No effect of habitat fragmentation on post-fledging, first-year and adult survival in the middle spotted woodpecker

The effective management of species requires detailed knowledge of key population parameters. A capture–mark–recapture study of the squirrel glider (Petaurus norfolcensis) was conducted in an urban forest remnant in Brisbane, south-east Queensland. A total of 187 adult gliders (96 females, 91 males) was captured 620 times, in 19 sessions over a 4-year period. A Cormack–Jolly–Seber model was employed to estimate adult survival and abundance. Factors that may affect survival (e.g. sex, year, season) were included in population models. The overall probability of annual apparent survival was 0.49 ± 0.08. The capture probability over the duration of the study was 0.38 ± 0.03. The size of the local population was highest in the first year of the study (70–113 individuals) but then declined and generally remained low in the last two years. Apparent survival may include an unknown component of dispersal. However, our study area was mostly surrounded by a hostile urban matrix, so the effect of dispersal may have been minimal. Further studies that assess the survival of squirrel gliders are needed to assess the extent to which this parameter varies among localities.

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The UK great bustard Otis tarda reintroduction trial: a 5-year progress report

Oryx ◽

10.1017/s0030605311000627 ◽

2011 ◽

Vol 46 (1) ◽

pp. 112-121 ◽

Cited By ~ 13

Author(s):

Robert J. Burnside ◽

Ian Carter ◽

Alasdair Dawes ◽

David Waters ◽

Leigh Lock ◽

...

Keyword(s):

Release Site ◽

Progress Report ◽

Adult Survival ◽

First Year ◽

Founder Population ◽

Trial Period ◽

Great Bustard ◽

Otis Tarda ◽

The Uk ◽

The 19Th Century

AbstractThe great bustard Otis tarda became extinct in the UK during the 19th century due to a combination of factors, including hunting, egg collection and changes in agriculture. In 2003 a 10-year licence was granted to begin a trial to reintroduce the species back to the UK. Here we report on the first 5 years of the trial and assess the progress made towards establishing a founder population. From April 2004 to September 2009 a total of 102 great bustard chicks were imported from Russia and 86 released on Salisbury Plain. Monitoring showed that post-release survival was 18% in the first year following release, and that mortality of released bustards was mainly attributable to predation and collisions. Estimated adult survival was 74%, although the sample size was small. All known surviving great bustards are faithful to the surroundings of the release site, returning throughout the year. A lek has been established where males have been observed displaying to females. The first nesting attempt was in 2007, and in 2009 two females aged 3 and 4 years successfully nested, fledging one chick each. Models incorporating the new demographic estimates suggest that at the end of the 10-year trial period the project can expect to have 8–26 adults as a founder population.

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Survival of Band-Tailed Manakins

The Condor ◽

10.1093/condor/109.1.167 ◽

2007 ◽

Vol 109 (1) ◽

pp. 167-172 ◽

Cited By ~ 1

Author(s):

James W. Pearce-Higgins ◽

Robin C. Brace ◽

Jon Hornbuckle

Keyword(s):

Survival Rates ◽

Adult Survival ◽

First Year ◽

Forest Site ◽

Forest Fragment ◽

Apparent Survival ◽

Age Related ◽

Capture Recapture ◽

Parsimonious Model ◽

Initial Capture

Abstract Abstract We modeled annual apparent survival of Band-tailed Manakins (Pipra fasciicauda) inhabiting a contiguous forest site and a 10.9 ha forest fragment in lowland Bolivia based on six years of capture-recapture data. There was significant age-related variation in apparent survival, but adult survival rates did not differ significantly with sex. Apparent survival rates of immature birds differed between the two locations, while adult survival rates did not. The most parsimonious model therefore estimated annual survival at 10% for immature birds in the contiguous forest site, 53% for immature birds in the forest fragment, 46% for adults in the first year after initial capture and 68% for adults in subsequent years. Forest fragmentation may have reduced immature dispersal, leading to inflated apparent survival rates in the forest fragment.

