Life-history implications of migratory Lesser Sandhill Cranes replacing adjacent blocks of primaries synchronously

The Auk ◽  
2020 ◽  
Vol 137 (4) ◽  
Author(s):  
Sievert Rohwer ◽  
Vanya G Rohwer ◽  
Meera Lee Sethi ◽  
Janneke HilleRisLambers
Keyword(s):  
Life History ◽  
Breeding Season ◽  
Field Studies ◽  
Flight Feather ◽  
Interesting Variation ◽  
Sandhill Cranes

Abstract Using the patterns of fault bars in their primaries, we studied the mode of primary replacement in non-molting Lesser Sandhill Cranes (Antigone c. canadensis) salvaged from hunters in southwestern Saskatchewan. About 80% of their primaries are used for 2 yr and 20% for 3 yr. Primaries are replaced during the breeding season and are lost in synchronous blocks representing about half the primaries, suggesting that most adults probably can fly weakly during flight feather replacement. Cranes are large, aggressive birds, and this interesting, and undescribed mode of flight feather replacement seems adapted to the ability of adult cranes to defend their precocial chicks from predators. Strikingly, juvenile Sandhill Cranes showed no fault marks in their primaries, suggesting that their parents’ ability to protect them shields them from the fright of predator attacks, which, in most birds, causes fault bars to be more prevalent and strongly expressed in juveniles than adults. Adults show interesting variation in the number of primaries replaced annually, which seems likely related to whether or not they are caring for chicks. Further, single primaries may or may not be replaced preferentially, suggesting sensitivity to feather function. Evaluating these observations must await field studies of molting adults.

Distribution and Seasonality of Macroalgae on Oyster Communities of Central Chesapeake Bay

1980 ◽  
Vol 23 (11) ◽  
Author(s):  
Judith L. Connor
Keyword(s):  
Life History ◽  
Sexual Reproduction ◽  
Chesapeake Bay ◽  
Physical Environment ◽  
Algal Species ◽  
Light Availability ◽  
Field Studies ◽  
Spatial And Temporal Distributions ◽  
Red Algal ◽  
Study Sites

AbstractField studies of the benthic macroalgae of fifteen selected Chesapeake Bay oyster communities were conducted over a period of a year (March 1977 to February 1978). Algal distribu tion and seasonal occurrence were studied in relation to changes in the physical environment. Salinity, temperature, and light availability were important factors in the spatial and temporal distributions of algae in these subtidal habitats.Seventeen species of Chlorophyta, Phaeophyta, and Rhodophyta were recorded from the fifteen study sites distributed over 130 kilometers within the Maryland portion of Chesapeake Bay. Species of Chlorophyta were associated with oyster communities throughout the year of study with maximum numbers of species and maximum biomass occurring in spring. Only once was a member of the Phaeophyta encountered; a single filamentous species, Ectocarpus, was collected during winter. Species of Rhodophyta were present throughout the year at the study sites.Most of the algae collected reproduced asexually by spores and/or vegetative fragments. Sexual reproduction occurred in some of the red algal species. The presence of tetrasporic and cystocarpic plants of Dasya baillouviana and Polysiphonia harveyi var. olneyi may indicate that the usual triphasic Florideophycean life history occurs in this estuary.

scholarly journals The biology of Limacina retroversa

1954 ◽  
Vol 33 (2) ◽  
pp. 297-312 ◽  
Author(s):  
J. E. Morton
Keyword(s):  
Life History ◽  
Breeding Season ◽  
Detailed Account ◽  
Larval Stages ◽  
Large Numbers ◽  
History Of ◽  
Clione Limacina

The Plymouth Fauna List contains records of two genera of pteropods, Limacina and Clione. Of the first, Limacina retroversa (Flem.) is by far the better-known species, apparently occurring regularly at Plymouth in large numbers in townettings from outside, and sometimes inside, the Sound. It breeds at Plymouth from June to August, and Lebour (1932) has given a detailed account of its breeding and larval stages and has discussed its role in the plankton. The second species of Limacina at Plymouth is lesueuri (d'Orbigny), which has been observed from time to time since 1906, when it was very common. The last record in the Fauna is off the Breakwater in 1920. Of the gymnosomatous pteropods, Clione limacina Phipps is the only species regularly occurring. Lebour (1931) has described the life history of this form, and mentions February to August as its months of greatest abundance. Its breeding season is June to August. Another gymnosome, tentatively referred to as Clionina longicauda, is reported by Russell (1936), and from the specimen department at Plymouth Laboratory the writer obtained some preserved specimens, not easily identifiable, of a Pneumodermopsis taken locally; its species is perhaps ciliata, recorded by Massy (1917) from the Irish Coast.

