Natal nutrition and the habitat distributions of male and female black-capped chickadees

2005 ◽  
Vol 83 (11) ◽  
pp. 1495-1501 ◽  
Author(s):  
Harry van Oort ◽  
Ken A Otter
Keyword(s):  
Body Condition ◽  
Mixed Forest ◽  
Breeding Habitat ◽  
Suitable Habitat ◽  
Poecile Atricapillus ◽  
The Past ◽  
Ideal Despotic Distribution ◽  
Similar Body ◽  
Similar Growth ◽  
Ideal Despotic

In nonmigratory passerines, dispersing juveniles may compete to settle in suitable habitat patches, leading to phenotypic assortment across habitat types. We compared the past natal nutrition of 1st year black-capped chickadees (Poecile atricapillus (L., 1766)) that settled in two adjacent patches known to differ in suitability as breeding habitat: a mature mixed forest (good habitat) versus a young regenerating forest dominated by conifers (poor habitat). The past natal nutrition of recruits was estimated by measuring growth bars on their tail feathers grown as nestlings; growth bars were positively associated with body condition of birds at the time of capture, suggesting this measure may accurately reflect individual condition. Males that settled in either habitat had similar growth bar size; however, females that settled in the mature habitat had slightly larger growth bars than those in poor habitat. Individuals occupying the disturbed site were of similar size and in similar body condition compared with those that settled in the mature forest. These findings suggest that females may be more discriminating of habitat quality than males during natal dispersal, matching what is known about chickadee dispersal behaviour. We suggest that males are distributed with a non-ideal despotic distribution, whereas females are distributed with an ideal despotic distribution.

scholarly journals Territoriality and time budgets in beavers during sequential settlement

1994 ◽  
Vol 72 (7) ◽  
pp. 1227-1237 ◽  
Author(s):  
Bart A. Nolet ◽  
Frank Rosell
Keyword(s):  
Body Condition ◽  
Territory Size ◽  
Time Budgets ◽  
Linear Habitats ◽  
Ideal Despotic Distribution ◽  
No Man's Land ◽  
Main Food Source ◽  
Ideal Despotic ◽  
Salix Spp

Beavers (Castor fiber) were sequentially released into a previously unoccupied area. The settlement of the animals approximated an ideal despotic distribution: they successively settled in rich habitat and then in poor habitat, and then became floaters. This pattern is regarded as evidence that territorial behavior limited density. The early arrivals showed a seasonal difference in territory size (small in winter, large in late spring and summer), which was expected from optimal territory size theory but which was not found in later arrivals. In the first 2 years, the beavers were swimming very large distances (up to 20.0 km per night), and were apparently undergoing a long-term decline in body condition. Body temperature decreased during swimming, especially in winter (daily amplitude 2.04 °C). Each year, winter territories were about the size (7.9 ± 0.9 (SE) km, including 3.0 ± 0.4 km of wooded banks) that beavers could patrol daily without losing body condition. The number of territories established at any one time during the 5 years of study was only half the carrying capacity calculated on the basis of the current length of wooded banks within territories, in accordance with the prediction for sequential settlement in linear habitats. However, extensive no-man's-land was not present between territories, but early arrivals claimed larger territories than later ones. Social and thermoregulatory factors seem to play an important role in determining the costs of territory defense, and hence territory size. Overexploitation of the beaver's main food source, willow (Salix spp.), seems unlikely in this productive habitat.

Assisted colonisation trial of the eastern barred bandicoot (Perameles gunnii) to a fox-free island

2017 ◽  
Vol 44 (7) ◽  
pp. 484 ◽  
Author(s):  
Rebecca Groenewegen ◽  
Dan Harley ◽  
Richard Hill ◽  
Graeme Coulson
Keyword(s):  
Habitat Use ◽  
Body Condition ◽  
Red Fox ◽  
Suitable Habitat ◽  
Viable Option ◽  
Predator Exclusion ◽  
In The Wild ◽  
Radio Transmitters ◽  
Release Group ◽  
Small Sites

