Spiders’ Sumptuous Repast

“Spiders could theoretically eat every human on Earth in one year.” “Think spiders are freaky? Wait 'til you hear how much they eat.” Those were the headlines in The Washington Post and USA Today.

Welcome back. A year ago, I was all set to blog about a research study on the impact of spiders preying on insects. Then I noticed even our local Wisconsin newspaper had a few sentences on the study findings. I decided to let the topic pass. 
  

Banana spider catching a wasp.
(photo from video
www.youtube.com/watch?v=PasIcWofgwE
by Angelique Herring; 3:37 min)

But I didn’t delete my notes. And then, I started wondering. Maybe you missed all the reports. Maybe you’d like more detail than most news reports offered. Or maybe, seeing “spiders” in the headline was enough for you. (NB: Spiders do not dine on humans, not even for a snack.)

So, I’m back with the study. It’s not that the research will cure your arachnophobia or make you a fan of spiders. It’s just that the findings are too interesting to miss. Plus, the study complements other blog posts I’ve written about spiders (Spider Role Model, Web Addresses Addendum, Predator-Mimicking Moth).

Spiders Are Global Predators
Spiders are among the most common and abundant predators in the terrestrial environment. They’re found nearly everywhere, tropics to the Arctic. Over 45,000 species have been recognized thus far, and they’re all carnivores, feeding on insects and even other spiders. How much do they eat? That’s what the study was about.

Collaborating scientists from Switzerland’s University of Basel, Sweden’s Lund University and Germany’s Brandenburg University of Technology Cottbus-Senftenberg developed estimates of the weight of prey that spiders kill annually in different biome types and worldwide.

How Many Spiders Are There?
First, the researchers obtained a measure of spiders in the world. The literature provided 65 values of spider biomass (i.e., weight per unit area), which they were able to assign to seven terrestrial biomes: (1) tropical forests, (2) temperate and boreal forests, (3) tropical grasslands and savannas, (4) temperate grasslands (including old fields, permanent pastures, mown meadows) and Mediterranean shrublands, (5) annual cropland, (6) deserts and (7) Arctic tundra.

Combining the average biomass weight per unit area for each biome and the biomes’ areas, the researchers determined the total weight of global spiders to be approximately 25 million metric tons. (One metric ton is 1000 kilograms or about 2200 pounds.) 

Jumping spider attacking a fly.
(photo from video
www.youtube.com/watch?v=XFZJLOm68UQ
by Andrew Huggins; 7:22 min)

How Much Do They Eat?
Next, the researchers estimated the weight of prey spiders kill annually. They used two different methods to validate their results.

The first method’s estimate was based on how much food spiders need. They combined the food requirements per unit body weight, derived from the literature, with their estimates of spiders’ weight per unit area for each biome.

The second method’s estimate was based directly on published assessments of spiders’ annual prey kill in selected biome types (e.g., prey censuses in the field combined with web density estimates).

Allowing for the range of estimates within biomes and accounting for factors such as reduced feeding on rainy days, the researchers arrived at total estimates of 460 to 700 million metric tons/year with the first method and 400 to 800 million metric tons/year with the second method. (That sentence should probably end with an exclamation point.)

Wrap Up
Putting the estimates together, the researchers concluded that the spiders’ global annual prey kill is in the range of 400 to 800 million metric tons/year. Over 95% of that is attributed to spiders in forest and grassland biomes.

So, before you swat, step on or vacuum your next spider, you’ll have to decide. Do you want 400 to 800 million metric tons of assorted insects or 25 million metric tons of spiders. As one of the other headlines from last year read, “Spiders eat twice as much animal prey as humans do in a year.” Thanks for stopping by.

P.S.
Global spider prey kill study in The Science of Nature journal: link.springer.com/article/10.1007%2Fs00114-017-1440-1
Example articles on the study:
www.sciencedaily.com/releases/2017/03/170314111251.htm
www.newscientist.com/article/2124693-spiders-eat-twice-as-much-animal-prey-as-humans-do-in-a-year
www.theguardian.com/environment/2017/mar/14/spiders-insects-food-prey-400-800-tonnes
www.businessinsider.com/spiders-eat-400-to-800-million-tons-of-insects-every-year-2017-3
www.washingtonpost.com/news/wonk/wp/2017/03/28/spiders-could-theoretically-eat-every-human-on-earth-in-one-year/?utm_term=.d9541f67d935
www.usatoday.com/story/tech/sciencefair/2017/03/15/spiders-bugs-food-study/99209394/
www.cnn.com/2017/03/15/health/spiders-eat-tons-insects-trnd/index.html

A version of this blog post appeared earlier on www.warrensnotice.com.

