Successive Broods Research Articles

Reproductive biology of two species of squat lobsters – female receptivity and interbrood intervals

The reproductive biology of many species of anomuran crabs is only poorly known. Herein we studied the reproductive biology of two species of squat lobsters, Cervimunida johni Porter, 1903 and Pleuroncodes monodon (H. Milne Edwards, 1837), which are target of a trawl fishery operating on the continental margin along the Chilean coast. During the reproductive period (May-November) we maintained squat lobsters in the laboratory to examine whether mating is related to the reproductive molt of the female and to determine the interbrood interval between successive broods. In both species females mated during the intermolt period. Females became receptive shortly after having released larvae from a previous brood, when they formed pairs with males. The interbrood interval (from larval release until having a subsequent brood) lasted <72 hour in the majority of female C. johni, but was longer in P. monodon, where most females took 72-144 hours before producing a new brood. Despite longer interbrood intervals, copulatory mate-guarding was substantially shorter in P. monodon than in C. johni. These differences in reproductive behavior might be due to differences in the general biology of the two species, including mobility and intraspecific aggression. Mating during the intermolt period may have several advantages, namely reducing the risk of cannibalism and energy costs of molting during the reproductive season.

Breeding ecology of an Australian estrildid, the Long-tailed Finch (Poephila acuticauda)

We studied the breeding ecology of the Long-tailed Finch (Poephila acuticauda) over three seasons between 2008 and 2010 in the Kimberley region, Western Australia. Breeding took place from February to September, with a peak in laying in March-April. Pairs produced up to three successful broods per season with a mean (±s.e.) clutch-size of 4.66 ± 1.13, mean broods of3.98 ± 1.10 young, and an average of3.87 ± 1.10 fledged young per successful nest. Nesting failure occurred frequently, with 66.2% of breeding attempts failing to fledge any offspring. In nests where at least one egg hatched (47% of nests), 87 ± 17% of the eggs hatched. In successful nests, 98 ± 9% of all nestlings fledged. Annual breeding success was relatively consistent over the three breeding seasons, with 26.8-40.8% of all eggs resulting in fledged young. Successful nesting attempts lasted an average of 39 ± 3.3 days, with both parents contributing to incubation (duration 13.6 ± 2.3 days) and brooding and feeding during the nestling period (duration 20.6 ± 2 days). Site-and mate-fidelity were high, with pairs staying together during and between breeding seasons and 60% of pairs breeding in the same area in a subsequent year.

Breeding biology and reproductive success of Polystictus superciliaris (Aves: Tyrannidae), an uncommon tyrant-flycatcher endemic to the highlands of eastern Brazil

Polystictus superciliaris (Wied, 1831) is a small tyrant-flycatcher endemic to mountaintops in the highlands of eastern Brazil. In this paper we present the first description of the breeding biology of P. superciliaris and estimate its reproductive success from a population inhabiting rocky outcrops. This study was conducted during 2005 in the Parque Estadual da Serra do Rola Moça, municipality of Nova Lima (20°03'S, 44°00'W), state of Minas Gerais, southeastern Brazil. Fourteen pairs of P. superciliaris were banded and monitored. The onset of the breeding season in 2005 was assumed to have been sometime before the 26th of July, while it was assumed to have ended on the 23rd of November based on the last observation of a successful brood. Clutch size was invariably two eggs (N = 21), the incubation period averaged 17.7 ± 1.3 days (N = 9), and the nestling period averaged 16.4 ± 1.3 days (N = 8). We estimated the probability of reproductive success for P. superciliaris to be 41.3%, during this particular breeding season. Of the 12 (57.1%) unsuccessful nests, eight (66.7%) had eggs and four (33.3%) had nestlings when they failed. In nine (42.8%) of these cases, the nests were lost to predation, two to parasitism by botflies, and one due to abandonment. This study suggests that the reproductive success of P. superciliaris is intermediate compared to the other species of Tyrannidae that have been studied and closer to the lower limit of the 40%-80% range which is characteristic of tyrant _ flycatcher species that breed in temperate regions.

