scholarly journals Double-brooding and annual breeding success of great tits in urban and forest habitats

2021 ◽  
Author(s):  
Boglárka Bukor ◽  
Gábor Seress ◽  
Ivett Pipoly ◽  
Krisztina Sándor ◽  
Csenge Sinkovics ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Urban Areas ◽  
Reproductive Output ◽  
Parus Major ◽  
Natural Habitats ◽  
Forest Sites ◽  
Habitat Differences ◽  
Double Brooding ◽  
Breeding Seasons ◽  
Forest Habitats

Abstract Urban areas differ from natural habitats in several environmental features that influence the characteristics of animals living there. For example, birds often start breeding seasonally earlier and fledge fewer offspring per brood in cities than in natural habitats. However, longer breeding seasons in cities may increase the frequency of double-brooding in urban compared to non-urban populations, thus potentially increasing urban birds’ annual reproductive output and resulting in lower habitat difference in reproductive success than estimated by studies focusing on first clutches only. In this study, we investigated two urban and two forests great tit Parus major populations from 2013 to 2019. We compared the probability of double-brooding and the total number of annually fledged chicks per female between urban and forest habitats, while controlling for the effects of potentially confounding variables. There was a trend for a higher probability of double-brooding in urban (44% of females) than in forest populations (36%), although this was not consistent between the two urban sites. Females produced significantly fewer fledglings annually in the cities than in the forest sites, and this difference was present both within single- and double-brooded females. Furthermore, double-brooded urban females produced a similar number of fledglings per season as single-brooded forest females. These results indicate that double-brooding increases the reproductive success of female great tits in both habitats, but urban females cannot effectively compensate in this way for their lower reproductive output per brood. However, other mechanisms, like increased post-fledging survival can mitigate habitat differences in reproductive success.

Influence on the variation in initiation of breeding in Peromyscus maniculatus

1991 ◽  
Vol 69 (3) ◽  
pp. 698-705 ◽  
Author(s):  
Sean T. Sharpe ◽  
J. S. Millar
Keyword(s):  
Reproductive Success ◽  
Peromyscus Maniculatus ◽  
Nest Site ◽  
Subalpine Forest ◽  
Stream Beds ◽  
Timing Of Initiation ◽  
Overwinter Mortality ◽  
Breeding Seasons ◽  
The Relationship ◽  
Forest Habitats

Correlates of the initiation of breeding by female Peromyscus maniculatus borealis (Mearns) were examined to test the hypotheses that asynchronous breeding was related to age, weight, matriline, and nest-site habitat. Life-history data were collected by mark–recapture techniques and by monitoring natal nests over two breeding seasons in 1985 and 1986. Timing of initiation of breeding was related significantly to nest-site habitat and age, but not to matriline or weight. At approximately the same altitude, females nesting in dry rocky stream beds bred first, followed by those in open rock fields, then shrub areas, and last in subalpine forest. Youngest animals bred first in all habitats, although the relationship between age and initiation date was weak. Habitat effects appeared to be primarily related to microclimatic effects. The influence of habitat on the timing of initiation of breeding also had consequences for reproductive success, total reproductive output, and survival. Reproductive success of first litters was greatest for females nesting in rocky stream beds in the spring and least for females nesting in shrub and forest habitats. The apparent advantages of early breeding in rocky stream beds were offset by greater overwinter mortality.

Clutch parameters and reproductive success of a translocated population of red-crowned parakeet (Cyanoramphus novaezelandiae)

2008 ◽  
Vol 56 (6) ◽  
pp. 389 ◽  
Author(s):  
Luis Ortiz-Catedral ◽  
Dianne H. Brunton
Keyword(s):  
Reproductive Success ◽  
Clutch Size ◽  
Brood Size ◽  
Reproductive Output ◽  
Hatching Success ◽  
Natural Populations ◽  
Reproductive Potential ◽  
Breeding Pair ◽  
Brood Rearing ◽  
Breeding Seasons

At least four populations of the red-crowned parakeet (Cyanoramphus novaezelandiae) have been established via translocation within New Zealand over the last 40 years, but reproductive parameters of these populations have not been documented. We quantified differences in clutch parameters and reproductive success for a translocated population of this species on Tiritiri Matangi Island over two breeding seasons. Overall clutch parameters and estimates of reproductive success were consistent with reported values from natural populations. However, we found previously unreported differences in clutch size, hatching success and brood size between breeding seasons. The number of fledglings produced per breeding pair increased significantly from 1.4 to 3.4 fledglings during our two-year study. In contrast, egg volume and fertility per clutch did not vary during the same period. Overall, 7 eggs were laid per breeding pair but only 2.22 nestlings fledged, representing a 63.8% loss of initial reproductive potential. Losses during the incubation stage were caused by partial and total hatching failure, whereas starvation of nestlings caused all losses during the brood-rearing stage. Hatching success during our study was lower than that reported for wild populations of this and other parrot species, and remained lower even during the most productive breeding season. We found no cases of predation on eggs or nestlings during our study despite the presence of native and exotic avian predators on Tiritiri Matangi Island. We show that clutch size, brood size and changes in loss between breeding seasons are determinants of reproductive output in translocated red-crowned parakeet and also that reproductive output can vary greatly between breeding seasons. Finally, if reduced hatching success is the result of small founder size, management of parakeets should consider the movement of larger and more genetically diverse flocks.

