Male harassment influences female movements and associations in Grevy's zebra (Equus grevyi)

In traditional models for social organization, female movementsand association patterns track resource distribution, whereasmales track females. More recently, this model has been expandedto include feedback effects of male behavior, especially sexualharassment, on female decisions. In Grevy's zebra (Equus grevyi),males defend territories containing resources attractive tofemales, who form unstable groups. Past research has explainedfemale behavior based on resource distribution and needs alone.Lactating females have been found to have restricted movementsand fewer male associates than nonlactating females, a patternwe find in our study. This pattern has previously been attributedsolely to the higher water needs of lactation. However, in ourpopulation, both lactating and nonlactating females are typicallyclose to water. We test the hypothesis that male harassmentalso influences female ranging and associations with males.This effect is predicted to be greater for lactating femalesbecause harassment has higher costs to them. We find that lactatingfemales experience higher harassment rates than those of nonlactatingfemales. Lactating females tend to move faster during harassmentperiods, whereas nonlactating individuals do not. Lactatingfemales experience lower harassment rates if they spend moretime with a particular male, whereas nonlactating females' harassmentrates do not depend on their allocation of time to a primarymale. We suggest that females concentrate their time with onemale in order to reduce male harassment. Even in species suchas Grevy's zebra without strong male–female bonds, socialinteractions may be a significant driver of female distribution.     

Urinary androgen concentrations and social status in two species of free ranging zebra (Equus burchelli and E. grevyi)

In both species of zebra, breeding males had higher urinary androgen concentrations (ng androgens/mg Cr) than did non-breeding bachelor males (30.0 +/- 5.0 (N = 9) versus 11.4 +/- 2.8, (N = 7) in the plains zebra; 19.0 +/- 2.2 (N = 17) versus 10.7 +/- 1.2 (N = 14) in the Grevy's zebra). In the more stable family structure of the plains zebra (single male non-territorial groups) variations in androgen concentrations could not be ascribed to any measured variable. In the Grevy's zebra, androgen values were significantly lower in samples taken from territorial (breeding) males which had temporarily abandoned their territories (N = 4) and the urinary androgen concentration for a male on his territory was negatively correlated with the time since females last visited the territory.     

Variability in the diet of New Zealand sea lion (Phocarctos hookeri) at the Auckland Islands, New Zealand

We examined the stomach contents of 121 New Zealand (NZ) sea lions ( Phocarctos hookeri ) caught by the squid fishery during the summer/autumn 1997–2006 around the Auckland Islands (51°S, 166°E). Dietary variation was assessed among juveniles, lactating females, nonlactating females and males, and between areas on the Auckland Islands shelf. The digested fraction of the contents consisted mostly of opalfish ( Hemerocoetes spp.) (50.1% by number [ N ], 4.7% by mass [ M ]), rattail ( Coelorinchus spp.) (12.0% N , 2.4% M ), arrow squid ( Nototodarus sloani ) (14.1% N , 17.9% M ), octopus ( Enteroctopus zealandicus ) (2.1% N , 27.8% M ), and red cod ( Pseudophycis bachus ) (3.8% N , 4.3% M ). Opalfish was found in greater proportions in the stomachs of females (lactating: 58.1% N , nonlactating: 62.4% N ) and juveniles (56.9% N ) than males (14.5% N ). Juveniles caught smaller opalfish and rattail than adults did. Over all classes, sea lions ate larger prey in the east than in the north of the Auckland Islands shelf. The common prey—arrow squid and rattail—constitute an abundant resource at the edges of the Auckland Islands shelf, where lactating NZ sea lions forage. Although these key areas are far from the rookeries and impacted by the squid fishery, they may provide the only reliable resource able to support the cost of benthic foraging behavior in the deepest diver of all otariids.     

