When those loving instincts leave you dangling

This was not a planned blog, but I recently observed something that simultaneously intrigued, amazed and astounded me, so I wanted to share it with those of you who may not have witnessed this either.

Like many gardens in my neighborhood, my yard has its fair share of leopard slugs (Limax maximus), but they don’t bother me as they do some other people who complain about them eating their vegetables. Until recently, I never thought about the slugs much and certainly didn’t wonder about their life cycle. Then my friend Mary posted a lovely photo of two intertwined leopard slugs mating and my interest and curiosity were piqued.

A few days later, a fellow nature lover, Ace, reported that he had a cool photo to show me – and there on his iPhone was a photo of mating leopard slugs. It turns out that their anatomy makes for a somewhat bizarre spectacle – at least to a human being if not a fellow slug. Now I really wanted to see this phenomenon, too, and I followed Ace’s recommendation, going out into my yard at night with a flashlight to see if I could find some amorous mollusks. Lo and behold – as I rounded the corner of my house, there were three pairs of large slugs getting ready to reproduce! They were leaving glistening slime trails on the brick wall as they slowly got into position.

The slime that the slugs exude has multiple purposes – they can leave a trail behind them as a signpost to the way home, they can numb the mouth of a potential predator with the mucus as a means of defense, and they can broadcast their interest in some reproductive behavior by emitting pheromones to attract a potential mate.

They don’t actually need to mate to reproduce – each slug is a hermaphrodite and can fertilize its own eggs with no need of outside assistance. Slugs have an organ called a spermoviduct (SO), which has two parts – one for the sperm (vas deferens, VD) and one for the ova (oviduct, OV), as seen as this drawing from the Wikipedia page.

Some slugs apparently like reproductive acrobatics, however, and seek out a partner. The mating begins with a pair of slugs following one another around and nudging and licking one another. (A couple photos look browner – I took those with a flash but most were taken with one hand holding a small camera and the other shining a flashlight near the slugs.)

 

They then begin to curl up together and suspend themselves from a long mucus rope, which is somewhat stronger than the slime that they usually exude. They form a kind of writhing ball as they intertwine their elongated bodies (see this video for an example).

Next comes the awesomely weird part – out of a gonopore on the right side of their heads (the elongated tentacles are for vision) come their translucent mating organs (penises)! This video, which is shown in a horizontal position, lets you see how this happens.

Wouldn’t this interesting anatomy and reproductive behavior make an interesting plotline for an SF novel about a genderless society?

 

      

Because the slugs are hanging upside down, gravity helps pull down their reproductive organs, which are pumped full of body fluids until they are as long as the slugs’ entire bodies! Their penises are everted (turned inside out) and the two mollusks intertwine these just like their bodies. They take a while to exchange spermatophores as the penises twirl, intertwine, elongate and pull back to look a bit like a chandelier.

  

When the creatures have been joined at the neck for some time, they begin to slowly withdraw their reproductive organs, which are now carrying genes from another parent.

              

After they separate, one of the pair usually consumes the mucus rope from which they dangled in love as it carries extra nutrients which they can use after their vigorous efforts.

          

 

 

Each slug may spend some time examining its gonopore (above) – and perhaps they are helping push back in the penis when they do this, too. After watching the process for two pairs of slugs, I decided to give the third pair some privacy during their mating tryst. On the wall beneath my screened porch, I discovered another slug with a mucus rope dangling from its tail – leaving me with a little mystery as to why this might have happened. A partner slug was not in evidence except for a much smaller slug – perhaps the big one tried to mate but the younger one was not ready. These mollusks with a life span of 2.5-3 years don’t become sexually mature until they are 2 years old.

    

I do know that at least three and perhaps six slugs will each be laying up to 200 eggs somewhere in the yard. And when I see them in the future, I will undoubtedly always be picturing them in my head doing their dangling dance with intertwined translucent blue tubes that will help promote their future generations. My discovery of their life cycle has also reinforced my support for scientist Hope Jahren’s (Lab Girl) observation: “…being able to derive happiness from discovery is a recipe for a beautiful life.”

Avian generations in the making – part 1: courtship

The tragedies being faced in the Caribbean islands after hurricanes Maria, Jose and Irma are horrible and other than donate cash to help alleviate the needs, I’m not in a position to offer more assistance. I’m grateful for all those who can and hope government assistance will be forthcoming to help all the people in those nations recover.
The effects of the hurricanes also will be noticeable for the wildlife. Many of those living on land will drown or die of hunger; some birds may be a little luckier – able to shelter against the winds if they are native to a place or able to change their migratory pattern (e.g., delay arrival on wintering grounds) for a time. But when the effects of the storms are immense with lots of habitat destruction, the birds, too, will lack places to shelter and not have sufficient food supplies to survive.

