Stress Break!

I've got too much on my plate this week to write a proper post, but this video has been a great stress-reliever. Enjoy!

Are Territory Disputes Between Male Butterflies Influenced by Motivation?

By Nick Gremban

Male speckled wood butterflies will “perch” on leaves
and ends of twigs to look out over their territory for females.
 However, they have been known to be quite aggressive
with any intruding males! Photo by Alvesgaspar at
Wikimedia Commons, modified by Nick Gremban.

Think about any territorial animal. Now think about its aggressiveness while it is defending its territory. Was your animal a butterfly? No? You mean the colorful wings and the natural association with flowers doesn’t strike a fierce image of aggression in your mind? Well, the truth is some butterflies are very territorial and aggressive toward one another, contrary to what we expect.

Male butterflies do not have physical means to inflict harm to one another when it comes to territorial disputes. Instead, two or more males may stage “contests” with each other which often involve elaborate aerial chases. For example, a male that flies into the territory of another male will set off a pursuit by the resident male, resulting in both flying in circles around each other until one eventually gives up and is chased out of the territory. Normally, winners of the contests are the males that are able to endure the longest flights. An example of what these competitions look like can be seen from this video:

Researchers have been puzzled by what determines which male butterfly wins a contest. Some researchers have thought body size should determine who wins the contest. After all, isn’t being bigger always better? Turns out for many butterflies, it’s quite the opposite, with smaller butterflies of some species winning contests more. What about age? Shouldn’t the most experienced butterflies have better odds at winning? Again, the opposite is often true, with some studies finding younger males having better odds at winning competitions. How about motivation? Could some male butterflies be motivated by something that gets them revved up? Researchers from Stockholm University in Sweden seem to think so!

In a study conducted by Martin Bergman, Martin Olofsson, and Christer Wiklund from Stockholm University, male speckled wood butterflies were tested by observing the number of contest rematches won by males that were subject to a source of motivation: a female speckled wood butterfly. Females are a primary purpose to why males hold territories, so interactions with them before a contest was thought to serve as motivation.

The researchers staged their experiment in a series of steps. The first step consisted of introduced contests between two male speckled wood butterflies over a territory, or in this experiment, a sunspot. In total, 60 pairs of males were used to conduct this experiment. Males that won five consecutive contests were considered “winners” and given the status of being the resident male over the sunspot. Afterwards, winners were temporarily removed from the sunspot they just previously won.

Get out of my sunspot! Photo by Martin Bergman.

All males that lost the contests were considered “losers” and were split in to two groups. The first group was allowed to interact with a female for 30 minutes. Males in the second group were placed alone in a cage for 30 minutes. Afterwards, each male was allowed back to the sunspot, now vacant of the winner. After each of the losing males took over the sunspot, therefore claiming themselves as the new resident male, the winners were then returned to the sunspot. The return of the winners allowed rematches of contests. Researchers recorded contest duration and if the males that lost the first round of contests won their rematches.

Loser males that had the chance to interact with a female won 53% of rematches while loser males placed alone only won 17% of rematches. In other words, males that interacted with a female endured longer flights to win their rematch. Furthermore, these same males were more likely to claim the vacant sunspot.

Male speckled wood butterflies
will “fight” over a female (such
as this one)…doesn’t this
concept sound familiar? Photo by
Mark Colvin at Wikimedia Commons.

Overall, the researchers suggested that the males which had interacted with a female had an increased motivation to fight harder on the rematch to win the sunspot. Just like with many other animals, male butterflies are willing to compete for the girl! The presence of a female may serve as a cue for the males that a particular territory is worth fighting for. After all, isn’t reproduction the name of the game?

Butterflies prove to be more mysterious and complex than we typically expect. Not only can they express territoriality without true physical means to harm each other, but they appear to be influenced by motivation! So, next time you see two butterflies fiercely circling each other in flight, you now know they mean serious business.


References

Bergman, M., Olofsson, M., & Wiklund, C. (2010). Contest outcome in a territorial butterfly: the role of motivation Proceedings of the Royal Society B: Biological Sciences, 277 (1696), 3027-3033 DOI: 10.1098/rspb.2010.0646

What To Do If You Find Orphaned Wildlife

A nest of baby cottontails waiting for sunset when their
mom will return. Image by Jhansonxi at Wikimedia.

Spring is finally in the air, and with Spring come babies! Finding baby animals in the wild is thrilling, but also concerning. Does this animal need your help? Where is its mom? What do you do?

Whenever possible, baby animals will do best when we leave them in the care of their mom. Even a well-meaning human is seen by a wild animal as a threat. Our interactions with them cause them extreme stress that can cause serious health problems and even death. Furthermore, if we take a baby animal home, it will not be able to learn its species-specific behaviors and skills and it can lose its natural and healthy fear of humans. It is also very hard to meet the specialized dietary needs of a wild animal in a captive setting. Taking a wild animal home can cause problems for us as well: many carry diseases that can be transmitted to our pets or even ourselves. And most wild animals are protected by state and federal laws that prohibit unlicensed citizens from possessing or raising them.

