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.     

Comparison of breeding biology aspects of Fluvicola nengeta (Aves: Tyrannidae) between two nesting sites

Fluvicola nengeta is an insectivorous bird that belongs to the Tyrannidae family, which lives close to bodies of water and can occur in urban areas as well. It makes use of natural and man-made substrates to build its nests. This study aims at describing the reproductive biology of F. nengeta by comparing nests built on vegetation and man-made structures as to their shapes, nest dimensions, building materials, distance from bodies of water and reproductive success. Forty-four nests were found, where 30 were located in vegetation and 14 on man-made structures. Nests did not exhibit any single pattern and were divided into three distinct shapes: closed/globular/base; closed/ovoid/base (45.5%; n = 5 for both) and low cup/base (9%; n = 1). Nests built on man-made structures exhibited a larger amount of anthropic material, such as plastic and paper, instead of plant-derived materials. Nests on man-made structures were found to be higher up from the ground (459.8 ± 46.9 m) and farther from water (232.9 ± 54.8 m) in comparison to those on vegetation (92.2 ± 28.6 m and 7.3 ± 4.7 m, respectively), aside from exhibiting a higher Mayfield reproductive success (37%) when compared to nests built on vegetation (34%). The estimated values of the daily survival rate (DSR) for vegetation nests were 0.997 for the incubation period and 0.928 for the nestling period. In man-made structure nests, DSRs were 0.968 and 0.964, respectively, during the incubation and nestling periods. The period survival rate (PSR) of nests in vegetation was significantly higher than the PSRs of nests in man-made structures during the incubation period. DSRs did not differ between incubation and nestling periods for either nesting sites.     

Breeding biology of the Sayaca Tanager (Thraupis sayaca) in southeast Brazil

ABSTRACT

Thraupis is a genus of the American endemic Thraupidae (subfamily Thraupinae), comprising seven species that inhabit tropical forests to urban centres. The Sayaca Tanager (Thraupis sayaca) is a disturbance-tolerant species of high representativeness in plant-frugivore networks, but information on its breeding biology is scarce and often restricted to non-systematic surveys. We studied the breeding biology of the T. sayaca, following 39 active nests in a periurban area of southeast Brazil during two breeding seasons (2017/2018, 2018/2019). The breeding season ranged from early September to middle December, and the nests were placed in native and exotic plants and human buildings (nest height above ground: 3.35 ± 1.73 m, mean ± SD). Only females incubated and brooded, but both adults built the nests, fed the nestlings, and removed their faecal sacs. Clutch size was 2.86 ± 0.38 eggs and nest attentiveness was 71.2%. The incubation and nestling periods were, respectively, 13.4 and 17.4 days. Males and females did not differ on nestling provisioning and nest sanitation rates. Nestling provisioning (13.35 ± 6.25 trips/hour) increased with nestling age, while mean brooding time was 37.2% and decreased with nestling age. Apparent nest success was 38.7%, and nest survival according to the Mayfield method was 27.2%. Five nests (20.8%) were parasitised by the Shiny cowbird (Molothrus bonariensis), and we recorded five events of nest-site reuse. We concluded that the most remarkable breeding traits of T. sayaca in comparison with close-related tanagers are the use of anthropogenic nest sites, the higher clutch size and number of feeding trips, and the longer nestling period.     

Gastrointestinal helminths of nine species of Cnemaspis (Squamata: Gekkonidae) from Peninsular Malaysia,one species from Cambodia and Thailand and two species from Vietnam