Aggressive behavior of adult meadow voles (Microtus pennsylvanicus) towards young

Summary Field evidence indicates that adult microtines, especially females, may be a major cause of poor juvenile survival and this may be instrumental in their population regulation. This suggests that males and females behave differently towards young animals. To examine how adult males, nonlactating females, and lactating females behave towards strange young, I introduced young animals into the home cage of the adults. Lactating females were most aggressive towards young; most males investigated them; most nonlactating females ignored them. However, discriminant function analysis indicated a great deal of overlap in the behavior of the classes. None of the classes behaved differently towards young of either sex. Females did not vary their behavior during lactation. Behavior varied among lactating females, with 55% showing little aggression and 20% showing a great deal. Most lactating females showed similar behavior in each of their bouts: docile females remained docile, aggressive females remained aggressive. I conclude that lactating females are most aggressive towards strange young. These results are consistent with the field evidence, which suggests that adult females depress juvenile survival and recruitment and that the main culprits are breeding females.     

Effects of traditional pastoralism on grasshopper (Caelifera) assemblages in East Africa

In East Africa, traditional pastoralists increase landscape heterogeneity by creating traditional livestock corrals (bomas). When these bomas are abandoned, they serve as long‐term hot spots of increased nutrients and unique vegetation. However, the effect of bomas on insect populations is unclear. Grasshopper (Suborder Caelifera) assemblages are thought to reflect vegetation, and within Caelifera, the subfamily Oedipodinae is known to be associated with degraded areas. We sampled vegetation and collected grasshoppers inside of abandoned bomas, 50 m from abandoned bomas and 250 m from abandoned bomas. Bomas had significantly lower grass abundance than background vegetation. Total grasshopper abundance was positively correlated with grass and forb abundance, while the proportion of grasshoppers in the subfamily Oedipodinae was negatively correlated with grass abundance. Grasshopper abundance was significantly lower inside of bomas than outside of them, but the proportion of grasshoppers in the subfamily Oedipodinae was significantly higher inside of bomas than outside of them. This suggests that the decreased vegetation in abandoned bomas supports fewer grasshoppers, but a higher fraction of the grasshopper assemblage in abandoned bomas is composed of Oedipodinae. Thus, traditional pastoralists can have long‐term effects on the size and composition of grasshopper assemblages through the use of bomas.     

Do Reproductive Status and Lamb Gender Affect the Foraging Behavior of Bighorn Ewes?

In female ungulates lactation carries a high energetic cost and mothers often devote more care to sons than to daughters. The aims of this study were to determine whether lactating bighorn ewes have higher foraging time, bite rate or selectivity of forage than barren ewes and whether reproductive status affects migration patterns. Ewes with male lambs were predicted to spend more time foraging and to have a higher bite rate than ewes with female lambs. There were no differences in foraging behavior according to ewe reproductive status from April to August. In September-November lactating ewes had a higher bite rate and spent more time foraging than nonlactating ewes but lamb gender did not affect foraging behavior. Lactating ewes gained less weight than nonlactating ones until mid-August; from mid-August to late September mass gain was similar for both groups of ewes. Nonlactating ewes spent more time standing but reproductive status did not affect vigilance behavior or step rate while foraging. Ewes with lambs did not differ from nonlactating ewes in step rate. Pregnant ewes migrated earlier than barren ewes to alpine areas in spring. By so doing they abandoned areas with good quality forage presumably to give birth in areas safer from predation. All ewes spent most of the summer in the alpine range but nonlactating ewes returned to the winter range earlier than lactating ewes, probably to profit from the abundant forage there.     

Ecology of Physaloptera capensis (Nematoda : Spiruroidea) infecting the Springhare Pedetes capensis (Mammalia) in Botswana

Incidence and intensity of the stomach nematode Physaloptera capensis in relation to the age, sex, reproductive status, physical condition, density and habitat of its host, the Springhare, were investigated in the Republic of Botswana (August 1971-August 1973). All data indicate that this nematode is a benign parasite of the Springhare. Infections were not randomly distributed within the Springhare population. Mean number of worms per Springhare was 83 and 34% of all Springhares were parasitized. Adults, females and lactating females showed significantly heavier infections than juveniles, males and non-lactating females, respectively. Infection was directly associated with the amount of grass cover in the Springhares' habitat but independent of the density and physical condition of Springhares. Possible causes of differences in rates of infection among Springhares of different age/reproductive classes and from populations of different density are mentioned. It is suggested that numbers of P. capensis may be regulated mainly by density-independent environmental factors operating upon rates of transmission.     

