Linear roadside remnants: Their influence on den‐use,home range and mating system in bobucks (Trichosurus cunninghami)

Abstract Forest clearance results in a marked change in the dispersion of resources such as food and shelter: from a relatively continuous distribution, to patches and strips of remnant habitat set in a more or less inhospitable matrix. Such changes in the patterns of resource dispersion have the potential to strongly influence the dynamics of social and mating systems of resident animal populations. We studied the den‐use patterns, home range characteristics and mating system of a population of bobucks, Trichosurus cunninghami (Marsupialia: Phalangeridae), permanently resident in linear roadside strips of vegetation in north‐eastern Victoria, Australia in order to gain a greater understanding of the impacts of occupying linear roadside habitats on the behavioural ecology of arboreal marsupials. We radio‐tracked 11 adult females and six adult males and collected 2126 diurnal fixes (mean 125/individual) and 1044 nocturnal fixes (mean 61/individual). Males used significantly more den‐trees (mean 16.5 ± 1.5 den‐trees/individual) than females (mean 7.4 ± 0.6 den‐trees/individual) and had home ranges more than twice the size of those of females (male mean 5.1 ± 0.8 ha, female mean 2.1 ± 0.3 ha). On average, each male's home range overlapped with those of three females; there was little intrasexual home range overlap in either sex. Genetic parentage analysis of all young sampled during the study (n = 22) established that only males that overlapped in home range with females had sired those females' young. All but one male in the study sired multiple young in each of the years they were recorded breeding. These behavioural and genetic data indicate that the roadside population was polygynous, in contrast to the socially monogamous bobuck population we studied in a neighbouring forest patch. These differences in behaviour may reflect patterns of resource distribution in the two habitats.     

What shapes intra‐specific variation in home range size? A case study of female roe deer

Spatial distribution in mammals, and thereby home range size, is influenced by many different factors including body size, sex, age, reproductive status, season, availability of forage, availability of water, fragmentation of landscape, trophic level and intra- and inter-specific competition. Using linear mixed models, we looked for factors shaping the variation in size of spring-summer and winter home ranges for 51 radio-collared adult female roe deer at Trois Fontaines forest, Champagne–Ardenne, France (1996–2005). Home range size of females was larger in winter than in spring–summer, decreased with age, and decreased with increasing quality. Females in low quality areas adjusted the size of their home range to include more patches of habitat so that all female deer obtained similar amounts of food resources (total biomass of 6.73±2.34 tons (mean±SE) for each home range). Such adjustments of home range size in response to patchiness of resources led to marked between-female variation in home range size. Our results demonstrate that roe deer females have different tactics of habitat use according to spatial variations in habitat quality so that females get similar food resources in highly productive environments such as the Trois Fontaines forest.     

Determinants of reproductive success in voles: space use in relation to food and litter size manipulation

Spacing behaviour of female mammals is suggested to depend on the distribution and abundance of food. In addition, food limitation has been found to constrain the reproductive success of females. However, whether females maximize their reproductive success by adjusting space use in relation to current food availability and reproductive effort (e.g. litter size) has not been experimentally studied. We examined these questions by manipulating simultaneously food resources (control vs. food supplementation) and litter sizes (control vs. plus two pups) of territorial female bank voles (Clethrionomys glareolus) in large outdoor enclosures. Females with supplementary food had smaller home ranges (foraging area) and home range overlaps than control females, whereas litter size manipulation had no effect on space use. In contrast, the size of territory (exclusive area) was not affected by food supplementation or litter size manipulation. As we have previously shown elsewhere, extra food increases the reproductive success of bank vole females in terms of size and proportion of weaned offspring. According to the present data, greater overlap of female home ranges had a negative effect on reproductive success of females, particularly on survival of offspring. We conclude that higher food availability increases the reproductive success of bank vole females, and this effect may be mediated through lower vulnerability of offspring to direct killing and/or detrimental effects from other females in the population. Moreover, it seems that when density of conspecifics is controlled for, home range sizes of females, but not territoriality, is related to food resources in Clethrionomys voles.     

