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.”

Who wants to eat?

First, let me welcome those of you who have become new followers of my blog – nice to have you reading here and I hope you comment on what you like! I am way behind on my postings for the blog but will try to remedy that. There are photos almost ready for a series on bird courtship and child-rearing, as well as some other non-bird topics, but various issues have been keeping me from completing the texts. Now that I have had to take my preferred camera in for repairs, however, I have a bit more time to work on the blog and a recent brief trip to Topsail Island is providing some almost ready-made postings.

The south end of Topsail Island has been eroded greatly by the Atlantic storms, including effects from Hurricane Irma. Where normally the beach sloped up gently to beautiful dunes, these have now been sheared off vertically and the sea grasses and other vegetation before the dunes have been swept away.

 

 

That is of concern as the sea turtles nest there; hopefully, there will be sufficient places for their eggs next year. There were far fewer shells on the beach but at low tide the swath of empty sand was very wide.

 

Mixed groups of birds were resting there in between ocean fishing expeditions. There were a couple immature common terns (Sterna hirundo) who were begging for food incessantly, but the adults pretty much ignored them, preferring to preen or settle down for a rest.

Some of the begging was pretty vigorous, accompanied by feather ruffling and shaking but I didn’t see any parents go off for food.

The sandwich terns (Thalasseus sandvicensis) were also resting but individuals took off frequently for a fishing flight. These terns are easily identifiable by the yellow tips on their black bills and their Groucho Mark hair-dos, a boon for people like me who are challenged in recognizing which shorebird they have before them. Sometimes, you could imagine a conversation taking place between them.

Hi! I’m back from fishing!

Didn’t take long, did it?

See, I got a fish!

Wanna smell it?

Not to your liking, huh?

Walking in circles around me won’t make it any different

I think I’ll go feed a young one!

There were two immature sandwich terns who were very persistent in asking for a meal.

Come on, Ma, I’m hungry!

I am really really hungry!

Oh yum, lunch!

That’s right, put it right here!

Thank goodness you brought me something!

I’m STILL hungry!

Perhaps the adult sandwich terns were accommodating to their young as they have a lot of experience in raising them – the oldest one on record lived in North Carolina and reached the ripe old age (for a bird) of 24 years and 2 months! (However, the oldest common tern on record was 25 years, so perhaps the sandwich terns are just more caring?)

The birds were quite entertaining to watch and I have more photos to share from that trip. I will try to intersperse them between postings on avian child-rearing. Have a nice day!

An evening at Bolin Creek

After a day waiting for four bluebirds to fledge (next blog!) and a health-care appointment, I decided to forego some chores and instead to spend some time at a bridge over Bolin Creek, a waterway in the local Carolina North Forest which belongs to the University of North Carolina. My naturalist friend Mary discovered that this spot is a favorite bathing spot for birds in the late afternoon and evening. Since the weather forecasters predicted rain most afternoons this week, I decided to make a quick foray there while I had the chance. I knew that photographing the wildlife could be difficult as the sky was dull, overcast and we were expecting a downpour but I was up for the challenge. And once in a while a bit of brightness emerged from behind the clouds to give me some encouragement.

At first, it seemed very quiet – no bird song or buzzing insects; I thought perhaps everyone was hunkering down in anticipation of a coming rainstorm. But then the sky lightened a bit and a handsome robber fly (Promachus) alighted on a nearby leaf. I think this is a red-footed cannibal fly; these insects look like little old men to me.

 

 

A little while later, there were suddenly three avian visitors. The female Eastern towhee (Pipilo erythrophthalmus) was the first to take a bath.

     

 

The blue-gray gnatcatcher (Polioptila caerulea) didn’t go to the water but flitted overhead.

 

The first of two American redstarts (Setophaga ruticilla) also hopped from branch to branch but eventually ducked behind some rocks to bathe.

A pair of damselflies hung out on the stream rocks; the blue-tipped dancer’s (Argia tibialis) dark purple made it look almost black in the twilight.

 

 

Then a beautiful female hooded warbler (Setophaga citrina) came by for a bath. Her golden feathers shone in the dark foliage and against the stream rocks.

 

 

 

A pair of gray catbirds (Dumetella carolinensis) came together but only one entered the stream for a thorough drenching of its plumage.

 

 

 

   

The redstarts returned but stayed on the branches as the daylight began leaking away.

A few other birds were in the vicinity but didn’t come near: American crows, Northern cardinals, a common grackle and two yellow-billed cuckoos. My visit ended when the sky really darkened — I started down the path in an effort to reach my car before the rain began. A Southern leopard frog (Lithobates sphenocephalus) crossed in front of me and paused in the grass, enabling me to get a quick portrait. And then a nettle of beautiful violet color called out for a photo, too. I made it to the car just as the first raindrops fell. Quite an enjoyable impromptu photography session!