Context Assisted colonisation has the potential to protect species from intractable threats within their historical ranges. The Australian mainland subspecies of the eastern barred bandicoot (Perameles gunnii) is extinct in the wild, with surviving populations restricted to small sites protected by predator–barrier fences. PVA modelling shows that a self-sustaining bandicoot population would require an area free of the introduced red fox (Vulpes vulpes) of at least 2500ha. French Island is outside the historic range of the species, but is fox-free and contains around 9000ha of potentially suitable habitat. Aims This study will assess the suitability of French Island as a potential site for a self-sustaining eastern barred bandicoot population by conducting a 1-year assisted colonisation trial to assess habitat use, body condition and survival. Methods Between July and September 2012, 18 adult bandicoots were released. We radio-tracked bandicoots using intraperitoneal radio-transmitters for up to 122 days and trapped fortnightly. Key results The release group met the three measures of success: (1) appropriate habitat use; (2) recovery of post-release bodyweight; and (3) founder survival exceeding 100 days. Habitat use and body condition throughout the trial reflected that of mainland populations, and seven bandicoots survived longer than 100 days. Mortality was greatest in the first month, with veterinary investigations confirming two deaths due to cat predation, two deaths from toxoplasmosis and one unknown cause of death. Bandicoots that survived longer than 100 days occupied higher, drier ground than those that did not. Toxoplasmosis cases were associated with lower topographic position on the site. Conclusions Our results suggest that French Island provides suitable habitat for the establishment of a population of eastern barred bandicoots. On French Island, toxoplasmosis was identified as an important source of mortality in addition to cat predation, and warrants further investigation. Implications Given the costs and challenges of predator control and the maintenance of predator exclusion fences, assisted colonisation to one or more fox-free islands remains the most viable option to establish self-sustaining bandicoot populations. Our results highlight the value in conducting trial releases ahead of major translocations.

A Comparison of Growth-Rates in Dependent Juveniles of Planigale-Gilesi and Planigale-Tenuirostris (Marsupialia, Dasyuridae)

1987 ◽  
Vol 35 (2) ◽  
pp. 161 ◽  
Author(s):  
DG Read
Keyword(s):  
Community Structure ◽  
Linear Regression ◽  
Body Condition ◽  
Growth Rates ◽  
Developmental Stages ◽  
Early Weaning ◽  
Body Sizes ◽  
Eye Opening ◽  
Body Parameters ◽  
Similar Growth

Growth rates are compared from birth to early weaning in Planigale gilesi and P. tenuirostris, by means of linear regression of body parameters plotted against age. Pouch young of each species had similar growth rates; an equation is given for the aging of pouch young of P. gilesi. Juveniles of P. gilesi grew faster than those of P. tenuirostris; in both species there was a trend for males to grow faster than females. Eye opening and the end of weaning were two important developmental stages, associated with changes to reduced growth rates. Changes in body condition of the juveniles indicated that the weaning process was initiated by the mother. The different growth rates between the species and sexes produced a range of body sizes in juveniles at independence. This has important implications for partitioning of food and for community structure.

Use of bioclimatic analysis to direct survey effort for the long-footed potoroo (Potorous longipes), a rare forest-dwelling rat-kangaroo

2002 ◽  
Vol 29 (2) ◽  
pp. 193 ◽  
Author(s):  
A. W. Claridge
Keyword(s):  
Environmental Variables ◽  
New Records ◽  
New South ◽  
New South Wales ◽  
Geographic Range ◽  
Suitable Habitat ◽  
The Past ◽  
South Wales ◽  
North Eastern ◽  
Survey Effort

The long-footed potoroo (Potorous longipes) is one of the rarest and most elusive forest-dwelling mammals in Australia. Survey effort for the species over the past decade or so in south-eastern New South Wales has been driven, primarily, by predictions derived from climatic analyses using BIOCLIM. These predictions were based on known locality records of the long-footed potoroo from adjacent East Gippsland, Victoria. While they have proven useful in confirming the occurrence of the species in New South Wales, recent fortuitous records of the species from north-eastern Victoria fall well outside of the range predicted earlier by BIOCLIM. Using these new records a revised predicted range is calculated, enlarging considerably the potential geographic extent of climatically suitable habitat for the species. The results presented here highlight the limitations of BIOCLIM when given locality records of a species from only a portion of its true geographic range. I argue that less emphasis might be based on this approach to direct survey effort for the species in the future. Instead, a range of other environmental variables might be used in combination with BIOCLIM-derived outputs when selecting survey sites. In this way a more representative picture of the distribution of the species may be obtained.

scholarly journals The benefits of using topographic features to predict climate-resilient habitat for migratory forest landbirds: An example for the Rusty Blackbird, Olive-sided Flycatcher, and Canada Warbler

The Condor ◽  
2020 ◽  
Vol 122 (1) ◽  
Author(s):  
Shannon Bale ◽  
Karen F Beazley ◽  
Alana Westwood ◽  
Peter Bush
Keyword(s):  
Nova Scotia ◽  
Species Distribution ◽  
Habitat Suitability ◽  
Strong Association ◽  
Breeding Habitat ◽  
Important Predictor ◽  
Suitable Habitat ◽  
Topographic Features ◽  
Precipitation Regimes ◽  
Rusty Blackbird

