Forage, Habitat use, and Sexual Segregation by a Tropical Deer (Cervus Eldi Thamin) in a Dipterocarp Forest

A total of 312 female leopard sharks (Triakis semifasciata) was sampled in Humboldt Bay, California, USA, an important nursery ground for this species, during the spring month of May from 1983 to 1984 and 1985. Sexual segregation is strong as only three males were observed in the study area. Females ranged in size from 120 to 154 cm total length, and all examined were determined to be mature. Overall, 130 out of 153 females examined in early May contained term embryos. The number of embryos per female ranged from 1 to 37 with larger females tending to possess more embryos. Of the 159 individuals examined in late May, no females were found carrying embryos and most were ovulating. Diet analyses revealed that, overall, fish eggs (Atherinopsis californiensis) at 48.0%, had the highest percentage Index of Relative Importance (%IRI), followed by the cancrid crabs, Cancer antennarius (29.8%) and C. magister (11.6%). All other prey were of relatively minor importance, cumulatively representing 10.6% of the overall diet. Adults shift their diet after parturition: early May sharks fed almost exclusively on fish eggs, while crabs were more important in those examined in late May.

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Male harassment drives females to alter habitat use and leads to segregation of the sexes

Biology Letters ◽

10.1098/rsbl.2008.0308 ◽

2008 ◽

Vol 4 (5) ◽

pp. 449-451 ◽

Cited By ~ 76

Author(s):

Safi K Darden ◽

Darren P Croft

Keyword(s):

Sexual Harassment ◽

Habitat Use ◽

Predation Risk ◽

Sexual Conflict ◽

Social Factors ◽

Poecilia Reticulata ◽

Sexual Segregation ◽

Male Harassment ◽

Mating Opportunities ◽

Female Behaviour

Sexual conflict is ubiquitous across taxa. It often results in male harassment of females for mating opportunities that are costly for females, in some cases reducing reproductive success and increasing mortality. One strategy that females may employ to avoid sexual harassment is to segregate spatially from males. In fact, we do find sexual segregation in habitat use in species that have high levels of sexual conflict; however, the role of sexual harassment in driving such segregation remains poorly understood. Here, we demonstrate experimentally in a population of wild Trinidadian guppies Poecilia reticulata that male sexual harassment drives females into habitats that they otherwise do not prefer to occupy. In support of the social factors hypothesis for sexual segregation, which states that social factors such as harassment drive sexual segregation, this female behaviour leads to segregation of the sexes. In the presence of males, females actively select areas of high predation risk, but low male presence, and thus trade off increased predation risk against reduced sexual harassment.

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Sexual segregation in habitat use is smaller than expected in a highly dimorphic marine predator, the southern sea lion

Marine Ecology Progress Series ◽

10.3354/meps11759 ◽

2016 ◽

Vol 554 ◽

pp. 201-211 ◽

Cited By ~ 10

Author(s):

AMM Baylis ◽

RA Orben ◽

DP Costa ◽

JPY Arnould ◽

IJ Staniland

Keyword(s):

Habitat Use ◽

Sexual Segregation ◽

Sea Lion ◽

Marine Predator

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Differential habitat use and sexual segregation in the Central Arctic caribou herd

Canadian Journal of Zoology ◽

10.1139/z87-083 ◽

1987 ◽

Vol 65 (3) ◽

pp. 534-541 ◽

Cited By ~ 38

Author(s):

R. D. Jakimchuk ◽

S. H. Ferguson ◽

L. G. Sopuck

Keyword(s):

Habitat Use ◽

Habitat Preferences ◽

Sexual Segregation ◽

Late Winter ◽

Adult Males ◽

Sedge Meadow ◽

Tussock Tundra ◽

Major River ◽

Riparian Habitats ◽

River Valleys

Distribution of the Central Arctic caribou herd is characterized by segregation of the sexes and different habitat preferences by male and female caribou over most of the annual cycle. During all periods except late winter and postcalving, females showed a more northern distribution than did males. Females used riparian habitats less than availability and were generally farther from major river valleys than expected during all seasons except late winter. In contrast, males preferred riparian habitats from late winter to calving and were generally found closer to river valleys than were females from late winter to August dispersal. During the spring and calving periods near the coast females preferred sedge meadow and used riparian habitat less than availability whereas males preferred riparian and tussock tundra and used sedge meadow less than availability. It is theorized that sexual segregation and differential habitat use reflect predator avoidance strategies of females with calves and optimal foraging by adult males.

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