Walnut orb-weaver spider, European Spider of the Year


This video is called Spider ID: Walnut Orb-Weaver.

The walnut orb-weaver spider has been named European Spider of the Year 2017.

Deutsche Welle radio in Germany writes about it:

Germany’s arachnologists put their focus on this cute creature: Many of us have likely met the walnut orb-weaver spider at some point – around the garden or house. It loves to dwell in old masonry or in the bark of old trees or dead wood. Its cobwebs are large and beautiful: up to 50 inches in diameter.

Animals and love


This video is called Bird Of Paradise Makes An Unforgettable First Impression – Animal Attraction – BBC.

From Science News:

The animal guide to finding love

by Sarah Zielinski

6:00am, February 14, 2017

Are you feeling the pressure of Valentine’s Day and in need of advice on how to find someone special? The animal world has some advice for you.

Make sure you look nice.

There’s no need to go for an entire makeover, but looking your best is usually a good idea when on the search for a partner. Male black-and-white snub-nosed monkeys appear to have taken a lesson from Revlon — they go for the rouge-lipped look during the mating season. Those with bright, red lips tend to be surrounded by females.

This 2016 video from Australia is called Peacock Spider 14 (Maratus fimbriatus).

Learn to dance …

As anyone who has ever watched John Travolta in Saturday Night Fever knows, having the right dance moves can make finding a mate easier. For some animals, it’s essential. That’s true for male peacock spiders, which raise colorful flaps on their behinds and wave them while lifting their third legs in an adorable dance aimed at luring a mate. And if a guy doesn’t have the best moves or try hard enough, females don’t just reject him — they get aggressive.

… and how to flirt.

Even if you’re an expert dancer, you’ll probably need to do at least a little flirting. It may be a bit more subtle than torrent frogs, though, who turn flirting into a big production. A male frog will get a female’s attention by first calling out and puffing up his vocal sacs. Then he’ll shake his hands and feet and wiggle his toes. If he’s successful, the female will let him know with a special call.

Attend a party.

The best place to put all of this on display is, of course, a party! And there are parties everywhere, even at the bottom of the ocean. Scientists exploring a seamount off the Pacific coast of Panama in 2015 found an enormous party of small, red crabs swarming all over each other. Such large aggregations are common among crab species and may be linked to reproduction.

Practice, practice, practice.

Once you’ve landed a partner, you might want to serenade him or her with the perfect love song. But first you’ll need to practice, just like great reed warblers (probably) do. Males spend their entire winter vacation singing the songs they seem to use to woo the ladies come spring. All that singing cuts into time the guys could spend foraging for food or resting, but that practice might pay off because female warblers prefer males that sing more complex tunes.

Keep an eye on the competition.

You may not be the only one interested in your partner, so make like a peacock and check out your competition. Peacocks fan out their feathers to lure the ladies, but females only pay attention to what’s happening at the bottom of the show, studies have revealed. Males do likewise, keeping their gaze tuned to the bottom of the competition’s display.

Bring a gift.

You probably don’t need to worry that your partner will go cannibal, but that doesn’t mean you can’t take a hint from a species where that does happen. When approaching a female, male nursery spiders are smart to bring a gift of a big dead insect wrapped up in silk. The gift will not only keep the female busy while the male mates with her, but it can also double as a shield if she sees him as a potential meal rather than a mate.

How scuba spiders live underwater


This video says about itself:

13 January 2017

The scuba spider is the only arachnid to live exclusively underwater, despite lacking gills. Its secret, like its name suggests, is a makeshift oxygen supply.

Palm warblers eat insects from spiders’ webs


This video from the USA says about itself:

9 January 2017

Several Palm Warblers hunt for insects in spiders‘ webs in the morning – just like going to the grocery store! The spiders do all the hard work and the Warblers wisely reap some rewards. This behavior has apparently not been too well documented on video, although there is a technical name for this that I just learned – Kleptoparasitism (a form of feeding in which one animal takes prey or other food from another that has caught, collected, or otherwise prepared the food, including stored food). Always something new to learn by observing Nature!