A total of 12 species of Cnemaspis (N = 104) from Southeast Asia were examined for gastrointestinal helminths. Samples consisted of nine species (n = 86) from Peninsular Malaysia: Cnemaspis affinis (n = 4); Cnemaspis baueri (n = 17); Cnemaspis biocellata (n = 12); Cnemaspis grismeri (n = 8); Cnemaspis kumpoli (n = 11); Cnemaspis limi (n = 9): Cnemaspis monachorum (n = 7); Cnemaspis pemanggilensis (n = 10); Cnemaspis peninsularis (n = 8); one species (n = 5) from Cambodia and Thailand, Cnemaspis chanthaburiensis (n = 5); and two species (n = 13) from Vietnam: Cnemaspis nuicamensis (n = 6) and Cnemaspis tucdupensis (n = 7). The aggregate helminth community consisted of one species of Cestoda, Cylindrotaenia malayi and nine species of Nematoda: Bakeria schadi, Meteterakis singaporensis, Parapharyngodon maplestoni, Maxvachonia sp., Physalopteroides sp., Physalopteridae gen. sp., Riticulariidae gen. sp., Seuratoidea gen. sp., Ascaridoidea gen. sp. Meteterakis singaporensis had the largest number of individuals (457) and greatest prevalence (24%). Twenty-eight new host records are reported.     

Natural history of the Lined Seedeater Sporophila lineola (Aves: Thraupidae) in southeastern Brazil

The Lined Seedeater (Sporophila lineola) is a migratory species that inhabits a variety of open habitats in South America. We studied the breeding biology and territorial behaviour of a colour-banded population of the species in the Universidade Federal de Viçosa, Campus Florestal (1–19,8808ºS, –44,4136ºW), during two breeding seasons (2014/2015 and 2015/2016), which spans from December to April. We monitored 74 nests of this species. The nest is a low cup supported between a fork. Nests are mainly built with grass stems and rootlets, with spider-web used to hold the material together and to bind the nest to its supporting plant. Females are solely responsible for nest building and incubation, which is synchronic, and also for feeding nestlings to a large extent. Males are responsible for defending the territory, which corresponds to a small portion of the home range restricted to the nest environs, and also feed the nestlings. Mean clutch size is two eggs (78% of nests monitored), with clutches of three (20.3%) and four (1.7%) eggs also observed. Eggs are whitish, covered with dark brown blotches and spots to a variable extent. Mean incubation period, considered as the period between the onset of incubation and hatching of the first egg, is 11 days. Nestling period, considered as the period between hatching of the first egg and fledging of the last young, is 10 days. During the first breeding season, the simple percentage of successful nests was 34.1%, while the Mayfield success was 29.8%, with slightly higher values observed during the second breeding season, with 39.4% and 35.7%, respectively. We recorded, for the first time, three cases of polygamy in the species. We also recorded breeding site fidelity for the first time in the species, with males returning to the same territory owned in a previous breeding season.     

Ecology of two Pittas (Pitta soror and Pitta nympha) in limestone forests of South China

The ecology and life history of bird species inhabiting limestone forests, which are under major conservation threats, is currently poorly known. To cover this gap of knowledge, in this study we report for the first time on several aspects of the breeding ecology of the Blue-rumped Pitta (Pitta soror) and the Fairy Pitta (P. nympha) inhabiting two typical limestone forests of south China. The mean density of Fairy Pittas in our study locations was 3.13 ± 2.82 and 1.05 ± 2.09 individuals/km². The Blue-rumped Pitta was common in Nonggang and showed a mean density of 4.67 ± 2.44 individuals/km², yet was absent in the other. We found nine nests between February 2009 and June 2015, including five of the Blue-rumped Pitta and four of the Fairy Pitta. Blue-rumped Pittas laid 4.8 ± 0.4 eggs with a mean fresh mass of 8.10 ± 0.40 g. Fairy Pittas had a clutch size of 5.2 ± 0.45 eggs with a mean fresh mass of 6.03 ± 0.22 g. Blue-rumped and Fairy Pitta parents fed their nestlings 4.0 ± 1.2 times and 3.9 ± 1.5 times per hour, respectively. Earthworms were the most common food item delivered to nestlings by Blue-rumped (93.6%) and Fairy Pitta (91.2%) parents. Blue-rumped Pittas bred successfully in 40% of nests (two of five), whilst in the case of Fairy Pittas nest success reached 75% (three of four). The two Pittas had larger clutch sizes than in southern populations of the same species and also than most other bird species inhabiting limestone forests. This would imply that Pittas show differences in life history traits within limestone ecosystems.     