It’s thought that some birds endemic to the islands may be severely endangered as a species. On 22 September, birders were happy to hear that eight Barbuda warblers (Setophaga subita) had been spotted on that island; not a lot but they may help ensure this tiny bird doesn’t become extinct.  At the time of writing this blog, the fate of some other bird species was still unknown. I hope that all the Caribbean bird species survive and will be thinking of them as I share this series with you on how birds take measures to ensure future generations. (It might seem odd to write this series now, but some birds are still feeding their young here.)

So, the process begins with courtship. Some birds mate for life, or at least form long-term (multiple-year) bonded relationships. They include bald eagles, black vultures, blue jays, Canada geese, white-breasted nuthatches, brown-headed nuthatches, Northern cardinals, Carolina chickadees, American crows, pileated woodpeckers and my favorite raptor shown above, the osprey (Pandion haliaetus).

Those who form ongoing bonds may have a courtship period that consists of the male bringing the female some food to indicate it’s time to get ready for nest-building. This was the case for these lovely Northern cardinals (Cardinalis cardinalis).

The American crow (Corvus brachyrhynchos) has a similar behavior; in my yard, I sometimes throw out bits of apple or bread for them in the spring as these seem to be considered real treats. The female will sit on a branch overhead calling until the male brings her some – and sometimes almost shoves it down her throat!

The Northern mockingbird (Mimus polyglottos) males will sing their repertoire in the spring to entice female mates – often they perch on the top of trees and fly up and down with spread wings in a beautiful display while singing.

        

   

The yellow-billed cuckoo (Coccyzus americanus) seeks new mates each year but has an interesting courtship behavior described by All About Birds: “A receptive female perches with its head up, pumping its tail slowly up and down…Just prior to mating, the male Yellow-Billed Cuckoo snaps off a short twig that he presents to the female as he perches on her back and leans over her shoulder. Both birds then grasp the twig as they copulate.”

 

     

 

The downy woodpecker (Picoides pubescens) females and males may both flutter between trees with slow wingbeats. Two females may also compete for the attention of a single male, a behavior I observed this past spring and which surprised me.

 

     

The male brown-headed cowbird (Molothrus ater) will vocalize for the female while spreading his wings in a display.

The killdeer (Charadrius vociferus) has a somewhat prettier courtship dance, bending forward and spreading its tail feathers to show off the colorful underside.

  

Next year, I hope to see more of the birds courting as it gives me a happy feeling.

The next step for the birds is nest-building. We don’t have the bowerbirds in North Carolina, who build elaborate nests as part of their courtship. But the species we have do spend a good deal of time on their nests and I’ll share some of their efforts in the next part of the series. (But one or two blogs on another topic will come first.)

 

Credit map: By Kmusser (Own work, all data from Vector Map.) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)%5D, via Wikimedia Commons

The dance of the sandhill cranes

sandhill crane I77A7926© Maria de Bruyn resDuring my trip to Yellowstone National Park, I had the privilege of seeing what birders call “lifers” – bird species that one sees for the first time. One spectacular sighting – for me – was of sandhill cranes (Grus canadensis). I didn’t spot them first; I was traveling with two photographers from Michigan who were used to seeing these beautiful birds in their backyards. We had already passed but they kindly returned so I could take a few photos – and then to our delight, the pair of birds performed their mating dance for us!

These birds mate for life and may live to a considerable age. The oldest known sandhill crane was 36.5 years old.

sandhill crane I77A7910© Maria de Bruyn resWhile many of these birds are grayish in color, some have rusty orange coloring, attributable to iron-rich mud in their environment. In Yellowstone, the birds use their long bills to spread the reddish mud over their feathers when they preen and this helps to camouflage them when nesting. Cranes that are not yet mature also have reddish upper parts. Their heads are topped by a red patch.

 

sandhill crane I77A7925© Maria de Bruyn res

 

These birds have very long legs and necks as you can see. Their windpipes curl up in the sternum and give their sounds a lower pitch. Mated pairs will sing in unison, with the female calling twice for every call that her mate makes.

 

 

The males dance when they display to one another. Courtship dances can involve bowing followed by leaps into the air. They may stretch their wings and pump their heads as well.

