Spring is in the air…. Uh, I mean water!

It was the sound that first attracted my attention. Initially, I thought that it sounded like a flock of birds, but as I approached a pond, I realized that was not the case. The almost chirruping sound didn’t fit with any frogs I had heard before. As I scanned the scene before, my roving vision finally alit on a small section of brownish water dappled with green algae and stalks of dead reeds – there were moving bumps there. When I came closer, I finally realized that it was a mass of writhing and continually moving toads, engaged in what resembled a bit of a battle. It was actually what could be called a mating contest. (Click on a photo to see it larger; then arrow back to return to blog.)

The sound made by the male Eastern American toad (Anaxyrus americanus americanus) when he is ready to breed has been likened to an old-fashioned ringing telephone. It can last from 6 to 30 seconds and when multiple toads are calling at the same time, they create a very loud and penetrating “concert”. It doesn’t sound like a phone to me; you can judge by listening to the video.

I only saw a couple of the toads with inflated throat sacs. The sound was very loud, however, and the water was roiling with moving heads topped by periscope eyes, warty bodies and thrashing legs.

Before examining how the toads were going about their reproductive endeavor, a little biology lesson. Toads are a sub-group of frogs; while most frogs have moist skin, toads generally have drier and wartier skins. They vary greatly in color, including shades of yellow, brown, black and red, and may be speckled or have solid hues. The skin color can also change in response to stress, temperature, humidity and habitat.

 

American toads have two glands at the top of their head behind the eye crest. These are parotid glands that produce a neurotoxin, bufotoxin, which can sicken and even kill a predator. The milky substance can produce skin irritation in human beings and can be dangerous to smaller mammals (like dogs).

 

 

Like birds, toads have nictitating membranes, transparent eyelids that help protect the eye. They sometimes raise the nictitating membrane half-way so that they retain sharper vision.

 

 

Toads actually spend a lot of their lives on dry land, eating insects as well as worms, slugs and other small invertebrates. A particularly fascinating fact is that they use their eyeballs to help swallow food – when they ingest their prey, the eyeballs sink down into their mouth and help push the food down their throats!!!

At times, they created little whirlpools as they bumped up against one another or tried to mount a neighbor.

 

 

Sometimes, a large female with a smaller male atop her would rest quietly under water, apparently trying to avoid notice. This strategy did not always work, however, and sometimes one or more other males would try to join the pair already in amplexus (i.e., when the male grasps the female with his front legs and fertilizes the eggs as she releases them from her body)..

The female toad ejects her eggs in two strings, which are immediately fertilized by a nearby male spurting out a stream of sperm. (Frogs lay their eggs in clusters.) Tadpoles will emerge from the eggs within 2–14 days and reach adulthood within 50–65 days. They become sexually mature at 2-3 years.

In one case, I developed a real sympathy for a particularly large female. She had a small male astride her who resembled her in coloring and they looked to be peacefully joined. Then another male spotted them and he launched a sneak attack, trying to usurp the position of her already-present suitor. The first male clung on tightly.

No. 1 pushed No. 2 away with a hind leg again and again.

In the meantime, a great blue heron (Ardea herodius) who had been feeding on the other side of the pond, made its way over to the site of toad frenzy. S/he had been eating small fish and amphibians.

I thought the heron would plunge into the midst of the numerous toads for an easy meal, but instead the bird looked around and then skirted the group, veering away to the shoreline. Perhaps some instinct made the heron avoid the group during a reproductive event? Or s/he was put off by the vigorous activity of the potential prey?

A second rival toad then joined the first, who was still trying to get the original mating male out of the way. Eventually, a third, fourth and yet another male joined the group and the poor female was weighted down by 5 – FIVE! – male toads all vying for the prime spot on her back. Often her head was pushed down under water.

The first male clung on with great determination, often being pushed down under water as well as the other males piled on. He was NOT going to give up.

Ms Toad did not like this state of affairs. She laboriously began moving from a deeper spot in the pond to the pond’s edge. This was a slow process, made difficult by the clinging crowd who must have weighed a good deal as a group.

I thought she might be trying to get to more shallow water so the toad “knot” would not keep her submerged. Toads can breathe under water like frogs because they can absorb oxygen through their skin. They do have lungs, however, and if these fill with water, they can drown. A fellow Facebook nature lover told me that she had seen expired female toads with males still clinging to them. A toad knot can therefore unfortunately result in maternal mortality – the demise of a mother giving birth (to several thousand eggs; most of the tadpoles do not survive).