Exclusive core areas and intrasexual territoriality in Eurasian red squirrels (<Emphasis Type="Italic">Sciurus vulgaris</Emphasis>) revealed by incremental cluster polygon analysis

When animal home ranges overlap extensively in species lacking overt territorial behaviours, identifying exclusive core areas within individual ranges can be difficult. By analysing the size and overlap of successively smaller core areas among individual Eurasian red squirrels (Sciurus vulgaris), we determined exclusive areas within the home ranges of resident males and females. Possible effects of habitat composition and food supplies were explored by monitoring squirrels in different conifer forests and during years with low and high tree seed production. Using outlier-exclusive cores (OEC) revealed that the total ranges consisted of large sally zones (on average, 35% of the total minimum convex polygon [MCP] range) around home ranges with multi-nucleate cores. The mean OEC home range size did not differ between the sexes but was larger with poor food availability. Home ranges (99% incremental cluster polygons [ICP]) overlapped extensively between sexes (average overlap high food–low food: males by females 21–40%, females by males 43–45%) and among males (males by males 26–44%), while intrasexual overlap among females was low (9–10%). The overlap of inner cores among females rapidly approached zero, suggesting the intrasexual territoriality of 75% core areas. This was not the case among male squirrels, for which intrasexual overlap averaged only 4% at 50% but 18% at 75% core areas. Even the smallest inner cores had some degree of intersexual overlap, indicating that complete territoriality did not occur in this species. Female home ranges were more strongly affected by annual fluctuations in food supplies than male ranges. Females reduced the size of their food-based intrasexual territories when food availability increases. Males probably benefit from using larger home ranges and core areas, which overlap with the ranges of several females, by increasing their probability of successful mating.     

Harem structure and female territoriality in the dwarf hawkfish <Emphasis Type="Italic">Cirrhitichthys falco</Emphasis> (Cirrhitidae)

We investigated the territoriality and the spatial and mating relationships of the haremic hawkfish, Cirrhitichthys falco, on a reef off Kuchierabu-jima Island in southern Japan. Each individual maintained a territorial home range which was defended against same-sex conspecifics at the boundary of the home range. The territory of each male encompassed the territories of 2–3 females, allowing the male to completely monopolize mating opportunities with those females. Based on our observations, we classified the harem type of C. falco as a territorial female type. Large juveniles maintained independent home ranges outside the female territories. In contrast, small juveniles were allowed to cohabit within the territory of an adult female. Stomach contents analysis revealed that the smallest size class of C. falco fed primarily on copepods. In contrast, all other size classes fed primarily on decapods. Together, these results suggest that female territoriality plays an important role in defending food resources.     

Space use and the evolution of social monogamy in eastern rock sengis

Limiting resources often differ between males and females. Reproductive success in females is constrained by resources such as food and shelter, while the availability of receptive females determines male reproductive success. In addition to limiting resources, low intra-sexual tolerances among females can affect their spacing. High intolerances coinciding with low population densities have been suggested as a cause for the evolution of monogamy in mammals, but the evidence for female intolerance is limited. We investigated long-term space use patterns (measured as home range sizes and centers of activity) in a wild population of eastern rock sengis (Elephantulus myurus) from Limpopo, South Africa. Between March 2012 and March 2016, we recorded capture locations for 93 sengis and home range size for 22 sengis and evaluated the contributions of study year, sex, and season on these measures. Sex had no significant effect on home range size, but ranges were significantly greater during the breeding compared to the non-breeding season, consistent with the increased energetic demands during reproduction. We found corroborative support for the role of energetic demands on home range size fluctuations. The activity centers of female–female dyads were further apart than those of male–male or mixed-sex dyads, suggesting lower female–female tolerances in the study species. Our results offer evidence that intolerances may affect female spacing behavior and may have contributed to the evolution of monogamy in sengis.     

The effects of seed availability on habitat use by a specialist seed predator

Space-use patterns of seed predators are strongly affected by spatiotemporal variation in the abundance of different tree seeds, their major food source. However, most studies have measured relationships between overall food availability and space use, and there are few cases where effects of different food resources have been explored. We studied the effects of two food resources, Norway spruce and silver fir seeds, on space and habitat use in red squirrel in a subalpine conifer forest from 2000 to 2006. Fir seeds disperse in the autumn of the year they are produced, spruce the following spring. We estimated spruce and fir seed availability within individual home ranges and monitored home-range size using radiotelemetry. Males had larger home ranges than females and the sexes responded differently to variation in food and density. Spruce seed availability negatively affected home-range and core-area sizes of males in spring–summer. Space use was not affected by fir seed availability. Squirrels positively selected spruce for foraging and spruce was always preferred over fir. Our results showed that spruce, but not fir, affected space and habitat use of squirrels, suggesting they do not behaviourally respond to early seed dispersal in fir.     

