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.     

Feeding or Resting? The Strategy of Rutting Male Alpine Chamois

Optimal foraging theory suggests that animals normally maximize energy intake to optimize their energy balance. However, when efficiency to assimilate energy falls below the level necessary to ascertain basal energetic requirements, they should shift to an energy saving strategy. Males of many ruminant species considerably reduce their food intake during the rut. Nevertheless, they are commonly assumed to maximize energy intake besides their investments in rutting activities. Based on predictions of optimal foraging theory and the specific ruminant digestive physiology, we propose, however, that rutting males in polygynous species with time consuming mating tactics should instead use an energy saving strategy. Particularly, we predict this to be the case in Alpine chamois (Rupicapra rupicapra rupicapra), a highly polygynous mountain ungulate, of which the males defend mating territories during the rut. By combining observational and telemetry data of eight radio‐collared males we constructed individual 24‐h time budgets, and compared the behavior of males before, during and after the rut. Males spent significantly less time feeding during the rut (0.9 h) compared with before (8.5 h) and afterwards (6.4 and 7.5 h, respectively), whereas time spent lying remained more or less unchanged (pre‐rut; 12.7 h, rut; 13.3 h, post‐rut; 12.9 and 13.9 h, respectively). The ratio of time spent feeding to lying dropped from 0.67 in the pre‐rut period to 0.05 in the rutting period. As a result, males allocated on average approx. 90% of their non‐rutting time to lying, and a negative relationship between rutting and lying time emerged. Hence, males seemed to trade lying time against rutting time. We conclude from these results that male Alpine chamois do not maximize their energy intake during the rut, but rather adopt an energy saving strategy to optimize their energy balance.     

To Feed or Not to Feed? Testing Different Hypotheses on Rut‐Induced Hypophagia in a Mountain Ungulate

In many ruminant species, males dramatically reduce forage intake during the rut. To date, different hypotheses have been suggested to explain this rut‐induced hypophagia. To assess the predictions of the main hypotheses, we analysed Alpine ibex (Capra ibex) activity budget and compared the behaviour of males and females before, during, and after the rut. Only males spent significantly less time foraging during the rut than outside of it, whereas females allocated a similar proportion of time to foraging before, during, and after the rut. Our results showed that during the rut males also reduced lying time, while the ratio of time spent feeding to time spent lying did not change for males among periods. In conclusion, during the breeding season males maximized energy intake when not actively engaged in mating activities and rut‐induced hypophagia appeared to result from time budget constraints generated by mating‐related activities. Accordingly, the foraging constraint hypothesis seems appropriate to explain this phenomenon in Alpine ibex males.     

Contrasting Effects of Climate Change on Alpine Chamois

Global climate change can affect animal ecology in numerous ways, but researchers usually emphasize undesirable consequences. Temperature increases, for instance, can induce direct physiological costs and indirect effects via mismatches in resource needs and availability. Species living in mountainous regions, however, could experience beneficial effects because winters might become less severe. We examined the potentially opposing effects of climate change during spring, summer, and winter on recruitment in Alpine chamois (Rupicapra rupicapra). We examined initial recruitment (i.e., the ratio of kids to adult females) and net recruitment (i.e., the ratio of yearlings to adult females) of Alpine chamois through the use of linear mixed effects models and data from block count censuses performed across a 1,500-km² study area in the Italian Alps during summer from 2001 to 2015. Initial recruitment was relatively resistant to the effects of climate change, declining slightly over the study period. We suggest that the effects of increased forage availability and lower snow cover in winter may benefit the reproductive output of adult females, compensating for any negative effects of trophic mismatch and higher temperatures during summer. By contrast, net recruitment strongly declined throughout the study period, consistent with the slight decline of initial recruitment and the negative effects of increasing summer temperatures on the survival of kids during their first winter. These negative effects seemed to outweigh positive effects of climate change, even in a species strongly challenged by winter conditions. These findings provide important information for hunted populations; setting more appropriate hunting bags for yearling chamois should be considered. The ecological plasticity of the chamois, which also inhabits low altitudes, may allow a possible evolutionary escape for the species. © 2020 The Wildlife Society.     

