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Age structure of adult Northern Flickers at the time of banding in the Riske Creek study area. Most newly banded birds are assumed to be immigrants. Data are for 541 individuals captured from the years 2000-2004.
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Although many forestry management strategies rely on population estimates of indicator species such as woodpeckers (Picidae), empirical estimates of demographic parameters within this taxon are few. We used program MARK to assess influences of age and sex on apparent survival of adult Northern Flickers (Colaptes auratus) from a six-year mark-recapt...
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... were newly banded in that particular year. A bird was considered resighted if it was seen in the following year of the study. Sample size is the total number of known color- banded adults or aluminum-banded fledglings that year. of four years when first captured, and the majority of immigrants to our population were younger than four years old (Fig. 1). To estimate age structure of the population, we used only the last three years of data from the field study. In these years, adults banded in 1998 and 1999 would have had time to reach eight years. The maximum age we observed for breeding males was 8 years (one of 303 individuals), and for females 7 years (one of 302; Fig. 2). ...
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Citations
... As trees with broken crowns were typically shorter, they act as an upper limit on cavity height. Other studies have shown decreased risk of predation with increasing nest cavity height (Nilsson, 1984;Fisher and Wiebe, 2006;Berkunsky et al., 2016). Redheaded woodpeckers that maximize cavity height, particularly when it is limited by tree height, protect their broods from depredation by ground predators (Hudson and Bollinger, 2013). ...
... Additionally, black bears (Ursus americanus) are frequent predators of sapsucker nests (Franzreb and Higgins 1975, Hannon and Cotterill 1998, Walters and Miller 2001, Tozer et al. 2009, and larger decayed trees may be easier for bears to climb and access nest cavities. The positive relationship of sapsucker nest survival with nest height is consistent with our prediction of better protection from ground-based nest predators (e.g., black bears likely find higher nests less accessible; Best and Stauffer 1980, Nilsson 1984, Li and Martin 1991, Fisher and Wiebe 2006. ...
Mountain pine beetle ( Dendroctonus ponderosae ) outbreaks in western North American coniferous forests are increasing in size and severity. An understanding of wildlife population responses to pine beetle outbreaks is needed to inform habitat conservation strategies. We monitored 355 nests of 5 woodpecker species during 2 sampling periods, before (2003–2006) and after (2009–2014) the peak of a pine beetle outbreak in dry mixed conifer forest of Montana, USA. Three of 5 woodpecker species represented the beetle‐foraging group: American three‐toed ( Picoides dorsalis ), hairy ( Dryobates villosus ), and downy ( D. pubescens ) woodpeckers. The other 2 species studied were northern flicker ( Colaptes auratus ), a foraging and habitat generalist, and red‐naped sapsucker ( Sphyrapicus nuchalis ), a sap forager and bark‐gleaning insectivore. We analyzed daily survival rate of nests in relation to pine beetle outbreak (445,000 ha) severity and timing, along with covariates unrelated to the outbreak (temp, nest height, and nest tree diameter). Our results provided stronger evidence for relationships between woodpecker nest survival and the non‐outbreak variables than those associated with outbreaks. Our results indicated limited support for nest survival relationships with beetle severity (annual and cumulative pine tree mortality at 0.81‐ha and 314‐ha scales). Nevertheless, we observed a significant increase in densities of hatched nests for beetle‐foraging woodpeckers following the outbreak. Our results suggest that woodpeckers, particularly beetle foragers, respond numerically to pine beetle outbreaks through increased nesting densities more so than functionally via nest survival. © 2019 The Authors. Journal of Wildlife Management Published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.
... Reproductive parameters were tracked for all breeding pairs by checking active nests every 4-5 days. Flickers have a relatively fast life history (Wiebe 2006a) with large and variable clutches ranging between 2 and 13 eggs and annual apparent mortality rates of 60% which do not vary with age (Fisher and Wiebe 2006c) or sex (Flockhart and Wiebe 2008). If both pair members survive to return in a subsequent year, which occurs with probability (0.4) 2 , and mates are retained 75% of the time (Wiebe 2005), the chance of breeding again with the same partner in the subsequent year is 12%. ...
