Resource Defence or Exploded Lek? – A Question of Perspective

It becomes increasingly obvious that animal mating systems cannot be classified into distinct categories, but transitions between mating system classes are continuous. Positioning a certain mating system at this continuum is often not straightforward, however. Depending on which characteristic is considered, a mating system may end up at very different positions on this gradient. Here, we explore the potential conflict between mating system classifications that may arise when they are based on different criteria by investigating the mating system of the cichlid fish Simochromis pleurospilus in which males defend small patches of homogeneously distributed food resources (turf algae) vigorously against food competitors, but they allow specific females to use them. We hypothesized that male defence may generate high‐quality feeding patches serving to attract females, and hence male territoriality constitutes a form of courtship. Our field data show that males selectively allow approximately one‐third of the visiting females to feed on their territory and that females preferentially feed in male territories and usually sample several territories successively. As males protect food patches against other algae grazers and guard females from harassment by food competitors, females gain nutritional benefits from visiting male territories. Hence, males appear to generate essential resources for females, which is the key feature of resource‐defence mating systems, although the distributions of resources and of males and females are characteristics of an exploded lek.     

Male aggressiveness in a polygynous ungulate varies with social and ecological context

Aggression is a social behaviour which can be affected by numerous factors. The quality and quantity of food resources may play an important role in the aggressiveness of territorial ungulates as the defence of these resources influences female choice and mating opportunities. However, the relationship between food resources and aggression remains poorly understood. We assessed the ecological and social factors that influence aggression in Lama guanicoe, a territorial ungulate exhibiting resource‐defence polygyny, during three periods (group‐formation, mating and post‐mating) in the reproductive seasons of 2014 and 2016. We recorded 460 focal observations of territorial (family groups, solitary) and non‐territorial (mixed and bachelor groups) males. We performed analyses at the population level (including all focal observations) and at the group level (each social unit separately), to test whether the factors that influence aggression differ at these different scales. We also identified proxies of vegetation quality as potential predictors of aggression. At the population level, we found that the presence of aggressive behaviour peaked during the mating season and that post‐mating aggression may have been driven by inter‐annual environmental variations. For family groups and solitary males, variables reflecting high vegetation quality/quantity were predictors of aggressive behaviour, reflecting the resource‐defence strategy of this species. Conversely, for mixed‐group males, aggression may be more associated with social instability and group size, although this hypothesis has yet to be tested. Our research reinforces the idea that aggression can occur in multiple contexts depending on male status (e.g. territorial or non‐territorial) and contributes to our understanding of how ecological (i.e. availability of food resources) and social factors influence aggression in a territorial ungulate.     

Heritable variation for territorial success in two Drosophila melanogaster populations

Male fruitflies from stocks from two localities were artificially selected for defence of a food area against intruding males. Both stocks showed a rapid replicable response to selection over a few generations, indicating considerable genetic variation for territorial success in the base populations. Crosses between lines indicate directional dominance for increased territorial success and no maternal or paternal effects. Selected males escalated relatively more frequently against territory residents than control males, and won relatively more escalated encounters. There was no correlated response in body weight. In the presence of territories, selected males had a higher mating success with inseminated females than control males, but did not differ in mating speed. Indirect selection for territorial success was carried out by allowing flies to mate in the presence of different types of resources. After 21–26 generations, males from lines held in cages with discrete resources where territories could be established had greater territorial success than males from lines held in cages with one large resource. This genetic divergence in response to resource type is consistent with the heritable variation in territorial success and mating success of territorial males.     

Kin‐bias,breeding site selection and female fitness in a cannibalistic Neotropical frog

Resource availability influences sexual selection within populations and determines whether behaviours such as territoriality or resource sharing are adaptive. In Thoropa taophora, a frog endemic to the Atlantic Coastal Rainforest of Brazil, males compete for and defend limited breeding sites while females often share breeding sites with other females; however, sharing breeding sites may involve costs due to cannibalism by conspecific tadpoles. We studied a breeding population of T. taophora to determine (i) whether this species exhibits polygynous mating involving female choice for territorial males and limited breeding resources; (ii) whether limited breeding resources create the potential for male–male cooperation in defence of neighbouring territories; and (iii) whether females sharing breeding sites exhibit kin‐biased breeding site choice, possibly driven by fitness losses due to cannibalism among offspring of females sharing sites. We used microsatellites to reconstruct parentage and quantify relatedness at eight breeding sites in our focal population, where these sites are scarce, and in a second population, where sites are abundant. We found that at localities where the appropriate sites for reproduction are spatially limited, the mating system for this species is polygynous, with typically two females sharing a breeding site with a male. We also found that females exhibit negative kin‐bias in their choice of breeding sites, potentially to maximize their inclusive fitness by avoiding tadpole cannibalism of highly related kin. Our results indicate that male territorial defence and female site sharing are likely important components of this mating system, and we propose that kinship‐dependent avoidance in mating strategies may be more general than previously realized.     