scholarly journals Does offspring sex ratio differ between urban and forest populations of great tits (Parus major)?

2020 ◽  
Author(s):  
Nóra Ágh ◽  
Ivett Pipoly ◽  
Krisztián Szabó ◽  
Ernő Vincze ◽  
Veronika Bókony ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Parus Major ◽  
Egg Laying ◽  
Urban Life ◽  
Male Offspring ◽  
Molecular Sexing ◽  
Natural Habitats ◽  
Offspring Sex Ratio ◽  
Nestling Development ◽  
Forest Habitats

SummarySince male and female offspring may have different costs and benefits, parents may use sex ratio adjustment to increase their fitness under different environmental conditions. Urban habitats provide poorer conditions for nestling development in many birds. Therefore, we investigated whether great tits (Parus major) produce different brood sex ratios in urban and natural habitats. We determined the sex of nestlings of 126 broods in two urban and two forest habitats between 2012 and 2014 by molecular sexing. We found that brood sex ratio did not differ significantly between urban and forest habitats either at egg-laying or near fledging. Male offspring were larger than females in both habitats. This latter result suggests that male offspring may be more costly to raise than females, yet our findings suggest that urban great tits do not produce more daughters despite the unfavourable breeding conditions. This raises the possibility that other aspects of urban life, such as better post-fledging survival, might favour males and thereby compensate for the extra energetic costs of producing male offspring.

The effects of an ectoparasite on reproductive success in the great tit: a 3-year experimental study

1998 ◽  
Vol 76 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Klas Allander
Keyword(s):  
Reproductive Success ◽  
Body Mass ◽  
Bird Species ◽  
Parus Major ◽  
Egg Laying ◽  
Parasite Abundance ◽  
Nest Boxes ◽  
Size Number ◽  
Social Habits ◽  
Breeding Seasons

The effects of ectoparasites on host reproductive success have been studied in a variety of bird species. Most of these studies concern either colonial or hole-nesting birds, which have been suspected of being particularly susceptible to parasites because of their social habits and (or) reuse of old nests. The effects of a horizontally transmitted flea, Ceratophyllus gallinae, on the reproductive success of hole-nesting great tits,Parus major, were experimentally studied over 3 years. Leaving nests in nest boxes in the intervals between breeding seasons does not result in a significant increase in parasite abundance in comparison with nest boxes cleaned between seasons. Flea abundance was reduced by spraying random nests with an insecticide during host egg laying. There were no significant effects of ectoparasite removal on clutch size, number of fledged young, hatching success, or fledging success in any of the 3 years, although a significant interaction between year and treatment in nestling body mass was observed. Thus, in 1 of the 3 years, body mass of nestlings in the sprayed boxes was, on average, significantly greater than that of controls. There was also a negative correlation between flea abundance and mean body mass of the brood. In addition, nestlings produced in flea-free boxes had a significantly higher probability of recruiting locally than nestlings from control nests. The effects of ectoparasites seem to vary over time and also among host populations, which implies that the effects of parasites may interact with other environmental factors.

scholarly journals A multiscale assessment of Red-tailed Hawk reproductive success relative to urban density and habitat type

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Justin H White ◽  
Jessi L Brown ◽  
Zachary E Ormsby
Keyword(s):  
Urban Areas ◽  
Urban Expansion ◽  
Habitat Type ◽  
Nesting Success ◽  
Arid Environments ◽  
Hatch Date ◽  
Urban Density ◽  
Landscape Characteristics ◽  
Suburban Areas ◽  
Breeding Seasons