I soon left the scene after Ms Toad had reached the side of the pond and could keep her head above water. It was noticeable that her throat pouch was inflating and deflating – perhaps she was breathing deeply to compensate for lack of oxygen when she had to suffer a submerged head due to the over-amorous males.

 

Inhale!                                                                  Exhale!

I know I am anthropomorphizing, but I do believe that she likely felt the amphibian equivalent of relief and was looking forward to the end of that day!

Oh, those ravishing raptors!

Numerous people who attract birds with feeders feel regret and sadness when one of their avian visitors is captured to serve as a meal for a raptor in the neighborhood. I, too, feel that pity and discomfort when I see one of the hawks or owls capture a bird or animal because my thoughts go to the pain and fear that the prey must feel. But of course all wildlife has to eat and I want members of the predator species to survive as well. And the beautiful predators can be really interesting to observe.

 

A Cooper’s hawk (Accipiter cooperii, left) sometimes frequents my yard looking for a bird to take. This particular day in November last year, the hawk flew to the front-yard feeders but came up empty-taloned. Raptors, also known as birds of prey, are not the only birds that eat something other than seed. Some smaller birds, like the shrike, do so and many songbirds eat insects. The raptors, however, often go after prey that is fairly large in comparison to their own body size. In January this year, I came across another Cooper’s hawk at a nature reserve. The bird flew soundlessly past me to land in a tree downslope and paused for a bit before flying on, providing time for me to get a gorgeous portrait.

I’ve been lucky lately in seeing barred owls (Strix varia) at the Brumley Nature Preserve North. This owl was sitting silently next to a walking path, looking out over the adjacent field.

A couple weeks ago, I was startled by this barred owl who suddenly flew in front of me from behind my right shoulder. I hadn’t noticed him/her in a tree behind me. I tried to follow its flight but lost it. I thanked the owl for letting me glimpse it and said it would be nice if s/he came back so I could get another look. Sure enough, after I had turned back to the vicinity where I originally was surprised by the silent predator, it flew in and perched on a branch. The bird had a snooze, keeping one eye partially open to keep me in view.

  

Lately, I’ve been seeing many red-shouldered hawks (Buteo lineatus). They have been flying overhead at the nature reserves. The other day, two flew by calling raucously and then they alighted at the top of a far distant tree. I couldn’t get a photo but did see them mating in silhouette against the late afternoon sky.

  

 

A few weeks ago, a pair of red-shouldered hawks began constructing a nest just down the street from where I live. One afternoon, I happened to see them and one was collecting twigs to build or refurbish a nest.

 

 

   

This pair roams our neighborhood looking for prey; sometimes, one or both will perch in my back-yard tree for a little rest.

    

When one of the red-shouldered or Cooper’s hawks pauses for some time in the tree over the small pond, I figure it is watching for frogs or one of the chipmunks that live in the rocks surrounding the pond. The chipmunks appear to be very good at eluding capture.

 

 

A couple weeks ago, our neighborhood family of American crows (Corvus brachyrhynchos) was making a racket in my yard and when I looked out the window, I could see them harassing a hawk. I couldn’t make out why they were so angry but grabbed my camera for some shots through the window.

 

  

It turned out that the Cooper’s hawk had caught one of the numerous Eastern gray squirrels that live here. The squirrels sometimes annoy me but on the whole, I enjoy watching their antics, so I felt badly for this squirrel, who obviously was not going down without some struggle.

What made it easier for me to watch was that I didn’t really see the squirrel’s head and it was not making a sound. I think the hawk had silenced it early on when it had its claws around its neck and chest.

The hawk was determined and kept hold of the rodent, eventually subduing it.

The hawk as not unscathed, however, as you can see from the wound on its leg.

When the raptor flew off suddenly with the squirrel hanging from its talons, the three crows chased it in hot pursuit. I don’t know if they were just upset that the hawk was present or if they wanted to steal the squirrel away. On walks through the neighborhood, I am now regularly seeing the hawks in trees and on power lines. They are not too shy and seem to be adapted to the human presence in their territory.

  

While I may be feeling a bit wary for the other animals and birds when the stunning raptors appear, it still is a thrill to see one up close. Only about half of the red-shouldered chicks make it through their first year of life, so I hope the hawks keep coming by. And who knows, maybe we will have some of the long-lived birds who can reach an age of 15-19 years!

 

 

 

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. 🙂