Scramble Competition Among <Emphasis Type="Italic">Colobus vellerosus</Emphasis> at Boabeng-Fiema,Ghana

We investigated the occurrence of scramble competition among Colobus vellerosus at Boabeng-Fiema, Ghana. If scramble competition had an impact on feeding efficiency among females, we expected a positive relationship between group size and the proportion of time spent feeding, day journey length, or home range size assuming resource availability is similar among the groups compared. We collected focal data on the feeding behavior of adult females and males over 11 mo (September 2000–August 2001) on 2 study groups: WW (n = 31–33 individuals) and B (n = 8–16 individuals). We also collected ranging data on group movements at half-hour intervals. The large group (WW1) had a significantly longer day journey length than the small group (B1), and females in the large group spent a significantly greater proportion of time feeding in the wet season, a period of low food availability, which suggests it may be a bottleneck period when food resources are scarce and Colobus vellerosus is close to being energy limited. The proximity data suggested females may be able to reduce or adjust for competition by having fewer neighbors when they feed and by spreading out when in a larger group. However, we found no relationship between home range size and group size or that females spent a greater proportion of time feeding than adult males did. Our results highlight the need to factor in differences in food availability when investigating scramble competition. Though equivocal, our results suggest scramble competition occurs among Colobus vellerosus, leading us to suggest there was a match with the potential competitive regime, i.e., food distribution.     

The function of aggression in the swordtail, Xiphophorus helleri: resource defence

Competition for mating opportunities may involve exclusion of intrasexual competitors (direct) or defending resources necessary to attract mates (indirect). Male swordtails (Xiphophorus helleri) engage in direct competition. Moreover in natural populations they defend a home range. This study aimed to test whether this home range defence is a form of food resource defence, which may therefore have a female attraction function. Male swordtails did defend a food resource and showed increased aggression in the presence of both food and females. However, food resource defence decreased when females were present, suggesting that both food and females are treated as defendable resources.     

Space use by the Japanese fluvial sculpin, Cottus pollux, related to spatio-temporal limitations in nest resources

Space use by the Japanese fluvial sculpin, Cottus pollux, as related to nest availability was studied in a Japanese mountain stream. Males had larger home ranges than females before breeding. A measure of nest resource limitation was L < 1 and the same nest rock was used by two males successively in three cases, indicating a limited supply of suitable nest rocks for males. All males included the nest rocks in their home ranges, but the timing of nest occupation was apparently dependent on male size, suggesting the presence of male-male competition for the nest rocks. Females, on the other hand, exhibited two different patterns in space use, independent of body size: (1) they spawned in their home ranges, or (2) they spawned out of their home ranges and returned. Nest cavity area did not affect male reproductive success. Spatial separation between female home ranges and nest location was the main reason for the females' movement out of their home ranges. The limitation in the male mating phase (5.7 days on average) might also have forced the females to move out of their home range to spawn. The reason behind such temporal limitation in the male mating interval was discussed from the viewpoint of the energy cost accompanying male parental care.     

Predicting the Competitive Regime of Female <Emphasis Type="Italic">Colobus vellerosus</Emphasis> from the Distribution of Food Resources

We examined the spatial and temporal distribution of the foods of ursine colobus (Colobus vellerosus) at Boabeng-Fiema, Ghana as a means to predict the monopolizablity and usurpability of their food resources. Recent evidence suggests that food may not be limiting for folivorous primates, and that male sexual coercion may be a more important influence on folivore social organization. To address the question, we collected focal data on the feeding behavior of adult females and males over 11 mo (September 2000-August 2001) on 2 groups: WW (n = 31–33 individuals) and B (n = 8–16 individuals). We also conducted phenological monitoring and a tree survey of the two-group home ranges to establish food availability and distribution. We used 2 behavioral or organism-defined indicators of feeding behavior to assess potential resource contestability: food site residence time and distance moved between food sites. The colobus fed on a high diversity of species, most of their food trees were not clumped in distribution, within-tree interfood distances were short, and food trees were large. The only condition associated with the potential for monopolization was low food tree density. However, low food tree density may be offset by the colobus’ use of large trees. Taken together, the ecological and behavioral indicators suggest the food resources of Colobus vellerosus had a low potential for monopolization. Our results also indicate mature leaves had the longest food site residence time, which may suggest they should be the most usurpable plant part, though their presumed low quality and high abundance probably counteracted the effect. The pattern implied the potential for direct feeding competition among Colobus vellerosus at Boabeng-Fiema was low and agonistic interactions over food are not expected. Instead, a group size effect on feeding efficiency should be a more predominant influence on feeding efficiency, if food is limiting for the species.     