Breeding biology and reproductive success of Polystictus superciliaris (Aves: Tyrannidae), an uncommon tyrant-flycatcher endemic to the highlands of eastern Brazil

Polystictus superciliaris (Wied, 1831) is a small tyrant-flycatcher endemic to mountaintops in the highlands of eastern Brazil. In this paper we present the first description of the breeding biology of P. superciliaris and estimate its reproductive success from a population inhabiting rocky outcrops. This study was conducted during 2005 in the Parque Estadual da Serra do Rola Moca, municipality of Nova Lima (20°03'S, 44°00'W), state of Minas Gerais, southeastern Brazil. Fourteen pairs of P. superciliaris were banded and monitored. The onset of the breeding season in 2005 was assumed to have been sometime before the 26th of July, while it was assumed to have ended on the 23rd of November based on the last observation of a successful brood. Clutch size was invariably two eggs (N = 21), the incubation period averaged 17.7 ± 1.3 days (N = 9), and the nestling period averaged 16.4 ± 1.3 days (N = 8). We estimated the probability of reproductive success for P. superciliaris to be 41.3%, during this particular breeding season. Of the 12 (57.1%) unsuccessful nests, eight (66.7%) had eggs and four (33.3%) had nestlings when they failed. In nine (42.8%) of these cases, the nests were lost to predation, two to parasitism by botflies, and one due to abandonment. This study suggests that the reproductive success of P. superciliaris is intermediate compared to the other species of Tyrannidae that have been studied and closer to the lower limit of the 40%-80% range which is characteristic of tyrant _ flycatcher species that breed in temperate regions.

Three Successful Broods of the Mourning Dove in One Season in Regina, Saskatchewan

Three Successful Broods of the Mourning Dove in One Season in Regina, Saskatchewan

17β-estradiol에 노출된 저서성 요각류 Tigriopus japonicus s.l.의 세대간 생활사 및 형태학적 변이 연구

To characterize ecotoxicological responses to a natural estrogen, 17β-estradiol, we evaluated the life-history of the parental (F?) and first generation (F₁) of the harpacticoid copepod, Tigriopus japonicus sensu lato. We evaluated the survival of nauplii and copepodites, the number of days until the emergence of copepodites and adult males, the sex ratio, brooding success, and the first brooding day of adult females. No significant differences in the survival rate were noted in response to treatments with different concentrations of 17β-estradiol. However, 17β-estradiol induced developmental delay and skewed the sex ratio toward males. Copepod development was delayed significantly in the 0.1 and 1 ㎍ l ?1 17β-estradiol treatment groups relative to the control group, with a more pronounced delay in the F1 group. Body length and biomass were significantly smaller in the 17β-estradiol treated groups than in the controls. The male emergence of T. japonicus s.l. was very high in the 10 and 30 ㎍ l ?1 17β-estradiol treatment group. Furthermore, exposure to 17β-estradiol resulted in morphological deformities such as shrinking and swelling of the urosome, twisted setae of the caudal rami, setal loss of swimming legs, abnormal segmentation of antennules, and dwarfism.

Exclusive Male Egg Care and Determinants of Brooding Success in a Millipede

AbstractThe evolution of exclusive male parental care is a major and controversial issue in behavioural ecology. Although arthropods practicing paternal care are thought to be key taxa for investigating this issue, few studies have attempted to clarify the selection factors associated with male behaviour and fitness consequences in arthropods. In the millipede Brachycybe nodulosa, males curl their bodies around egg masses on the undersides of decaying logs. Male‐removal experiments in the laboratory strongly suggest that males defend the eggs against fungal infection. Orphaned eggs were soon covered by hyphae and no eggs hatched, whereas almost all eggs brooded by males successfully hatched. The egg‐brooding males showed no aggressive responses when disturbed. Only some mature males bred in the field. Furthermore, the number of eggs brooded varied greatly among the males. Selected generalized linear models revealed that males with a wide seventh body segment, which possesses gonopods (genital legs), tended to succeed in brooding; and males with a wider body also obtained more eggs. Colony attributes had no significant effects on male brooding. We discuss the possible sexual selection mechanisms that could accomplish this pattern of brooding success among male B. nodulosa.