Abstract Maintaining a functionally connected network of high-quality habitat is one of the most effective responses to biodiversity loss. However, the spatial distribution of suitable habitat may shift over time in response to climate change. Taxa such as migratory forest landbirds are already undergoing climate-driven range shifts. Therefore, patches of climate-resilient habitat (also known as “climate refugia”) are especially valuable from a conservation perspective. Here, we performed maximum entropy (Maxent) species distribution modeling to predict suitable and potentially climate-resilient habitat in Nova Scotia, Canada, for 3 migratory forest landbirds: Rusty Blackbird (Euphagus carolinus), Olive-sided Flycatcher (Contopus cooperi), and Canada Warbler (Cardellina canadensis). We used a reverse stepwise elimination technique to identify covariates that influence habitat suitability for the target species at broad scales, including abiotic (topographic control of moisture and nutrient accumulation) and biotic (forest characteristics) covariates. As topography should be relatively unaffected by a changing climate and helps regulate the structure and composition of forest habitat, we posit that the inclusion of appropriate topographic features may support the identification of climate-resilient habitat. Of all covariates, depth to water table was the most important predictor of relative habitat suitability for the Rusty Blackbird and Canada Warbler, with both species showing a strong association with wet areas. Mean canopy height was the most important predictor for the Olive-sided Flycatcher, whereby the species was associated with taller trees. Our models, which comprise the finest-scale species distribution models available for these species in this region, further indicated that, for all species, habitat (1) remains relatively abundant and well distributed in Nova Scotia and (2) is often located in wet lowlands (a climate-resilient topographic landform). These findings suggest that opportunities remain to conserve breeding habitat for these species despite changing temperature and precipitation regimes.

scholarly journals A Propensity Score Cohort Study on the Long-Term Safety and Efficacy of Sleeve Gastrectomy in Patients Older Than Age 60

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Judith Molero ◽  
Romina Olbeyra ◽  
Josep Vidal ◽  
Ferran Torres ◽  
Silvia Cañizares ◽  
...  
Keyword(s):  
Statistical Difference ◽  
Control Group ◽  
Normal Range ◽  
Inverse Probability ◽  
The Past ◽  
Obese Subjects ◽  
Similar Body

Background. Bariatric surgery (BS) in older obese subjects (>60 years of age) has risen in the past decade and will continue to rise in the coming years due to ageing of the population. Aim. To evaluate the short- (12 months) and long-term (60 months) results of laparoscopic sleeve gastroscopy (LSG) in patients older than age 60. Methods. We performed a retrospective review of patients prospectively included in a database from January 2007 to December 2013. All patients >60 [older group (OG)] who had undergone LSG were included. The control group (CG) included patients aged 50 to 59 years who had undergone LSG during the same period. Results. 116 (8.4 % of total surgery) and 145 patients were included in the OG and CG, respectively. BS in patients >60 years increased from 2.4% in 2003 to 14% in the last 2 years of the study. After inverse probability of treatment weighting (IPTW) analysis, all absolute standardized differences were <0.15. A 60-month follow-up was attained in 90% of patients in the OG and 74% in the CG. There were no significant differences in postoperative complications between the two groups. At 12 and 60 months after LSG, both groups achieved a similar body mass index. There was no statistical difference in the percentage of resolution of type 2 diabetes, hypertension, dyslipidemia, and SAHS between the two groups. In both groups, all the nutritional parameters evaluated remained within the normal range throughout the study. Conclusions. LSG provides acceptable outcomes and is safe in older adults indicating that age should not be a limitation to perform BS in this population.

Post-weaning growth of Hereford and first-cross heifers grazing three pasture systems

1989 ◽  
Vol 112 (1) ◽  
pp. 19-32 ◽  
Author(s):  
Helen Hearnshaw ◽  
R. E. Darnell ◽  
R. Barlow ◽  
Virginia Finch
Keyword(s):  
Growth Rate ◽  
Body Condition ◽  
Subcutaneous Fat ◽  
Live Weight ◽  
The Other ◽  
Frame Size ◽  
Skeletal Size ◽  
Pelvic Area ◽  
Genotype Interaction ◽  
Similar Body

SummaryThe post-weaning growth, frame size and body condition of Hereford (H × H), Brahman × Hereford (B × H), Simmental × Hereford (S × H) and Friesian × Hereford (F × H) heifers were evaluated on three pasture systems in each of five years. One group of heifers was grown from weaning (at 8 months of age) to 18 months on the high-pasture system, which included supplementation with grain, while the other two groups were grown to 30 months on pastures of medium or low quality. Pasture effects were large compared with differences between years, with average daily gains between weaning and 18 months of 552, 275 and 97 g/day on high, medium and low pastures, respectively. Genotype had a significant effect on all measurements. Pasture × genotype interaction was significant in most instances. While crosses grew faster and were heavier than H × H on all pastures, S × H were heaviest by 18 months on high pasture, with B × H heaviest at all ages up to 30 months on both medium and low pastures. There was little difference in live weight between B × H and F × H on high pasture, or between S × H and F × H on medium pasture, whereas F × H was heavier than S × H on low pasture. There were concomitant differences in measures of skeletal size, but when adjusted allometrically to a common live weight, pasture effects were removed, while differences between genotypes remained. At a common live weight F × H had the largest height, length and pelvic area, but shared the lowest body condition with S × H. Pelvic height was greatest among B × H heifers, but this cross had similar body length, condition and subcutaneous fat cover to H × H. The pattern of genotype × pasture interaction observed in this study was similar to that observed by Darnell, Hearnshaw & Barlow (1987) for growth rate among contemporary steers located in different environments.