Reproductive biology of the endangered wattled curassow (Crax globulosa; Galliformes: Cracidae) in the Juruá River Basin,Western Brazilian Amazonia

The reproductive biology of Crax globulosa is virtually unknown, this knowledge comprised of only a few anecdotal notes. We found nine nests of Crax globulosa in the middle section of the Juruá River, western Brazilian Amazon, during the dry season. Nests averaged 22.5 m from water and 13.3 m above the ground. We observed two nest types: five made of twigs, leaves and vines, and four within a bromeliad. All nests contained two eggs, but six (67%) were subsequently predated. A female tagged with a transmitter nested twice during the same breeding season. A chick was monitored together with its parents for > 10 months. In addition to hunting and habitat loss, nest predation could be another threat to this endangered species.     

Helminths of some tree frogs of the families Hylidae and Phyllomedusidae in an Atlantic rainforest fragment,Brazil

Despite the fact that Brazil is the most-studied country regarding helminths of amphibians, only around 8% of Brazilian anurans have had at least one study made of their helminth fauna. Therefore, the aim of this study was to describe the helminth community of nine species of Atlantic Rainforest anurans of two different families, eight of them with no previous study, and six of which are endemic to Brazil. The analysed hosts for their parasites were: Dendropsophus minutus (n = 48), Scinax auratus (n = 36), D. branneri (n = 33), D. elegans (n = 26), Hypsiboas albomarginatus (n = 22), Pithecopus nordestinus (n = 19), D. decipiens (n = 12), D. haddadi (n = 11) and S. x-signatus (n = 11). A total of 781 helminths were collected from 106 (48.6%) of 218 analysed hosts, 656 Centrorhyncus sp. cystacanths and 125 nematodes: 76 adults (25 Cosmocerca sp.; three Cosmocerceidae gen. sp.; 20 Cosmocerca parva, 20 Cosmocercella phyllomedusae, five Aplectana sp., two Oswaldocruzia sp. and one Rhabdias sp.), 43 encysted larvae (nine Porrocaecum sp. and 34 Brevimulticaecum sp.) and six Physaloptera sp. larvae. Anurans may display many roles within the helminth life cycles, as they act as both predator and prey to a wide variety of animals. Consequently, we have found helminths that use anurans as definitive, intermediate and paratenic hosts. Opposing other surveys in which nematodes are the most prevalent and abundant parasites, acanthocephalans were the most prevalent taxa. These findings highlight the lack of knowledge regarding the helminth fauna of anurans and reveal many gaps with respect to their infection patterns in amphibians.     

Reproductive ecology of a Tibetan frog Nanorana parkeri (Anura: Ranidae)

Endemic to the Tibetan Plateau, Nanorana parkeri figures among the highest altitude amphibians in the world. The present work, which was conducted in an alpine marsh at 4300 m altitude, is the first report of the species’ reproductive ecology. The breeding season, as indicated by the presence of amplectant pairs and fresh eggs in ponds, lasted from early Mary to early July. The ratios of adult male to female were 1.3 in hibernation ponds and 2.3 in spawning ones. Males were smaller than females. Amplexus was typically axillary (81.7%), with a few exceptional amplexus in which a male clasped another male or object rather than gravid females. Scramble competition occurred in 6.8% of the normal amplexus located. The body sizes of amplexed couples correlated positively. Deposited eggs were attached to submerged plants solitarily (60.5%) or in small clusters (39.5%), and the scattered arrangement of individual eggs could be a strategy to ensure embryonic development in oxygen-poor environments. Clutch size averaged 189 [standard deviation (SD) = 64], and correlated positively with female body size; egg size averaged 2.18 mm (SD = 0.10), independent of female body size; both traits within a clutch were negatively related with each other even controlling for female body size. Relatively few and large eggs laid by the Tibetan frogs, compared with those by lowland aquatic-spawning anuran species, should be adaptive to the harsh high-altitude conditions. Larvae hatched from eggs after 16.4 days on average (SD = 5.8). Froglets emerged between late July and early August, but some tadpoles were present in winter. These findings may help to understand the evolution of amphibians in extreme environments and to protect these remote species.     