Home ranges of introduced rats on Christmas Island: A pilot study

Understanding the spatial ecology of invasive rats (Rattus spp.) is necessary to inform management actions to reduce their impact on native flora and fauna. This study investigates home range sizes of exotic rats around seabird colonies and urban areas on Christmas Island, where rat predation is suspected to be adversely affecting fledgling success among local seabirds. It was hypothesised that rat home range sizes would be smaller in urban areas owing to more consistent food availability. Home ranges of male rats were significantly larger compared with their female counterparts, with male rats maintaining larger home ranges in urban areas compared with seabird colonies. Conversely, female rats had smaller home ranges in urban areas compared with seabird colonies. Our findings suggest a possible correlation between the spatial distribution of food resources and home range size. Additionally, the spatial distribution of breeding females across the landscape had a significant influence on the home ranges of male rats. These findings have important implications for proposed efforts to manage rat populations on Christmas Island, while also providing valuable information regarding the ecology of invasive rats on tropical islands.     

Relative Effect of Food Supplementation and Natural Resources on Female Red Deer Distribution in a Mediterranean Ecosystem

ABSTRACT Supplementary feeding is a widespread game management practice in several red deer (Cervus elaphus) populations, with important potential consequences on the biology of this species. In Mediterranean ecosystems food supplementation occurs in the rutting period, when it may change mating system characteristics. We studied the role of food supplementation relative to natural resources in the spatial distribution, aggregation, and mean harem size of females in Iberian red deer (Cervus elaphus hispanicus) during the rut. We studied 30 red deer populations of southwestern Spain, 63% of which experienced supplementary feeding. Using multivariate spatial analyses we found that food supplementation affected distribution of females in 95% of the populations in which it occurred. Green meadows present during the mating season acted as an important natural resource influencing female distribution. Additionally, the level of female aggregation and mean harem size were significantly higher in those populations in which food supplementation determined female distribution than in populations in which female distribution did not depend on supplementary feeding. Because female aggregation and mean harem size are key elements in sexual selection, supplementary feeding may constitute an important anthropogenic element with potential evolutionary implications for populations of Iberian red deer.     

Ranging behaviour of male capercaillie Tetrao urogallus outside the lekking ground in spring

During the breeding season, adult male capercaillies Tetrao urogallus display on leks in the early morning. During the day, they occupy more or less exclusive home ranges within 1 km of the lekking ground, but little is known about their movements and range use patterns during this period. In three spring seasons we monitored the daily movement of 15 radio-tagged adult males, associated with six different leks, in a coniferous forest of southeast Norway. The objective was to relate dynamics of male movement and spatial distribution to changes in food resource availability and mating-related activities. In late winter, males exhibited a pattern of short daily relocations (distance between bird locations in successive days) within small ranges. Relocation distances and home ranges then increased markedly during two weeks preceeding the main mating period. During the mating and post-mating periods, movements again decreased, followed by another short peak at the time when females with depredated nests return to the lek for remating. These temporal changes in range use were not related to changes in food resources and probably not to shifts in anti-predator behaviour, and they differed between age groups: The increase in relocation distance during the pre-mating period was most pronounced among young resident males (3 and 4 year-olds), and range area of older males were smaller and did not increase as much during this period. The observed age-related changes in space use may reflect an alternative mating strategy by young and subdominant males; they seek out females outside the lekking ground where competition from more dominant males is less intense.     

