewing and often changing the names and family relationships of many known spider species. As a consequence of this activity some well known species have been given new names and/have been moved to Families other than the ones to which they have previously belonged. So what does this mean for you? Maybe you are someone who is not an expert arachnologist but would still like to be able to call individual spiders by their correct scientific names. If so then you need to understand that it is unwise to totally trust any printed book about spiders, especially one that was published more than a decade or two ago because many of the names such books contain will no longer be valid. The sad reality is that any printed spider book or published research paper could easily contain taxonomic errors almost from the day it first enters circulation and even websites such as this one will inevitably include at least a few taxonomic errors. Fortunately, newer publications and good spider websites will often indicate older names that have been assigned to particular species along with the currently approved one. The presently accepted final arbiter of the correct scientific name and family for each spider species is the World Spider Catalog but this is a massive task so the people who update the Catalog are sometimes several months behind in their revisions. In addition, they have an uncritical acceptance of every published spider paper so it is always possible for a spider name change to have to be reversed at a later date.