Spatial behaviour of adult male Alpine ibex<Emphasis Type="Italic">Capra ibex ibex</Emphasis> in the Gran Paradiso National Park,Italy

During a two year preliminary study, the spatial organization of a group of male Alpine ibexCapra ibex ibex Linnaeus, 1758 was examined in the Gran Paradiso National Park, Western Italian Alps, Italy. From December 1995 to January 1998 we measured annual, seasonal home range and home range during the rut, plus altitudinal migration of 13 radio-collared adult Alpine ibex. The small annual home range size showed a traditional use of space, confirmed by the high overlapping values between home ranges of consecutive years: the ibex used the same places from year to year. This was also true during periods of rut. Home ranges closely overlapped in consecutive ruts, while their size changed from winter to winter. Snow cover limited the movements of the ibex; winter and spring home ranges were smaller than those in summer and autumn. Mean vertical movement patterns were similar in the two years, showing the highest values in summer and the lowest in spring. Space use was never proportional to availability for each altitudinal range.     

Unbiased sex-specific survival in Alpine chamois

Many polygynous ungulates show higher mortality of males than of females, because of the intense male–male competition during the rut and the costs associated with the development of sexual-size dimorphism. In the weakly dimorphic Alpine chamois Rupicapra rupicapra the occurrence of differential sex-specific survival strategies is controversial. To date, only two studies investigated the survivorship of males and females in this species, producing conflicting results: these works, based on the use of life tables, require confirmation from researches carried out on living populations. We assessed the survival pattern of a protected Alpine chamois population in the Swiss National Park, where 116 individuals were marked and monitored over 13 years (1996–2008). We tested for sex-, age- and year-dependence of survival by means of capture-mark-resight models. Resighting probabilities were sex-dependent, and survival rates were time-dependent. Females had higher resighting probabilities (0.84) than males (0.74). All over the time periods, sex had a weak influence on survival probability (males = 0.91; females = 0.92) and survival rates remained surprisingly high until late age (1 year = 0.90; 2–7 years = 0.91; 8+ years = 0.92). The growing evidence for a high adult survival and a weak differential mortality of the two sexes, together with the highly seasonal sexual-size dimorphism observed for Alpine chamois, might indicate the occurrence of a unique conservative survival strategy in both sexes and a low-risk mating strategy by males.     

Blackcaps Sylvia atricapilla stopping over at the desert edge; inter- and intra-sexual differences in spring and autumn migration

Spring and autumn Palaearctic-African migration patterns of Blackcaps Sylvia atricapilla during stopover at Elat, Israel, showed that males appeared significantly earlier than females during spring but not during autumn migration, suggesting that in males there is a stronger drive to reaching breeding territories early. The difference in mean appearance dates between sexes in spring tended to be greatest in years when the males appeared earliest. Longer spread of passage (the dates between which the central 50% of individuals were captured) for each sex in spring was found in years with an early mean passage datebut was significant only for females. These observations suggest that the timing of Blackcap migration is governed not only by endogenous factors but also by exogenous factors, and when the environmental conditions are unfavourable, the differences in passage dates between sexes decrease and the passage lengths shorten. The early individuals (both males and females) that stopped over at Elat in spring were those with relatively small body size (as indicated by relatively short wings) and relatively large fat reserves and in good body condition (as indicated from fat score and body mass/wing-length ratio). No differences in body size between early and late transients were detected during the autumn migration, but late birds of both sexes carried larger fat reserves. These phenomena may be explained either by leap-frog migration or by differential fitness among wintering males and females or both, with only the fittest Blackcaps being capable of an early departure. These individuals probably face much less intensive intra- and interspecific competition with residents and other transients in stopover sites than do later transients.     

