Life history of the white-breasted robin, Eopsaltria georgiana (Petroicidae), in south-western Australia

2004 ◽  
Vol 52 (2) ◽  
pp. 111 ◽  
Author(s):  
E. M. Russell ◽  
the late R. J. Brown ◽  
M. N. Brown
Keyword(s):  
Life History ◽  
Western Australia ◽  
Reproductive Rate ◽  
First Year ◽  
High Survival ◽  
Breeding Dispersal ◽  
Territory Quality ◽  
History Of ◽  
Mayfield Method ◽  
Eucalyptus Diversicolor

The white-breasted robin, Eopsaltria georgiana, is endemic to south-western Australia. We studied breeding, dispersal and survival in known groups from 1978 until 1987, with some groups followed until 1992, in Eucalyptus diversicolor (karri) forest near Manjimup, Western Australia. E. georgiana bred cooperatively, with 66% of groups including one or more birds in addition to the breeding pair (mean group size 3.1); these helpers were predominantly males and assisted the senior male in feeding the female on the nest and the young and defending the territory. The survival of adults was high (males 86%; females 79%). Breeding territories and groups persisted from year to year, although in the non-breeding season, males ranged more widely. Dispersal was female-biased; most females and some males dispersed in their first year. Divorce was rare; breeding males that disappeared were replaced by a helper from within the group if one was present, and females were replaced from outside the group. Eggs were laid between July and December. Clutch size was almost always 2, incubation lasted 16–17 days and nestlings fledged 13–14 days later. Juveniles were dependent on adult provisioning for 6–8 weeks. We found no parasitism by cuckoos. Of 429 nests found, 74% fledged at least one young, and overall nesting success calculated by the Mayfield method was 63%. The median time between initiation of two successive clutches was 54 days, and 52% of females renested after fledging one brood; at least two broods per year were fledged by 44% of females. Groups produced a mean of 2.8 fledglings, 1.3 independent young and 0.7 yearlings per year. The most productive groups were those with two or more helpers on high-quality territories, but we could not separate the effects of helpers and territory quality. E. georgiana has the 'slow' life history typical of many Australian passerines – cooperative breeding, sedentary, resident all year round in an equable habitat that promotes high survival of breeding adults. Their low reproductive rate produces a small crop of yearlings, some of which may stay in the parental home range.

Life History of the Endemic Saddleback Crayfish, Faxonius medius (Faxon, 1884), (Decapoda: Cambaridae) in Missouri, USA

2019 ◽  
Vol 24 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Robert DiStefano ◽  
Jacob Westhoff ◽  
Christopher Rice ◽  
Amanda Rosenberger
Keyword(s):  
Life History ◽  
Sympatric Species ◽  
First Year ◽  
Geographic Context ◽  
Ratio Size ◽  
Small Streams ◽  
History Of ◽  
Egg Brooding ◽  
First Year Of Life ◽  
Sexually Mature

Abstract The saddleback crayfish, Faxonius medius (Faxon, 1884), is endemic to a single drainage in eastern Missouri, USA, that is affected by heavy metals mining, and adjacent to a rapidly-expanding urban area. We studied populations of F. medius in two small streams for 18 months to describe the annual reproductive cycle and gather information about fecundity, sex ratio, size at maturity, and size-class structure. We also obtained information about the species’ density at supplemental sites. The species, though rare in a geographic context, is locally abundant; we captured a monthly average of more than 75 F. medius from each of the two study populations. Densities of F. medius were high relative to several sympatric species of Faxonius Cope, 1872 and Cambarus Erichson, 1846. The species exhibited traits of an r-strategist life history; it was relatively short-lived and early to maturity. Its fecundity and egg size were comparable to Ozark congeners. Breeding season occurred in autumn, perhaps extending into early winter. Egg brooding occurred primarily in April. Young-of-year first appeared in samples in June. We estimated that these populations contained 2 to 3 size-classes, and most individuals became sexually mature in their first year of life. Life history information presented herein will be important for future conservation efforts.