Here is a link to a short scientific paper on the subject.

Insects, the biggest migration


This video says about itself:

Charles Anderson discovers dragonflies that cross oceans

17 December 2009

While living and working as a marine biologist in Maldives, Charles Anderson noticed sudden explosions of dragonflies at certain times of year. He explains how he carefully tracked the path of a plain, little dragonfly called the globe skimmer, only to discover that it had the longest migratory journey of any insect in the world.

From Science News:

Long-ignored, high-flying arthropods could make up largest land migrations

Each year, 3.5 trillion aphids, moths, flies and their kin fly over southern United Kingdom

By Susan Milius

2:46pm, December 22, 2016

Forget honking Vs of geese or gathering herds of wildebeests. The biggest yearly mass movements of land animals may be the largely overlooked flights of aphids, moths, beetles, flies, spiders and their kin.

About 3.5 trillion arthropods fly or windsurf over the southern United Kingdom annually, researchers say after analyzing a decade of data from special entomological radar and net sweeps. The larger species in the study tended to flow in a consistent direction, suggesting that more species may have specialized biology for seasonal migrations than scientists realized, says study coauthor Jason Chapman, now at the University of Exeter in Penryn, England.

The creatures detected in the study may be little, but they add up to roughly 3,200 metric tons of animal weight, Chapman and colleagues report in the Dec. 23 Science. That’s 7.7 times the tonnage of U.K. songbirds migrating to Africa and equivalent to about 20,000 (flying) reindeer.

These are “huge flows of biomass and nutrients,” Chapman says. “One of the things we hope to achieve in this work is to convince people who are studying terrestrial ecosystems that they cannot ignore what’s happening in the skies above them.”

Biologist Martin Wikelski of the Max Planck Institute for Ornithology in Radolfzell, Germany, who wasn’t part of the study, calls these migrants “aerial plankton.” It’s a reference to the much-studied tiny sea creatures whose movements and blooms power oceanic food webs. Understanding insect migrations and abundances is crucial for figuring out food webs on land, including those that link insects and birds. That’s “particularly important nowadays as we are starting to lose many of our songbirds,” he says.

The word migration applied to arthropod movements doesn’t mean one animal’s roundtrip, Chapman says. Instead, the term describes leaving the home range and undertaking a sustained journey, maybe cued by seasons changing or food dwindling. A return trip, if there is one, could be the job of a future generation.

The migrants he studied, traveling at least 150 meters aboveground, aren’t just accidentally blowing in the wind, he says. Many of the tiniest — aphids and such that weigh less than 10 milligrams — take specific measures to start their journey, such as trekking to the top of a plant to catch a gust. Juvenile spiders stand on tiptoe reeling out silk until a breeze tugs a strand, and them, into the air. “They only do this when wind conditions will enable them to be caught and taken up; otherwise, it’s a terrible waste of silk,” Chapman says. Some caterpillars also spin silk to travel, and mites, with neither wings nor silk, can surf themselves into a good breeze.

The basic idea that a lot of arthropods migrate overhead is “absolutely not” a surprise to behavioral and evolutionary biologist Hugh Dingle of the University of California, Davis. He says so not dismissively, but joyously: “Now we have really good data.”

This smallest class of migrants, sampled with nets suspended from a big balloon, makes up more than 99 percent of the individual arthropods and about 80 percent of the total mass. They didn’t show an overall trend in flight direction. But radar techniques refined at Rothamsted Research in Harpenden, England, showed distinct seasonal patterns in direction for medium-sized and larger insects.

“That’s the big surprise for us,” Chapman says. “We assumed that those flows would just be determined by the wind.” But medium-sized and large insects such as lacewings and moths overall tended to head northward from May through June regardless of typical wind direction. And in August and September, they tended southward. “Lots of insects we didn’t think capable of this are clearly doing it,” he says.

Managing such a feat takes specialized biology for directed, seasonal migrations. Many of these arthropods must have some form of built-in compass plus a preferred direction and the genetics that change that preference as they or their offspring make the return migration.