Dynamic social system in Nubian ibex: can a second mating season develop in response to arid climate?

We studied a population of Nubian ibex Capra ibex nubiana in the eastern extreme of its range, the hyper-arid central desert of the Sultanate of Oman. Long-term data were collected from January 1983 to December 1997 by direct observation, as well as VHF telemetry on 12 animals (eight from 1987 to 1990; four from 1994 to 1996). We recorded 884 sightings: 40.4% of single animals and 59.6% of groups. Although no significant monthly variation of group size (Jarman's Typical Group Size) was found, there were distinct peaks in March (4.0 ind. group⁻¹) and September (5.1 ind. group⁻¹). Groups of males and females formed especially in March and November, and female–kid groups in February and July–August. Our data may suggest two mating periods: the first one in autumn (similar to the rut of ibex in temperate mountain areas), with kids born in spring/early summer, after winter–spring rainfall, and the second one in spring, with kids born in late summer/autumn, before winter–spring rainfalls. We suggest that the second rutting period may have evolved as a micro-evolutionary process, with the local population adapting to hyper-arid environment constraints. The spring mating season may favour only females in prime conditions, who can afford a pregnancy in the local severe summers and will deliver kids when plant greening begins, in the autumn, whereas the autumn (original) mating season may be afforded by any female, but kids will be born in an unfavourable period, before the summer drought.     

Seasonal changes in the abundance of Microcrustacea in a small pond

Sampling methods, and methods used in extracting, identifying and counting the Microcrustacea in samples are outlined. Numbers of parthenogenetic females and young stages of Daphnia obtusa were highest from March/June to Sept./Nov., with a trough in July. Ephippial females were recorded during some or all of the months from March to Nov. with two numerical maxima, one in early summer and one in autumn. Males were present during the same period as ephippial females. Naupliar, copepodid and adult stages of Cyclops strenuus strenuus were recorded in every month; numbers of all three stages tended to be high from March to Nov. and low from Dec. to Feb. Females were present in smaller sumber than males. Females with eggs sacs occurred every month with two peaks of abundance in April–July and Oct. Adult Canthocamptus staphylinus were absent during the summer/early autumn from June/July/Aug. to Sept./Oct. Numbers were highest from Nov. to May/June with a peak in spring. Females carrying an egg sac were recorded each month with the highest proportion occurring sometime in the period Feb. to May. Possibly two peaks, one in early summer and one in autumn, of total numbers of Cyclocypris ovum were recorded. Comparisons with other available information on the life-cycle of the species are made. The effects on the species of a six-week period of drought in the autumn of 1969 are considered.     

Red deer females collect on male clumps at mating areas

Mating strategies in mammalian herbivores are adapted to thedispersion of females, and female dispersion is mainly determinedby resource dispersion, although it is frequently unclear whetherfemales may also be influenced by the location of males. Inthe red deer (Cervus elaphus) the distribution of females beforethe rut predicts the places were males should establish territoriesand even their relative success. However, the number of femalesusing the mating areas in Doñana increases during therut. We observed 20 areas of meadows, used by grazing femalesbefore the rut. At the onset of the rut, the number of females increasedin some of these areas and decreased in others, and the opposite patternwas found after the rutting period. Changes in the vegetationat mating and nonmating areas could not account for the changesin female distribution; even some of the highest quality meadowswere vacated by females during rut. In selecting the matingareas, females avoided isolated small meadows within the scrubarea and preferred larger meadows where a number of neighboringrutting males could be found. Females also avoided those areas heavilyused by fallow deer (Dama dama), a competing sympatric species.We found that females suffered less sexual harassment when inlarger harems and when their harem was surrounded by other harems.Our results, together with those in the literature about thispopulation, indicate that red deer females collect during theearly rut in mating areas containing several rutting males,although once there they may select particular sites based on availabilityof food rather than based on the presence of a particular male. Byjoining harems in large meadows they are less harassed, andat the same time they probably increase their chances of matingwith highly competitive males. The results from Doñanasupport the idea that harassment avoidance may lead to femalemovements to areas with male territories without lek breedingor female comparison of male phenotypes and may bring an insightinto those factors leading to clumps of male territories andleks.     

