Reproduction and Social Organization of the Black-Capped Donacobius (Donacobius atricapillus) in Southeastern Peru

The Auk ◽  
1984 ◽  
Vol 101 (4) ◽  
pp. 804-811 ◽  
Author(s):  
Richard A. Kiltie ◽  
John W. Fitzpatrick

Abstract A color-banded population of Black-capped Donacobius (Donacobius atricapillus) on a Peruvian oxbow lake was studied during one breeding season and censused for 3 yr thereafter. Eighteen territories along a marshy shoreline were occupied by groups of 2-4 donacobius. Each group contained a mated pair and 0-2 helpers, apparently offspring produced during 1-2 preceding breeding seasons. Helpers participated in nest surveillance, territorial displays, and feeding nestlings. Displays occurred at territory boundaries and consisted of loud duetting by the pair or group. Breeding coincided with the rainy months, October through April, and peaked in November-January. Clutch size was always two. Egg and nestling periods each lasted 17-18 days. No correlation was demonstrable between group size and overall fledging success. Trios, however, accounted for all cases in which both young successfully fledged, whereas pairs never fledged more than one young. Annual survivorship of breeding adults averaged 71%. Cooperative breeding in donacobius is associated with limited opportunities for acquiring breeding territories, as in many other cooperative breeders. The relatively short period during which young serve as helpers (and the resulting small family sizes), however, suggests that at other times or places breeding territories are more readily available to young.

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.


2004 ◽  
Vol 30 ◽  
pp. 327-329
Author(s):  
L.M. Mitchell ◽  
M.J.A. Mylne ◽  
J. Hunton ◽  
K. Matthews ◽  
T.G. McEvoy ◽  
...  

Sheep are seasonally-polyoestrous short-day breeders. Although the domesticated breeds have longer breeding seasons than the feral breeds, their maximum ovulation rates are only achieved over a relatively short period. The effect of these seasonal shifts in ovarian response on the success of ovum recovery for genetic improvement or breed conservation is unknown. The aim of the present study was to assess the efficiency of ovum recovery procedures for genetic conservation outwith the normal breeding season.


1987 ◽  
Vol 14 (3) ◽  
pp. 319 ◽  
Author(s):  
Yoram Yom-Tov

The relationships between body weight, clutch size, length of breeding season, breeding frequency, incubation and nestling periods were studied in the Australian passerines. The means of the above factors as well as allometric equations were calculated for all Australian passerines and separately for the four major families (Maluridae, Meliphagidae, Muscicapidae and Ploceidae) and six zones of distribution (all Australia; Bassian; Torresian; Torresian and Bassian; Irian; Eyrean). The mean clutch size of Australian passerines is significantly smaller than that of North African passerines. This is because the old invaders to Australia (e.g. the Meliphagidae, Maluridae and Muscicapidae) have significantly smaller clutches than the new invaders (e.g. Ploceidae and Corvidae). A significant difference in clutch size was found between the Irian and Eyrean zones, supporting an early claim by Kikkawa. Negative correlations were found between body weight and clutch size, length of breeding season and breeding frequency. These indicate that small passerines in Australia tend to have larger clutches and longer breeding seasons and to breed more frequently than larger species. Body weight is positively correlated with both incubation and nestling period, as found for other altricial birds. There are no significant differences in incubation length between the zones, but there are differences among the families. The ecological implications and the possible reasons for the above correlations and differences between the groups are discussed.


2020 ◽  
Vol 287 (1941) ◽  
pp. 20202482
Author(s):  
Emily L. Keenan ◽  
Karan J. Odom ◽  
Marcelo Araya-Salas ◽  
Kyle G. Horton ◽  
Matthew Strimas-Mackey ◽  
...  

Many animals produce coordinated signals, but few are more striking than the elaborate male–female vocal duets produced by some tropical songbirds. Yet, little is known about the factors driving the extreme levels of vocal coordination between mated pairs in these taxa. We examined evolutionary patterns of duet coordination and their potential evolutionary drivers in Neotropical wrens (Troglodytidae), a songbird family well known for highly coordinated duets. Across 23 wren species, we show that the degree of coordination and precision with which pairs combine their songs into duets varies by species. This includes some species that alternate their song phrases with exceptional coordination to produce rapidly alternating duets that are highly consistent across renditions. These highly coordinated, consistent duets evolved independently in multiple wren species. Duet coordination and consistency are greatest in species with especially long breeding seasons, but neither duet coordination nor consistency are correlated with clutch size, conspecific abundance or vegetation density. These results suggest that tightly coordinated duets play an important role in mediating breeding behaviour, possibly by signalling commitment or coalition of the pair to mates and other conspecifics.