SANDHILL CRANE I77A7932© Maria de Bruyn RES

sandhill crane I77A7934© Maria de Bruyn res

The pair would dance and stop, dance and stop. A real pas de deux (in French and ballet terms)!

sandhill crane I77A7931© Maria de Bruyn res

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Perhaps some ballet terminology was inspired (unconsciously) by the graceful cranes.

sandhill crane I77A7915© Maria de Bruyn res

Grand jeté (jump from one foot to the other)

sandhill crane I77A8005© Maria de Bruyn res

Sur les pointes (on tiptoes)

sandhill crane I77A7935© Maria de Bruyn res

Demi-plié (Half-bend of the knees)

`11111111111111111 sandhill crane I77A7940© Maria de Bruyn

Fondu (sinking down)

Dancers have tried to mimic cranes and while they created a beautiful dance, the sandhill cranes had more varied moves.

sandhill crane I77A7947© Maria de Bruyn res sandhill crane I77A7952© Maria de Bruyn res

sandhill crane I77A8010© Maria de Bruyn ressandhill crane I77A7917© Maria de Bruyn2 res

 

 

sandhill crane I77A7928© Maria de Bruyn res

 

The courtship dance was a tour de force and a highlight of my first day at this national park. In hindsight, I wish I had taped it but I was so enthralled, I forgot. 🙂

 

Mammal merriment, misery and markings

Lately, many of my blogs have been about birds, mostly because they have been the easiest wildlife to photograph during the colder months. The mammals – and insects, reptiles and amphibians – have not been around much and likely have often visited when I’m not watching. I’m fairly certain that raccoons (Procyon lotor) and opossums (Didelphis virginiana) come to my yard after dark; perhaps the odd fox or coyote does as well. Nevertheless, after she stopped weaning her young and since summer ended, I haven’t seen Raquel raccoon all winter.

raccoon DK7A4351© Maria de Bruyn   raccoon DK7A4248© Maria de Bruyn res

Eastern chipmunk I77A8790© Maria de Bruyn resThere a couple mammals, however, that I can count on to see every day because they have grown accustomed to having a food source at my house. Fallen bird seed (and seed and apples put out deliberately for ground feeders) does not get entirely gobbled up by the avian visitors, leaving pickings for the Eastern gray squirrels (Sciurus carolinensis), Eastern chipmunks (Tamias striatus) and white-tailed deer (Odocoileus virginianus).

The squirrels keep a watch from the trees and underbrush and appear very quickly after the bird seed is replenished. My combined squirrel and raccoon baffles – and placing the feeder poles at least 10 feet away from any structures from which they launch themselves onto the poles – have proved successful in keeping them from the feeders. But they continue to look for vantage points from which they can attempt a jump to the feeders.

Eastern gray squirrel I77A5504© Maria de Bruyn res  Eastern gray squirrel I77A5494© Maria de Bruyn res

Eastern gray squirrel IMG_3643 mdb

 

Before I learned how to thwart them, they made off with plenty of seed and suet – one squirrel even carrying off the entire suet feeder when s/he couldn’t get it open. I saw it happening and chased that squirrel, but they were faster than me!

They will share space happily with birds but don’t always want to share with other squirrels or chipmunks.

 

 

Eastern gray squirrel I77A8350© Maria de Bruyn Eastern gray squirrel I77A0711© Maria de Bruyn res

The chipmunks don’t let that selfish attitude deter them; they just keep a sharp eye out for when a squirrel might turn on them. They wolf down seed after seed, giving themselves a very fat-cheeked countenance!

Eastern chipmunk I77A3326© Maria de Bruyn  Eastern chipmunk I77A3335© Maria de Bruyn

The past few days, the squirrels have continued their chasing, but now it is not always in rivalry or play. Instead, their romantic side is showing and the merriment goes on for a good length of time. They appear to have designated a particular tree stump/snag in my back yard as their trysting spot.

Eastern gray squirrel I77A1104© Maria de Bruyn res              Eastern gray squirrel I77A0980© Maria de Bruyn

white-tailed deer I77A0963© Maria de Bruyn resThe white-tailed deer carry on their mating elsewhere but I know it’s happening as the males are evidence. Usually, one small family group comes to my home – mom, her one-year-old daughter and one-year-old son (a button buck, so-called for his tiny little antler nubs). They were occasionally accompanied by a couple second-year bucks with little antlers – I suspect mama’s sons from the previous year.

white-tailed deer I77A1367© Maria de Bruyn res    white-tailed deer I77A2025© Maria de Bruyn res

white-tailed deer I77A1366© Maria de Bruyn res

 

One of them lost one of his antlers early, but whether this was the result of a fight or accident is unknown to me. It seems that mama has allowed an orphaned button buck to join their group occasionally, too.