Entomologists have known some migratory details of monarch butterflies in North America and a handful of other such insects, many of them pest moths. But speculating about specialized migrants, Chapman says, “there must be thousands of these.”

Orchard orb weaver spider videos


This video from the USA says about itself:

10 December 2016

Large Orchard Orb Weaver Spider with a choice web over a small stream with a nice sound. This is prime real estate and this big Orb weaver is not sharing its space with others. It is fairly common for small Orchard Orb Weavers to share a tangle of webs until they get larger. As is typical this big spider has multiple layers of webs making an effective 3D construction.

Another video of a smaller version of this spider is below here.

This video from the USA says about itself:

Orchard Orb Weaver Spider catching and eating a Carpenter Ant. This Orb Weaver spider is relatively common in Florida and looks like it has red lights glowing on it for defensive purposes, Despite the appearance of two bright red triangles on its abdomen that look like at first glance like an hourglass it is not poisonous like the Black Widow – its “teeth” would have trouble penetrating human skin in any case, but it is very beneficial feasting mostly on mosquitoes and small flies.

These colorful, delicate spiders make circular webs that are usually positioned horizontally or at an angle to the ground, and they typically hang in the middle of their webs. The carapace appears yellow-green, darker on the sides. The abdomen is somewhat elongated and can be variably colored with silver, greens, yellows, reds and some blues. The legs are slender and long.

Male spiders caring for youngsters


This video says about itself:

5 December 2016

Rafael Rios Moura says spider moms handle most of the parental care, but not the Manogea porracea species he studied. Both spider parents take responsibility to protect their egg sac. Linda Rayor of Cornell University said, “To the best of my knowledge, there really aren’t other examples where male spiders step up to care for young or eggs.” Sometimes at the cost of their own lives, male Manogea porracea switch from solitary life to a dad-web upstairs, brushing rainwater off egg sacs. Moura hypothesizes that the females are very delicious to predators considering that many females disappeared by the end of breeding season.

From Science News:

First spider superdads discovered
Males give up solitary life to protect egg sacs, spiderlings — often as single parent

By Susan Milius

9:00am, December 5, 2016

The first normally solitary spider to win Dad of the Year sets up housekeeping in a web above his offspring and often ends up as their sole defender and single parent.

Moms handle most parental care known in spiders, says Rafael Rios Moura at the Federal University of Uberlândia in Brazil. But either or both parents care for egg sacs and spiderlings in the small Manogea porracea species he and colleagues studied in a eucalyptus plantation. The dad builds a dome-shaped web above the mom’s web, and either parent will fight hungry invaders looking for baby-spider lunch. In webs with no parents, only about four spiderlings survived per egg sac. But with dad, mom or both on duty, survival more than doubled, the researchers report in the January 2017 Animal Behaviour.

“To the best of my knowledge, there really aren’t other examples where male spiders step up to care for young or eggs,” says Linda Rayor of Cornell University, who has studied spider maternal care. In a group-living Stegodyphus species, some of the males in a communal web will attack intruders, but Manogea dads do much more. They switch from solitary life to a dad-web upstairs, brush rainwater off egg sacs and share defense, sometimes at the cost of their own lives.

Many male web-building spiders stop feeding as adults because they’re out searching for mates instead of catching food with their web, Moura says. Manogea males, however, stick with a female they mated with and build a new food-catching web. Now Moura would like to know whether such commitment makes males unusually choosy about females, he says.

To predators, females “must be very delicious,” Moura says. In the wild he found that many females disappeared, probably eaten, by the end of the breeding season, leaving dads as the sole protector for 68 percent of the egg sacs.

That high female mortality could have been important for evolution of the dads’ care-taking, says behavioral ecologist Eric Yip of Penn State. Just why this species has such high female mortality puzzles him, though.  Females, geared up for egg-laying, have rich nutrient stores. Yet, he says, “that’s generally true for all spiders — that females are going to be more nutritious and males are going to be mostly legs.”