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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jade Carver ◽  
Morgan Meidell ◽  
Zachary J. Cannizzo ◽  
Blaine D. Griffen

AbstractTwo common strategies organisms use to finance reproduction are capital breeding (using energy stored prior to reproduction) and income breeding (using energy gathered during the reproductive period). Understanding which of these two strategies a species uses can help in predicting its population dynamics and how it will respond to environmental change. Brachyuran crabs have historically been considered capital breeders as a group, but recent evidence has challenged this assumption. Here, we focus on the mangrove tree crab, Aratus pisonii, and examine its breeding strategy on the Atlantic Florida coast. We collected crabs during and after their breeding season (March–October) and dissected them to discern how energy was stored and utilized for reproduction. We found patterns of reproduction and energy storage that are consistent with both the use of stored energy (capital) and energy acquired (income) during the breeding season. We also found that energy acquisition and storage patterns that supported reproduction were influenced by unequal tidal patterns associated with the syzygy tide inequality cycle. Contrary to previous assumptions for crabs, we suggest that species of crab that produce multiple clutches of eggs during long breeding seasons (many tropical and subtropical species) may commonly use income breeding strategies.


Ring ◽  
2006 ◽  
Vol 28 (2) ◽  
pp. 119-125
Author(s):  
Michał Ciach ◽  
Dominik Wikar ◽  
Małgorzata Bylicka

Density and Flock Size of the Raven (Corvus corax) In the Orawa - Nowy Targ Basin During Non-Breeding Season During the 2002/2003-2004/2005 non-breeding seasons the density of the Raven in the open habitats of the Orawa - Nowy Targ Basin was studied by line transect method. The results were analysed in four periods (autumn, early winter, winter and early spring). The median density of Ravens did not differ significantly between individual periods and was respectively: 3.5, 3.8, 4.8 and 3.8 indiv. / 10 km. Number of birds during particular controls varied from 1.0 to 24.8 indiv. / 10 km. However, while excluding flocks, the median density of single individuals and pairs of the Raven was considerably lower and in subsequent periods reached respectively: 2.2, 2.4, 2.2 and 1.7 indiv. / 10 km. Flock size did not differ significantly between individual periods. Single individuals and, less often, groups of two birds were recorded mostly. Small (3-5 indiv.) and medium (6-15 indiv.) flocks were recorded rarely and large flocks (16 indiv. and above) - only exceptionally. The high density and strong fluctuations of abundance of Ravens were determined by flocks presence, which was probably linked to irregular occurrence of food resources.


1992 ◽  
Vol 70 (11) ◽  
pp. 2121-2124 ◽  
Author(s):  
Norman C. Negus ◽  
Patricia J. Berger ◽  
Aelita J. Pinter

From 1987 to 1989, the cohort dynamics of Microtus montanus populations were studied at two montane meadow sites approximately 160 km apart, in northwestern Wyoming. The 1987 and 1988 breeding seasons differed markedly from each other. In 1987, melt off occurred in April, and the first cohort was born in May (cohort 1). The entire breeding season was favorable owing to frequent rainfall throughout the summer. Cohort 1 animals grew rapidly and females began breeding at 4–5 weeks of age. Likewise, cohort 2 (June) animals exhibited rapid growth and females were breeding at 7–8 weeks of age. Cohort 3 (July and August) animals grew more slowly and most entered the winter as prepubertal animals of subadult size. At the end of the summer, cohort 3 animals represented >70% of the voles recruited during the breeding season. In 1988, following melt off in late April, precipitation was below normal and the situation intensified to severe drought through the summer. The growth rates of cohort 1 and 2 animals were significantly lower than 1987 growth rates, and very few females attained sexual maturity. At the end of the summer, cohort 3 animals represented <25% of the total recruitment at both study sites. Such apparent phenotypic plasticity of growth and maturation appears to be an evolved adaptive strategy that is responsive to several environmental cues. Both study sites, although widely separated, exhibited virtually identical patterns throughout the study.


Ibis ◽  
2008 ◽  
Vol 142 (1) ◽  
pp. 75-81 ◽  
Author(s):  
PRAMOD PADMANABHAN ◽  
YORAM YOM-TOV
Keyword(s):  

Author(s):  
Rachel Corney ◽  
Anne Haley ◽  
Laura Weir

Nuptial colouration in animals may serve as a signal of competitor and/or mate quality during breeding. In many temperate fishes, nuptial colouration develops during discrete breeding seasons and is a target of sexual selection. We examine nuptial colouration and behaviour of a unique ecotype of Threespine Stickleback (Gasterosteus aculeatus Linnaeus, 1758), wherein males turn from dull brown-grey to pearlescent white during the breeding season. The main goal of this work was to determine the relative role of white colouration in intersexual competition and mate choice. In a combination of a field and laboratory work, we found that males are brightest white when engaging in courtship activities in the presence of a female; this indicates that white colouration may be primarily related to enhancing signalling during mate attraction. White colouration intensity increased as the breeding season progressed and may be related to an influx of conspecifics. Colour change from cryptic grey to bright white occurred rapidly (< 90 seconds) and may be deployed to enhance behavioural signals. We conclude that bright white colouration in the white ecotype is a potential signal of mate quality and may have evolved from a previously existing capacity for colour plasticity in common Threespine Stickleback.


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