The prediapause copulation and its significance in the butterflyEurema hecabe

In the pierid butterflyEurema hecabe, which shows seasonal polymorphism (summer and autumn morphs) and overwinters at adult stage, whether or not the prediapause copulation may be of usual occurrence and reproductively functional was examined. From the counts of the spermatophores carried by the females, it is clear that the prediapause copulation characteristically occurs in reproductively inactive females of the autumn corph. From behavioral observations in the field, mating partners of those females are mostly males of the summer morph rather than from the autumn morph. In autumn, males of the summer morph remained abundant and searched for females on the larval food plants. Furthermore, they mated frequently with autumn morph females. Autumn morph males seemed to be sexually less active or inactive before hibernation. Microscopic examinations of the spermathecae were made in mated autumn-morph females collected before and after hibernation. The results indicate that sperm is passed by the males at autumnal copulation. The sperm may be stored in the female reproductive tract and utilized for fertilization in spring. This supposition is strongly supported by field data; that is, once-mated autumn-morph females laid fertilized eggs in spring. Finally, physiological basis of the prediapause copulation, its adaptive signficance and the behavioral advantage inE. hecabe are discussed from the viewpoint of seasonal adaptation.     

Mate preference in males of the cabbage butterfly, Pieris rapae crucivora, changes seasonally with the change in female UV color

We initially investigated whether females of the cabbage butterfly, Pieris rapae crucivora, exhibit a seasonal change in ultraviolet wing color, which is a key stimulus for mate recognition by conspecific males, and whether and how a seasonal change affects the mating behavior of the males. We found that female UV wing color changes seasonally, the color being more pronounced in summer than in spring or autumn. We also demonstrated that male mate preference changes seasonally, concomitantly with the change in female UV color. Specifically, males appearing in summer exhibit a mating preference for summer-form females over spring- or autumn-form females, while those appearing in spring or autumn exhibit no seasonal preference, thereby facilitating more effective mate location. Our results suggest that this field of study will require more strictly controlled experimental investigation in which the seasonal change in UV color is considered when UV-influenced mating behaviors such as mate choice are investigated.     

Social and Spatial Segregation in Alpine Ibex (Capra ibex) in Bargy,French Alps

Outside the rut, a gradual social and spatial segregation was observed between the sexes as male Alpine ibex (Capra ibex) aged. In addition, males joined similar-age peer groups and segregated spatially as the age difference increased. The patterns varied seasonally, influenced by biological and ecological events. During the rut, males and females intermingled and used greatly overlapping ranges. Males ≥ 9 years first left female groups but social and spatial segregation were not complete until May. Younger males shifted to male groups more gradually. Females and males over 2 years of age used almost exclusive ranges in summer and early autumn. Social grouping and range overlap between ibex classes were correlated outside the rut. Grouping and spatial overlap between young and old males were negatively related to association with females.     

Mate-locating behavior of the butterfly Lethe diana (Lepidoptera: Satyridae): do males diurnally or seasonally change their mating strategy?

The mate-locating behavior of male butterflies has been classified into two major types, territorial and patrolling. Territorial males defend a specific site, whereas patrolling males fly around a wider area without having to defend a site. In this study, I investigated the use of these tactics by males of the satyrine butterfly, Lethe diana. A previous study suggested that the males of L. diana change their mate-locating behavior during the day (they patrol in the morning and defend territories in the afternoon) and that patrolling is the primary mating strategy, whereas defending territories is a supplementary one. In the present study, I found that the daily activity pattern of the males of L. diana was similar to that described in the previous study: males often flew around in the morning and competed for territories in the afternoon. However, contrary to the previous study, all courtships and copulations were performed within male territories during their territorial activity. Closer observations revealed that copulations found in male territories were achieved by the owner of the territory. Males tended to feed in the morning, suggesting that the males flying in the morning searched for food rather than females. I conclude that territory holding is the primary male matelocating tactic in L. diana. I further found that, in summer, males exhibited territorial behavior later than in spring or autumn, which may be a strategy for preventing heat stress.     