Estimating the young evolutionary age of marbled crayfish from museum samples

ABSTRACT

The obligately parthenogenetic, all-female marbled crayfish, Procambarus virginalis, is a triploid descendant of the similarly looking, sexually reproducing slough crayfish, Procambarus fallax, native to Florida and southern Georgia. We have earlier hypothesised that marbled crayfish may have originated from P. fallax only some 25 years ago, perhaps in captivity. In order to investigate the young evolutionary age hypothesis in more detail, I searched the P. fallax collection of the Smithsonian Institution Museum of Natural History (USNM, Washington, D.C.) for evidence of marbled crayfish before its detection in the German aquarium trade in 1995. In particular, I analysed the sex ratio of P. fallax and the frequency of pure female samples throughout its entire distribution range to detect potentially misidentified marbled crayfish among the P. fallax. If marbled crayfish had originated from P. fallax long ago, spread throughout Florida and Georgia and erroneously been sampled as P. fallax, then the sex ratio of the P. fallax in the collection should be significantly biased towards females and pure female samples should be much more frequent than in related Procambarus species. Comparison of P. fallax (n = 2299) with its closest relatives P. seminolae (n = 801) and P. leonensis (n = 150) revealed female proportions of 55.33%, 53.93% and 54.67%, respectively, which are not significantly different from each other. The average female proportion of the 14 Procambarus species investigated (8641 specimens) was 52.54 ± 7.54% (mean ± standard deviation). Moreover, pure female samples consisting of more than 3 specimens that could represent hidden marbled crayfish were not conspicuously more common in P. fallax (2.33%) than in all Procambarus species investigated (1.24 ± 1.79%). These data suggest that the P. fallax collection of the USNM consists of real, sexually reproducing P. fallax and does most likely not include hidden marbled crayfish, supporting the young evolutionary age hypothesis for marbled crayfish.     

Life history of Paraselenis (Spaethiechoma) dichroa (Germar, 1824) (Coleoptera: Chrysomelidae: Cassidinae) in natural conditions of Atlantic Forest from Brazil

Cassidinae Gyllenhaal? is the second largest subfamily of Chrysomelidae (Coleoptera), which presents characteristic morphology, biology and behaviour. The current study describes the life cycle of Paraselenis(Spaetiechoma) dichroa (Germar), ?determining biological and behavioural aspects as well as the action of natural enemies on populations, when the species has maternal care. The study was conducted between February and April 2015 in the National Forest of Passa Quatro, municipality of Passa Quatro, Minas Gerais state, Brazil. Daily observations were made (morning and afternoon) to evaluate the offspring of females on Ipomoea sp. and Merremia macrocalyx (O’Donell?) (Convolvulaceae), as well as the actions of natural enemies on the young. The eggs are deposited on the midrib and abaxial surface of leaves (n = 25). Egg clusters are pedunculated, arranged in groups and devoid of any cover. On average, each female produced 27.3 ± 5.6 (n = 16) eggs, with a mean incubation period of 12.7 ± 2.9 days (n = 10 females with their young). The larvae remained grouped in the leaves throughout development, except when they fed. They retained faeces and exuviae as a stacked faecal structure on their mobile urogomphi (caudal process) like a faecal shield. The mean number of larvae per female was 12.7 ± 10.1 (n = 19) and the larval period lasted 24.9 ± 4.5 days (n = 12). Pupation occurred on the stem of the plant (n = 16). On average there were 8.1 ± 8.5 individuals for pupae progeny (n = 14). The mean duration of the pupal stage was 10.4 ± 3.3 days (n = 5). Overall, 3% of adults emerged (n = 13 individuals), with a total cycle time of 41.3 ± 8.4 days (n = 6). Adults are sexually dimorphic in the elytral shape. Females remain with the offspring throughout development. The natural enemies of immatures were Emersonella pubipennis Hansson? (Hymenoptera: Eulophidae), Tachinidae (Diptera) and Stiretrus decastigmus (Herrich-Schaeffer?) (Heteroptera: Pentatomidae), Conura sp. Spinola? (Hymenoptera: Chalcididae) and Brachymeria sp. Westwood? (Hymenoptera: Chalcididae). The information presented here on the natural history of P. dichroa are important as they may serve as a starting point to understand evolutionary questions and multispecies interactions.     