Identification of human–carnivore conflict hotspots to prioritize mitigation efforts

Human–carnivore conflict is a primary driver of carnivore declines worldwide and resolving these conflicts is a conservation priority. However, resources to mitigate conflicts are limited and should be focused on areas of highest priority. We conducted 820 semistructured interviews with community members living within Kenya's Maasai Mara ecosystem. A multiscale analysis was used to determine the influence of husbandry and environmental factors on livestock depredation inside livestock enclosures (bomas). Areas with a high proportion of closed habitat and protected areas had the highest risk of depredation. Depredation was most likely to occur at weak bomas and at households where there were fewer dogs. We used the results to identify potential conflict hotspots by mapping the probability of livestock depredation across the landscape. 21.4% of the landscape was classified as high risk, and within these areas, 53.4% of the households that were interviewed had weak bomas. Synthesis and applications. With limited resources available to mitigate human–carnivore conflicts, it is imperative that areas are identified where livestock is most at risk of depredation. Focusing mitigation measures on high‐risk areas may reduce conflict and lead to a decrease in retaliatory killings of predators.     

Home range dynamics,habitat selection,and survival of Greater Roadrunners

ABSTRACT Greater Roadrunners (Geococcyx californianus) are common, poorly studied birds of arid and semi‐arid ecosystems in the southwestern United States. Conservation of this avian predator requires a detailed understanding of their movements and spatial requirements that is currently lacking. From 2006 to 2009, we quantified home‐range and core area sizes and overlap, habitat selection, and survival of roadrunners (N= 14 males and 20 females) in north‐central Texas using radio‐telemetry and fixed kernel estimators. Median home‐range and core‐area sizes were 90.4 ha and 19.2 ha for males and 80.1 ha and 16.7 ha for females, respectively. The size of home range and core areas did not differ significantly by either sex or season. Our home range estimates were twice as large (x?= 108.9 ha) as earlier published estimates based on visual observations (x?= 28–50 ha). Mean percent overlap was 38.4% for home ranges and 13.7% for core areas. Male roadrunners preferred mesquite woodland and mesquite savanna cover types, and avoided the grass‐forb cover type. Female roadrunners preferred mesquite savanna and riparian woodland cover types, and avoided grass‐forb habitat. Kaplan‐Meier annual survival probabilities for females (0.452 ± 0.118[SE]) were twice that estimated for males (0.210 ± 0.108), but this difference was not significant. Mortality rates of male roadrunners were higher than those of females during the spring when males call from elevated perches, court females, and chase competing males. Current land use practices that target woody‐shrub removal to enhance livestock forage production could be detrimental to roadrunner populations by reducing availability of mesquite woodland and mesquite savanna habitat required for nesting and roosting and increasing the amount of grass‐forb habitat that roadrunners avoid.     

Linking alternative reproductive tactics and habitat selection in Northern chamois

In polygynous ungulates, males may achieve fertilization through the use of alternative reproductive tactics (ARTs), discrete phenotypic variations evolved to maximize fitness. ARTs are often associated with different male spatial strategies during the rut, from territoriality to female‐following. Although variation in space use patterns of rutting male ungulates is known to be largely affected by the spatial distribution of females, information on the year‐round habitat selection of alternative reproductive types is scant. Here, we investigate the seasonal variation in habitat choice of a large mammal with ARTs (territoriality and nonterritoriality), the Northern chamois Rupicapra rupicapra. Global Positioning System (GPS) data on 28 adult males were collected between February 2010 and December 2013 in the Gran Paradiso National Park (Italy) and used to fit resource selection functions to explore the ART‐specific use of key topographic features, such as elevation, aspect, and slope, and vegetation phenology expressed as NDVI values. Territorial and nonterritorial chamois profoundly differed in their habitat selection not only during the rutting season. Compared to nonterritorial males, territorial males used lower elevations in summer and autumn, preferred southern slopes in spring and summer, and used steeper areas in summer but not in winter. We found no difference in seasonal selection of NDVI values between males adopting ARTs. Our results suggest that territorial males tend to occupy warmer, lower‐food‐quality habitats in late spring and summer, whereas nonterritorial males are free to follow and exploit vegetation phenology and more favorable temperatures. Different patterns of habitat selection may reflect different trade‐offs between the optimization of energy balances throughout the year and the increase of mating opportunities during the rut in males adopting alternative reproductive tactics.     