The beautiful “baker” bird

Recently, I’ve had the good fortune to observe a small bird at close quarters that I had only seen in a couple glimpses in the past, the ovenbird (Seiurus aurocapilla). Like the ruby-crowned and golden-crowned kinglets, this little avian also has a stripe atop its head. Like the golden-crowned kinglet, the stripe is always visible and orange in color, blending in nicely with its other muted brownish and cream colors.

 

The ovenbird gets its name from the shape of its nest, which is built on the ground in a shape reminiscent of an outdoor or Hopi oven. It is domed and has a side entrance and can be difficult to see.

The ovenbirds spend the winters in the Caribbean region and Central America and then come North for the summer breeding season. My sightings of the singing male have been at our local nature reserve, Mason Farm Biological Reserve, where I volunteer as an invasive plant eradicator and sometime planter of native flowers.

 

The male sings a three- to-five note call in the spring as part of his courting behavior and the call varies among individuals. When males are in neighboring territories, they will sing together in duets and it can be difficult to know how many birds are singing.

   

The sound is so loud that you expect to see a much larger bird and his song inspired poet Robert Frost to dedicate a poem to him.

 

If he is sitting on a branch, you can eventually find him but it can be a challenge since they prefer to reside in forests with heavy canopy cover so that it is fairly dark.

 

   

Once you see him, you may be able to watch for a while as they don’t seem to be very wary of people. This individual let me observe as he groomed on a low tree branch, pausing now and again to let out a few notes.

  

   

These birds prefer areas with heavy leaf litter for their homes – the leaves provide cover for their ground nests and they blend in really, really well as they scurry about foraging in the leaves for insects, worms and snails to eat. Both the females and males participate in feeding the fledglings until they can fly at about 30 days.

When they emerge into a patch with a bit of sunlight filtering down through the leaves overhead, you have a bit better chance to see them. Otherwise, you may end up staring at ground cover until you catch a bit of movement and can zero in on the motion to see them.

 

Photographing the bird is a challenge since they spend their time in areas with so little direct light. My first photos were a bit dark, but then I increased the ISO on my camera considerably (a tip from fellow photographer, Mary – thanks!) and the photos were a bit better. Still, the somewhat darker photos reflect the environment in which you discover these little troubadour warblers. Now that I know where to look for them, I hope to see them more often in years to come.

Back to blogging with the golden crowns!

Litter boxes scrubbed, bird feeders filled, other chores waiting but I’ve decided to end my blogging hiatus on this rainy and somewhat gloomy Sunday morning. This and my next blog will feature two of my favorite birds and then I hope to treat you with a nesting saga as spring is well underway.

With a lovely ruby-crowned kinglet visiting my yard every year for the past four years, I’ve developed a particular fondness for this tiny avian species. This past autumn and winter, my partiality expanded to include their jeweled cousins, the golden-crowned kinglets (Regulus satrapa), who seemed to have favored our geographical area with an irruption (an ecological term for a sudden increase in an animal population). Whereas in previous years, I felt lucky to catch a glimpse of a golden crown during their months-long stay in North Carolina, they appeared to be everywhere this past winter and in full view to boot.

 

The golden-crowned kinglets are about the same size as the ruby crowns and similar in overall body color except that they also have a black eyebrow stripe.

While the ruby-crowned males only flash their red crests when mating or upset, however, the golden crowns have a permanent yellow stripe atop their heads.

 

         

The male golden crowns can sometimes be distinguished by the fact that there will be a hint of red in their golden crest.

         

Like the ruby crowns, these little insect foragers are in constant movement as they scour branches, shrubs and plants for a meal. Their varied diet includes beetles, flies, crickets, butterflies, spiders, and bees and wasps. In the winter, they will also eat some seeds.

     

Searching for the insects often means they hang upside down from branches as they look at the underside and in crevices for their next bite to eat.

 

They also hover mid-air to snatch an insect or fly.

The golden crowns sometimes sit still a bit longer than ruby crowns so that you have a chance to get off a few photographic shots before they resume their dietary searching. And this year, one of those photos placed me among the winners in a small local competition.

These birds are not much bigger than hummingbirds, but like the hummers, they also undertake a long migration twice yearly. Their winters are spent throughout North America but for breeding they travel to the far North and mountainous Northwestern areas of this hemisphere.

This year, many places had mild winters but if they arrive in the North before spring-like temperatures arrive, they are able to survive nights as cold as –40 degrees; sometimes, they huddle together to keep a bit of warmth. Their lifespan is several years, with the oldest recorded golden crown being a banded male who was at least 6 years and 4 months when he was recaptured in Minnesota in 1976.

       

 

This species prefers life in coniferous forests but it seems if a few spruce and pines are around, they will settle in. I saw them in a small and somewhat sparsely vegetated area near a senior center, an arboretum, along the Haw River, and in the woods and bogs of various nature reserves.

 

 

In the United States, the number of golden-crowned kinglets declined 75% between 1966 and 2014. Habitat loss has contributed to this. However, spruce reforestation in the Eastern USA may have contributed to a more recently seen increase in numbers of kinglets. I’m very glad that they are not (yet) an endangered species and I hope we get to see them a lot next winter, too!