scholarly journals Life History Implications of Complete and Incomplete Primary Molts in Pelagic Cormorants

The Condor ◽  
2001 ◽  
Vol 103 (3) ◽  
pp. 555-569 ◽  
Author(s):  
Christopher E. Filardi ◽  
Sievert Rohwer
Keyword(s):  
Life History ◽  
North America ◽  
North American ◽  
Northeastern Asia ◽  
Flight Feather ◽  
Historia De Vida

Abstract We describe the rules of primary flight-feather replacement for Pelagic Cormorants (Phalacrocorax pelagicus), and contrast the completeness of primary replacement in individuals from Asia and North America. In adult Pelagic Cormorants primary replacement is stepwise, with multiple waves of molt, each initiated at the innermost primary (P1), proceeding simultaneously toward the tip of the wing. Shugart and Rohwer's (1996) ontogenetic model for generating and maintaining stepwise primary replacement depended upon incomplete molts. In each new episode of molt, waves of primary replacement were thought to be initiated at P1 and at each arrested wave that had failed to replace all old feathers in the preceding molt. Because most adult Pelagic Cormorants from North America completely replace their primaries but maintain stepwise primary molts, the latter assumption must be relaxed. In contrast to the present-day situation in North America, Pelagic Cormorants from northeastern Asia have incomplete molts of their primaries, and may be forced to skip breeding in some years to clear their wings of overworn primaries. Young birds from Asia start the replacement of their juvenile primaries later than North American birds and replace more feathers simultaneously. Implicancias de la Muda Primaria Completa e Incompleta en la Historia de Vida de Phalacrocorax pelagicus Resumen. Describimos las reglas de reemplazo de plumas primarias para Phalacrocorax pelagicus y contrastamos la totalización del reemplazo de primarias entre individuos de Asia y América del Norte. En individuos adultos, el reemplazo de primarias ocurre en varias etapas, con múltiples secuencias de muda cada una iniciada en la primaria más interna (P1), procediendo simultáneamente hacia la punta del ala. El modelo ontogenético de Shugart y Rohwer (1996) para la generación y mantenimiento del reemplazo en etapas de las plumas primarias depende de mudas incompletas. Se pensaba que en cada nuevo episodio de muda las secuencias de reemplazo de primarias eran iniciadas en P1 y en cada punto de interrupción de la muda precedente que hubiera impedido el reemplazo de todas las plumas viejas. Debido a que la mayoría de los individuos adultos de P. pelagicus de Norteamérica reeemplazan completamente sus primarias pero aún lo hacen en etapas, la última suposición debe ser re-evaluada. En contraste con la situación actual en Norteamérica, individuos del noreste de Asia tienen mudas incompletas de sus primarias y pueden verse forzados a no reproducirse en algunos años para despojarse de la presencia de primarias desgastadas. Las aves juveniles de Asia comienzan el reemplazo de sus primarias más tarde y reemplazan más plumas simultáneamente que las aves de Norteamérica.

Life history and demography of an uncooperative Australian passerine, the brown thornbill

1999 ◽  
Vol 47 (6) ◽  
pp. 633 ◽  
Author(s):  
David J. Green ◽  
Andrew Cockburn
Keyword(s):  
Phylogenetic Analysis ◽  
Life History ◽  
Breeding Season ◽  
Cooperative Breeding ◽  
Mating Systems ◽  
Survival Rates ◽  
Reproductive Conflict ◽  
Annual Survival ◽  
Shed Light ◽  
C 63

The genus Acanthiza may be important in understanding the evolution of avian mating systems because while brown thornbills, Acanthiza pusilla, are thought to breed only in pairs, a recent phylogenetic analysis suggests that cooperative breeding is the ancestral trait within this genus. We provide a detailed account of the breeding biology of the brown thornbill, confirm that they breed exclusively in pairs, and compare their population demography with what is known for other members of the Pardalotidae. We found that brown thornbills produced small clutches (3 eggs) with a two-day laying interval, had a long incubation period (declining from 19 to 16 days through the season), and had a long breeding season (4.0 months) that allowed females to occasionally raise two successful broods. Brown thornbills, in our study, produced an average of 1.57 fledglings per pair and had relatively high annual survival rates (c. 63%). We found no evidence to suggest that the evolution of pair-breeding within the Pardalotidae is associated with a reduction in annual survival rates, a short breeding season with reduced productivity, or high levels of predation post-fledging. Since there also appear to be no ecological correlates with mating system in the Pardalotidae we suggest that examination of reproductive conflict between parents and young may shed light on the evolution of pairbreeding in this family.