Primary moult of continental Black-tailed Godwits Limosa limosa limosa in the Doñana wetlands,Spain

Capsule: Most Continental Black-tailed Godwits Limosa limosa limosa using the Doñana wetlands during post-breeding migration appear to begin moult before they arrive and suspend moult before they migrate onwards to West Africa.

Aims: We aim to describe the primary moult strategies and patterns in the Continental Black-tailed Godwits using the Doñana wetlands, a major passage and wintering area for waterbirds in southern Spain.

Methods: Individual godwits were captured, marked and their primary moult was scored in Doñana during the non-breeding season (June–March) in 2011 and 2012. Data from resightings of colour-marked godwits and birds equipped with satellite transmitters were used to estimate stopover duration during post-breeding migration (June–September) to determine if godwits move to West Africa before completing their primary moult.

Results: Average primary moult duration was estimated to be 84 days?±?9 se, during 29 June–21 September and did not differ between sexes. Only 2% of individuals were observed with suspended moult. We estimated stopover duration in Doñana to be 13 days?±?2 se before migrating to West Africa.

Conclusions: Most godwits stage for about two weeks in the Doñana wetlands during southward migration, moult their primaries and appear to suspend moult before crossing the Sahara. Others may complete their primary moult in Doñana, or elsewhere in Europe and overwinter in Doñana where increasing numbers of godwits have been detected in recent years. A few individuals may finish the moult in Doñana and migrate to West Africa late in the post-breeding season.     

Territorial cooperation and social monogamy: factors affecting intersexual behaviours in pair-living snapping shrimp

Among the factors that may contribute to the evolution of social monogamy are selection for extended mate guarding of females and selection for territorial ‘cooperation’. Many socially monogamous taxa are also territorial, with ‘partners’ sharing a single territory, suggesting that one or both partners may benefit by sharing territorial maintenance. Snapping shrimp (genus Alpheus) are socially monogamous and territorial, living in excavated burrows or with host organisms, with females performing all parental care. The territorial cooperation hypothesis predicts that male and female partners share (1) territorial defence, resulting in a reduction in the risk of eviction from the burrow, (2) burrow construction duties, such that individuals in pairs spend less time in burrow construction relative to solitary individuals, and/or (3) foraging duties, by returning food to the burrow, where it is consumed by both partners. UsingA. angulatus as a model species, a territorial defence experiment revealed that females in pairs were significantly less likely than solitary females to be evicted by female intruders, but males in pairs were not significantly less likely than solitary males to be evicted by male intruders. A subsequent experiment revealed that paired males were significantly less likely to be evicted by an intruding male if paired with sexually receptive females than if paired with nonreceptive females. Another experiment revealed that (1) paired females spent significantly more time in burrow construction than paired males, and (2) both males and females consistently returned food items to the burrow, perhaps incidentally provisioning their mates. These data suggest that social monogamy may have been selected for in part because of the advantages of territorial cooperation, as both males and females are likely to benefit by dividing the labour of territorial defence and maintenance. These tests of the territorial cooperation hypothesis are synthesized with data from tests of the extended mate-guarding hypothesis to place snapping shrimp pairing behaviour into a larger construct incorporating both the influence of ecological pressures (territoriality) and mating interactions between the sexes. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.     

