(AOS 17 May 2017; Photo: J. Welklin)
Male birds that have already paired up with a female aren’t above looking for a little action on the side. A new study from The Auk: Ornithological Advances explores how male juncos adjust their courtship behavior to their social landscape, finding that while both paired and unpaired males will try to get the attention of a new female on their turf, they go about it in different ways.
A male bird’s courtship behavior can be affected by factors like his size and hormone levels, but ornithologists are increasingly realizing that social context—whether or not the male already has a mate, and what other birds are around to witness his exploits—also plays a role. Dustin Reichard of Ohio Wesleyan University (formerly Indiana University) and his colleagues set out to tease apart the roles these different issues play in the courtship of Dark-eyed Juncos, comparing how unpaired males, paired males whose mates were present, and paired males whose mates were elsewhere behaved when presented with a new female.
They found that paired males approached females more rapidly, spent more time close to the females, were more active, and spent more time with their body feathers erect than unpaired males. Paired males also sang fewer long-range songs than their single counterparts, perhaps not wanting other birds to overhear, although the actual presence or absence of their mates didn’t affect their behavior.
(Physorg; Photo: Nao Ota; 17 April 2017)
Java sparrows are more likely to mate after dancing together, according to a study from Hokkaido University, contradictory to the belief that songs are the primary sexual signal.
Songbirds are well-known to sing duets for various purposes such as mutual mate guarding and joint resource defense. For Java Sparrows, songs are performed only by males for courtship, but both males and females dance in a duet-like manner. The male’s song is thought to play an essential role in attracting female mates but the role of dancing has been unclear until now.
In a new study published in the journal PLoS ONE, Associate Professor Masayo Soma and Midori Iwama at Hokkaido University in Japan examined how duet-dancing influences the mating success of pairs during a first encounter.
The researchers found that although both duet-dancing and male-singing are associated to a higher rate of mating success, the former played an essential role in mating. Females often gave a copulation solicitation display (CSD), meaning they are ready to mate, before the males started to sing, or after listening to the introductory notes. These results suggest that dance is more important than the males’ singing.
Masayo Soma says “It is surprising that females select mating partners without hearing the main song. The main song varies greatly among individuals and is thought to be important for selecting a mate in similar species.”
They also found that duet-dancing could be initiated by either sex, confirming the existing knowledge that courtship is a bilateral process in this species. Duet-dancing might also be part of a “matchmaking” process since males and females performed it on their first meeting. Solo-dancing by either the male or female did not result in a higher mating success in their study.
“Our current research didn’t look at how well their dances fit together. Future studies should look into the duration and degree of coordination in duet-dancing to better understand the role of dancing and its relative importance to singing. We are also interested in how dance routines change among pairs over time,” Masayo Soma added.
(Pat Leonard; March 9, 2017)
Just for a moment, think back to those hormone-fueled years of teen angst when personal relationships hijacked rational thought and sparked endless hallway drama. In the competition for female attention, it was usually clear that the the captain of the football team had much better odds than the skinny chess club whiz. And ultimately, the females called the shots.
Male Red-backed Fairywrens feel the same pain.
They’re tiny Australian songbirds (sometimes likened to chickadees of the outback). Males come in two forms: the gorgeous mature males with gleaming red-and-black plumage (the “attractive” ones); and young brown males (the “unattractive” ones) that have yet to acquire their stunning plumage and look pretty much like females.
Past studies have made it clear female fairywrens are more attracted to males with red-black plumage. The red-black males nearly always sire way more offspring than the brown birds. They pair up and raise young with a long-term social mate, but they also court and mate with every willing female they can find (extrapair paternity is the scientific term for this philandering). But the brown males are not completely shut out—they can still pair up with a female and sire offspring.
Scientists studying a population of banded Red-backed Fairywrens near Cairns, Australia, have found that the two types of male employ drastically different strategies for mating success. Their work was published in the January issue of Biology Letters.
“The brown males stay close to home, sing more duets with their mates, guard their mates more, and take good care of their young,” explains lead author Jenélle Dowling, who was a Cornell Lab postdoctoral researcher at the time of the study. “The red-black males spend 98% of their time seeking out other females to mate with, putting on elaborate courtship displays all day long, rarely guarding their mates or taking care of the young.”