Nesting territory characteristics of a migratory South American forest hawk,the White-throated Hawk (Buteo albigula) (Aves: Accipitridae), in temperate rainforest remnants of Araucanía,southern Chile

During four successive breeding periods (2007–11) we characterized the nesting territories of the white-throated hawk (Buteo albigula) in southern Chile. Territories were located in mountainous areas with mature native forest (n = 17) or mature pine plantations (n = 1). Most of the territories were distant from urban centres (>2 km). Only one or two adult hawks and one young per pair/year were observed in each territory. All nest sites were located in the upper parts of ravines. Nests were built on large, living mature trees. Platforms were bulky (>50 cm diameter) and oval or round. Eggs were white and subelliptical in shape (40.0 × 50.0 mm). Hawk pairs reproduced asynchronically extending the reproductive period for 6 months. Although some white-throated hawk pairs were tolerant of human-modified habitats, it is possible that decline in forest cover represents a potential threat for the population viability of this migratory forest hawk.     

Camera traps capture images of predators of Caiman crocodilus yacare eggs (Reptilia: Crocodylia) in Brazil’s Pantanal wetlands

Camera traps were set up in forest nests in 2009, 2010 and 2012 to capture images of possible predators eating eggs of the Pantanal caiman, Caiman crocodilus yacare. We monitored 57 caiman nests; 42 nests were opened and the eggs were counted (mean = 25 eggs/nest, SD = 4.3). Females were present and captured at 38 of those nests. The remaining 15 nests were used as controls, and we did not capture the females or open the egg cavities of these nests. Most of the nests had the eggs eaten by predators, in both the disturbed group (38 nests) and the control group (13 nests). The main predators were carnivorous mammals, such as crab-eating foxes (Cerdocyon thous), coatis (Nasua nasua) and tayras (Eira barbara), although feral pigs (Sus scrofa) and armadillos (Dasypus novemcinctus) were also photographed eating caiman eggs. The lizard Salvator merianae was photographed eating eggs of two nests.     

Breeding in the gray-headed tody-flycatcher (Aves: Tyrannidae) with comments on geographical variation in reproductive traits within the genus Todirostrum

The gray-headed tody-flycatcher Todirostrum poliocephalum is a passerine endemic to the Atlantic Forest of Brazil. We describe the nest and nesting behaviour of this species and investigate geographical variation in breeding traits in the genus using data from the literature, museum collections, and citizen science projects. We located 21 nests of the gray-headed tody-flycatcher, 13 of which we monitored. Nest height above the ground averaged 3.3 ± 3.4 m (n = 21). Nests were built over a 16.8 ± 5.6-day period (n = 6) by both adults. Clutch sizes ranged from two to three eggs, with a mean of 2.9 ± 0.3 eggs (n = 10). Eggs measured 16.6 ± 0.5 × 12.0 ± 0.5 mm (n = 23) and weighed 1.1 ± 0.1 g (n = 19). Mean incubation period was 17 days (n = 3) and mean nestling period was 15.5 days (n = 2). Apparent reproductive success was 30.8%, with predation being the primary cause of nest failure (46.1%). Mayfield’s reproductive success was 25.9%, and daily survival rates for eggs and nestlings were 0.957 and 0.971, respectively. Clutch sizes increased with latitude, but temperature and precipitation seasonality had very low importance in explaining clutch size variation.     