Influences of Mating Group Composition on the Behavioral Time-Budget of Male and Female Alpine Ibex (Capra ibex) during the Rut

During the rut, polygynous ungulates gather in mixed groups of individuals of different sex and age. Group social composition, which may vary on a daily basis, is likely to have strong influences on individual’s time-budget, with emerging properties at the group-level. To date, few studies have considered the influence of group composition on male and female behavioral time budget in mating groups. Focusing on a wild population of Alpine ibex, we investigated the influence of group composition (adult sex ratio, the proportion of dominant to subordinate males, and group size) on three behavioral axes obtained by Principal Components Analysis, describing male and female group time-budget. For both sexes, the first behavioral axis discerned a trade-off between grazing and standing/vigilance behavior. In females, group vigilance behavior increased with increasingly male-biased sex ratio, whereas in males, the effect of adult sex ratio on standing/vigilance behavior depended on the relative proportion of dominant males in the mating group. The second axis characterized courtship and male-male agonistic behavior in males, and moving and male-directed agonistic behavior in females. Mating group composition did not substantially influence this axis in males. However, moving and male-directed agonistic behavior increased at highly biased sex ratios (quadratic effect) in females. Finally, the third axis highlighted a trade-off between moving and lying behavior in males, and distinguished moving and female-female agonistic behavior from lying behavior in females. For males, those behaviors were influenced by a complex interaction between group size and adult sex ratio, whereas in females, moving and female-female agonistic behaviors increased in a quadratic fashion at highly biased sex ratios, and also increased with increasing group size. Our results reveal complex behavioral trade-offs depending on group composition in the Alpine ibex, and emphasize the importance of social factors in influencing behavioral time-budgets of wild ungulates during the rut.     

GENETIC VARIATION AND TERRITORIALITY IN WILLOW PTARMIGAN (LAGOPUS LAGOPUS LAGOPUS)

We examined eight polymorphic esterase loci in 526 juvenile and adult willow ptarmigan (Lagopus lagopus lagopus) collected during autumn and spring over five years. The genetic structure of territorial birds during spring differed from birds on the study area in autumn. This can not be explained by selective winter mortality since juvenile birds in the autumn had the same genetic structure as the adults who had lived through at least one winter. In the spring, birds with intermediate heterozygosity had the largest territories and were more frequently mated than expected from random mating among autumn birds. The results suggest selective access to territories by genotype and stabilizing selection, especially among males, since natural selection is assumed to favor large territories and reproduction. Our data also suggest that the spring population consisted of both territorial and non-territorial birds. The genetic relationship between birds of established pairs in spring was lower than that between randomly drawn birds on the study area in the autumn. This together with the finding that parents with an intermediate level of genetic relationship produced the largest broods, suggest that optimal rather than maximal outbreeding is the most successful breeding strategy in this species.     

Temporal shifts in the pair-bond dynamics of New Zealand robins (

Winter is a challenging time for temperate insectivorous songbirds, due to colder temperatures, reduced prey activity and shorter diurnal foraging times. For species that are non-migratory, territorial and monogamous, winter conditions may result in within-pair competition. However, little is known about how monogamous pairs coexist on their winter territories. We investigated temporal patterns in male?female interactions of the New Zealand robin (Petroica australis to better understand mechanisms of coexistence during winter. Previous work has shown that male robins are physically dominant over females and maintain priority access to food year-round. We quantified female behaviour throughout the 2008 non-breeding season to better understand how females coexist with physically dominant males on winter territories. Results showed that pairs rarely forage in close proximity in autumn and winter, suggesting females avoid males at this time of year. Males and females begin to spend more time foraging together as winter turns to spring. During this winter?spring transitional period, females steal large amounts of food hoarded by males. These results indicate that male and female New Zealand robins use different behavioural mechanisms to coexist on their winter territories. While males are dominant physically, females show a seasonally variable strategy where they avoid males in autumn and winter, and then steal male-made caches from early spring until the onset of inter-pair cooperation and the breeding season.     