Indirect measures of reproductive effort in a resource-defense polygynous ungulate: territorial defense by male guanacos

Trade-offs between reproductive effort and activities that are likely to enhance survival have been studied extensively in harem defense ungulates. However, among resource defense systems, ecological determinants of the variation in male reproductive effort are less understood. The aim of this study was to assess the extent of the effort devoted to territorial defense by male guanacos and how this is affected by predation risk. Time allocation to different activities and displays of aggressive behavior were compared between territorial and bachelor male guanacos within two populations with contrasting levels of predation risk. Territorial males devoted almost twice the time than bachelors to vigilance and moving, at the expense of foraging time. Aggressive interactions were more frequent and severe for territorial males than for bachelors, based on observation. These differences were larger during the reproductive season but remained statistically significant after this period, highlighting the extended effort towards territorial defense beyond the peak of reproductive activity. In contrast to previous observations on females of the same populations, there was no effect of predation risk level or group size on male time allocation, suggesting that under the ecological conditions of the study, intra-sexual competition entails a stronger influence on male individual behavior than predation risk level.     

Nutritional ecology of dimorphic herbivores: digestion and passage rates in Nubian ibex

We compared forage digestion and passage rates among three groups of Nubian ibex (Capra ibex nubiana) — mature males, non-lactating females, and lactating females — to test hypotheses relating intraspecific digestive ability to body mass and reproduction costs. We hypothesized that large males (60 kg) would exhibit longer forage retention times and more complete digestion of fermentable cell walls than adult females (23 kg). We tested these predictions by measuring digestion and retention of a grass hay and an alfalfa hay, forages that exhibited contrasting rates and extents of cell wall digestion. Consistent with predictions, males retained both forages longer than non-lactating females. However, by substantially increasing gut fill, lactating females increased both intake and retention time with respect to non-lactating females. Contrary to predictions, all three groups digested the grass (66% digestible) and alfalfa hay (63%) equally well. Alfalfa cell wall was less digestible than that of grass hay (60% vs 69% digestible), and retention time of alfalfa was consistently, but not statistically significantly, shorter. Fiber digestion was not correlated with retention time, emphasizing the ability of behavioral processes to modify digestion rate. We postulate that females achieved their greater digestion rate by masticating forages much more thoroughly than males.     

Age and reproductive investment in grass goby females in the Venice lagoon

The present work describes the relationship between age and reproductive investment in the grass goby females in the Venice Lagoon. Age was estimated by otoliths reading, while reproductive investment was assessed by either the relative number of mature females across the breeding season and their gonadosomatic index. Females from different size/age classes differed in the timing and level of reproductive investment. The oldest females (3+ years old) appeared earlier in the spawning habitat, investing more at the beginning of the breeding season. In turn a later arrival in the spawning habitats has been observed for younger females (0+) and smaller individuals of 1+ and 2+ age classes. Present results gave evidence of an earlier age/size at sexual maturity of the grass goby in the Venice Lagoon compared to previous information on the species from the same lagoon and from other Mediterranean areas. Results were discussed in the light of previous data on reproductive strategy of nesting males and of the relationship between fishing pressure and life history traits in the Venice lagoon.     

Territoriality and nutritional condition in Cynotilapia afra (Gunther) and Pseudotropheus zebra (Boulenger), cichlidae in Lake Malawi National Park, Malawi

The standard length, diurnal activities, territory sizes, and areas over which individuals foraged and the nutritional condition of territorial and non-territorial Cynotilapia afra and Pseudotropheus zebra were compared. Results show that territorial tenureship in these fishes does not depend on the male size, implying that aggressiveness, experience and motivation are more important in the maintenance of territory. However, terri-toriality in C. afra (t = 10.93, P < 0.05) and P. zebra (t = 3.31, P < 0.05) manifests itself in the reduction of nutritional condition because territorial males engage in energetically more demanding activities, e.g. courtship displays, fertilizing ripe females and chasing intruders that trespass into their territories. Territorial C. afra (t = 4.77; P < 0.05) and P. zebra (t = 5.89; P < 0.05) also fed over significantly smaller areas and spent significantly less time feeding than did non-territorial males. The biological significance of territoriality in these fish species is therefore not food intake, but mate attraction and reproductive success for which they trade off their nutritional condition. However, there might be a nutritional threshold below which the cost out-weighs the benefit. Hence, territorial males in poorer health abandon their territories in order to regain their condition.     