Web Addresses Addendum

Once again, I spent more time on an addendum than on the main blog post, last Friday's New Web Addresses. First I thought I would compose a list of amusing domain names using new web address endings. After starting, I realized that I had already provided enough for you to amuse yourself better than I could.

Then I considered expanding on expired domain names, summarizing how thousands of domain names expire every day and are eventually offered for sale. After plowing through different sources, I decided there would be little interest--unless, of course, someone wanted to buy this blog’s domain name. (Contact me directly.)

And then I came across a book and articles on domain names that could be read differently than intended, such as a travel website www.choosespain.com, which might be read “chooses pain.” All the domain names were old, and most of those I checked were either gone or changed and of a sexual nature. (Search for slurls if you like that sort of thing.)

Finally, while getting the trash and recycling containers ready for pick up, I was enwrapped in spider webs. Webs. That’s it! The topic for an addendum on web addresses.

Identifying Spiders by their Web (Addresses)

As spider taxonomy goes, over 40,000 species have been identified and discoveries continue. All spiders produce silk, yet not all construct webs. Of those that do, certain taxonomic families are associated with certain types of webs. Perhaps you’ll recognize some of these. 

Orb webs are generally associated with spiders in the Araneoidea superfamily, particularly those in the Araneidae and Tetragnathidae families, but there are orb-weaver spiders in the Uloboridae superfamily whose webs are quite different. (Photo from smithsonianscience.si.edu)

A triangle spider web built by Hyptiotes paradoxus of the Uloboridae family (Uloboridae superfamily) is an example of a reduced orb web. (Photo from www.flickr.com/photos/myriorama/8142595190)

Funnel webs are generally associated with the Agelenidae family of spiders, yet there are funnel-web tarantula, which fall under an entirely different superfamily. (Photo from fireflyforest.net/firefly/2008/05/12/funnel-web-spider/)

“Funnel” and “tube” (or “tunnel”) denote different shapes; there are webs so labeled and spiders associated with each. Though funnel and tube webs appear similar at their openings, this web appears to extend up the tree and is likely tubular. The habitat of Europe’s tube web spider Segestria florentina is often a building crack. (Photo from tjsgardendotcom1.files.wordpress.com/2012/08/web-tunnel.jpg)

Sheet webs are associated with the Linyphiidae or Hahniidae spider families. While all Linyphiidae webs are interwoven sheets, the shapes vary with the species--platforms, bowls, domes. (Photo from btweenblinks.files.wordpress.com/2014/01/p1030235-e1389481419950.jpg)

This photo isn’t upside down. It’s a dome or tent spider web built by the species Prolinyphia marginata, also known as Neriene radiate, of the Linyphiidae family. (Photo from www.asergeev.com/pictures/k/Spider_web.htm)

Tangled webs are shapeless jumbles of fibers generally associated with spiders of the Theridiidae family, but also with spiders of the Amaurobiidae, Nesticidae and Linyphiidae families. (Photo from blogbydonna.com/wp-content/uploads/2012/09/SpiderWeb3.jpg)

Cobwebs are a version of the tangled spider web. Spiders of the Theridiidae family are also known as tangle-web, cobweb and comb-footed spiders. (Photo from multiple websites)

Mesh spider webs are another version of tangled webs, being similar to but more organized than cobwebs. They’re associated with spiders of the dictynidae family. (Photo from sense-of-place-concord.blogspot.com/2015/08/dawn-to-dusk-summer-at-great-meadows-nwr.html)

The nursery web spider, Pisaurina mira, carries her eggs in a sac and builds a web just before they hatch. Although there are "sac" spiders that construct silken tubes or sacs in protected areas, they don’t build webs. (Photo from www.projectnoah.org/spottings/8152819)