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First-year and adult survival of the endangered Lesser KestrelFalco naumanniin southern France

Bird Study ◽

10.1080/00063650309461292 ◽

2003 ◽

Vol 50 (1) ◽

pp. 68-72 ◽

Cited By ~ 20

Author(s):

Franck Prugnolle ◽

Philippe Pilard ◽

Luc Brun ◽

Giacomo Tavecchia

Keyword(s):

Adult Survival ◽

First Year ◽

Southern France

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Conserving declining species using incomplete demographic information: what help can we expect from the use of matrix population models?

Animal Biology ◽

10.1163/157075606778967865 ◽

2006 ◽

Vol 56 (4) ◽

pp. 519-533 ◽

Cited By ~ 3

Author(s):

Lia Hemerik ◽

Chris Klok

Keyword(s):

Growth Rate ◽

General Framework ◽

Bird Species ◽

Population Models ◽

Adult Survival ◽

First Year ◽

Matrix Population Models ◽

Survival And Reproduction ◽

Declining Species ◽

Set Up

AbstractDue to human activity, many species have strongly declined in number and are currently threatened with extinction. Management directed at conservation of these species can benefit from the use of simple population models such as matrix models. However, for many species, data on survival and reproduction are scarce. Therefore, we set up a general framework based on a matrix model with three parameters: reproduction, juvenile (=first year survival) and adult survival in which incomplete data can be analysed. This framework is applicable to species that can mature after their first year of life. The point in a calendar year at which the population size is determined, i.e. the census time, is varied. We discuss the differences and the similarities between matrices modelling the same population at different census times. The population growth rate and the elasticity of the survival and reproduction parameters have been determined analytically. From these we made, as a visual diagnostic tool (general framework), plots of the growth rate and the elasticity pattern and their dependence on actual values of the reproduction parameter and the juvenile and adult survival. To illustrate the use of this framework we plot and discuss literature data on survival and/or reproduction of a few bird species with a juvenile stage of one year in the light of our modelling results.

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Survival and Movements of Juvenile Burrowing Owls During the Postfledging Period

The Condor ◽

10.1093/condor/108.2.282 ◽

2006 ◽

Vol 108 (2) ◽

pp. 282-291 ◽

Cited By ~ 2

Author(s):

J. Morgan Davies ◽

Marco Restani

Keyword(s):

Brood Size ◽

Cynomys Ludovicianus ◽

Adult Survival ◽

First Year ◽

Juvenile Survival ◽

Athene Cunicularia ◽

Prairie Dog ◽

Burrowing Owls ◽

Burrowing Owl ◽

First Year Of Life

AbstractBurrowing Owl (Athene cunicularia) populations have declined extensively throughout much of North America, and modeling demography may assist conservation. However, few studies have estimated adult survival, and fewer still have determined juvenile survival. In 2003 and 2004 we monitored survival of 40 radio-tagged juveniles during the postfledging period in the Little Missouri National Grassland, North Dakota, where owls nested in black-tailed prairie dog (Cynomys ludovicianus) colonies. Survival averaged 0.57 (95% CI: 0.41–0.73) prior to autumn migration. Mortality was highest during the first two weeks after nest departure when juveniles were flightless, and two to three weeks later when juveniles became independent. Predation or starvation was implicated in most deaths. Distribution and abundance of escape cover (number of prairie dog burrows within 30 m of nests and size of the natal prairie dog colony) did not affect survival. Body condition and brood size at the time of radio-tagging also did not influence survival. Juvenile owls exhibited nest-centered dispersal, and averaged 108 ± 21 (SE) m and 82 ± 17 m from nests at initiation of migration in 2003 and 2004, respectively. Mean dates of departure from the study area were 2 September (± 3 days) 2003 and 24 August (± 2 days) 2004. Mortality during the postfledging period accounted for approximately two-thirds of mortality in the first year of life.