A couple weeks ago, two of the older males came down from the woods in search of does and food in the cold weather. This pair was traveling together but that didn’t stop some rivalry where first-access to the available food was concerned.

 

white-tailed deer I77A1061© Maria de Bruyn res white-tailed deer I77A1005© Maria de Bruyn res

 

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Then one day about a week ago when we had some very icy weather, I was surprised by a new and unfamiliar family group for a day. I didn’t mind them eating some seed and the resident family wasn’t around to chase them away. But then I felt immensely sad as I saw that one of them had been injured. Her tongue was lolling out but it was only when she came into the yard that I saw she must have been in an accident.

 

I felt miserable for her, seeing her face had been smashed in but after watching for a while, I realized the accident must have happened some time ago as she had no open wounds.

white-tailed deer I77A1917© Maria de Bruyn res white-tailed deer I77A1869© Maria de Bruyn

It must have been terribly painful though. I decided to call her Camelia as her profile reminded me of a camel.

white-tailed deer I77A1932© Maria de Bruyn res   white-tailed deer I77A1906© Maria de Bruyn res

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I put out some soft bread for her because I don’t know how easily she can eat. She does seem well-fed, however, so perhaps her disability is not hampering her nutritional intake. I haven’t seen her or her family again and don’t know if they will ever return, but it reminded me of how many deer are hurt and killed in accidents. I continue to think it would be worthwhile for research to continue on reducing deer populations through contraceptive use.

 

Beaver DK7A4173©Maria de Bruyn resOutside my yard, I’ve been seeing many signs of beavers (Castor canadensis) in the parks and reserves I visit. Their teeth are strong and I recently learned why their teeth are reddish brown – the enamel contains iron!

 

They have left tree stumps, half-gnawed trees and detached trees that they have apparently not yet been able to drag over to their dams and dens.

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One downed tree in particular looked to me like they had been working on a bird sculpture!

beaver I77A0090© Maria de Bruyn res

 

Eastern chipmunk I77A6221© Maria de Bruyn resI’m guessing that some of the other animals will be coming out in the daytime soon around my home – at the very least, the frogs and rabbits, whom I have seen only very occasionally. Spring is coming and while I enjoy seasonal variety, I will welcome it with open arms!

Corvid courtship – something to crow about

American crow DK7A7017©Maria de Bruyn res

American crow DK7A5544© Maria de Bruyn resAs I was sorting out photos of birds in our recent snow and sleet storm, my attention was drawn by the raucous cawing of one of our neighborhood crows. He had found some apple slices that I had put out with the bird seed and was one happy bird. He spent a lot of time calling, presumably to alert family members to the presence of this desired food source. And his enthusiasm made me decide to post a blog about corvid courtship now, since this late winter/early springtime ritual may be coming sooner than I thought.

Depending on geographic location and weather conditions, some birds begin nest building quite early in the year and American crows (Corvus brachyrhynchos) are among the early mating pairs and nest builders. Last year, a male crow who visited my home discovered and enjoyed both grape jelly and apple slices around early March.American crow DK7A7423©Maria de Bruyn res

American crow DK7A0779© Maria de Bruyn

 

 

 

 

American crow DK7A5569© Maria de Bruyn resHe even tried to add the homemade suet to his diet but he was a bit large to balance well on the small feeder.

Last year, he only had to visit my yard a few times before he was accompanied by his mate. She would sit on a branch or on the ground and caw loudly like him, but she was demanding that he feed her.

American crow DK7A7678©Maria de Bruyn res

He met her demands but was not about to just give up his treats. He would often grab a piece of apple, fly up to a branch near her but then first eat about half of it himself as she continued her raucous cries for food.

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She could have easily flown down to the ground to grab a piece of apple but refused. On a few occasions, she did fly down but just refused to pick up the apple herself, waiting for him to stuff it down her throat.

 

American crow DK7A8031© Maria de Bruyn res

 

He fed her in the trees and on the ground, pushing the food way down her throat.

 

 


American crow DK7A7655©Maria de Bruyn (2) res

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Some preening went on as they perched in the backyard oak tree, too.

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American crow DK7A7504©Maria de Bruyn (2) resAmerican crow DK7A7530©Maria de Bruyn res

 

 

 

 

 

.I learned that offspring will remain with their parents up to five years. These “helpers” will assist in feeding the female as she incubates eggs and also bring food to their new siblings.

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It seems that our warm days in December and January this year may be getting my faithful crow in a romantic mood a bit sooner this year.The crows are loud, especially when three or more show up at a time, but I do enjoy their visits and look forward to watching the corvid courtship again this spring.

American crow DK7A8461©Maria de Bruyn res