Correlates of Territoriality in Rutting Red Deer

The mating strategy most commonly reported for male red deer, Cervus elaphus, is the defence of females (harems), territoriality having been described only in Doñana, Spain. We observed rutting males at five different populations in Spain and during 4 consecutive yr in Doñana. Female defence was the only strategy observed in two of the populations, whereas territorial defence coexisted with female defence in the remaining three populations. Territorial defence appeared to be more costly than female defence, in terms of rates of aggressive interaction, and territorial males tended to gather more females per d than non-territorial ones. Both mating strategies seemed to respond to local variations in habitat, which in turn affected female distribution. Females concentrated in areas with high-quality forage, and most territories contained patches of high-quality food (i.e. greater quality within boundaries) or were located along main routes used by females. The results are interpreted in the light of environmental conditions in southern Europe, where the rut coincides with the less favourable season for herbivores (in terms of food resources) after the hot and dry summer. Under such conditions of food scarcity coupled with patchy distribution, females tend to concentrate on the remaining patches of green swards, and males benefit from defending the food resources that attract females.     

Natal dispersal and its consequences in Black Grouse Tetrao tetrix

Data on dispersal distances of juveniles are important for understanding the genetic structure of populations, population regulation processes and the effects of landscape ecology on metapopulation dynamics. We studied dispersal in juvenile Black Grouse Tetrao tetrix in the French Alps between 1990 and 1998, by radiotracking 39 young grouse captured in August or autumn in a study area of 836 ha. Natal dispersal occurred in two discrete phases, autumn (October) and spring (mid-April to early May), with periods of reduced mobility between. The mean distance travelled by females exceeded that of males in autumn but not in spring. The natal dispersal distance of females was greater than that of males, and resulted in 81% of females leaving the study area to nest 5–29 km from their site of capture. This emigration must have been compensated for by immigrants because the number of hens in the study area increased during the study. Males were more philopatric. By the summer after capture, only 9% had emigrated from the study area. Despite the longer dispersal distances of females, there was no difference in the survival functions of the sexes between the ages of 6 weeks and 13 months.     

Effect of mating on survival at low temperature in females of the Japanese common grass yellow,Eurema mandarina

1. In some insects that overwinter as adults, mating occurs both before and after overwintering. Two hypotheses have been proposed to explain the adaptive significance of pre‐overwintering copulation of females. One is the bet‐hedging hypothesis, which explains pre‐overwintering copulation as a preparation for less chance of mating in the following spring. The other is the nuptial gift hypothesis, which states that secretions derived from males increase overwintering success of females. 2. In Eurema mandarina, both diapause autumn‐ and non‐diapause summer‐form male adults emerge with autumn‐form female adults in the last generation in a year. Most autumn‐form females mate with summer‐form males before winter, and re‐mate with autumn‐form males in the following spring. Because autumn‐form females have sufficient chances for mating after overwintering, the nuptial gift hypothesis has been regarded as the more probable hypothesis. 3. To test the nuptial gift hypothesis, the survival period was compared under short‐day conditions at 10 °C between mated and unmated females that had been reared on sucrose solution at 25 °C for 15–21 days. The mated females had significantly greater longevity than the unmated females, supporting the nuptial gift hypothesis. Body size also affected the survival period. 4. The results suggest that the nuptial gift is an important factor for the evolution of pre‐overwintering copulation in species in which females mate both before and after overwintering.