During their breeding season, or rut, bull moose display a number of behaviors that are not commonly seen any other time of year, and many of these behaviors leave obvious signs, including broken branches, scraped bark, wallows and tracks. Bulls roam their home ranges, thrashing their antlers back and forth against shrubbery and saplings while leaving their scent. The sound of their antlers beating against vegetation is thought to signal the bull’s dominance to other males, as well as serve to attract females. The pictured broken balsam fir sapling and its frayed bark are evidence of this behavior.
Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.
Spotted Sandpipers are a relatively easy shorebird to identify, with their spotted breasts, their constant body-bobbing/teetering and the stiff beat of their wings. Although they are a shorebird, they can be found near freshwater ponds and streams throughout North America. Spotted Sandpipers differ from most birds in that the male and female roles are completely reversed when it comes to breeding – from courtship to parental care. The females establish and defend their territory, often arriving on nesting grounds before the males. Females court the males, performing display flights as well as strutting displays on the ground. Males, usually less aggressive and smaller in size, do the lion’s share of incubating the eggs and brooding the young chicks.
Most of us are familiar with the American toad’s breeding call – a long trill that advertises his presence to potential mates in the area. However, American toads have three other calls, as well. A shortened version of the courtship trill, which sounds like a chirp, is given by male toad with its vocal pouch just slightly inflated. A second, release call, is often heard when a male is clasped by another male. (If you want to hear it, just pick up a male toad during the breeding season – it will vibrate as it chirps right in your hand. The combination of the call and the vibrations usually causes a clasping male to release his grip.) A fourth call, which has been recorded in the lab but not in the field, is a series of quiet clicks given by the male while clasping a female.
Numerous displays lead up to the mating of great blue herons – neck stretching, bill clacking, wing preening, circling flights, twig shaking, crest raising, neck fluffing, to name but a few. After this elaborate courtship comes copulation, which is not nearly as showy. Copulation typically takes place on the nest. The male places one foot gently in the center of the female’s back. The female leans forward, bends her ankles and holds her wings slightly away from her sides while the male lowers himself, often flapping his wings. Once the job is done, the male flies off. If you look closely you can perhaps make out that the male is grasping the female’s head/neck while copulation takes place.
It’s been my life’s dream to witness the fledging of young wood ducks from their tree cavity nest in response to their mother’s calls below – perhaps this will be the year! Adult wood ducks have recently returned to northern New England, having already formed mating pairs. They now proceed to perform a number of courtship displays which enable them to maintain this pair bond. The most common display involves the male’s turning the back of his head towards the female as he swims in front of her while holding his wings and tail high. Chin-lifting, feather-shaking, wing-preening, neck-stretching and bill-jerking are just some of the displays that occur during wood duck courtship.
Winter must be on the wane, as a tufted titmouse was recently singing its fast-repeated, clear whistle song, “Peter—Peter—Peter,” in nearby woods. Male titmice repeat this phrase over and over, up to 11 times in succession. Occasionally females sing a softer version of this song. The calls of tufted titmice, on the other hand, are very nasal and mechanical-sounding. Songs are typically more musical and complex than calls, and are often sung only by males during the breeding season, to attract a mate and claim territory. Calls, on the other hand, have many purposes – there are calls for aggression, warning, identification, flocking, hunger and to announce a food source, among others.
The mating season for moose (Alces alces) is just starting, and it peaks around the end of September or the first week in October. By this time bulls have shed the velvet that provided a blood supply to their antlers while they were growing during the summer. Occasionally you see the remains of the velvet hanging from their antlers at this time of year (see photograph). During mating season, bulls are rushing through the forest, seeking a receptive cow and engaging in mock battles with other bulls for the female’s attention. A bull uses his antlers in these challenges, engaging in “antler-pushing” with other males. He also uses his antlers as a tool for thrashing brush and for rooting plants from the bottom of ponds.
There is something irrepressibly cheery about the song of an Indigo Bunting. The male’s paired notes ring out from a high perch, where this unbelievably blue bird positively sparkles in the sunlight. According to Cornell’s “All About Birds” site, the male sings as many as 200 songs per hour at dawn and for the rest of the day averages a song per minute. To hear an indigo bunting sing, go to http://www.allaboutbirds.org/guide/Indigo_Bunting/sounds .
