scholarly journals How Many Baskets? Clutch Sizes That Maximize Annual Fecundity of Multiple-Brooded Birds

The Auk ◽  
2001 ◽  
Vol 118 (4) ◽  
pp. 973-982 ◽  
Author(s):  
George L. Farnsworth ◽  
Theodore R. Simons ◽  
J. Brawn
Keyword(s):  
Clutch Size ◽  
Breeding Season ◽  
Nest Predation ◽  
Reproductive Effort ◽  
Nest Survival ◽  
Survival Rates ◽  
Season Length ◽  
Deterministic Models ◽  
Cavity Nesting ◽  
Theoretical Issues

Abstract We developed deterministic models on the basis of nest survival rates and renesting behavior capable of predicting annual fecundity in birds. The models calculate probabilities of fledging from one to four nests within a discrete breeding season. We used those models to address theoretical issues related to clutch size. In general, birds require at least one day to lay an egg, and many species delay incubation until their entire clutch is laid. Because it takes longer to complete a larger clutch, and fewer such clutches can fit into a limited breeding season, there exists a clutch size for which annual fecundity is maximized. We asked, for a given amount of reproductive effort (i.e. a set number of eggs), does the age-old maxim “don't put all your eggs in one basket” apply? If so, in how many “baskets” should a nesting bird place its eggs? The answer depends on both likelihood of nest predation and length of the breeding season. Those results are consistent with the observed increase in clutch size with latitude (shorter breeding season length) and larger clutch sizes characteristic of cavity-nesting species (with higher nest survival rates). The models also predict that the size of replacement clutches should decrease as the breeding season progresses, and that intraseasonal decline in clutch size should be more pronounced when the breeding season is short.

scholarly journals Effects of storms, angling, and nest predation during angling on smallmouth bass (Micropterus dolomieu) nest success

2005 ◽  
Vol 62 (11) ◽  
pp. 2649-2660 ◽  
Author(s):  
Geoffrey B Steinhart ◽  
Nancy J Leonard ◽  
Roy A Stein ◽  
Elizabeth A Marschall
Keyword(s):  
Nest Predation ◽  
Lake Erie ◽  
Nest Success ◽  
Nest Survival ◽  
Survival Rates ◽  
Round Goby ◽  
Smallmouth Bass ◽  
Micropterus Dolomieu ◽  
Daily Survival ◽  
Daily Nest Survival

We studied how storms, angling, and nest predation during angling affected smallmouth bass (Micropterus dolomieu) nest survival in the Bass Islands, Lake Erie, Ohio, USA. Increasing angler effort and introduction of an exotic nest predator, round goby (Neogobious melanostomus), have raised concerns about smallmouth bass recruitment in Lake Erie. We surveyed smallmouth bass nests and calculated daily survival rates for nests assigned to different angling treatments: control, angling without predation, or angling with predation treatments. Only 30% of control nests were successful compared with 11% of angling without predation and 14% of angling with predation treatments. We used the Mayfield method and maximum likelihood models in the program MARK to estimate the survival rates for nests of different treatments and exposed to different numbers of storms. Although nest predators consumed about 35% of broods during angling, daily nest survival rates of both angling treatments were similar. Angling reduced nest survival compared with controls by approximately 5%. Storms reduced both nest success and daily survival. The best model predicting daily nest survival included the added effects of angling treatment and number of storms. Thus, whereas storms and angling affected smallmouth bass nest survival, nest predation during angling did not.

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.

scholarly journals Long-term monitoring reveals invariant clutch size and unequal reproductive costs between sexes in a subtropical lacertid lizard

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Jhan-Wei Lin ◽  
Ying-Rong Chen ◽  
Tsui-Wen Li ◽  
Pei-Jen L. Shaner ◽  
Si-Min Lin
Keyword(s):  
Clutch Size ◽  
Breeding Season ◽  
Survival Rates ◽  
Reproductive Potential ◽  
Seasonal Fluctuation ◽  
Cost Of Reproduction ◽  
Short Lifespan ◽  
Lacertid Lizard ◽  
One Year ◽  
Succession Stage