Evaluating mortality rates and causalities in a critically endangered felid across its whole distribution range

The conservation of endangered species requires accurate data, and knowledge of cause-specific mortality rates is one of the most important issues. In recent years, conservation programs for the critically endangered Iberian lynx Lynx pardinus have been developed on the basis of mortality data derived 30 years ago from the small Doñana population. Thus, there is an urgent need for an update of mortality rates and causes in both populations (Sierra Morena and Doñana). Here we use radio-tracking information from the whole range of the Iberian lynx to quantify mortality rates and identify their causes. Between 2006 and 2011, we radio-tagged 78 Iberian lynxes from its two remaining populations (39 from Sierra Morena and 39 from Doñana). Mortality events were evaluated to identify causes, and cause-specific annual mortality rates (AMR) were obtained using the nonparametric cumulative incidence function estimator. Overall, AMR was estimated at 0.16?±?0.05 (0.19?±?0.09 in Sierra Morena and 0.12?±?0.07 in Doñana). Disease was the main cause of mortality both for the whole population and the Doñana population. Poaching was the main cause of mortality in Sierra Morena. Our results suggest that the best strategy for conserving this species is to focus action on decreasing the fatal effect of disease and poaching. Given the possible existence of an underlying inbreeding-mediated immunosuppression, genetic management aimed at increasing the genetic diversity of this population is also recommended.     

Analysis of trophic structure of two carnivore assemblages by means of guild identification

We evaluated the existence of trophic guild structure, considering seasonal and annual variation, in two terrestrial carnivore assemblages: one from Santa Cruz province (Argentinean Patagonia, composed by six carnivore species), and the other from Doñana National Park (SW Spain, composed by five carnivore species). To identify trophic guilds, we first studied seasonal and annual diets of predators, calculated trophic overlap among species pairs, and then constructed overlap matrices (similarity matrices). We determined guild membership objectively by entering the similarity matrices into the clustering technique unweighted pair-group method with arithmetic averaging. Carnivores from both assemblages were grouped, respectively, into four feeding guilds. Lagomorphs and rodents promoted the formation of two feeding guilds in both study sites, although the taxonomic composition of predator species that composed them was different. The ungulates-edentates feeding guild was only present at Santa Cruz, whereas the birds and reptiles feeding guild was only present at Doñana. Invertebrates and fruits were the base for the formation of a guild composed by species of the same taxonomic origin both in Santa Cruz and Doñana. Guild structure of Santa Cruz and Doñana assemblages did not exhibit seasonal or annual variation, although the specific guild composition changed over the two studied periods for both assemblages. This structure probably responded to discontinuities in resource spectra in Santa Cruz and fluctuations in rabbit abundance in Doñana. Our results support the hypothesis that establishes that guilds are originated by opportunistic convergence of species on abundant and energetically rewarding resources.     

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.     

Why are Male Columbian Ground Squirrels Territorial?

Male territorial defence is a component of many vertebrate mating systems and is often regarded as a tactic for acquiring mates. Traditionally considered within the context of overt site‐specific defence, territoriality actually may have several components which encompass a variety of behavioural tactics (e.g. post‐copulatory mate‐guarding, defence of resources that females need, defence of area around females) that underlie a mating system. The purpose of our study was to evaluate such influences on the territorial behaviour of male Columbian ground squirrels in southwestern Alberta, Canada. Males were dominant and territorial if they defended a minimum convex polygon activity range by chasing other males more within the activity range than they were chased. Subordinate males had no territory and were chased throughout their ranges, but they competed for mates by increasing chases in their activity range when nearby females were oestrous. Dominant males exhibited conditional breeding tactics, tending to chase other dominant males from their territory when nearby females were oestrous, but travelling outside their activity ranges to chase subordinate males when females were not oestrous. Although females mated first with a dominant male on whose territory they resided (and in order from oldest to youngest if several territories overlapped), mating pairs were not exclusive, as females usually mated with additional males. Males also guarded females after copulation and defended females directly just before oestrus, rather than defending territory per se during those times. Thus, males possess a repertoire of behaviours that complement site‐specific territoriality, and territory ownership serves to facilitate a first mating with females that live on the territory.     

Territorial Advertisement and Mate Attraction in the Bat Pipistrellus pipistrellus

A South Swedish population of the vespertilionid bat Pipistrellus pipistrellus was studied by means of bat boxes from April to the beginning of October in 1984. The mating system of the pipistrelle bat is a “resource defence polygyny”. Three territorial males were studied to determine the relative importance of two potential resources, food and roost sites, for male reproductive success. The day roost was found to be the crucial resource for the male's chances to get access to females. A territorial male advertises the location of his day roost to the females by a songflight display. The male who spent most time in songflight display was visited by the greatest number of females.     