Breeding variation in female kakapo (

We investigated why some mature females of New?Zealand?s critically endangered parrot, the kakapo (Strigops habroptilus), did not attempt to breed during the 2005 breeding season on Codfish Island. At a population level, the initiation of kakapo breeding appears to correspond with years of mast fruiting of rimu (Dacrydium cupressinum) trees, with the proportion of females that breed each season dependent on the quantity of rimu fruit available. This research investigates possible links between habitat quality within individual home ranges and the breeding status of adult females during 2005, when the abundance of available rimu fruit was low. We assessed the importance of both home range size and habitat characteristics in determining breeding attempts. Foraging home ranges were characterised using radio-tracking and triangulation techniques. The relative importance of habitat variables in optimal breeding habitat was assessed using ecological niche factor analysis. Our results show that female kakapo breeding in 2005 had, on average, home ranges twice the size of those females that did not breed that season and the ranges contained a significantly greater quantity of mature rimu forest. Multivariate analysis illustrates female kakapo were effectively partitioning available habitat, as breeders? foraging locations were positively correlated with high-abundance rimu forest with a tall canopy, described as optimal breeding habitat. In contrast non-breeders? locations were weakly correlated with short forest containing little or no mature rimu forest. To maximise reproductive output each breeding season, conservation managers need to ensure that all breeding-aged females occupy optimal breeding habitat on Codfish Island. Removal to other islands of kakapo not required in the breeding population may enable females to increase their home range size and occupy better breeding habitat.     

Cheetah behaviour at scent-marking sites indicates differential use by sex and social rank

Scent-marking is an important form of communication for solitary species, as the information remains for the receiver after the sender has left the area. Individuals of different demographic or dominance classes (ranks) need to provide different information to conspecifics. Therefore, the use of scent-marking sites is of particular value for solitary species, but their functional role may vary between demographic classes. Using camera traps, we video-recorded the behaviour of cheetahs at scent-marking sites, assessing how individuals of different sex and social rank use the sites for different roles. We tested hypotheses that these sites are for territorial marking, reproductive signalling and information gathering. We found that females visit the sites infrequently, apparently to signal oestrous events, while males visit the sites frequently for territorial marking and information gathering. Among males, dominant individuals scent-marked the most and reacted to female visitation by vocalizing. In contrast, subordinate males, although also visiting the sites, were not recorded scent-marking nor vocalizing. These differences in the functional use of scent-marking sites among sex and social rank support the hypotheses that cheetah s use these scent-marking sites for both territorial and reproductive signalling, as well as to gather information.     

Sexual segregation in ungulates: a comparative test of three hypotheses

In most social ungulate species, males are larger than females and the sexes live in separate groups outside the breeding season. It is important for our understanding of the evolution of sociality to find out why sexual segregation is so widespread not only in ungulates but also in other mammals. Sexual body size dimorphism was proposed as a central factor in the evolution of sexual segregation in ungulates. We tested three hypotheses put forward to explain sexual segregation: the predation-risk, the forage-selection, and the activity budget hypothesis. We included in our analyses ungulate species ranging from non-dimorphic to extremely dimorphic in body size. We observed oryx, zebra, bighorn sheep and ibex in the field and relied on literature data for 31 additional species. The predation-risk hypothesis predicts that females will use relatively predator-safe habitats, while males are predicted to use habitats with higher predation risk but better food quality. Out of 24 studies on different species of ungulates, females and their offspring chose poorer quality but safer habitat in only eight cases. The forage-selection hypothesis predicts that females would select habitat based on food quality, while males should prefer high forage biomass. In fact, females selected higher quality food in only six out of 18 studies where males and females segregated, in eight studies there was no difference in forage quality and in four studies males were in better quality habitat. The activity budget hypothesis predicts that with increasing dimorphism in body size males and females will increasingly differ in the time spent in different activities. Differences in activity budgets would make it difficult for males and females to stay in mixed-sex groups due to increased costs of synchrony to maintain group cohesion. The predictions of the activity budget hypothesis were confirmed in most cases (22 out of 23 studies). The heavier males were compared to females, the more time females spent foraging compared to males. The bigger the dimorphism in body mass, the more males spent time walking compared to females. Lactating females spent more time foraging than did non-lactating females or males. Whether species were mainly bulk or intermediate feeders did not affect sexual differences in time spent foraging. We conclude that sexual differences in activity budgets are most likely driving sexual segregation and that sexual differences in predation risk or forage selection are additive factors.     