Adjustment of brood care behaviour in the absence of a mate in two species of Nicaraguan crater lake cichlids

In many taxa, parental strategies can vary among individuals. This is especially true in species with biparental care, with males, more often than females, deserting their mates. While there is an abundance of theoretical predictions and empirical data on factors inducing mate abandonment by males, much less is known about what consequences this may have on female behaviour, particularly in the field and in non-avian systems. Here, we compared brood defence rate, behavioural defence types, and brood success of solitary and paired females in two species of Neotropical cichlid fish in their natural habitat. In terms of the rate of territorial aggression towards potential brood predators, solitary females were able to fully compensate in the absence of a male but, in so doing, ended up maintaining smaller territories, which appeared to compromise offspring fitness in at least one of the two species. Hence, our results suggest that even extensive quantitative compensation in parental effort by solitary females may not be enough to ensure adequate qualitative compensation for the lack of male participation, highlighting the importance of distinguishing between these two aspects of compensatory parental care.

The post‐fledging period in a tropical bird: patterns of parental care and survival

How environmental conditions affect the timing and extent of parental care is a fundamental question in comparative studies of life histories. The post‐fledging period is deemed critical for offspring fitness, yet few studies have examined this period, particularly in tropical birds. Tropical birds are predicted to have extended parental care during the post‐fledging period and this period may be key to understanding geographic variation in avian reproductive strategies. We studied a neotropical passerine, the western slaty‐antshrikeThamnophilus atrinucha, and predicted greater care and higher survival during the post‐fledging period compared to earlier stages. Furthermore, we predicted that duration of post‐fledging parental care and survival would be at the upper end of the distribution for Northern Hemisphere passerines. Correspondingly, we observed that provisioning continued for 6–12 weeks after fledging. In addition, provisioning rate was greater after fledging and offspring survival from fledging to independence was 75%, greater than all estimates from north‐temperate passerines. Intervals between nesting attempts were longer when the first brood produced successful fledglings compared to nests where offspring died either in the nest or upon fledging. Parents delayed initiating second nests after the first successful brood until fledglings were near independence. Our results indicate that parents provide greater care after fledging and this extended care likely increased offspring survival. Moreover, our findings of extended post‐fledging parental care and higher post‐fledging survival compared to Northern Hemisphere species have implications for understanding latitudinal variation in reproductive effort and parental investment strategies.

Annual Precipitation Affects Reproduction of the Southern Grey Shrike (Lanius meridionalis)

Abstract We studied the breeding ecology of the Southern Grey Shrike (Lanius meridionalis) at the Shezaf Nature Reserve, Arava Valley, Israel, an extremely arid desert with mean annual rainfall of 30 mm. We color-banded 128 shrikes during 2007–2009. The breeding season lasted from late February until late June. We found 34 nests and a correlation between years with amount of precipitation and number of breeding pairs. Second broods after successful broods were found only in 2007 and were all unsuccessful. Most nests were in Acacia trees; pairs that nested in dry trees, lacking foliage, were more likely to fail. The average clutch size was 3.44; average number of nestlings was 1.95; and average number of nestlings that fledged was 1.24. These results are lower than other studies of the species, probably a result of the scarcity of food in the arid environment. Nest survival rate was higher during incubation than during rearing of nestlings (0.71vs. 0.62), and total nest survival was 44.5%. The arid Arava V...

Reproduction Parameters of the Great BitternBotaurus stellarisin the Fish Ponds of Eastern Poland

Reproduction of the Great Bittern Botaurus stellaris was studied in fishponds in eastern Poland from 2003 to 2009. Study areas were surveyed from March to early July, and the booming period of the Great Bittern was from March to July, varying between 58 to 108 days. The start of booming activity was linked to climatic factors. We visited 143 active nests in the study population, with the majority of females starting to lay eggs at the end of April to the beginning of May. The mean clutch size was 4.8 ± 0.8 (n = 109, range 1–6). There was no significant difference in clutch size between years or within years as the season progressed. Hatching success was high 92% (n = 78 broods). For all years of the study the breeding success (measured as a proportion of successful broods to all broods) was 51% (n = 120). The mean number of fledglings (15-days old chicks) per breeding female was 1.5 (SD ± 1.7, n = 116) and the mean number of fledglings per successful female was 3.0 (SD ± 1.2, n = 58). The main mortality factor for eggs and nestlings was mammalian predation. The high breeding parameters obtained for this population were probably due to extensive fish management and the good and stable food resources in the fishponds surveyed. Long-term monitoring and study of the population structure and breeding parameters of the Great Bittern in relation to known environmental factors are an essential tool for the conservation and management plans for this threatened species.

