Jessica Starrett

9 Added | 1 Magazine | @JessicaStarrett | I'm a mommy, a wife; love God, taking pictures, & beautiful views.

#Neotropical #bird #Behavior #Ecology [#Ornithology • 2014] Bills as Daggers? A Test for Sexually Dimorphic Weapons in A Lekking #Hummingbird http://novataxa.blogspot.com/2014/11/phaethornis-bills-as-daggers.html [Long-billed #Hermit /#Phaethornis longirostris/ in flight, at Cope Wildlife, Guapiles, Costa Rica. || Photo: Chris Jimenez] | doi: 10.1093/beheco/aru182 Abstract One way in which secondary sexual traits can influence differential reproductive success is by playing a key role in the outcome of direct physical contests for mates. Here we describe an undocumented trait in a species of hummingbird with a lek mating system, the Long-billed hermit (LBH, Phaethornis longirostris). The trait under consideration is a dagger-like structure at the bill tip, which we hypothesize is a secondary sexual trait that functions as a sexually dimorphic weapon. We tested our hypothesis by examining 5 leks during 4 consecutive years, and by employing morphological analyses, performance experiments, and behavioral observations. We found that 1) adult male bill tips were longer and pointier than their counterparts in females and juvenile males, 2) juvenile males acquired dagger-like tips during their transition to adulthood, 3) variation in bill tip morphology reflected puncture capability, and 4) males with larger and pointier bill tips were more successful in achieving lek territory tenure. Our study provides the first evidence of sexually dimorphic weapons in bird bills and stands as one of the few examples of male weaponry in birds. Our results suggest a role of sexual selection on the evolution of overall bill morphology, an alternative hypothesis to the prevailing “ecological causation” explanation for bill sexual dimorphism in hummingbirds. Key words: animal weaponry, bill morphology, ecological causation, intrasexual competition, male combat, secondary sexual traits, sexual dimorphism, trochilidae. Alejandro Rico-Guevara and Marcelo Araya-Salas. 2014. Bills as Daggers? #BehavioralEcology (2014), xx(xx), 1–9. doi: dx.doi.org/10.1093/beheco/aru182 http://marceloarayasalas.weebly.com/uploads/2/5/5/2/25524573/rico-guevara__araya-salas_2014.pdf Fighting for Females: The Evolution of a Hummingbird http://today.uconn.edu/blog/2014/11/fighting-for-females-the-evolution-of-a-hummingbird/ https://www.sciencenews.org/article/hummingbirds-take-stab-rivals-dagger-tipped-bills

#wildlife #USA || #Manatee surrounded by fish. Carol Grant: Manatees–Sirens of Crystal River :: @Wetpixel http://wetpixel.com/full_frame/carol-grant-manateessirens-of-crystal-river

wearevanity:

Muore un fiore e nace una speranza in un'altro cuore... http://t.co/pFQ19C6DYN

Nature's Fury: Gripping Images of Natural Disasters

From earthquakes to volcanic eruptions to hurricanes, natural disasters reveal the fearsome power of Mother Nature. Scientists are studying these …

Underwater Pictures Capture Life Inside World's Newest Marine Sanctuary

Wildlife

Winter Nature

4K HD Wallpaper: Winter Nature - "The colors of snow"<p>Widescreen Desktop / Macbook: 2560x1600 (fits on: 1920x1200, 1440x900, 1280x800) <br>High Definition …