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Reduction of first-year survival threatens the viability of the Mariana Crow Corvus kubaryi population on Rota, CNMI

Bird Conservation International ◽

10.1017/s0959270909990281 ◽

2010 ◽

Vol 20 (4) ◽

pp. 335-342 ◽

Cited By ~ 8

Author(s):

JAMES C. HA ◽

ALYSSA BUTLER ◽

RENEE ROBINETTE HA

Keyword(s):

Captive Breeding ◽

Adult Survival ◽

Future Research ◽

Rapid Decline ◽

First Year ◽

Mariana Islands ◽

Conservation Action ◽

Conservation Programme ◽

Leslie Matrices ◽

Precipitous Decline

SummaryThe Mariana Crow Corvus kubaryi is a species of forest crow originally found only on the adjacent islands of Guam and Rota in the Mariana Islands of the western Pacific Ocean. Rapid and continuing declines led to it being listed by IUCN as "Critically Endangered" in 2008. Using 97 birds marked and resighted over the course of a 21 year period, we showed there was a rapid decline in first-year (fledgling to one year old) survival from 0.7 to 0.4 between 1990 and 2010, representing a doubling in mortality, and a smaller reduction in adult survival from 0.86 to 0.82 over the same period. A population model based on Leslie matrices incorporated the effects of catastrophic events, such as typhoons and human nest removal for captive breeding. All simulations predicted a precipitous decline in future populations and the inclusion of nest removals only shortened the life of the wild population by a few years. Identifying the underlying processes behind the decline in survival is the key research priority and, given the inevitable likelihood of a continuing rapid decline, conservation action should focus on securing the future of the species through captive breeding or captive rearing of wild-born chicks and ensuring that an adaptive management conservation programme is focused on countering the factors (e.g. predation) that are currently thought to impact first-year survival and productivity. Future research may identify other causes behind the Mariana Crow's decline and the conservation programme should be flexible enough to adapt to changing needs.

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HABITAT STRUCTURE AND DEMOGRAPHIC VARIABILITY OF A HABITAT SPECIALIST: THE ROCK MOUSE (Peromyscus difficilis)

Revista Mexicana de Mastozoologia ◽

10.22201/ie.20074484e.1997.2.1.72 ◽

1997 ◽

Vol 2 (1) ◽

pp. 72

Author(s):

Carlos Galindo Leal ◽

Charles J. Krebs

Keyword(s):

Habitat Structure ◽

Biosphere Reserve ◽

Adult Survival ◽

First Year ◽

Microhabitat Use ◽

Habitat Specialist ◽

Use Patterns ◽

Habitat Specialists ◽

Vegetation Characteristics ◽

Second Year

Abstract: We used a gradient ofhabitats in manzanita-oak shrubland in Durango, Mexico, to analyze demographic variability and microhabitat use patterns ofthe rock mouse (Peromyscus difficilis). We tested two hypotheses: First, demographic parameters of habitat specialists should be closely associated with habitat structure. Second, popu!ations with higher breeding densities should have higher adult survival, less recruitment and more stable densities. In addition, we analyzed the habitat structure correlates of demographic stability. Demographic characteristics were more dissimilar in those grids with the greatest differences in vegetation characteristics. The areas with highest breeding densities had low juvenile and subadult recruitment in the breeding season. Most populations were relatively stable during the first year of study, but one declined to extinction during the second year. There were differences in microhabitat use among sexes and ages, as well as among resident and ransient individuals, particularly in the breeding season.Resumen: Utilizamos un gradiente de hábitats en el matorral de manzanita y encino en Durango, México, para analizar la variabilidad demográfica del ratón de las rocas Peromyscus difficilis). Examinamos dos hipótesis. Primera, los parámetros demográficos de los especialistas de hábitat deben de estar muy relacionados con la estructura del hábitat.Segunda, las poblaciones con densidades altas de individuos reproductores deben tener mejor sobrevivencia de adultos, menor reclutamiento y mayor estabilidad. Además, analizamos la correlación entre la estructura del hábitat y la estabilidad demográfica. Las características demográficas fueron menos similares en aquellas áreas en donde existieron mayores diferencias en las características de la vegetación. Las áreas con densidades más altas de individuos reproductores tuvieron un bajo reclutamiento de individuos jóvenes y subadultos durante la época reproductiva. La mayoría de las poblaciones estuvieron relativamente estables durante el primer año de estudio, sin embargo, durante el segundo año, una población disminuyó hasta extinguirse.Key Words: Peromyscus difficilis, demography, habitat structure, habitat specialists, Durango, Michilia Biosphere Reserve.

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