Asynchronous reproduction in three species of crocodilians in south-eastern Amazonia

We studied reproduction of three species of crocodilians, Paleosuchus trigonatus, Caiman crocodilus and Melanosuchus niger, in the Xingu River, near the Belo Monte hydroelectric dam. The periods of laying and hatching of eggs were estimated for each nest before (2013–2014) and after (2016–2017) the river was dammed and the reservoir was formed. Nesting of the three species occurred between August and December, but was largely asynchronous; nest construction peaked in September for P. trigonatus, October for M. niger and November for C. crocodilus. Reservoir filling had little effect on the laying period of any of the species. Nests of P. trigonatus and M. niger were always within 0–12 m of the bank, whereas nests of C. crocodilus, which nests later in the season when flooding is more likely, were up to 100 m from the nearest water body. There was no relationship between distance from water and the number of eggs in nests, suggesting that larger and presumably more experienced females do not lay at different distances from the bank in any of the species.     

Early life history of the sheepnose (Plethobasus cyphyus) (Mollusca: Bivalvia: Unionoida)

Managing a rare species can be improved with knowledge of its natural history. The sheepnose (Plethobasus cyphyus) is a freshwater mussel recently listed by the US as federally endangered. We used standard methods to study P. cyphyus brooding behaviour, host fishes in the laboratory and under natural conditions, and glochidial morphology. We monitored a population of P. cyphyus in the Chippewa River, WI during spring and summer 2007–2009 and 2011 and found brooding animals between mid-May and early August. Gravid individuals ranged between 5 and 27 yr (mean age ± 1 s.d. = 13 ± 4 yr). Plethobasus cyphyus brooded glochidia in outer gills, which varied in colour from red, orange, pink, cream, or white. We observed mature glochidia more commonly in individuals with cream or white gills and these glochidia were released in a clear, adhesive, mucus matrix. In laboratory trials we found several minnow and topminnow species (29 spp.) served as productive suitable native hosts. The mean number of juvenile mussels released per cyprinid per day was significantly higher for trials conducted at 22–25°C compared with those at 18–20°C, and 83% of trials conducted at 18–20°C using suitable host species produced no juveniles. Glochidia had a unique outline and shell morphometrics that distinguished P. cyphyus from seven other Chippewa River mussel species that produce similar sized glochidia. Using morphometrics we determined that mimic shiners (Notropis volucellus) were natural hosts for P. cyphyus, round pigtoe (Pleurobema sintoxia), and Wabash pigtoe (Fusconaia flava). Releasing mucus-bound glochidia has evolved in a variety of mussel species and may be more common than is currently realized. Our data show that P. cyphyus is a cyprinid host specialist, and propagation efforts for this species can be strengthened through improved access to mature glochidia by using females with cream-coloured gills and increased juvenile production through warmer fish holding temperatures.     

Architecture,composition and placement of nests of the Cipo Canastero Asthenes luizae (Aves: Furnariidae), a bird endemic to Brazilian mountaintops

Cipo Canastero (Asthenes luizae) is a bird endemic to Brazilian mountaintops, inhabiting rock outcrop habitats of the campos rupestres in the southern Espinhaço Range. Available data about Cipo Canastero’s breeding biology are scarce, incomplete or inconsistent. All nests found to date were built in the plant Vellozia nivea. Based on 84 nests found from 2009 to 2017 in four sites at Serra do Cipó, we described in detail their nesting habits focusing on three groups of characters: nest architecture, composition, and placement. Also, we described nest building. Our major new findings on the nesting habits of A. luizae were: three nest layers distinguishable, inner lining covering the entire nest interior, tunnels and tubes are absent, and the nest sites are not restricted to V. nivea. We recorded a wide range of nest sites, from ground, grasses and rupicolous bromeliads to shrubs and trees, including at least 30 supporting-plant species. Nest supports varied among study sites. Nest building lasted 22 days (one nest) and was done by both members of the pair. Our data can be useful for species conservation and contribute to the knowledge of the natural history of the genus Asthenes.