Gastrointestinal parasites of critically endangered primates endemic to Tana River, Kenya: Tana River red colobus (Procolobus rufomitratus) and crested mangabey (Cercocebus galeritus)

We conducted fecal egg counts of gastrointestinal parasites of 2 critically endangered primates endemic to the forest of Tana River, Kenya. We aimed to use the fecal egg counts as proxies to quantify the prevalence of gastrointestinal parasites between the 2 primates. The Tana River red colobus (Procolobus rufomitratus) and crested mangabey (Cercocebus galeritus) are of similar body size, but their behavioral ecology is very different. We predicted that mangabeys would have a higher prevalence of parasites because they are mostly terrestrial omnivores, live in larger social groups, and therefore range widely. We detected 10 nematodes and 3 protozoans in mangabeys and 7 nematodes and 2 protozoans in colobus. We detected a higher number of different parasite species in individual mangabeys, and 4 of the 5 nematodes requiring intermediate hosts were found in mangabeys. The overall prevalence of parasites was higher for mangabeys, but this difference was not statistically significant. For colobus, we found a trend whereby the number of different parasite species in individual monkeys was higher in males and in lactating females. However, there was no difference in the prevalence of parasites between the sexes or between lactating and nonlactating females.     

Time Allocation during the Reproductive Season in Vicuñas

Vicuñas (Vicugna vicugna) are wild South American camelids that live in high-altitude grasslands (Puna). Their social organization is based on family and bachelor groups. The amount of time they allocated to walking, running, lying, grazing and alert behaviour was studied in Abrapampa, northwestern Argentina, during the 1988–1990 reproductive seasons. Females and yearlings spent significantly more time grazing, and less time walking, running and alert than territorial males and bachelors. This result suggests that females maximized the time spent foraging to fulfil the energetic demands of reproduction. The alertness of the territorial males increased and the grazing decreased with the number of females in the families, suggesting that males that incurred a higher cost of lost feeding time through vigilance activities increased their mating success.     

Sex-Specific Elk Resource Selection during the Anthrax Risk Period

Anthrax, caused by the spore-forming bacterium Bacillus anthracis, is a zoonosis affecting animals and humans globally. In the United States, anthrax outbreaks occur in wildlife and livestock, with frequent outbreaks in native and exotic wildlife species in Texas, livestock outbreaks in the Dakotas, and sporadic mixed outbreaks in Montana. Understanding where pathogen and host habitat selection overlap is essential for anthrax management. Resource selection and habitat use of ungulates may be sex-specific and lead to differential anthrax exposure risks across the landscape for males and females. We evaluated female elk (Cervus canadensis) resource selection in the same study areas as male elk in a previous anthrax risk study to identify risk of anthrax transmission to females and compare transmission risk between females and males. We developed a generalized linear mixed-effect model to estimate resource selection for female elk in southwest Montana during the June to August anthrax transmission risk period. We then predicted habitat selection of female and male elk across the study area and compared selection with the distribution of anthrax risk to identify spatial distributions of potential anthrax exposure for the male and female elk. Female and male elk selected different resources during the anthrax risk period, which resulted in different anthrax exposure areas for females and males. The sex-specific resource selection and habitat use could infer different areas of risk for anthrax transmission, which can improve anthrax and wildlife management and have important public health and economic implications. © 2020 The Wildlife Society.