Structural peculiarities of the penis of Semibalanus balanoides (Linnaeus, 1767) and Chthamalus stellatus (Poli, 1791) (Crustacea: Cirripedia: Thoracica)

We present an electron microscopical study of peculiar structures that appear during the growth and degeneration of the penis in some thoracican barnacles. In Semibalanus balanoides, a species with only one brood per year, special elongate processes develop on the solid cuticle of the growing penis. These processes form several layers that reach their maximum number during the copulatory period and subsequent period of degeneration. This hitherto undescribed structural complexity of the cuticle combines mechanical strength with flexibility. We also detected a small triclinic crystal in the longitudinal muscles of the degenerating penis, close to the sarcoplasmic reticulum. TEM lattice-plane images, the corresponding selected-area TEM diffraction patterns, and Fourier transformation of these patterns revealed that the crystal parameters differ from those of any other biocrystal described so far. In places, its unit cells adjoin the membranes of the sarcoplasmic reticulum; therefore, we suspect that the crystal may be lipoprotein. Two types of giant mitochondria can be distinguished in the muscles of the degenerating penis. One type is multilobed, and sections of differently orientated cristae within the dense matrix indicate an origin by the fusion of several single mitochondria. The other type is rounded and paracrystalline. So far it has only been observed in Chthamalus stellatus, a species with successive broods in a year.

Parental Attendance and Brood Success in American Oystercatchers in South Carolina

Abstract. Research on breeding American Oystercatchers has focused on identifying factors that affect reproductive success but little attention has been paid to parent behavior during chick-rearing. Parental attendance of American Oystercatchers was measured in Bulls Bay and along the Atlantic Intracoastal Waterway (Waterway) within the Cape Romain Region, South Carolina, USA, during 2006. Parental attendance rates averaged 90.9% in Bulls Bay and 81.4% along the Waterway. Daily survival of chicks was higher in Bulls Bay (0.989 ± 0.007) compared to the Waterway (0.966 ± 0.012). The extent of shellfish reefs (i.e. foraging areas) adjacent to nest sites was greater in Bulls Bay (5,633 ± 658 m2) compared to the Waterway (3,273 ± 850 m2). Mean parental attendance in Bulls Bay was higher for successful broods (90.5%) compared to failed broods (79.8%). In contrast, mean parental attendance along the Waterway was higher for failed broods (93.4%) compared to successful broods (67.5%). Less extensive shellfish reef...

Brood overlap and male ornamentation in the double-brooded barn swallow

Brood overlap can be an optimal solution to the intraseasonal trade-off in the allocation of time between successive broods. In line with life-history theory, the extent of brood overlap should be adjusted according to the individual costs and benefits of the simultaneous investment into 2 broods. Phenotypic quality can affect these costs and benefits. In barn swallows (Hirundo rustica), male tail streamer length is a phenotypic quality trait, which is related to reproductive decisions, resulting in pairs with long-tailed males showing higher annual output than those with short-tailed males. We predict that the extent of brood overlap in barn swallows is positively associated with the male’s tail ornamentation. Using radiotelemetry, we assessed the duration of postfledging care and juvenile survival and quantified brood overlap with unprecedented accuracy. Broods of pairs with highly ornamented males overlapped to a larger extent than those of pairs with short-tailed males. Brood overlap depended on the reproductive value of the previous brood and on female phenotypic quality. Clutch initiation after a short interbrood interval was associated with a great brood overlap. Short duration of postfledging care but not brood overlap reduced fledgling survival in first broods, and earlier second broods were associated with enlarged clutches. Thus, pairs with long-tailed males managed to increase clutch size and survival of the second brood by an early onset without incurring survival costs in the first brood. This is in line with the hypothesis that brood overlap enforces differential annual reproductive output among individuals varying in phenotypic quality.