AbstractBased on 20,000 records representing c. 11,000 individuals from an 8-year capture-mark-recapture (CMR) study, we tested and confirmed a new case of invariant clutch size (ICS) in a sexually dichromatic lacertid lizard, Takydromus viridipunctatus. In the grassland habitat of the early succession stage, females showed strictly low and invariant clutch size, multiple clutches in a breeding season, high reproductive potential, and annual breeding cycles that correspond to the emergence of male courtship coloration. The hatchlings mature quickly, and join the adult cohort for breeding within a few months, whereas adults show low survival rates and a short lifespan, such that most die within one year. Mortality increased in both sexes during the breeding season, especially in females, indicating an unequal cost of reproduction in survival. These life history characters may be explained by two non-exclusive hypotheses of ICS—arboreal hypothesis and predation hypothesis—within the ecological context of their habitat. Our study highlights a confirmed case of ICS, which adapts well to this r-selected grassland habitat that experiences seasonal fluctuation and frequent disturbance.

Reproductive variation corresponding to breeding season length in three tropical frog species

2009 ◽  
Vol 25 (6) ◽  
pp. 583-592 ◽  
Author(s):  
Jennifer A. Sheridan
Keyword(s):  
Clutch Size ◽  
Breeding Season ◽  
Common Species ◽  
The Other ◽  
Female Size ◽  
Season Length ◽  
Widespread Species ◽  
Frog Species ◽  
Polypedates Leucomystax ◽  
Central Thailand

Abstract:Several South-East Asian anuran species can breed year-round near the equator (due to abundant rainfall in all months in Singapore, for example) but are limited to a 6-mo breeding season in other areas (including central Thailand). In order to investigate the extent to which such differences in breeding season length are associated with differences in reproductive measures such as clutch size, reproduction of three common species, Polypedates leucomystax, Microhyla heymonsi and Hylarana erythraea, was compared in Singapore and Thailand over a 2-y period. All three species produce nearly twice as many eggs per clutch in seasonal environments compared with aseasonal environments, although annual fecundity may be similar in both environments. In Polypedates leucomystax, increased clutch size and volume are associated with larger female size, but in the other two species female size is unchanged with respect to latitude. In H. erythraea, the increased clutch size in Thailand was observed early in the breeding season; later clutches were not significantly different between sites. Collectively, these data suggest that these widespread species have adapted to shortened breeding season length by increasing clutch size.

scholarly journals Climatic Variability, Nest Predation, and Reproductive Output of Lilac-Crowned Parrots (Amazona Finschi) in Tropical Dry Forest of Western Mexico

The Auk ◽  
2004 ◽  
Vol 121 (4) ◽  
pp. 1214-1225
Author(s):  
Katherine Renton ◽  
Alejandro Salinas-Melgoza
Keyword(s):  
Clutch Size ◽  
Breeding Season ◽  
Nest Predation ◽  
Reproductive Output ◽  
Climatic Variability ◽  
Tropical Dry Forest ◽  
Dry Forest ◽  
Western Mexico ◽  
Nestling Survival ◽  
Interannual Fluctuations

Abstract For 1996–2003, we determined reproductive output and success of 70 Lilaccrowned Parrot (Amazona finschi) nests in tropical dry forest of the Chamela-Cuixmala Biosphere Reserve in western Mexico. Only 42% of nests had young that fledged; predation was the main cause of nest failure. Low brood survival in 2000 and 2003 caused significant between-year variation in the probability of nest success during the nestling phase of the nest cycle. Reproductive output of Lilac-crowned Parrots was low, with females producing an average of 0.99 fledglings on an initial investment of 2.6 eggs. The fecundity component of clutch size varied significantly between years, because of the high median clutch size recorded in 2000. Nestling survival also varied significantly between years, creating large interannual fluctuations in reproductive output. The most productive breeding season was 1999, with an average output of 1.7 fledglings on an investment of 2.7 eggs; whereas the poorest breeding season was 2000, with an output of 0.57 fledglings from 3.3 eggs. Loss of reproductive potential was greatest in 2000 and 2003, because of brood reduction through starvation of later-hatched nestlings, with hatching order influencing the probability of nestling survival. Mean number of nestlings per egg-laying female was associated with interannual fluctuations in precipitation resulting from the El Niño-La Niña weather cycle in the Pacific Ocean. Both nest predation and food availability may limit parrot reproduction in tropical dry forests, with populations of threatened species in dry habitats being vulnerable to effects of climatic variability and habitat fragmentation.