Growth and carcass characteristics of crossbred and straightbred Hereford steers. III. Post-weaning growth in seven environments in New South Wales

1987 ◽  
Vol 38 (5) ◽  
pp. 941 ◽  
Author(s):  
RE Darnell ◽  
H Hearnshaw ◽  
R Barlow
Keyword(s):  
Body Condition ◽  
Bos Taurus ◽  
New South ◽  
Average Daily Gain ◽  
New South Wales ◽  
Coastal Environments ◽  
South Wales ◽  
Similar Body ◽  
Daily Gain ◽  
Constant Growth

Post-weaning growth, liveweight and body condition at slaughter were examined in 289 steers comprised of straightbred Hereford and first cross Brahman x Hereford, Simmental x Hereford and Friesian x Hereford. The steers were grown from weaning in seven environments throughout New South Wales. All steers were slaughtered when the average fat cover of the Herefords was in the range of 6-10 mm at the 12/13th rib. Brahman crossbreds were in similar body condition to Herefords at slaughter, which in turn were generally in better condition than both Simmental and Friesian crossbreds. Crossbred steers were heavier than Herefords at slaughter. Simmental crosses and Friesian crosses were 53 kg (12%) heavier on average over all environments, and Brahman crosses 41 kg (10%) and 83 kg (16%) heavier in inland and coastal environments respectively. Mean average daily gain (ADG) of the crossbred steers was always greater than that of the Hereford steers. There was a trend for ADG to be greater among the Brahman crosses earlier in the post-weaning period, but for the Simmental and Friesian crosses to grow faster later in the post-weaning period. Simmental crosses maintained a constant ADG advantage relative to Friesian crosses throughout the post-weaning period in environments where growth was favoured. Significant genotype x environment interactions occurred. Relative to Herefords, Simmental and Friesian crossbreds responded more to improved conditions, while Brahman crossbreds maintained a constant growth advantage regardless of environmental conditions. Bos taurus crosses grew faster than Brahman crosses, and Simmental crosses faster than Friesian crosses, only when environments were highly favourable.

scholarly journals Life form dynamics of the tree layer in evergreen and deciduous broad-leaved mixed forest during 1996–2017 in Tianmu Mountains, eastern China

Silva Fennica ◽  
2020 ◽  
Vol 54 (2) ◽  
Author(s):  
Cheng Bai ◽  
Shixue You ◽  
Weipeng Ku ◽  
Qilin Dai ◽  
Zhengyi Wang ◽  
...  
Keyword(s):  
Mortality Rate ◽  
Life Form ◽  
Eastern China ◽  
Mixed Forest ◽  
Small Diameter ◽  
Life Forms ◽  
Recruitment Rate ◽  
Diameter Class ◽  
Evergreen Species ◽  
The Past

In the forest areas of eastern China, there is a change from forest dominated by deciduous broad-leaved trees to forest dominated by evergreen broad-leaved trees as the latitude or altitude decreases. Different life forms have different survival strategies to deal with climate change, and studying the life form dynamics of the tree layers in the mixed forest in eastern China, with increasing temperature, can help us understand how the forest responds. This study was performed in a 1 ha plot in evergreen and deciduous broad-leaved mixed forest in Tianmu Mountain National Nature Reserve. Based on the data from two surveys (1996 and 2017), the changes in life form composition and biodiversity over the past 21 years were analyzed. We obtained the following results: (1) The proportion of evergreen trees increased from 55.0% in 1996 to 67.5% in 2017, and the dominance of evergreen species was enhanced. (2) The diversity of both life forms increased, and the tree species were more abundant. (3) The average annual recruitment rate of the evergreen species was 2.1% greater than their mortality rate, and the average annual recruitment rate of the deciduous species was 0.5% less than their mortality rate. (4) The competition among the trees in the small-diameter class (10 cm ≤ DBH < 20 cm) was fierce for many tree species. The proportion of the evergreen species in the small-diameter class was high. The life forms making up the mixed climax forest community has changed over the past 21 years, with the proportion and dominance of evergreen trees increasing significantly.

Sign in / Sign up

Export Citation Format

Share Document