Laboratory culture of Dreissena polymorpha larvae: spawning success, adult fecundity, and larval mortality patterns

2004 ◽  
Vol 82 (9) ◽  
pp. 1436-1443 ◽  
Author(s):  
James A Stoeckel ◽  
Dianna K Padilla ◽  
Daniel W Schneider ◽  
Chris R Rehmann
Keyword(s):  
Life History ◽  
Dreissena Polymorpha ◽  
Egg Production ◽  
Larval Mortality ◽  
Field Studies ◽  
Laboratory Culture ◽  
Minimum Size ◽  
Critical Periods ◽  
Brood Stock ◽  
Wide Range

Understanding the entire life history, especially critical periods during the life cycle of a species, is important for understanding population dynamics and is crucial for control of nuisance species. Errors in estimates of growth rates and recruitment in field and modeling studies are likely to occur if one assumes uniform rather than size- or stage-specific mortalities for larval stages. Similarly, effects of brood-stock health on adult fecundity and larval mortality patterns might affect results of laboratory studies investigating larval life history. We maintained zebra mussels, Dreissena polymorpha (Pallas, 1771), in spawning condition in the laboratory for 24 weeks. Healthy larvae were produced for 18 weeks. However, induction of spawning and egg production declined through time. Fecundity increased with size per female, but sperm production did not for males. We found no correlation between clutch size and egg size across a wide range of clutch sizes. Survivorship was greater when larvae were reared at lower densities. Daily larval mortality was strongly size dependent; the average size of dead larvae was similar to the minimum size of live larvae. Highest daily larval mortality occurred during the transition from D stage to umbonal stage, supporting the suggestion of a developmental bottleneck as found in previous field studies.

Winter corticosterone and body condition predict breeding investment in a nonmigratory bird

2019 ◽  
Vol 30 (6) ◽  
pp. 1642-1652 ◽  
Author(s):  
Chloé Montreuil-Spencer ◽  
Kelsey Schoenemann ◽  
Ádám Z Lendvai ◽  
Frances Bonier
Keyword(s):  
Life History ◽  
Breeding Season ◽  
Body Condition ◽  
Reproductive Investment ◽  
Phenotypic Traits ◽  
Residual Body ◽  
Life History Stage ◽  
Nonbreeding Season ◽  
Fat Reserves ◽  
Fat Score

Abstract Reproduction is an energetically demanding life history stage that requires costly physiological and behavioral changes, yet some individuals will invest more into reproduction and breed more successfully than others. To understand variation in reproductive investment, previous studies have evaluated factors during breeding, but conditions outside of this life history stage may also play a role. Using a free-ranging population of black-capped chickadees (Poecile atricapillus), we assessed the repeatability of plastic traits relating to energetic condition (circulating initial corticosterone concentrations and body condition) during the nonbreeding season and evaluated whether these traits predicted reproductive investment in the subsequent breeding season. We found that initial corticosterone concentrations and an index of body condition, but not fat score, were moderately repeatable over a 1-week period in winter. This trait repeatability supports the interpretation that among-individual variation in these phenotypic traits could reflect an intrinsic strategy to cope with challenging conditions across life history stages. We found that females with larger fat reserves during winter laid eggs sooner and tended to spend more time incubating their eggs and feeding their offspring. In contrast, we found that females with higher residual body mass delayed breeding, after controlling for the relationship between fat score and timing of breeding. Additionally, females with higher initial corticosterone in winter laid lighter eggs. Our findings suggest that conditions experienced outside of the breeding season may be important factors explaining variation in reproductive investment.