scholarly journals Striped-tailed Yellow-finch nesting success in abandoned mining pits from central Brazilian cerrado

2015 ◽  
Vol 75 (1) ◽  
pp. 191-197 ◽  
Author(s):  
DT. Gressler ◽  
MÂ. Marini
Keyword(s):  
Breeding Season ◽  
Nest Success ◽  
Nest Survival ◽  
Survival Rates ◽  
Survival Models ◽  
Nest Size ◽  
Suitable Alternative ◽  
Daily Survival ◽  
Breeding Habitats ◽  
Nest Height

Suitability of degraded areas as breeding habitats can be tested through assessment of nest predation rates. In this study we estimated nest success in relation to several potential predictors of nest survival in the Stripe-tailed Yellow-finch (Sicalis citrina) breeding in abandoned mining pits at Brasília National Park. We monitored 73 nests during the 2007-breeding season. Predation was the main cause of nest failure (n = 48, 66%); while six nests were abandoned (8%) and 19 nests produced young (26%). Mayfield’s daily survival rates and nest success were 0.94 and 23%, respectively. Our results from nest survival models on program MARK indicated that daily survival rates increase linearly towards the end of the breeding season and decrease as nests aged. None of the nest individual covariates we tested - nest height, nest size, nest substrate, and edge effect - were important predictors of nest survival; however, nests placed on the most common plant tended to have higher survival probabilities. Also, there was no observer effect on daily survival rates. Our study suggests that abandoned mining pits may be suitable alternative breeding habitats for Striped-tailed Yellow-finches since nest survival rates were similar to other studies in the central cerrado region.

scholarly journals Breeding season length predicts duet coordination and consistency in Neotropical wrens (Troglodytidae)

2020 ◽  
Vol 287 (1941) ◽  
pp. 20202482
Author(s):  
Emily L. Keenan ◽  
Karan J. Odom ◽  
Marcelo Araya-Salas ◽  
Kyle G. Horton ◽  
Matthew Strimas-Mackey ◽  
...  
Keyword(s):  
Clutch Size ◽  
Breeding Season ◽  
Vegetation Density ◽  
Season Length ◽  
Evolutionary Patterns ◽  
Breeding Behaviour ◽  
Breeding Seasons ◽  
Vocal Duets

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.

scholarly journals Reassessing the Cowbird Threat

The Auk ◽  
2007 ◽  
Vol 124 (1) ◽  
pp. 210-223
Author(s):  
Liana Zanette ◽  
Daniel T. Haydon ◽  
James N. M. Smith ◽  
Mary J. Taitt ◽  
Michael Clinchy
Keyword(s):  
Nest Predation ◽  
Molothrus Ater ◽  
Nest Survival ◽  
Survival Rates ◽  
Song Sparrows ◽  
Parasitism Rates ◽  
Common Technique ◽  
Stochastic Simulation Model ◽  
The Common ◽  
Egg Removal

Abstract The demographic significance of parasitism by Brown-headed Cowbirds (Molothrus ater; hereafter “cowbirds”) has been debated for years, because manipulative studies are few and mathematical models of cowbird-host systems have not led to tests of their predictions. We combine results from a cowbird- removal experiment (Smith et al. 2002, 2003) with a stochastic simulation model that we developed, to reassess the effect of cowbirds on the annual reproductive success (ARS) and nesting success in Song Sparrows (Melospiza melodia). Our model followed the breeding success of individual Song Sparrow nests and extrapolated to output variables including ARS, nest survival, and parasitism rates. We parameterized the model with field data from cowbird control sites (i.e., cowbirds not manipulated) and found that output variables matched those observed. We used the reduced parasitism rates observed on cowbird-removal sites, reran the model, and compared output with observed values. On removal sites, ARS was greater than predicted by the model, which indicates that the model failed to account for some biological phenomenon that occurred when cowbirds were in the system. To assess what this phenomenon might be, we conducted further analyses that indicated that cowbirds may facilitate nest predation by “conventional” predators. Using elasticity analyses, we show that cowbirds have their largest effect on ARS through egg removal and that conventional predators are more important than cowbirds in directly affecting nest survival rates. We report that to assess the effect of cowbirds on nest survival, researchers must avoid using the common technique of comparing survival rates of parasitized and unparasitized nests within populations. Réévaluation de la Menace du Vacher

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