Mating system structure and population density in a polygynous lizard, Sauromalus obesus (= ater)

Increases in population density often are associated with achange in mating system structure in numerous taxa. Typically,male interactions are minimal in extremely low density populations.As density increases, males exhibit territoriality but if densitybecomes too high, the energetic cost of defending a territorywill eventually outweigh the reproductive benefits associatedwith territoriality. Consequently, males in high density populationsmay abandon territoriality and adopt dominance polygyny, lekking behavior, or scramble competition. We investigated the relationshipbetween population density and mating system structure in threepopulations of the chuckwalla, Sauromalus obesus (= ater),near Phoenix, Arizona. Densities in the Phoenix Mountains (2.7chuckwallas/ha) were lower than any population previously studied.In the Santan Mountains (10.9 chuckwallas/ha), densities weresimilar to populations studied in the Mojave Desert, and inthe South Mountains (65 chuckwallas/ha), densities were the highest yet recorded. Male mating behavior was examined by determininghome range overlap and by making direct behavioral observations.Male home range size decreased with increasing population density.There was little overlap in home ranges among males in allthree populations, whereas home ranges of males and femalesconsistently overlapped, indicating that males were strictly territorial. This conclusion was supported by behavioral observationsof interactions among individuals in a natural setting. Thenumber of females wihin male territories was correlated withfood resources (plants) in all three populations. Female homerange size appeard to be related to food resources whereasmale home ranges appeared to be related to female distribution,population density, and geology. The retention of territoriality in spite of high population densities raises new questions aboutthe relationship between density and resource defense.     

Food Shortage Disrupts Social Organization: The Case of Red Squirrels in Conifer Forests

A recent conceptual model of spatial organization in vertebrates, based upon changes in home range overlap with habitat quality, ‘the space-use model’, predicts large and strongly overlapping home ranges and absence of territorial behaviour in habitats with poor food availability. We investigated whether the model can be extended to predict intra-population variation in space-use in a habitat with strong temporal variation in resource abundance. We studied space use of Eurasian red squirrels (Sciurus vulgaris) in subalpine conifer forests over 4 years with strong fluctuations in seed production. Norway spruce dominated forests are resource limited habitats for squirrels, and tree seed availability is gradually depleted in the year following a poor seed-crop. Male and female squirrels responded to spruce seed-crop failure in 2000 by strongly increasing their home ranges and core-areas in the following year (mean MCP ± SE in summer and autumn, respectively: 2001, 122.9±14.1 ha and 84.3±9.4 ha, against 43.0±6.4 ha and 20.8±3.8 ha in 2002, and 22.7±1.5 ha and 21.4±2.0 ha in 2003). In 2001, half of the animals, those with the poorest quality pre-dispersal home ranges, emigrated to areas with more larch. Residents had multi-nuclear core-areas. Also, intra-sexual core-area overlap (males by males, females by females) was higher in 2001 and summer 2002, than in autumn 2002 and in 2003 (means ± SE in summer and autumn, respectively: males by males, 2001, 52±8 and 44±7%, 2002, 80±30 and 15±11%, 2003, 37±19 and 26±14%; females by females 2001, 52±10 and 112±32%, 2002, 55±27 and 0±0%, 2003, 12±8 and 0.1±0%). Red squirrels responded to food shortage by moving to patches with other food resources and abandoned the spacing pattern of reduced core-area overlap among males and nearly exclusive core-areas among females, found in less variable habitats. After richer seed-crops in 2001 and 2002, it took squirrels about a year to reduce the size of their home ranges and core-areas and return to a spacing pattern of stable home ranges and intra-sexual territoriality of adult females. These results are consistent with the space-use model and show that spacing behaviour in red squirrels is a plastic, conditional strategy with individuals adapting the size and/or location of their home ranges in relation to local distribution and abundance of food resources.Co-ordinating editor: R. Härdling     

Do male roe deer clump together during the rut?

Movement s an d habitat use of 7 male and 7 female roe deerCapreolus capreolus (Linnaeus, 1758) were studied by radioteleme try from March 1999 to February 2001. Annual and bimonthly home ranges of males were small (ca 10 ha, 95% kernel), with large overlap among individuals throughout the year. Exclusive core areas (ca 0.4 ha, 25% kernel) were concentrated in the forest, a limited and sought-after resource in the study area. The difference in overlap between male exclusive core areas and female home ranges in the pre-rut and rut periods suggested that females made excursions to search for territorial males during the rut Our results support the mating strategy hypothesis of territorial behaviour Different space use patterns occurred between the sexes, with females apparently playing an active role in mate choice by visiting males at clumps of core areas in the forest.     