Effects of vertebrate and invertebrate predators on the life history of Daphnia similis and Moina macrocopa (Crustacea: Cladocera)

2018 ◽  
Vol 54 ◽  
pp. 25 ◽  
Author(s):  
Jayme Magalhães Santangelo ◽  
Bruno Nascimento Soares ◽  
Thecia Paes ◽  
Paulina Maia-Barbosa ◽  
Ralph Tollrian ◽  
...  
Keyword(s):  
Life History ◽  
Reproductive Rate ◽  
Tropical Lakes ◽  
Net Reproductive Rate ◽  
Moina Macrocopa ◽  
Lake Ecosystems ◽  
Daphnia Similis ◽  
Invertebrate Predators ◽  
History Of ◽  
Reproductive Rates

Cladocerans serve as prey for several aquatic predators like fish and Chaoborus larvae. However, because different predators consume different sized prey, cladocerans may display differing life-history responses depending on predator type. Although most studies use the genus Daphnia to evaluate phenotypic plasticity in cladocerans, other genera might also respond to predator infochemicals. In this study, we compared life-history responses of Daphnia similis and Moina macrocopa to infochemicals released by a vertebrate (fish) and an invertebrate (Chaoborus) predator. As expected, some life-history parameters were altered depending on the type of predator. Overall, fish infochemicals increased the size at primipara, clutch size, net reproductive rate and longevity in both cladocerans. We argue that increased body lengths in the presence of fish promote bigger clutch sizes. Conversely, responses to Chaoborus were weaker, affecting only the net reproductive rates and longevity. Non-daphniid cladocerans may display similar responses to Daphnia when exposed to predators. However, as Daphnia is usually underrepresented in tropical lakes, studying other genera might offer new insights into predator-prey relationships and food webs in lake ecosystems.

New Terrestrial Amphipods (Amphipoda:Talitridae) From Australian Forests.

1982 ◽  
Vol 30 (3) ◽  
pp. 461 ◽  
Author(s):  
JA Friend
Keyword(s):  
Life History ◽  
New Species ◽  
Western Australia ◽  
New South ◽  
New South Wales ◽  
New Genera ◽  
South West ◽  
South Wales ◽  
Two New Species ◽  
History Of

Descriptions of two new genera including five new species of Australian landhoppers are presented. Two new species are recorded from south-west Western Australia (Austrotroides pectinalis and A. occidentalis) and one each from the Adelaide area (A. crenatus), southern Victoria (Agilestia hyperocha) and southern Queensland-northern New South Wales (A. hylaea). Notes on the life history of Austrotoides crenatus are provided.

Ecological and evolutionary significance of molt in lowland Neotropical landbirds

The Auk ◽  
2021 ◽  
Vol 138 (1) ◽  
Author(s):  
Jared D Wolfe ◽  
Ryan S Terrill ◽  
Erik I Johnson ◽  
Luke L Powell ◽  
T Brandt Ryder
Keyword(s):  
Life History ◽  
Home Range ◽  
Home Range Size ◽  
Range Size ◽  
Evolutionary Significance ◽  
High Survival ◽  
Life History Variation ◽  
Trade Offs ◽  
History Of

Abstract The slow-paced life history of many Neotropical birds (e.g., high survival and low fecundity) is hypothesized to increase lifetime fitness through investments in self-maintenance over reproduction relative to their temperate counterparts. Molt is a key investment in self-maintenance and is readily shaped by environmental conditions. As such, variation in molt strategies may be a key mechanism underlying life-history trade-offs and adaptation to new environments. Here, we review molt strategies from a diversity of lowland Neotropical landbirds and examine how variation in molt strategies, characterized by differences in molt insertions, timing, extent, and duration contribute to life-history variation and adaptation to diverse ecological conditions. In addition to our synthesis, we present a case study to examine the relationship between home range size and duration of the definitive prebasic molt of a well-studied subset of Amazonian landbirds. Our results suggest a connection between prolonged molt duration and larger home range size of small-to-medium-sized Amazonian landbirds. Our aims were to identify key gaps in our knowledge of Neotropical bird molt, to stimulate further comparative studies into the evolution of molt strategies, and to highlight how variation in molt strategies may be a key mechanism underlying life-history variation across latitudes.

scholarly journals Life history of Kermes quercus (LINNAEUS) (Hemiptera: Kermesidae) in Poland

2013 ◽  
Vol 82 (3) ◽  
pp. 151-158 ◽  
Author(s):  
Elżbieta Podsiadło
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Climatic Conditions ◽  
First Year ◽  
History Of ◽  
Second Year ◽  
New Generation

ABSTRACT This research complements the results of a study of the life cycle of Kermes quercus (L.) performed in Poland in 2008-2009. The latest observations were carried out in 2010 from the beginning of March until the end of November. They showed that K. quercus overwintered as 2nd-instar nymphs. These developed into adults at the beginning of May. Reproduction began at the beginning of June. The 1st-instar nymphs of the new generation appeared in mid-June. They then developed for about 5 months, after which they entered the winter diapause. All the observations, carried out in 2008-2010, showed that, under the climatic conditions of Poland, K. quercus is not a univoltine species. One generation develops over two years. In the first year it overwinters as 1st-instar nymphs and in the second year as 2nd-instar nymphs.