Luckily, most baby animals that seem alone actually have a mom that is not far away, either looking for food to feed herself and her babies or simply hiding from you. For example, rabbit mothers actively avoid their nests most of the time so as to not attract predators to the nest. Cottontail moms visit their babies only briefly at dawn and dusk for quick feedings. If you find a bunny nest, you can test to see if the mom is visiting by placing a few blades of grass or thin twigs in an X-shape over the babies. If you come back the next day and the pattern has been disturbed, then their mom is still caring for them and you should leave them be.

Many animal moms are prevented from taking care of their young when concerned people are hovering. Deer moms, for example, also actively avoid their babies (called fawns) so as to not attract predators to it. They generally return to nurse the fawns every few hours, but they won’t return to nurse if people or pets are around. If you find a fawn and it is not wandering and crying non-stop all day, then leave it alone so its mom will come back.

A red fox mom and baby. Photo by Nicke at Wikimedia.

Even if you find a baby all by itself in the open, the best course of action is often still to leave it alone. Many mammal moms, like squirrels, raccoons, mice, rats, foxes, and coyotes, will retrieve their young if they fall out of their nest or wander away from their den. Although it is a myth that most animal moms will abandon their babies if you get your smell on them, your odor can attract predators. It is best not to touch wildlife babies if you can avoid it.

Awww... as tempting as it is to pick up an adorable baby skunk, don't do it
unless you are a trained and licensed wildlife rehabilitator (like this woman is).
Image by AnimalPhotos at Wikimedia.

So when should you get involved? If an animal is in a dangerous location (like a busy street), then it may need to be moved. You can slowly, quietly and gently try to guide a mobile baby animal away from hazards and to a safer location. If the animal is not yet mobile, in most cases, you can use clean gloves to pick up the animal and move it to a safer location, placing it as close as possible to where you found it.

If you know that the mom is dead or has been relocated, then you are dealing with a truly orphaned baby animal. Likewise, if an animal has been attacked (or brought to you by your “helpful” cat), or is bleeding, injured, wet and emaciated, weak, infested with parasites, or has diarrhea, then it may need medical attention. In these cases, contact a licensed wildlife rehabilitator. Wildlife rehabilitators have been trained and have the necessary equipment to temporarily care for and treat injured, sick and orphaned wild animals so they can be released back into the wild. If you can’t find a wildlife rehabilitator, contact the Department of Natural Resources, a state wildlife agency, animal shelter, humane society, animal control agency, nature center, or veterinarian. Ideally, they will come to pick up the animal themselves. If they can’t, then they should give you detailed instructions for your situation on how to catch and transport the animal.

For more information, check here:

The Humane Society of the United States

The Wisconsin Department of Natural Resources

The Virginia Department of Game and Inland Fisheries

Deception!

If you saw Friday’s video about the device that converts octopus gestures into English, hopefully you caught on that it was a pretty good (and hilarious) April Fool’s prank by Oregon Sea Grant. Although there is not a lot of evidence of animals deceiving one another for fun, deception is pretty common in the animal kingdom. Here are some examples:

1) Male nursery web spiders often court females with gifts of a tasty fly wrapped in silk to appease her while he mates with her. But some stingy sneaks will eat the fly themselves and wrap up the carcass, or worse yet, wrap up some random piece of junk. If she tries to snatch the gift from him, he hangs on and plays dead until she stops running, only to “come back to life” to mate with her then.

2) Cowbird moms lay their eggs in the nests of other species, relieving themselves of parental duties. But they stack the deck in favor of their own chicks: they often push eggs of the host bird out of the nest and color their own eggs to match that of the host. Their eggs hatch sooner and their chicks grow faster than their “siblings”, which the chicks promptly push out of the nest to their death.

This is a picture of begging chicks in a parasitized nest of a chalk-browed mockingbird, taken from a video. The chick with the smaller, redder gape at the top of the image is the cowbird. The other larger gapes belong to the mockingbird's own chicks. Photo by Ros Gloag.

3) Crocodiles have been found to place sticks on their snouts to lure in birds that are collecting nest material.

I’m just a floating log and sticks… Really. Photo by Dinets published in Ethology, Ecology & Evoluton 2013

4) A queen ant wears a chemical disguise to smell like another species, only to sneak into their nest and lay her eggs for this other host species to raise. The queen’s offspring then grow into an army that enslaves their adoptive colony, to serve their needs for life.

A 1975 cover of Galaxie/Bis, a French science fiction magazine,
 by Philippe Legendre-Kvater. Image from Wikimedia.

5) The mimic octopus pretends to be venomous fish and sea snakes so predators will avoid it.

The disguises of the mimic octopus: (a) shows a mimic octopus looking out of its burrow; (b) is a foraging mimic octopus with coloration to blend with the sand; (c) shows a mimic octopus as a sole fish and (d) is an actual sole fish; (e) shows a mimic octopus as a lion-fish and (f) is an actual lion-fish; and (g) shows a mimic octopus as a banded sea-snake and (h) is an actual banded sea-snake. Images from the Norman, 2001 article in Proc. R. Soc. Lond. B.

Octopus Thoughts Interpreted!

This is AMAZING! Scientists have developed a device that translates octopus gestures into English! Here is what this octopus was thinking: