Habitat selection and nest construction behaviour in some Afrotropical species of Ammophila (Hymenoptera: Sphecidae)

Nest construction behaviour and nest site selection are described for seven species of Afrotropical Ammophila.

Four species were atypical in their nest siting. Ammophila beniniensis selected shaded sites in well vegetated habitats, A. vulcania selected small clumps of vegetation in otherwise open habitats. A. insignis nested in vertical banks, old animal burrows and caves. A. braunsi is unique amongst Ammophila in its use of abandoned burrows of other wasps in non-friable clay soils. A. ferrugineipes, A. dolichodera and A. dolichocephala nested mostly in open habitats.

Methods of soil waste disposal, sealing of nests and their final coverage, differed interspecifically, in some cases intraspecifically, but often apparently in response to the habitat.

Temperature conditions, affected by habitat, influenced the depth to which nests were dug by some species. A. insignis switched sites in response to seasonal changes in temperature regimes in vertical banks.

The existence in particular species of both primitive and advanced aspects of nesting behaviour questions their use in assessing the evolutionary status of these species.     

Foraging ecology and behaviour of the ponerine ant Ectatomma opaciventre Roger in a Brazilian savannah

This study provides a detailed account of the foraging behaviour of the ponerine ant Ectatomma opaciventre in a ‘cerrado’ savannah in south-east Brazil. Our observations suggest that this species has an exclusively diurnal foraging pattern. Feeding habits included both predation and scavenging, with termite workers and leaf-cutting ants as the most important food items. Contrary to all other Ectatomma species studied to date, no liquid food such as hemipteran honeydew or plant nectar was collected. Foragers showed clear individual foraging area fidelity.Workers of E. opaciventre employed a typical individual foraging strategy, i.e. there was no co-operation between foragers in the search for or retrieval of food, neither by tandem running nor by trail laying. Nest density was considerably lower than in other Ectatomma (0.015 nests per m²). The observed mean distance to the nearest neighbouring nest was 5.85 m, with a significant tendency toward over-dispersion. Nests were more frequently found in specific microhabitats, which may suggest active choice of nesting site by founding queens.     

Spawning behaviour of Engystomops pustulatus (Anura: Leptodactylidae)

Foam nests have evolved independently in several amphibian groups as an adaptive response to prevent predation and desiccation in dry environments. Nests are normally laid on ponds, or in underground galleries, humid forest leaf litter or terrestrial bromeliads. They are built when males or females beat a foam precursor associated with the egg masses extruded by the female. The spawning process requires the synchronic actions of the mating pair to obtain a hemispheric nest that protects the offspring. Herein, we describe the spawning behaviour of Engystomops pustulatus based on videos from 13 nesting couples from the lowlands of western Ecuador. Three variables were measured as indicators of male effort: duration of mixing events, duration of resting periods, and number of kicks per mixing event. We consider that not only male physical effort but also female behaviour influences nest structure. We suggest that nest building requires prolonged and intense physical activity by the male as well as the female’s steady position during spawning and female’s oviposition site selection. Nest building has two phases. In the first phase, the duration of resting periods, the duration of mixing events, and the number of kicks increase and are highly variable. During the second phase the three variables stabilise until the end. The volume of the nest increased mainly during the second phase. In four nesting events we observed kicking movements by the female. To our knowledge, this is the first time that female kicking has been observed in leptodactylid frogs. The function of this behaviour is unknown but our observations suggest that it may be triggered by insufficient male effort. Traditionally, female mate choice in Engystomops has been explained under models of indirect benefits exclusively. We argue that the prolonged male activity during nesting could influence female fitness directly. This will allow the operation of sexual selection via direct benefits.     

Nesting habits of the Japanese foliage spider,Cheiracanthium japonicum (Araneae: Miturgidae): host plant preference based on the physical traits of plant leaves

A Japanese foliage spider, Cheiracanthium japonicum, builds nests with plant leaves. The nests are classified into seven types in relation to the seasons and purposes of nesting. We investigated whether the spider selects a plant species according to the nest type and how the physical traits of leaves influence the spider's plant selection. The difference between the composition of the host plant species used for nesting and that of the seasonal vegetation cover was confirmed. This suggests that the spider chooses the host plant species regardless of its abundance in their habitat. Early juveniles use small living or large dead leaves of various plant species to build moulting nests. Females prefer long and large leaves found in Miscanthus sinensis and Phragmites japonica over other plant leaves to build breeding nests.     

Specialization in the choice and use of spider silk in the nest of the chaffinch (Fringilla coelebs) (Aves,Fringillidae)

The chaffinch, Fringilla coelebs, is one of a large number of birds from many families that use silk in the construction of their nests. Thirty-eight chaffinch nests collected from around the UK were examined to determine the nature and role of silk in nest construction. A regular survey of web, retreat and cocoon silk availability was made at a study site close to Glasgow, Scotland, over a 12 month period. The only spider web silk found in the nests was of the type produced by cribellate spiders. The majority of silk in nests, however, was spider cocoons, but there was no correlation between the amount of cocoon and web silk used. Nests with more lichen decoration contained more silk, and cocoon silk was particularly associated with the attachment of lichen. Nest construction at the study site took place from late April to mid-May. When nest building began, the availability of suitable web silk had doubled from its winter (lowest) level; however, its abundance continued to rise sharply until the end of May. The possible influence of silk availability on the timing of chaffinch nesting is discussed.     

Carton nest building and trophobiont manipulation in the south-east Asian ant Dolichoderus sulcaticeps (Mayr 1870) (Hymenoptera: Formicidae)

Dolichoderus sulcaticeps, a rare canopy living dolichoderine ant, was studied in the rainforest of Malaysia. It forms large polycalyc colonies comprising partial nests on trees and climbers. The three dimensional multichambered partial nests are situated on the leaf underside. Fibrous nest material is gathered from the surface of the nesting plants and soaked with water from the plant surface. Building activity, therefore, is strictly dependent on the presence of rainfall or dew. Within the cell with plant leaf surface contact, as well as on free feeding sites, non specific coccid and membracid throphobionts, are tended. Free feeding sites are permanently protected. Mealybugs are transported between existing and new free feeding sites, as well as to and from nest pavilions, especially during their construction or destruction. Prey hunting has not been observed in D. sulcaticeps. The workers, however, recruit to offered dead prey, and scavenged. During the day they were permanently on the surface of plants around their nests and feeding sites.     

A preliminary study of nest structure and composition of the weaver ant Polyrhachis (Cyrtomyrma) delecta (Hymenoptera: Formicidae)

Polyrhachis weaver ants build their nests from vegetation bound together using silk produced by their larvae. Here we provide a pilot study of the composition and the physical structure of three arboreal silk nests of Polyrhachis (Cyrtomyrma) delecta based on examination of three colonies. We found broadly similar nest architecture and size of the nests with each containing six or seven identifiable chambers, and describe the distribution of ants of different castes and life stages between them. We also note the construction of silk ‘girder’ structures, which spanned larger chambers, and we hypothesize that these provide additional strength to the internal nest structure. This study highlights the importance of more detailed investigation of the internal nest structure and composition in Polyrhachis, and other weaver ant species, which will help to develop our understanding of this specialized form of nest construction and nesting habits in a diverse group of ants.     

Ecology and behaviour of the weaver ant Camponotus (Myrmobrachys) senex

Abstract

Weaver ants use silk produced by their larvae to build their nests. This behaviour is one of the more notable instances of social cooperation in animals; however, there are few studies of Brazilian species. This study investigated the ecology, natural history and behaviour of the weaver ant Camponotus (Myrmobrachys) senex in Brazil and showed that the weaver larvae have a fundamental function in nest building. The nests were always arboreal (one nest/plant), with a round form, beige in colour, and with leaves and shoots adhered to the silk nest. The average size was 34.24 cm and the average weight was 163.87 g; nests contained up to 50,000 individuals and several queens. Fusion and fission of colony parts were observed for C. senex. Worker ants were frequently observed feeding on honeydew, fruits and insects; and defended their territory. We suggest that C. senex larvae could be considered an effective caste, valuable in nest construction.     

The evolution of nest building and communal nesting in Ageniellini (Insecta: Hymenoptera: Pompilidae)

Pompilid wasps prey upon spiders and use a single spider per nest cell. The majority of species dig simple burrows in the soil in which to cache their spider, on which an egg is laid. The nest is not revisited, but another nest is prepared elsewhere. However, members of the tribe Ageniellini show much diversity in nesting behaviour. Species of the genus Ageniella nest in pre-existing cavities in the soil, closing off their cells with bits of debris. Most other Ageniellini that have been studied carry water to make mud pellets, from which ovoid nest cells are made. Usually a series of such cells is made in close proximity, often under loose bark or stones or in hollow stems. A few species make free nests above ground, usually in protected places or with thick mud walls. In some cases nest sites are known to be re-occupied by members of successive generations. Several species are known to nest communally, co-operating in nest defense and in cell building. In many ways the evolution of nesting behaviour in this group parallels that in the mud-using Vespidae, but the use of a single prey per cell precludes development of progressive provisioning and of eusociality similar to that of many Vespidae.     

Nesting biology and behavioural ecology of the solitary bee Monoeca haemorrhoidalis (Smith) and its cleptoparasite Protosiris gigas Melo (Hymenoptera: Apidae: Tapinotaspidini; Osirini)

The species Monoeca haemorrhoidalis, the largest species in the genus, occurs in the Atlantic rainforest of southeastern and southern Brazil. The aim of this study was to investigate the nesting ecology of M. haemorrhoidalis and its interactions with natural enemies. Nest aggregations were studied in an area at the transition between Dense and Mixed Temperate Rainforest, south Brazil. The period of nest construction and cell provisioning started in October and stopped in February. Plant species of the families Orchidaceae, Styracaceae and, mainly, Malpighiaceae, were the most important pollen and floral oil resources that were used in brood cell provisioning. During the nest construction activities, 27 insect species were observed at the nesting sites. The cleptoparasitic bee Protosiris gigas was one of the main causes of M. haemorrhoidalis mortality. Some behavioural and biological data of P. gigas are also reported.     

Botanical composition and structure of hummingbird nests in different habitats from northwestern Patagonia (Argentina)

There are few detailed analyses of the building materials used in bird nests. This study was part of a project on interrelations between northern Patagonian plants and birds. Nests of two hummingbird species distributed in the Andean portion of southern South America: the Green‐backed Firecrown Sephanoides sephaniodes and the White‐sided Hillstar Oreotrochilus leucopleurus, were collected along a precipitation gradient in northwestern Patagonia (Argentina). Nest morphology, structure, and composition (mostly botanical in origin) were analysed. Plants used as building materials are presented for each nest, arranged by location. The main structural materials were mosses (especially those with falcate leaves) entangled with spider web. Nests were concealed in their environments by the presence of mimetic material on the outer layer (spider cocoons, leprose lichens, feathers, and hairs). Soft material was the main component of the lining (pappi, feathers, spider web, and manufactured cotton). The variety of nesting materials decreased along the precipitation gradient, while the main structural components are generally fixed.     

Observations on the nesting behaviour of the spider wasp Eragenia congrua (Hymenoptera: Pompilidae), with the first record of the host

We describe, for the first time, the nesting behaviour of an Eragenia spider wasp, Eragenia congrua, based on field observations in the Brazilian Amazon. This species was observed nesting in holes at the base of the trunk of a Jacaranda copaia tree and provisioning nests with both amputated and non-amputated species of undetermined Corinna sp. (Corinnidae) spiders. The spiders are carried forward and grasped at the base of the chelicerae. Nesting is gregarious with females nesting in the same small area on successive days.     

Breeding biology of the threatened Campo Miner Geositta poeciloptera (Aves: Scleruridae), a Neotropical grassland specialist

The Campo Miner is a threatened grassland passerine endemic to the South American Cerrado, whose life history is almost unknown. In this paper, we studied during three breeding seasons (2014 to 2016) the breeding biology of a colour banded population of the species found in the Upper Rio Grande Grasslands, south-eastern Brazil. We found 98 nests, 81 of which became active and were monitored. The Campo Miner breeds in frequently burnt-and-grazed natural grasslands, successfully nesting in highly disturbed sites, such as dirt banks along roads and even in mine pits. The species is socially monogamous and both parents build the nest, which is a cavity/with-tunnel/simple/platform type. The nest chamber is lined with a platform made of grass fragments, charcoal, hairs, and mammal faeces. The most common clutch size is three eggs (n = 66), with some nests containing one (n = 1), two (n = 12) or four eggs (n = 2). The egg is white and pyriform and the incubation, performed by both parents, lasts 17.5 days. Mean nestling period is 15.5 days, with both parents feeding the young. Breeding season lasted for about 125 days (August to December) and multiple breeding attempts in a single season were common, with a maximum of three attempts recorded. All species of Scleruridae built their nests inside cavities dug in the soil with an access tunnel to it, where they lay a small clutch (usually 2–3 white eggs), but no other species in the family has been studied in detail to date. Further studies are required to understand why a species apparently tolerant to anthropogenic impacts such as G. poeciloptera can be so rare, patchily distributed and threatened throughout its range.     

Nest architecture in polydomous grass-cutting ants (Acromyrmex balzani)

Acromyrmex balzani is a grass-cutting ant species frequently found in Cerrado areas. However, little is known about the architecture of the polydomous nests of this ant. Fifteen A. balzani nests located in a cerrado region in Botucatu, São Paulo, Brazil, were studied. The polydomous nests were studied in three ways. First, we investigated the architecture in nests moulded with cement and without moulding. Second, we performed an aggressiveness test among workers in different subnests and nests. Third, we excavated the nest and collected the colony to measure the population, verifying the existence or not of a queen in all nests. A cement mould was made of seven nests to permit better visualization of internal structures such as chambers and tunnels. Eight nests were excavated without moulding and white neutral talc was used to highlight the parts of the nests. After excavation, the depth and dimensions (length, width and height) of the chambers were measured. The results showed that the nests had a single entrance hole whose structure consisted of straw and other plant residues in winter. Mounds of loose soil, if present, were found 6–48 cm from the hole. The number of chambers containing fungus ranged from one to five, with the first being found a few centimetres beneath the ground surface (4 cm) and the last up to a maximum depth of 160 cm. The length of the tunnels ranged from 12 to 28 cm. These tunnels were built in a vertical or inclined position, leading to the chambers. No waste chambers were found, with the waste being deposited externally. Additionally, the polydomous nests contained one to eight subnests. In the aggressiveness test, when concolonial workers were confronted, no aggressiveness was observed. In contrast, when allocolonial workers were confronted, there was a high incidence of aggression among them. Excavation of polydomous nests showed only one queen for each polydomous nest, i.e. subnests with a single queen. Our study contributes to a better understanding of the so far unknown nest architecture of the polydomous grass-cutting ant A. balzani.     

Comparisons in nesting biology of two sympatric carpenter bee species (Apidae: Xylocopini)

This work analyses the biology and nesting behaviour of Xylocopa ordinaria and Xylocopa frontalis, providing information for their conservation and management. The study was performed from August 2006 to December 2007 and considered 25 nests of X. ordinaria and 23 of X. frontalis. The X. frontalis nested between December and April, while X. ordinaria nested throughout the year. Nests of X. ordinaria dug in wider substrates had more tunnels, and the width of nest tunnels and the dimensions of brood cells were smaller than were observed for X. frontalis. Females spent most of their time in activities inside their nests, followed by nectar and pollen flights and nectar dehydration. Pollen resources used by these bees presented more than 40% similarity, and they were constant to flower resources while provisioning cells. Cissites maculata and a Diptera species were the natural enemies found.     

Reproductive ecology of Dusky Flycatchers in montane meadows of the central Sierra Nevada

Avian species with expansive ranges or those that occupy more than one vegetative association may vary in aspects of their life histories across their ranges. The distribution of Dusky Flycatchers encompasses a variety of vegetative associations, including riparian communities. However, much of the literature on this species details studies conducted in upland areas. Our objectives were to describe the breeding ecology and fecundity of Dusky Flycatchers nesting in montane meadows of the central Sierra Nevada, California. We monitored 36 territories and located 37 Dusky Flycatcher nests in 8 meadows. Average clutch size was 3.9 eggs. Egg laying, incubation, and nestling stages were 4, 15.4, and 16.4 days, respectively. Eighteen nests successfully fledged young, with an average of 3.3 fledglings per successful nest. Nest success was 43% and nest predation was the leading cause of nest failure. Estimated annual fecundity was 1.62 fledglings per pair; however, because all renesting attempts were not located, this should be viewed as the minimum annual fecundity. Dusky Flycatchers we monitored may have had higher fecundity than those nesting in upland areas because riparian areas often have higher arthropod abundances. While the importance of riparian conservation to riparian-obligate bird species is obvious, our study indicates that these areas also may be of value to Dusky Flycatchers that breed in riparian areas and upland areas.     

Habitat,egg‐laying behaviour,eggs and tadpoles of four sympatric species of Pseudopaludicola (Anura,Leiuperidae)

In contrast to most leiuperid frogs, Pseudopaludicola falcipes does not lay eggs in foam nests; this could represent a reversion to the primitive state. We found that in four other Pseudopaludicola species, eggs were also not embedded in foam nests and had a well‐defined outermost jelly layer. The females also constantly moved or dived and males lacked vigorous “wiping/kicking” leg motions while eggs were being laid, features that make foam nesting difficult. The tadpoles of three species have two gaps in the marginal papillae along the lower labium and two posterior rows of labial teeth; the tadpoles of one species had three gaps and three rows, a pattern resembling that of some Physalaemus (Leiuperidae) species. Our data on tadpole morphology and reproductive behaviour do not allow us to rule out the paraphyletic nature of Physalaemus in relation to Pseudopaludicola but they provide some support against the “foam‐loss hypothesis” in Pseudopaludicola.     

Patterns of artificial avian nest predation by introduced rats in a fragmented laurel forest (Tenerife,Canary Islands)

The importance of introduced rats as damaging factors on island biotas is globally recognized. The predation of artificial avian nests by Ship rats (Rattus rattus) in fragmented laurel forests in Tenerife (Canary Islands) was explored. The influence of road edge, patch type, and position (ground versus tree) on nest survival in two forest remnants differing in conservation degree, were assessed using failure‐time analysis. Overall, nest predation was greater in the preserved than in the disturbed remnant. Nest predation also differed among and within patches, variation being greater within the disturbed remnant. The probability of nest failure was higher at the interior than along the road edge in both remnants, but the road edge effect on nest predation was more intense in the disturbed remnant. Predation pressure was higher in patches of mature, closed canopy or dense understorey with stump sprouting. Ground nests were predated at higher rates than tree nests at any location. These results contrast with other nest predation studies in fragmented landscapes where forest edges rather than the interior are more frequently used by predators. Predatory activity by rats seems negatively affected by forest disturbance and road edge effect. Overall, artificial nest predation patterns by rats confirm a potential predation risk for the avifauna of the Canarian laurel forest. This should be considered in implementing conservation management programmes.     

Nest-site selection by Sage Thrashers in southeastern Idaho

Nest sites selected by Sage Thrashers ( Oreoscoptes montanus ) in southeastern Idaho were characterized and compared with available habitat. Microhabitats within 5 m of nests had taller and more aggregated shrubs and less bare ground than the study area in general. Big sagebrush ( Artemisia tridentata wyomingensis ) plants used for nesting were taller than average ,available shrubs, had greater foliage density, were more often living, and more frequently had branches and foliage within 30 cm of the ground. Nest placement was specific with respect to relative nest height and distance from the top and perimeter of the support shrub. Sage Thrashers disproportionately used easterly exposures and underused westerly exposures for their nests.