The life history of Pseudocheirus occidentalis (Pseudocheiridae) in the jarrah forest of south-western Australia

2005 ◽  
Vol 53 (5) ◽  
pp. 325 ◽  
Author(s):  
A. F. Wayne ◽  
J. F. Rooney ◽  
C. G. Ward ◽  
C. V. Vellios ◽  
D. B. Lindenmayer
Keyword(s):  
Life History ◽  
Western Australia ◽  
Conservation Status ◽  
Temporal Variations ◽  
Jarrah Forest ◽  
Eucalyptus Marginata ◽  
Introduced Predators ◽  
Eastern Australia ◽  
History Of ◽  
Ringtail Possum

Life-history attributes are described for the threatened ngwayir or western ringtail possum (Pseudocheirus occidentalis) in inland jarrah (Eucalyptus marginata) forest east of Manjimup, south-western Australia. Data on 81 individuals were collected over 18 months. There was no sexual dimorphism and body size was similar to that found in other P. occidentalis populations, but larger than the closely related P. peregrinus in eastern Australia. Breeding at Chariup was more strongly seasonal than that of coastal populations, with 77% of births in May–June and the remainder in October–November. All neonates were singletons except for one instance of non-viable twins. No females bred twice in the same year. The growth rate of the head length of pouch young (<5 months of age) was 0.245–0.362 mm day–1 and curvilinear toward an asymptote thereafter. Temporal variations in body condition, coat condition and ectoparasites were significant. Mortality was highly seasonal (84% of deaths were April–September) and predominantly caused by predation, mainly by fox (Vulpes vulpes) and cat (Felis catus). More effective and strategic control of introduced predators prior to and during autumn/winter, could therefore improve the viability of jarrah forest populations. Nutrition appears to influence many of the life-history traits of P. occidentalis. Nutrition also may partly explain the differences in size, life history and conservation status between P. occidentalis and P. peregrinus.

Variation in the life History of Diadromous and Lanlocked populations of the Spotted Galaxias, Galoxias truttaceus Valenciennes, in Tasmania

1989 ◽  
Vol 40 (5) ◽  
pp. 501 ◽  
Author(s):  
P Humphries
Keyword(s):  
Life History ◽  
Egg Size ◽  
Reproductive Investment ◽  
Gonadal Development ◽  
Early Spring ◽  
First Year ◽  
Age Class ◽  
Large Numbers ◽  
History Of ◽  
Spawning Time

Variations in life history traits such as age class distribution, growth, gonadal development, reproductive investment and spawning time were studied in two stream-dwelling diadromous and two landlocked freshwater lake populations of the spotted galaxias, Galaxias truttaceus, in Tasmania. Whereas stream populations were dominated by 0+, I+ and 2+ age-class fish, lake populations had a smaller proportion of these younger individuals and a larger proportion of age classes older than 2 +. Growth in both lake and stream populations was slow over winter and more rapid during spring and summer. The majority of fish of both sexes matured at age two, irrespective of size, although some lake-dwelling males matured in their first year. Gonadal development commenced at the beginning of summer (December) in all populations. Spawning in stream-dwelling populations occurred before winter (May) and was associated with decreasing water temperature and photoperiod. By contrast, landlocked populations spawned in early spring (September), at which time both temperature and photoperiod were increasing. At spawning, landlocked females invested more energy in reproduction than did riverine females. This appeared to be a function of larger egg size in females from one lake population and greater fecundity in females from the other. Although G. truttaceus fits the general life-history model for diadromous galaxiids, having relatively large numbers of small eggs, the shift in spawning time for landlocked populations, and the inter-population variations in egg size and fecundity suggest considerable flexibility in the characteristics of this species' life history.

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