Monitoring the invasion of the aquatic bug <Emphasis Type="Italic">Trichocorixa verticalis verticalis</Emphasis> (Hemiptera: Corixidae) in the wetlands of Doñana National Park (SW Spain)

We have detected the presence of the North American native corixid Trichocorixa verticalis verticalis (Fieber, 1851) in Doñana wetlands (SW Spain). We have collected data from different research projects done in the area during the period of 2001–2007. We have sampled 134 different sites in Doñana and we found the exotic corixid in 66 occasions. We have found two reproductive populations that might act as sources for the colonization of other waterbodies in the area. When reproduction occurred T. v. verticalis outcompeted native corixids. Its presence out of the waterbodies where we detected reproduction was in small numbers and probably due to vagrant individuals.     

Nest and mate choice in the red bishop (Euplectes orix) : female settlement rules

We investigated female settlement in a colony of red bishops(Euplectes orix), a territorial and highly polygynous weaverbirdwidely distributed over sub-Saharan Africa. An earlier studyshowed that male reproductive success is mainly determinedby the number of nests a male builds in his territory, whichappeared to be a good indicator of male quality. Because malesprovide no parental care or food resources within the territory,females sharing a territory do not compete for material resourcesand might therefore be expected to settle preferentially interritories of males that build many nests to gain the possiblegenetic benefit of high-quality offspring. An analysis of femalesettlement, however, revealed that females did not show a preferencefor territories of males with many nests and that the distribution of female breeding attempts with regard to the number of vacantnests within a territory could be explained best by randomfemale settlement in 3 out of 4 years. Females settled moreoften than expected by chance (in 3 out of 4 years) in territoriesalready containing occupied nests, indicating that residentfemales did not discourage settlement of additional females.However, sharing a territory with other females might imposecosts in terms of an increased predation risk because nestsin territories that contained other nests with young sufferedfrom higher predation than nests in territories that did notcontain other nests with young. Females therefore might tradethe possible benefits of settling in territories of males withmany nests against the costs of sharing a territory with otherfemales. This might result in the mating pattern found withrandom female settlement and male reproductive success beingdirectly proportional to the number of nests built. We discuss possible implications of this mating pattern for sexual selectionon males.     

Male territoriality and mating tactics in the wool-carder bee,Anthidium septemspinosum Lepeletier (Hymenoptera: Megachilidae)

Mate-seeking behaviours in males ofAnthidium septemspinosum are described. Mating occurred at the females' food plant patches, as in other congeneric species previously studied. Males were behaviourally classified either as territorial or non-territorial. Territorial males were generally larger, and superior in mating. Smaller males were forced to be non-territorial, adopting a different mating tactic of creeping into the territories to intercept females. This compensated for their physical inferiority in mating competition. The adaptive significance of this tactic is discussed.     

Social organization in the pheasant (Phasianus colchicus): harem formation, mate selection and the role of mate guarding

Harem formation and mate selection were studied in the pheasant in order to determine the advantages of territorial harem defence polygyny to the two sexes. We investigated the factors affecting harem size and the advantage to a female in remaining with one territorial male during breeding.
Female group size declined during late March and early April as females moved from large overlapping ranges into smaller, more widely dispersed breeding ranges. The proportion of female groups accompanied by males increased during this period.
Some males had a disproportionate share of females. Settled females were monogamous but, because a female's nest was generally outside the male's territory, her home range was larger than his territory.
Harem members were usually from the same winter group. Harem size was not related to territory quality in terms of food supply or nesting cover. Females were loyal to one male in more than one year even if his territory position changed. Older, territory-owning males had more females, both adult and immature, than males with newly-established territories. Harem size was not correlated with territory size.
We conclude that the mating system of the pheasant is based on mate guarding which protects females not only from the risk of predation or injury, but also from excessive energy expenditure incurred through being chased by other males. When escorted by a territorial male, females spent three times as much time feeding, one-fifth as much time running, and one-tenth as much time alert, as they did when not guarded.     