Feeding ecology and life-history strategy of nesting males in a fish with long parental care, Lusitanian toadfish (Halobatrachus didactylus, Batrachoididae)

2015 ◽  
pp. 1-9 ◽  
Author(s):  
P.M. Félix ◽  
M.C.P. Amorim ◽  
T.J. Pereira ◽  
P.J. Fonseca ◽  
C. Sousa-Santos ◽  
...  
Keyword(s):  
Life History ◽  
Parental Care ◽  
Breeding Season ◽  
Feeding Behaviour ◽  
Life History Strategy ◽  
Otter Trawl ◽  
Artificial Nests ◽  
Limited Mobility ◽  
Egg Cannibalism ◽  
Male Condition

The Lusitanian toadfish,Halobatrachus didactylus, like other batrachoidids, is a benthic fish species with nesting behaviour during the breeding season. During this prolonged period it engages in mating activities and remains in the nest providing parental care. It is not known whether males feed while providing parental care but it is likely that their limited mobility may restrict their diet and influence their fitness. As a consequence, egg cannibalism could occur as a life-history strategy. The aim of the present study is to ascertain the feeding behaviour of nesting males, in comparison to mature non-nesting males, and to identify potential life-history traits related to egg cannibalism. Nest-holders were sampled from artificial nests placed in an intertidal area of the Tagus estuary, only exposed during spring low tides. The diet of nest-holders was compared with that of non-nesting mature males from the same area, captured by otter trawl. The present study demonstrates that despite their constrained mobility nest-holders feed during the breeding season, although in a more opportunistic fashion than non-nesting males. Nest-holders showed a generalist feeding behaviour, with a more heterogeneous diet. Egg cannibalism was not related to male condition, paternity or brood size but showed a higher incidence early in the season when water temperatures were lower. The results suggest a possible seasonal trade-off strategy between care and energy recovery, triggered by environmental factors, where under unfavourable conditions to sustain viable eggs the male may recover energy by eating eggs, thus benefiting future reproductive success, later in the season.

The Life History and Some Aspects of the Ecology of the Large Aspen Tortrix, Choristoneura conflictana (Wlkr.) (N. Comb.) (Lepidoptera: Tortricidae)

1955 ◽  
Vol 87 (11) ◽  
pp. 461-473 ◽  
Author(s):  
R. M. Prentice
Keyword(s):  
Life History ◽  
Populus Tremuloides ◽  
Field Studies ◽  
Trembling Aspen ◽  
Factors Affecting ◽  
Choristoneura Conflictana

Periodic outbreaks of the large aspen tortrix, Choristoneura conflictana (Wlkr.) severely defoliate trembling aspen, Populus tremuloides Michx., in parts of Manitoba and Saskatchewan. The inadequacy of information on the insect prompted further investigation of its life history and the factors affecting its abundance. Field studies were conducted in Northern Manitoba and Saskatchewan, where from 1950 to 1954 the insect was found at various population levels.

scholarly journals Corticosterone, testosterone and life-history strategies of birds

2010 ◽  
Vol 277 (1697) ◽  
pp. 3203-3212 ◽  
Author(s):  
Michaela Hau ◽  
Robert E. Ricklefs ◽  
Martin Wikelski ◽  
Kelly A. Lee ◽  
Jeffrey D. Brawn
Keyword(s):  
Life History ◽  
Body Mass ◽  
Breeding Season ◽  
Life History Traits ◽  
Survival Rates ◽  
Life History Strategies ◽  
Adult Survival ◽  
Tropical Species ◽  
Published Data ◽  
Season Length

Steroid hormones have similar functions across vertebrates, but circulating concentrations can vary dramatically among species. We examined the hypothesis that variation in titres of corticosterone (Cort) and testosterone (T) is related to life-history traits of avian species. We predicted that Cort would reach higher levels under stress in species with higher annual adult survival rates since Cort is thought to promote physiological and behavioural responses that reduce risk to the individual. Conversely, we predicted that peak T during the breeding season would be higher in short-lived species with high mating effort as this hormone is known to promote male fecundity traits. We quantified circulating hormone concentrations and key life-history traits (annual adult survival rate, breeding season length, body mass) in males of free-living bird species during the breeding season at a temperate site (northern USA) and a tropical site (central Panama). We analysed our original data by themselves, and also combined with published data on passerine birds to enhance sample size. In both approaches, variation in baseline Cort (Cort0) among species was inversely related to breeding season length and body mass. Stress-induced corticosterone (MaxCort) also varied inversely with body mass and, as predicted, also varied positively with annual adult survival rates. Furthermore, species from drier and colder environments exhibited lower MaxCort than mesic and tropical species; T was lowest in species from tropical environments. These findings suggest that Cort0, MaxCort and T modulate key vertebrate life-history responses to the environment, with Cort0 supporting energetically demanding processes, MaxCort promoting survival and T being related to mating success.

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