Detecting points as developmental delay based on the life-history development and urosome deformity of the harpacticoid copepod, Tigriopus japonicus sensu lato, following exposure to benzo( a)pyrene

To identify ecotoxicological responses to an endocrine disrupter, benzo( a)pyrene, we examined the life-history of the harpacticoid copepod, Tigriopus japonicus sensu lato. Based on the life-history of copepods, survival rate of nauplii (NSR) and copepodites (CSR), copepodite emergence day (CED) and adult male emergence day (AMED), sex ratio (MER), brooding success rate (BSR), and first brooding day of adult females (FBD) were measured. Significant differences were observed in the survival and development of nauplii (NSR and CED) and sex ratio (MER) of exposed and non-exposed copepods. Moreover, high concentration of BaP can be lethal to copepodite and exhibited a delay of growth. In this study, the CED and AMED among ecotoxicological response based on life-history developments were delayed and the body characteristics decreased in response to exposure to benzo( a)pyrene. The dwarfism and urosome deformity of the T. japonicus s.l. was exhibited in response to chemical exposure. Specifically, the body characteristics and biomass of dwarf copepods that had been exposed to benzo( a)pyrene were 30% and 50% lower than the control group, respectively. The incidence of abnormal urosomes was divided into two types. The first deformity type was signs of shrinkage in the middle of the urosome or the entire urosome was narrower than those of the control organisms. In the second type, the anal somite and the distal side of the urosome had abnormally swelled. Taken together, the nauplii and copepodid development of T. japonicus s.l. can be used as a useful biomaker for detecting developmental delay based on their entire life-history. In addition, the urosome deformity was used a good potential monitoring tool invading various chemicals and environmental contamination into water system.

Markov chain estimation of avian seasonal fecundity

Avian seasonal fecundity is of interest from evolutionary, ecological, and conservation perspectives. However, direct estimation of seasonal fecundity is difficult, especially with multi-brooded birds, and models representing the renesting and quitting processes are usually required. To explore the consequences of modeling decisions on inference about avian seasonal fecundity, we generalize previous Markov chain (MC) models of avian nest success to formulate two different MC models of avian seasonal fecundity that represent two different ways to model renesting decisions and breeding cessation. We parameterize both Markov chains (regular and absorbing) for two species (Eastern Meadowlark, Sturnella magna, and Dickcissel, Spiza americana) and compare the results using mean-square error of the estimated number of successful broods per breeding female. We also provide formulae for estimating the expected variation in female breeding success. The absorbing MC performed better for both species, although the regular MC performed almost as well when the duration of the breeding season was estimated by taking the 95th percentile of a negative binomial distribution fit to the observed durations among all females. In their simplest form the models contain very few parameters (four or five) and should also prove useful as a foundation for more complex models of avian seasonal fecundity and demography.

Use of the Sterile Male Technique to Investigate Sperm Competition, Storage, and Use in a Pill Box Crab, Halicarcinus Cookii (Brachyura: Hymenosomatidae)

Halicarcinus cookii is a small intertidal New Zealand crab that has high levels of ovigerous females in all months. Continuous breeding requires continuous mating. Mating is not linked to moulting because the pubertal moult is terminal. Spermathecal fullness is modelled in terms of the difference between the rates of copulation and rates of brood production. It is estimated that females can fill their spermathecae with sperm after 3-4 copulations (depending on male size) and that approximately 15% of an ejaculate is used to fertilize each brood. Given the fact that females have multiple partners we asked the question: is it worthwhile for males to spend any time mate guarding? Using sterile males we showed that the majority of each brood is sired by the last male to mate. In females prevented from mating again, more of each successive brood is likely to be sired by earlier males who had mated with the female. This suggests that over periods exceeding one brood cycle (i.e., months) sperm slowly becomes mixed. Therefore, it is worthwhile for male H. cookii to invest time in guarding female partners.