Testing the adaptive significance of sex‐specific mating tactics in collared lizards (Crotaphytus collaris)

We tested whether territorial defence is adaptive in male collared lizards by examining the extent to which territory owners monopolize females. We also tested whether females benefit by mating with multiple males using alternative tactics when local sex ratios varied. Surprisingly, neither the number of offspring that males sired, nor the number of females that males mated with varied as a consequence of highly variable local sex ratios. Moreover, both the number of offspring sired and the number of female mates were independent of male social status. Courtship frequency was under positive directional sexual selection for mating success for territorial males. None of the phenotypic traits that we examined were targets of sexual selection in nonterritorial males. Although offspring survivorship decreased with the degree of multiple mating, females mated multiply with similar numbers of territorial and nonterritorial males during all three seasons. Females did not obtain material or genetic benefits that balanced the apparent offspring survival cost imposed by mating with multiple males. Instead, females appeared to be ‘making the best of a bad job’, perhaps because the abundance of hiding places used by subordinate males makes it difficult for females to avoid male harassment. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 115 , 423–436.     

A comparison of the song and territorial behaviour of a long-distance migrant, the Marsh Warbler Acrocephalus palustris, in summer and winter

Colour-ringed populations of Marsh Warblers Acrocephalus palustris on breeding and wintering grounds were compared with respect to song and territorial behaviour. Song and territorial defence had a short duration on the breeding grounds, peaking during the period of mate acquisition and mate-guarding. Some males later showed polyterritorial behaviour. Wintering Marsh Warblers sang and showed defensive behaviour for a longer period which included moult. This behaviour could be described in terms of defence of a short-term resource (a fertile female) in the summer and long-term defence of a reliable food resource in the winter.     

Species Richness and Distribution of Copepods and Cladocerans and their Relation to Hydroperiod and Other Environmental Variables in Doñana, South-west Spain

Twenty-five sites located in five wetland zones within Doñana, south-west Spain were studied for copepod and cladoceran species richness and composition in relation to habitat characteristics from January to March 2004. The γ-diversity of copepods and cladocerans combined varied between wetland zones, which differed significantly in conductivity, surface area and abundance of vegetation. However, there were no significant differences between zones in local species richness of either copepods or cladocerans or the two combined. Species richness was significantly higher in sites with intermediate hydroperiods (duration between 3 and 5 months) than in sites with shorter or longer hydroperiods. CCA analyses performed separately for copepods and cladocerans extracted conductivity, surface area, and vegetation cover as the main factors structuring species composition of both groups. Ours is one of the first studies of zooplankton in the natural marshes of the Doñana World Heritage Site, and we recorded five species new to the Doñana area.     

Mating with large males decreases the immune defence of females in Drosophila melanogaster

Mating has been widely reported to be a costly event for females. Studies indicate that female cost of mating in terms of fecundity and survivorship can be affected by their mates, leading to antagonistic coevolution between the sexes. However, as of now, there is no evidence that the female cost of mating in terms of immune defence is affected by their mates. We assess the effect of different sized males on antibacterial immune defence and reproductive fitness of their mates. We used a large outbred population of Drososphila melanogaster as the host and Serratia marcescens as the pathogen. We generated three different male phenotypes: small, medium and large, by manipulating larval densities. Compared to females mating with small males, those mating with large males had higher bacterial loads and lower fecundity. There was no significant effect of male phenotype on the fraction of females mated or copulation duration (an indicator of ejaculate investment). Thus, our study is the first clear demonstration that male phenotype can affect the cost of mating to females in terms of their antibacterial immune defence. Mating with large males imposes an additional cost of mating to females in terms of reduced immune defence. The observed results are very likely due to qualitative/quantitative differences in the ejaculates of the three different types of males. If the phenotypic variation that we observed in males in our study is mirrored by genetic variation, then, it can potentially lead to antagonistic coevolution of the sexes over immune defence.     

TErritorial defence and mating success in males of the small heath butterfly, coenonympha pamphilus L. (Lepidoptera: Satyridae)

It has long been recognized that territorial defence in male butterflies must be some sort of mating strategy and that the territories are used as mating stations. However, so far, no systematic study has established the adaptive significance of territorial behaviour. This study is an attempt to fill this gap. By comparing the distribution of territories with the distribution of locations where wild and released virgin females mated this study shows that, in the small heath butterfly (Coenonympha pamphilus), males in territories have higher mating success than males outside territories. This supported the hypotheses that the function of territorial behaviour is to secure more matings and that the territories are mating stations. Wing length measurements suggest the same. Large males residing in territories tended to mate more often than small males, which were usually found outside territories. Since resident males were larger than non-resident males, this size difference was used to see how territorial occupancy influenced longevity. Mark-recapture of measured males revealed no significant correlation between wing length and the further life expectancy of males, strongly suggesting that the mating success of males in territories is also higher when measured over their whole lifetime.