Although Spring Peepers emerged from hibernation about two months ago, on warm nights the males are still advertising for mates and will continue to do so into June. Let your ears guide you to the peepers as they call repeatedly, often while perched on low vegetation near water. Armed with a flashlight, look for the movement of their vocal sacs as they inflate and deflate as the peepers sing.
Under the stealth of a rainy night, subterranean-dwelling spotted salamanders migrated to their ancestral breeding pools this week. Groups, or “congresses,” of males gather, followed by females. Once a female locates a congress of males, she eventually pairs up with one of them. The pair of salamanders then engages in a courtship dance ending with the male depositing a tiny white packet of sperm called a spermatophore on the bottom of the vernal pool. If he has sufficiently stimulated the female, she picks up this packet into her cloaca, or vent, and fertilization takes place. The next morning the only sign that spotted salamanders have been and gone are the unclaimed spermatophores scattered on the leaves that lie on the pool bottom.
I heard my first peeper on March 18th, roughly two weeks earlier than in past years. These tiny members of the treefrog family begin mating rituals shortly after the end of hibernation. The males gather at small pools by the hundreds. Each male establishes a small territory and begins calling the familiar high-pitched “peep” quite frequently. The louder and faster he peeps, the better his chances are of attracting a receptive female. Males usually compete in trios, and the male with the lowest-pitched call usually starts the vocal competition. If you look closely at the peeper in the photograph you can see some snow fleas hitching a ride.
The return of song sparrows and their energetic songs tells us spring has definitely arrived. The males sing a sequence of notes, including clear whistles and buzzy sounds. According to nature recordist Lang Elliott, each male has about ten songs in its repertoire and tends to repeat one pattern for several minutes before changing to another. Although other birds may produce more musical songs, you’d have to search far and wide for more enthusiastic outbursts than those of a song sparrow.
If the increased yelping of eastern coyotes hasn’t caught your attention, you may not be aware that this is the peak of their breeding season. Female coyotes come into estrus once a year, for a period of about 10 days. For the past two or three months, working up to this, male and female coyotes have been increasing their scent marking. Occasionally you can find where a female has marked with urine, leaving behind a spot of blood (see photograph). Eventually she attracts one or more sexually active males, and mating ensues. Something I’ve never witnessed, but would love to, is the howling duet of a pair of coyotes prior to mating.
Eastern bluebirds have already been seen checking out nest boxes – behavior that usually isn’t observed for another month or so. Interestingly, even though most people religiously clean out their bluebird boxes every year prior to the nesting season, experiments show that bluebirds prefer nesting boxes containing old nests. While breeding has not yet begun, it won’t be long before males will be trying to attract females to their nest site by carrying material in and out of the hole, perching, and fluttering their wings. After the males choose the nest site and perform for a mate, the females actually do the hard work of building the nest.
Every track you see in this photograph was made by a red fox. Coming from every direction, they all lead to the tree stump. This stump is to foxes what our general stores, post offices and libraries are to us – a place to catch up on all the local news. Red foxes have these “bulletin boards” scattered throughout their territories. By marking a stump, they convey information such as their age, sex, availability, and much more to every other fox that passes by. Foxes will revisit these posts regularly in order to refresh their scent and update the information they’ve left. They also mark the boundaries of their territory to keep other foxes out. To save themselves unnecessary hunting, they mark spots where they have previously searched for prey or cached prey and eaten it, as a signal not to bother to investigate that area. During mating season, which we are in the height of, the fox also uses a scent from a gland on its tail to mark objects. At this time of year the combination of fox urine and glandular secretions create a skunk-like fragrance discernible by the human nose.
Earlier this week, when temperatures were in the 40’s and the sun was shining in the late afternoon, there were clusters of male winter crane flies (Trichocera sp.) hovering two or three feet above the snow, bobbing up and down as they did their mating dance. Females are on the surface of the snow most of the time, but join a swarm in order to find a mate. Winter crane flies are active throughout the winter, as their name implies, and are a source of food for resident songbirds. The larvae feed on decaying vegetation, and can be found in leaf litter, shelf fungi and compost heaps.