Species differences and geographic variation in the communal roosting behavior ofPrionostemmaharvestmen in Central American rainforests

Proporción sexual de la comunidad de pseudoescorpiones (Arachnida: Pseudoscorpiones) en bosque de manglar, San Antero-Córdoba, Caribe colombiano

“…Sin embargo, se han reportado marcadas variaciones entre las arañas, Anelosimus eximius Keyserling, 1884 (Theridiidae) presenta una proporción sexual que favorece a las hembras de 5:1; mientras que Larinioides cornutus (Clerk, 1757) (Araneidae) y especies de la familia Pholcidae (Carapoia ocaina Huber, 2000 y Mesabolivar aurantiacus Mello-Leitao, 1930) exhiben una proporción 1:1; mientras que, Metagonia taruma Huber, 2000 presenta diferencias que se atribuyen a variaciones estocásticas (VOLLRATH, 1986;YSNEL, 1991;MACHADO et al, 2007;CARVALHO et al, 2010;FOELIX, 2011). De igual forma, algunas especies de escorpiones presentan una proporción sexual que favorece a las hembras de 1:3 y de opiliones Megabunus diadema (Fabricius, 1799) (Phalangiidae) se considera partenogénica, sin embargo, especies de Prionostemma (Opilionida) presentan una proporción 1:1 (MERINO- SÁINZ et al, 2013;GRETHER et al, 2014;KASSIRI et al, 2015). A pesar de esto, la proporción de sexos presente en la naturaleza, tiende a ser siempre 1:1 e indica roles de igual importancia entre machos y hembras, dado que, la selección podría minimizar al sexo menos productivo, por tanto, la proporción sexual 1:1 sugiere, que el costo de criar con éxito las ninfas, es más o menos el mismo independientemente de su sexo (FISHER, 1930;SMITH, 1999;WADE et al, 2003;TABADKANI et al, 2012;WEDEKIND, 2012).…”

Experimental test of the mechanism underlying sexual segregation at communal roosts of harvestmen (Prionostemma spp.)

“…1 and Prionostemma sp. 2 (Grether et al., ; Proud et al., ). Both species roost during the day (dawn to dusk) and leave the roosts to forage at night (Donaldson & Grether, ; Grether et al., ).…”

“…2 (Grether et al., ; Proud et al., ). Both species roost during the day (dawn to dusk) and leave the roosts to forage at night (Donaldson & Grether, ; Grether et al., ). Individual site fidelity varies (Donaldson & Grether, ; Grether et al., ), but roosting aggregations tend to form repeatedly in the same locations, with some sites being used for over a decade (Grether et al., ; Teng, Dao, Donaldson, & Grether, ).…”

“…2 usually forms loose roosting aggregations in spiny palms ( Bactris , Astrocaryum ) (Grether & Donaldson, ). The roost sex ratio varies and most roosts are consistently skewed toward one sex or the other (Grether et al., ). Surprisingly, roosts with skewed sex ratios remained skewed in the same direction even after all of the animals were experimentally removed and the roosts were recolonized by new individuals (Grether et al., ).…”

“…The roost sex ratio varies and most roosts are consistently skewed toward one sex or the other (Grether et al., ). Surprisingly, roosts with skewed sex ratios remained skewed in the same direction even after all of the animals were experimentally removed and the roosts were recolonized by new individuals (Grether et al., ). A possible explanation is that the sexes differ in their roost site microhabitat preferences, but no microhabitat differences have been found between male‐biased and female‐biased roosts of this species (Grether et al., ).…”