Determinants of female fecundity in a simultaneous hermaphrodite: the role of polyandry and food availability

Classical sexual selection theory assumes that the reproductive success of females is primarily limited by the resources available for egg production rather than by the number of mating partners. However, there is now accumulating evidence that multiple mating can entail fitness costs or benefits for females. In this study we investigated the effect of polyandry (i.e., the mating with different mating partners) and food availability on the reproductive output of the female sex function in an outcrossing simultaneous hermaphrodite, the free-living flatworm Macrostomum lignano. We exposed virgin worms to different group sizes, a treatment that has previously been shown to affect the level of polyandry in this species. Moreover, we manipulated the food availability throughout the subsequent egg laying period, during which the worms were kept in isolation. The number of offspring produced was used as an estimate of female fecundity. We found that food availability, but not group size, had a significant effect on female fecundity. Additionally, female fecundity was positively correlated with the number of stored sperm in the female sperm-storage organ at the time of isolation, but it was not correlated with body or ovary size of the worms. Our results suggest that female fecundity in M. lignano is primarily determined by the resources available for egg production, and not by the level of polyandry, confirming classic sexual selection theory for simultaneous hermaphrodites.     

Female–female aggression is linked to food defence in a poison frog

Habitat occupancy by territorial animals is expected to depend on the distribution of critical resources. Knowledge on female territoriality is scarce, but it has been suggested as a mechanism to defend limited resources for reproduction. A previous study showed female intrasexual aggression to be associated with territorial behaviour in the strawberry poison frog Oophaga pumilio, a diurnal aposematic species with complex maternal care. Here, we investigate the link between spatial distribution of resources important for reproduction and female distribution and behaviour. We observed focal females in their natural habitat in Costa Rica, and recorded the distribution of ecological predictor variables in a grid system. We used the data for calculating home range and territory sizes and for connecting female habitat use to the distribution of potential resources by computing spatial habitat occupancy models. Even though we found females to occupy large home ranges, they were highly aggressive towards other females only inside a small part of their home range, here termed core area. Among the ecological factors, the sustained abundance of ants (main food item of the frogs), the presence of leaf litter and suitable rearing sites for tadpoles predicted female site occupancy patterns. The number of ants per grid was twice as high in the core areas compared to the rest of the female home ranges. Our results suggest that female spacing behaviour is principally driven by the spatial distribution of its main food resource, but that hiding places (leaf litter) and tadpole‐rearing sites also play a role. The defence of areas with sustainably high abundance of ants could be relevant, as egg production and maternal care are energetically highly demanding in this prolonged‐breeding species. Regarding the link between resource defence and maternal care, the reproductive strategy of female strawberry poison frogs resembles that of the females of small mammals comprising same‐sex competition for food and high investment in producing and rearing young.     

Gray-brown Mouse Lemurs (<Emphasis Type="Italic">Microcebus griseorufus</Emphasis>) as an Example of Distributional Constraints through Increasing Desertification

Climate change will impose new constraints on the distribution of species through desertification. Small-scale endemists common in biodiversity hotspots such as Madagascar are especially threatened. Among them are the gray-brown mouse lemurs (Microcebus griseorufus), which occupy the driest habitats in Madagascar of all Microcebus spp. We studied impacts of aridity on this species to identify critical factors for distributional limits. Accordingly, we compared populations of 2 adjacent habitats that differ in their humidity levels. We found that the more humid habitat provided more high-quality food and maintained a higher population density of Microcebus griseorufus, with individuals in better condition compared to the drier habitat. At the end of the wet, but not in the dry season, Microcebus griseorufus adjusted its home range size to local food plant density, which indicates that individuals optimize food intake in the wet season to prepare for the dry season. We found a negative exponential relationship between food plant density and home range size, which suggests an upper limit for the size of home ranges. According to this relationship, individuals from the drier habitat could not compensate for reduced food availability by enlarging their home range beyond this threshold. Thus, in case of declining food availability during the wet season due to a generally drier climate, individuals will not be able to extend their home ranges to include more food resources, and hence to accumulate enough fat reserves for the dry season. In consequence, they will have to migrate toward more mesic refugia. Migration, however, requires habitat connectivity, which is scarce in Madagascar’s largely anthropogenic and heavily fragmented landscape. Our data suggest that upper limits in home range sizes can limit a species’ ability to adapt to increasing aridity.