Abstract Despite the unique threats to wildlife in urban areas, many raptors have established successfully reproducing urban populations. To identify variations in raptor breeding ecology within an urban area, we compared metrics of Red-tailed Hawk reproductive attempts to landscape characteristics in Reno and Sparks, NV, USA during the 2015 and 2016 breeding seasons. We used the Apparent Nesting Success and logistic exposure methods to measure nesting success of the Red-tailed Hawks. We used generalized linear models to relate nesting success and fledge rate to habitat type, productivity to hatch date (Julian day) and hatch date to urban density. Nesting success was 86% and 83% for the respective years. Nesting success increased in grassland-agricultural and shrub habitats and decreased in riparian habitat within the urban landscape. Productivity was 2.23 and 2.03 per nest for the breeding seasons. Fledge rates were 72% and 77%, respectively, and decreased in riparian areas. Nestlings hatched earlier with increased urban density and earliest in suburban areas, following a negative quadratic curve. Nesting success and productivity for this population were high relative to others in North America. Productivity increased in habitats where ground prey was more accessible. We suggest that suburban areas, if not frequently disturbed, provide sufficient resources to sustain Red-tailed Hawks over extended periods. As urban expansion continues in arid environments globally, we stress that researchers monitor reproductive output across the urban predator guild to elucidate patterns in population dynamics and adaptation.

scholarly journals Decline in the frequency and benefits of multiple brooding in great tits as a consequence of a changing environment

2009 ◽  
Vol 276 (1663) ◽  
pp. 1845-1854 ◽  
Author(s):  
Arild Husby ◽  
Loeske E.B. Kruuk ◽  
Marcel E. Visser
Keyword(s):  
Life History Traits ◽  
Parus Major ◽  
Population Level ◽  
Climatic Conditions ◽  
Long Term Study ◽  
Double Brooding ◽  
First Clutch ◽  
Second Clutch ◽  
Reproductive Events

For multiple-brooded species, the number of reproductive events per year is a major determinant of an individual's fitness. Where multiple brooding is facultative, its occurrence is likely to change with environmental conditions, and, as a consequence, the current rates of environmental change could have substantial impacts on breeding patterns. Here we examine temporal population-level trends in the proportion of female great tits ( Parus major ) producing two clutches per year (‘double brooding’) in four long-term study populations in The Netherlands, and show that the proportion of females that double brood has declined in all populations, with the strongest decline taking place in the last 30 years of the study. For one of the populations, for which we have data on caterpillar abundance, we show that the probability that a female produces a second clutch was related to the timing of her first clutch relative to the peak in caterpillar abundance, and that the probability of double brooding declined over the study period. We further show that the number of recruits from the second clutch decreased significantly over the period 1973–2004 in all populations. Our results indicate that adjustment to changing climatic conditions may involve shifts in life-history traits other than simply the timing of breeding.

scholarly journals The effect of pollen source on seed traits and dispersability in the heterocarpic annual Crepis sancta

2020 ◽  
Author(s):  
Efrat Dener ◽  
Hagai Shemesh ◽  
Itamar Giladi
Keyword(s):  
Reproductive Success ◽  
Reproductive Output ◽  
Seed Traits ◽  
Dispersal Strategy ◽  
Physiological Constraints ◽  
Dispersal Traits ◽  
Distant Neighbor ◽  
The Common ◽  
Nonsignificant Effect ◽  
Crepis Sancta

Abstract Aims The evolution and expression of dispersal-related traits are intertwined with those of other life-history functions and are manifested within various physiological constraints. Such a relationship is predicted between inbreeding levels and dispersability, which may be anatomically and ontogenetically linked so that the selection pressures on one may affect the other. While both the effect of inbreeding on reproductive success and on dispersal strategies received much attention, only a few studies considered both simultaneously. Furthermore, such studies often rely on two dichotomic representations of breeding and dispersal: using selfing vs. outcrossing as a representation of breeding level, and dispersal ratio as the sole representation of dispersal strategy. Methods Here we used pollination experiments in the heterocarpic Crepis sancta (Asteraceae) to expand in two different manners on the common practice of using dichotomic representations of breeding and dispersal. First, we used pollination treatments that represent a continuum from selfing through pollination by kin to pollination by a distant neighbor. Second, we measured a whole set of continuous morphological and dispersal-related traits, in addition to measurements of reproductive success and dispersal ratio. Important findings The proportion of developed capitula and the number of both dispersed and non-dispersed achenes were significantly lower in the self-pollination treatment in comparison to the out-crossed treatments. The effect of pollen sources on dispersal ratio was not statistically significant, though self-pollinated plants rarely produced non-dispersing seeds. Achene’s biomass increased with distance between parent plants, but pappus width did not, leading to a nonsignificant effect of pollination on falling velocity. Overall, pollen source affected mainly traits that were associated with reproductive output, but it had no clear effect on predominately dispersal-related traits. Such differences in the response of reproduction and dispersal traits to variation in pollen source suggest that dispersal-related selection is probably weak and/or masked by other forces.