Brooding behaviour and reproductive success in two species of free-living simultaneous hermaphrodites

Although polyclads are amongst the most structurally simple of the triploblastic metazoans, they adopt a wide range of reproductive strategies. Parental care behaviour in this group is yet to be quantified for any species. We assessed the significance of brooding behaviour to the reproductive success of two free-living marine flatworms. Echinoplana celerrima and Stylochus pygmaeus were collected from the field and placed in pairs in containers of filtered seawater where they laid batches of eggs. Both parents were then removed from half of the containers and the brooding behaviour and hatching success of eggs were quantified. There were interspecific differences in brooding behaviour. Egg masses were covered by one E. celerrima parent for 12 ± 2% of time, whereas egg masses of S. pygmaeus were covered by one or both parents simultaneously for 85 ± 8% of time. Egg batches were abandoned by both species immediately prior to the onset of hatching (10–12 days). Hatching success was generally high (~90%) and brooding did not enhance the hatching success of eggs. We assessed the significance of parental care to hatching success of E. celerrima egg masses in the presence of three potential egg predators; in the presence of other organisms. E. celerrima devoted less time to brooding; however, hatching success was not affected. The amount of time spent brooding eggs differed greatly between the two polyclad species but was not essential to their reproductive success under benign conditions. Parental care may be of adaptive value under more stressful environmental conditions commonly experienced in estuarine environments such as lowered salinity, increased hypoxia or turbidity. Covering egg batches may play an additional role of advertising sexual status and a willingness to care for eggs.

Genetics of inbred Drosophila melanogaster

In two inbred lines of Drosophila melanogaster, marker genes had been induced (y, wa, ex, v and f in Oregon, code “2”; and w in Karsnäs, code “K”). As well as the two original lines, two derived lines with mutual exchange of cytoplasm and genome were obtained by more than 40 generations of back-crossing of reciprocal hybrids to males from the paternal line. Both XX and XXBsYy + females were available from the four lines. Isogenic hybrids with mothers from the two original and the two derived lines were tested for recombination in the y-cx-v-f regions. Simultaneous comparisons were made between hybrids from XX mothers and both XX and XXY daughters of XXY mothers. There was no difference between the two groups of XX females. In the distal region, y-ex, there was in all tests an increasing frequency of recombination over successive broods with the pattern influenced by the maternal genotype, the origin of the cytoplasm and the presence of an extra Y-chromosome. The median region, cx-v, showed a tendency towards decreasing recombination, with some influence exerted by the cytoplasm. The sub-proximal region, v-f, showed a slight tendency towards decreasing frequencies, in early broods related to the maternal genotype. The XXY females had lower frequencies than XX females. – It was shown that the Y-chromosome in XXY hybrids had, in all four combinations, a tendency to be included in the same nucleus as the centromere of the “K”-line more often than randomly. The similarity in the increasing frequency of recombination in the distal region, y-ex, in regular and secondary non-disjunction exceptionals as well as the decreasing frequencies of both recombination in the v-f region in XXY females and secondary non-disjunction are discussed.

Genetics of inbred Drosophila melanogaster XXIV. Effects on the strength of the M-type

Several branches with genome from either of two inbred lines of Drosophila melanogaster, introduced into various sources of cytoplasms, were used in tests of the strength of the M-type. In contrast to the conventional tests of dysgenesis, we examined primary non-disjunction and chromosome loss in successive broods from M/P hybrid females. In broods from the 2nd week of egg-laying, there were increased frequencies of X0-males and a strong depression of fertility. There were no indications of cytoplasmic influence on the M-type. In a third line with the same cytoplasm as in a couple of the above mentioned ones, there was a lower effect on chromosome loss and on fertility. Crosses between different genotypes, but with the same source of cytoplasm, suggested a delayed genic influence in maternal inheritance. Tests of recombination in the X-chromosome indicated a gradual depression from the mid part to the distal end. There seemed to be no genic effect on the depression of recombination. It is suggested that there are pleiotropic effects of the P-factors and that the response to the various processes could be under both genic and cytoplasmic control in the M-type females.