scholarly journals Multiple nesting attempts and long breeding seasons of Mimus gilvus (Aves: Mimidae) in southeastern Brazil

2019 ◽  
Vol 36 ◽  
pp. 1-8 ◽  
Author(s):  
Rodrigo Morais ◽  
Luiz Carlos Araújo ◽  
Gleidson Ramos Silva ◽  
Charles Duca

This study describes aspects of the life history of the Tropical MockingbirdMimusgilvus(Vieillot, 1808), including the breeding period, clutch size, nestlings and a list of plants used for nesting. Nests were monitored in an area of Restinga (sand-coastal plain) habitat in a protected area in southeastern Brazil. The data from 181 nests during five breeding seasons (2010-2014) showed that the Tropical Mockingbird has a long breeding season (26.1 ± 2.6 weeks) with up to two peaks of active nests from August to March. The breeding pairs made up to four nesting attempts in the same breeding season. The mean (± SD) clutch size was 2.4 ± 0.6 eggs (n = 169). The mean (± SD) incubation period was 14 ± 0.6 days, and the nestling remained in the nest for 14.5 ± 2.2 days. The nests were built on thirty plant species, andProtiumicicariba(DC.) Marchand. was the plant species most commonly used for nesting. The breeding parameters of the Tropical Mockingbird are similar to those of other Mimidae species. The knowledge gained from this study makes the Tropical Mockingbird a good choice for future studies, particularly for testing ecological and evolutionary hypotheses regarding life history attributes, habitat selection and parental investment.

2018 ◽  
Vol 35 ◽  
pp. 1-10 ◽  
Author(s):  
Hermes Daros ◽  
William Barbosa Dutra ◽  
Charles Duca

Existing knowledge of the breeding success and life history characteristics of most Neotropical bird species is scarce. Here, we help fill this gap by analyzing aspects of the breeding biology of the Tropical Kingbird Tyrannusmelancholicus (Vieillot, 1819), which is a good model for this kind of study as it is a common species occurring in various environments, including urban areas, but little is known about its life history. We provide results concerning the breeding period, clutch size, incubation and nestling periods, description of nests, eggs and nestlings, and the plants used for nest sites by this species. Fifty-four nests were monitored over two seasons (2012–2014) in a protected area in southeastern Brazil. Nesting began at the end of the dry season and the beginning of the rainy season. The frequency of active nests varied according to variations in rainfall for each breeding season analyzed. The means and standard deviations of the incubation period (14.2 ± 1.9 days), nestling period (15.1 ± 0.8 days) and clutch size (2.5 ± 0.7 eggs) were similar to values reported for other Neotropical passerines. Twenty-one plant species used as nest trees and for the construction of the nests were identified. The results show that T.melancholicus is not highly selective when choosing plant species used for nest construction.


2021 ◽  
Vol 61 ◽  
pp. e20216184
Author(s):  
Jairo José Zocche ◽  
Fernando Carvalho ◽  
Ariovaldo Pereira Cruz-Neto

Cinclodes pabsti is an endemic passerine restricted to the highland areas in southern Brazil. The aim of this study was to provide information on its breeding biology. The nesting cavities along road cuts were monitored from May 2008 to March 2011. The survey was carried out monthly from May to July 2008, February to July 2009, 2010 (non-breeding season), weekly from August 2008 to January 2009, 2010 (breeding season), and on a 2 to 4-days basis from August 2010 to January 2011. The geographic location, physical characteristics, and soil/substrate type in which the nesting cavities were situated were recorded. The total number of cavities used in the three breeding seasons was 136, resulting in 295 nests. The distance of a nest to its nearest neighbor ranged from 24-2,368 m, with a higher number of nests (n = 34; 59.7%) in the distance interval of 24-500 m. There was a greater usage of cavities located in Inceptisols, and the distances of nesting cavity entrances to the ground and to the top of road cuts were 1.6 ± 0.9 m and 0.8 ± 0.62 m, respectively. The breeding season lasted 148 days from mid-August to early January. Clutch size (n = 256) varied from 2 to 3 eggs, and the eggs (n = 155) had a total length of 27.2 ± 1.3 mm, breadth of 20.9 ± 0.8 mm, and mass of 6.2 ± 0.7 g. The incubation phase lasted 17.3 ± 0.8 days and the nestling phase for 18.3 ± 1.5 days. The body mass of the chicks was 6.0 ± 1.0 g just after hatching and reached a maximum of 59.6 ± 2.4 g at 16 days of age. Our results can contribute to filling the gaps in knowledge of C. pabsti ecology, because its habitat is under high anthropic pressures and the information on its life history is yet limited.


2015 ◽  
Vol 42 (2) ◽  
pp. 169-181
Author(s):  
Md Lokman Hossain ◽  
Shorab Uddin Sarker ◽  
Noor Jahan Sarker

This study was conducted to determine the breeding season, gonad development, egg laying period, clutch size and other biological aspects of Bengal Eyed Turtle, Morenia petersi of Bangladesh. The egg-laying period was found between November and February. The nesting sites were elevated fallow lands in secluded areas. The female turtle laid all the mature eggs at a time for each clutch at night. A gravid female turtle laid two clutches of eggs in each breeding season and the mean clutch size was 9.7 ± 1.5 eggs and mean weight of each egg was 8.9 ± 1.3 g. The eggs are elongated in shape and whitish in colour. The mean incubation period was 119 ± 30 days. The incubation period of first clutch was the longer than the second clutch. The hatchlings emerged out between April and May. Hatchery success was found 56.8%. The percentage of weight gain and specific growth rate (SGR) by weight of hatchlings in the first year was greater than second and third year. Present investigation was made to explore the possibility to raise turtle farming in captive condition.Bangladesh J. Zool. 42(2): 169-181, 2014


The Auk ◽  
1978 ◽  
Vol 95 (2) ◽  
pp. 235-246 ◽  
Author(s):  
Clara L. Dixon

Abstract I studied the breeding biology of the Savannah Sparrow (Passerculus sandwichensis) on Kent Island, New Brunswick, Canada from 1964 through 1968. I estimated the breeding population to be 125-135 pairs $(412-445\ \text{individuals}/{\rm km}^{2})$. The mean number of nests produced per female, including those destroyed by predators, was 2.97. Clutch size ranged from 2 to 5. The mean clutch size based on 1,142 eggs in 284 nests of known clutch size was 4.02. Not only was the four-egg clutch most numerous but a greater percentage of eggs in the four-egg clutches hatched and the mean number of young fledged per nest was also highest. The mean incubation period was 12.2 days, the mean duration of nestling life was 9 days, and the approximate length of the breeding season as 52 days. The daily mortality rate of eggs was 11.9% and of nestlings 2.1%. Predation was the major factor affecting reproductive success; 50.5% of all nests located were destroyed by predators. The main nest predators were Common Crows and Herring Gulls. Of the nests destroyed by predators, 87.8% contained eggs rather than nestlings. The intense predation necessitated high nest replacement. The mean interval between the termination of one nest and the appearance of the first egg in the succeeding nest was 6.3 days. If successive nests are destroyed on the day incubation begins, it is hypothetically possible for a pair to produce four nests during a single breeding season; many birds in the population produce at least three. Although enough time was available for birds to fledge two broods in a season, few of them fledged more than one. Thus, the nesting success was low (success from egg to hatching 18.1%). High nest replacement compensated for high egg mortality, and an average of 2.16 young per pair were fledged per season.


2014 ◽  
Vol 8 (2) ◽  
pp. 113-122 ◽  
Author(s):  
Hasber Salim ◽  
Hafidzi Mohd Noor ◽  
Dzolkhifli Omar ◽  
Noor Hisham Hamid ◽  
Mohd Rizuan Zainal Abidin ◽  
...  

Abstract This study investigated the effects of the first generation anticoagulant rodenticide chlorophacinone and the second generation rodenticide bromadiolone on the population and breeding performances of barn owls at oil palm plantations. Three treatment plots were established: one baited with chlorophacinone, one with bromadiolone, and the third kept rodenticide-free. Four rat-baiting campaigns which coincided with barn owl breeding season were carried in the rodenticide-treated plots. The occupancy rate of nest boxes, clutch size, brood size and fledging rates of the barn owls in each plot were monitored weekly throughout the study. Freshly regurgitated pellets from barn owls were collected from all occupied nest boxes at weekly intervals during the development of nestlings in each breeding season. The results show that the occupancy rate of the nest boxes was significantly higher in the rodenticide-free area compared with both rodenticide-treated areas. Similarly, the breeding performances, such as clutch size, brood size and fledging success, were higher in the rodenticide-free area compared with the rodenticide-treated areas. Results of high performance liquid chromatography (HPLC) analysis showed that 20.56% (mean residue: 1 .335 ± 0.073 lg/g) and 28.89% (mean residue: 0.777 ± 0.032 lg/g) of the collected regurgitated pellet samples from the rodenticide-treated areas contained bromadiolone and chlorophacinone residue, respectively. The mean brood size and fledging success of the barn owls showed a strong negative correlation with the mean concentration of rodenticide residues present in the regurgitated pellets and with the percentages of pellets detected having such residues (R2 k 0.44, P < 0.05). Similarly, the mean clutch size of barn owls was negatively correlated with the mean concentration of rodenticide residues and with the percentages of pellets detected with these residues. However, the correlation was not significantly different (R2 k 0.34, P > 0.05). In general, the higher the amount of residues detected, the lower the breeding performance parameters measured in this study


2011 ◽  
Vol 101 (1-2) ◽  
pp. 61-64 ◽  
Author(s):  
Conrado A. B Galdino ◽  
Monique Van Sluys

We studied life history traits of females of the lizard Eurolophosaurus nanuzae (Rodrigues, 1981), an endemic species of rock outcrop habitats in southeastern Brazil. During October 2002 and 2003 we sampled three populations in sites that encompass the meridional portion of the geographic range of the species. Clutch size varied from one to three eggs, with most females carrying two eggs. Clutch size did not vary among populations, but was correlated to female body size. Only larger females produced clutches of three eggs. Females of the small-sized E. nanuzae produce eggs as large as those of medium-sized tropidurids, thus investing a considerable amount of energy to produce clutches resulting in high values of relative clutch mass.


1991 ◽  
Vol 21 (6) ◽  
pp. 813-820 ◽  
Author(s):  
Donald L. Copes ◽  
Richard A. Sniezko

Reproductive bud phenology from 1983 through 1989 limited potential outcross efficiency to a maximum of 58 to 87%, in a Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) clonal orchard near Monmouth, Oregon. Potential outcross efficiency was calculated for 20 clones from dates of male and female bud opening and pollination mechanism information. Cool weather before bud opening of the earliest clones delayed and compressed the breeding period and resulted in a greater percentage of trees having synchronous periods of pollen release and receptive seed strobili. Length of breeding season among years averaged 20 days and ranged from 16 to 27 days. Differences in phenology significantly impacted the breeding system because the overall breeding period of the orchard clones exceeded the 8-day receptive period of individual clones by two or three times and often prohibited or limited potential outcrossing between the earliest and latest clones. Outcrossing was greatest in clones with intermediate phenology and least in the earliest clones. The breeding system appears to be an almost continuous series of overlapping breeding subpopulations. Each year's breeding subpopulations were different from those of other years because of large shifts in rank order of bud opening by 10 to 20% of the clones and because of great differences in the length of breeding season. Average temperature during March was linearly associated with time of floral bud opening. Geneticists may be able to use average temperature of the 4-week periods prior to opening of the earliest floral buds as a tool to identify seed crops formed during years with compressed breeding seasons. Such seed crops have potential of being more diverse than do seed crops produced during years with extended breeding seasons. Use of procedures in this report will allow tree-improvement workers to calculate the maximum outcross efficiency of each seed crop produced by their orchards.


2009 ◽  
Vol 36 (4) ◽  
pp. 289 ◽  
Author(s):  
Michael A. Weston ◽  
Glenn C. Ehmke ◽  
Grainne S. Maguire

An understanding of space use and dispersal of a wildlife species is essential for effective management. We examined the movements of a beach-dwelling, threatened population of hooded plover (Thinornis rubricollis) in southern central Victoria, Australia, by analysing sightings of colour-banded birds (4897 sightings; 194 birds tracked for up to 9 years). Most movements were relatively short (5050 ± 305 m), with 61.4% <1 km and 95.3% <20 km; they lacked directional or sexual bias. The extent of coastline used by individual birds was 47.8 ± 58.0 km. Regional differences in average distances moved by adults were apparent. For adults, movement rates (mean distance per day) were higher during the non-breeding season than during the breeding season. Non-breeding adults generally remained close to their partners (non-breeding, 456.3 ± 163.9 m; breeding, 148.2 ± 45.3 m). Largest flock sizes were recorded during the non-breeding period, and flocking was not uniformly distributed along the coast but appeared to be concentrated in particular locations. The frequency of pair cohesion (i.e. when the distance between partners was zero on a given day) was similar during the breeding (69.6%) and non-breeding seasons (67.7%). Breeding territories (kernel analysis) were 36.7 ± 5.7 ha and overlapped from year to year in all cases (23 pairwise comparisons; 47.9 ± 7.1% overlap). The high fidelity and constancy of territories confirms they warrant ongoing management investment, although the species relies on a matrix of breeding and non-breeding sites. The latter appear to occur in specific parts of the coast and warrant enhanced protection and more research attention. Fragmentation of the breeding population might occur where habitat is rendered unsuitable for > ~50 km.


2001 ◽  
Vol 28 (2) ◽  
pp. 165 ◽  
Author(s):  
Craig Miller ◽  
Mike Elliot ◽  
Nic Alterio

The home range of stoats (Mustela erminea) was determined as part of a programme to protect Okarito brown kiwi chicks (Apteryx australis) ‘Okarito’, from predation. Twenty-seven stoats were fitted with radio-transmitters and tracked in two podocarp (Podocarpaceae) forests, in south Westland, New Zealand, from July 1997 to May 1998. Home-range area was determined for 19 animals by minimum convex polygons and restricted-edge polygons, and core areas were determined by hierarchical cluster analysis. The mean home ranges of males across all seasons calculated by minimum convex polygon (210 28 ha ( s.e.)) and restricted-edge polygon (176 29 ha) were significantly larger than those of females across all seasons (89 14 ha and 82 12 ha). The mean home range of males calculated by minimum convex polygon during the breeding season (256 38 ha) was significantly larger than the mean home range pooled across the non-breeding seasons (149 16 ha), whereas that calculated by restricted-edge polygon was not significantly different. The mean home range of females during the breeding season was not significantly different from that in the non-breeding seasons when estimated by either method. Overlap of home ranges was observed within and between sexes in all seasons, with the greatest proportion of home range overlap being male–female. The mean home range of females in spring and summer is used to guide the spacing of control stations.


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