Effects of forest–clearcut edges on a forest-breeding songbird

2002 ◽  
Vol 80 (6) ◽  
pp. 1026-1037 ◽  
Author(s):  
Rebecca J Harris ◽  
J Michael Reed
Keyword(s):  
Reproductive Success ◽  
Food Source ◽  
Forest Landscape ◽  
Resource Abundance ◽  
Neotropical Migrant ◽  
Dendroica Caerulescens ◽  
Forestry Practices ◽  
Forest Sites ◽  
Interior Forest ◽  
Negative Impacts

To understand local and regional changes in Neotropical migrant songbird populations it is important to determine whether forest-breeders can use and persist in the dynamic, variegated landscapes created by modern forestry practices. We made detailed observations of a species classified as a mature-forest specialist, the black-throated blue warbler (Dendroica caerulescens), adjacent to clearcut edges and in intact forest in a large industrial forest landscape. We measured reproductive success, habitat use, resource abundance, the potential for inter- and intra-specific competition, and predator densities. Unlike most studies of edge effects, our study showed both positive and negative impacts of associations with edges. We recorded a lower density of potential avian competitors within intact forest, as well as a higher proportion of older male black-throated blue warblers at interior forest sites. In addition, proportionally more fledglings were observed in intact forest. However, males at edge sites had higher pairing success and edges had higher understory density (which is positively associated with reproductive success in other studies), evidence of higher abundance of their primary food source and lower densities of diurnal egg and nestling predators. The net result of these mixed patterns is that males gaining a territory at edge or interior sites appeared to have similar probabilities of producing fledglings.

scholarly journals Comparative stages of atretic oocytes between Episesarma versicolor and E. singaporense from Thailand: Implication on the reproductive success

2020 ◽  
Vol 19 (1) ◽  
pp. 75-86
Author(s):  
Chanyut Sudtongkong ◽  
◽  
Sinlapachai Senarat ◽  
Supparat Kong-oh ◽  
Pisit Poolprasert ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Secondary Growth ◽  
Follicular Cell ◽  
Ovarian Maturation ◽  
Natural Habitats ◽  
Degenerative Process ◽  
Mangrove Area ◽  
Primary Growth

Informative reviews on the oocyte atresia referring to degeneration and resorptive mechanism are warranted in common animals, but it is rarely still found in carbs. In this current study, we focused on characteristics and stage of the atretic oocyte from two important female sesarmid carbs (violet vinegar crab, Episesarma versicolor, and Singapore vinegar crab, E. singaporense) during ovarian maturation. A total of 30 female samples in each carb species were collected from the Palian mangrove area of Trang province, Thailand. The results shared among those carb samples that both primary growth (PGs) and secondary growth (SGs) phases underwent a degenerative process of atresia. The latter of atresia during SGs was also divided into five stages (I, II, III, IV, and V). The degeneration of follicular cell and yolk architecture identifying in the SGs were highlighted. The number of atresias was slightly compared between E. versicolor and E. singaporense; therefore, there were no significant differences. Our observation suggested that the low number of atresia might be associated with the increased reproductive success of two female sesarmid carb living in natural habitats.

scholarly journals Recover and They’ll Come: Flower Visiting Bees Benefit from the Continuous of Micro-Environments Set by Regenerating Forest Fragments

Sociobiology ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 5861
Author(s):  
Ana Isabel Sobreiro ◽  
Lucas Lopes da Silveira Peres ◽  
Jessica Amaral Henrique ◽  
Rosilda Mara Mussury ◽  
Valter Vieira Alves-Junior
Keyword(s):  
Urban Areas ◽  
Environmental Changes ◽  
Climatic Conditions ◽  
Agricultural Activity ◽  
Forest Fragments ◽  
Forest Types ◽  
Continuous Forest ◽  
Flower Visiting ◽  
Bee Communities ◽  
Forest Habitats

Forest habitats are important sources of food and nesting resources for pollinators, primarily in urban areas and landscapes with intense agricultural activity. The forest fragmentation and environmental changes occurring in these green refuges are known to impose survival challenges to pollinating bees, leading to species loss. However, it is not well known how the species of bees that visit flowers are distributed in forest micro-environments. To fill this gap, we sampled flower visiting bees in a continuous forest matrix with micro-environments of two forest types (mature and regenerating forest). We examined how the local environmental changes and climatic conditions affect the composition and uniformity of bee communities in the different micro-environments. Our results indicated that both abundance and richness were similar between forest types studied here, however climatic conditions and plant flowering patterns affect the composition of bees. Thus, our results demonstrated that the continuous micro-environments can favor floral visits and the reintegration of bee communities, and still, that this strategy can be used to minimize the impacts of environmental changes at local scales.

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