And then there are lots of spider webs that seem rather unique, such as this one--or are there two?--observed in New Zealand. (Photo from bestkindoflost.com/wp-content/uploads/2014/03/Spider-web-2-copy.jpg)

P.S.

en.wikipedia.org/wiki/Spider_taxonomy
en.wikipedia.org/wiki/Spider_web
www.spiderzrule.com/spiderweb.htm
animals.mom.me/identify-spider-pattern-8791.html
www.pestproducts.com/spider-webs.htm
animals.sandiegozoo.org/animals/spider

New Web Addresses

Welcome back. Tell me. Would you be more inclined to click on this blog’s web address, its URL, if instead of being www.Retired--NowWhat.com and ending in .com, it ended in .blog or .club or .fyi? Or how about www.Retired--NowWhat.exposed? There are a boatload of new endings. Some are very cool, including .cool. 

Some of the new domain endings. (From
 www.forbes.com but on multiple websites)

Come to think of it, you might want to grab or sign up for an address with one of the new endings. You could certainly find uses other than blogging. I’ll get to that, but let me continue with the blog’s web address.

Blog Address History

When I started this blog in 2011, I picked the blog’s name, Retired--Now What?, and that was that. The blog web address was fixed. The domain name, which is everything after the www., was predetermined by the account holder and that included the ending, the generic top-level domain, which was .com.

Though I later switched to the blog’s current web address, whose domain name is shorter than the original, the only choice was to stay with .com.

Then, about 18 months ago, the blog’s domain name expired due to my oversight. I had to reclaim it from another account holder, and I was offered the opportunity to change the ending to .net or .org. I also learned that all sorts of new endings, new generic top-level domains, were coming. They’ve arrived.

New Generic Top-Level Domains

Today there are several hundred endings which you can buy or register for as part of a domain name, presuming the domain name isn’t already taken. If that’s not enough, there will be many more; expect about a 1000 this year. 

One website categorizes the current endings under 19 headings. Here’s a sample with examples of new endings: Arts and Entertainment (.actor, .art, .band, .photography), Education (.mba, .phd, .science), Food and Drink (.catering, .cooking, .recipes, .wine), Identity and Lifestyle (.bio, .black, .ceo, .republican), Interests (from .active and .app to .yoga and, in Chinese, .gossip), Money and Finance (.broker, .cpa, .gold, .rich), Novelty (.best, .fun, .wow), Sports (all the majors) and, of course, Adult (.adult, .porn, .sex).

There’s been a fair amount of discussion about the benefits of having a more focused web address. Are the benefits less than they seem? At least initially, business and trade associations thought the proliferation of endings was unnecessary, confusing and costly. Further, not all browsers and applications are ready to recognize the new endings; extra steps may be needed. Probably the pivotal question is if domain names are at all important. People increasing rely on social media or aggregators to round up the content they see.

Wrap Up

Beyond blogging, I see this as The Moment for anyone who wishes to stand out, to be noticed, to be distinct, whether it’s through a personal website, résumé, social media account or email address.

Imagine having a domain name that consists of your name or expertise with the ending .expert, .guru or .vip. Or how about integrating the ending with what’s before the ending: NoPain.dentist, IPlay.guitars, IAmThe.one? If your surname happens to be one of the endings--black, coffee, glass, gold, green, irish--you could add your first name and…well, there so many possibilities. I should forget the blog and sell web domains.

Thanks for stopping by.

P.S.

Background and example articles on new generic top-level domains:
en.wikipedia.org/wiki/Generic_top-level_domain#New_top-level_domains
iwantmyname.com/blog/2015/06/how-to-pick-the-right-domain-extension.html
www.inc.com/peter-roesler/will-new-top-level-domains-matter-in-2015.html
name.kitchen/stand-out-from-the-crowd-a-new-way-to-get-creative-with-your-online-resume/
Lists of generic top-level domains:
iwantmyname.com/domains/new-gtld-domain-extensions
www.newtldlist.com/
Example web domain sellers offering new generic top-level domains:
www.godaddy.com/tlds/gtld.aspx
www.enom.com/tld-queue/pages/watchlist.aspx#q=watchlist|pre-registration
www.hover.com/