Age-related improvement in reproductive performance is widespread in vertebrates and constraints at young ages are a common cause. The sex that invests energetically more in reproduction, typically the female, is predicted to show stronger age-related performance but the effect of the male’s age on reproduction has often been ignored. I studied age-related reproduction of both sexes in northern flickers, in which males invest more parental care than females, predicting that the effect of age would be stronger in males than in females. Longitudinal data on individuals collected during an 18-year field study confirmed this prediction. Laying dates for females improved only between the first 2 years of her life and no other reproductive parameter changed over her lifetime when the male’s age was statistically controlled. In contrast, males improved up to age five for laying date, clutch size, hatching success and fledging success. Partner familiarity (fidelity) was further associated with earlier laying, larger clutches, improved fledging success and more fledglings. There was significant assortative pairing by age but there is apparently little benefit for males to choose older females, but a benefit to females with older males. Females appear to strategically lay larger clutches when paired to old males which invest more in paternal care than younger males. This is the first example of clutch size being influenced by only male age and not female age in any bird and suggests that sex roles in parental care are important determinants of aging patterns in vertebrates with diverse life histories.
... Male flickers typically provide parental care for at least 14 d post-fledging (Gow and Wiebe 2014a), so I assumed birds were in breeding territories from the date of deployment until 14 d after young fledged. Return rates for flickers with geolocators (ß39%) were similar to those for flickers without geolocators (ß42%; Fisher and Wiebe 2006). ...
The use of light-level geolocators for monitoring migration has been limited to non-cavity roosting species because light transitions for cavity-roosting species are obscured. Using Northern Flickers (Colaptes auratus), nocturnal cavity-roosting woodpeckers, as a model, I describe a method for analyzing geolocator data that initially adjusts light transitions to account for differences between the time of minimum light threshold and when a bird enters or exits a cavity. Using known locations from the breeding grounds, I assessed the precision of this adjustment method for estimating location by examining the associated error, the repeatability of the length of time individuals roosted in cavities, and by conducting a sensitivity analysis to assess uncertainty. Mean location error decreased from 1417 ± 277 km (SD) to 129 ± 194 km when sunrise and sunset times were adjusted and locations from >25 d were averaged. Sensitivity analysis showed that if an adjusted sunrise or sunset time was "incorrect" by 10 min, the error was 121-137 km from the actual location. This adjustment method significantly improved location estimates at known sites, suggesting that adjusting light transitions based off a calibration is a good initial step for determining location. However, to account for behavioral changes in entrance and emergence times, applying state-space Kalman filter models can further improve the accuracy of location estimates. The combination of adjusting transitions and applying a state-space Kalman filter thus allows location estimates to be obtained from cavity-roosting species using geolocator data.
... K.L.W. trapped and measured all Northern Flickers to eliminate observer bias. The apparent annual mortality rate of adults is relatively high compared with that of other woodpeckers (~60%; Fisher and Wiebe 2006), so there is a rapid turnover of individuals in the population and most birds breed in their first year (summer after hatching; hereafter ''yearlings''). ...
Melanin is a common pigment in the plumage of birds, but the extent to which its deposition in feathers is condition dependent and can be used as a reliable signal of quality and reproductive performance is still much debated. In addition, the existence and function of melanin ornaments in female birds or in birds of different age classes has rarely been addressed. We studied the size and color of 4 melanin ornaments in the Northern Flicker (Colaptes auratus), a woodpecker, and found that the plumage patches became larger or darker with age class in both sexes. Consistent with the partly reversed sex roles of Northern Flickers and sexual selection in both sexes, several melanin ornaments were the same size in males and females and were correlated with body size or body condition. There was assortative pairing according to melanin ornaments when controlling for age, and 1 or more ornaments predicted laying date or clutch size of the pair independent of age. The results suggest that melanin ornaments in Northern Flickers may contain multiple messages and be used as cues of quality.
... The breeding effort of~100-160 breeding flicker pairs has been monitored here since 1998. Flickers weigh~150 g, and have a relatively ''r-selected'' or ''fast'' life history strategy with large and variable clutch sizes (mean 8 eggs, range of 3-13 in the absence of brood parasitism; Wiebe and Moore 2008) and relatively low annual apparent survival rates of adults of~42% (Fisher and Wiebe 2006). Incubation lasts~12 days and the nestling period 25-27 days (Wiebe and Moore 2008). ...
... In another species of woodpecker, however, the provisioning strategy to natural broods was sex-specific; female, but not male, Lesser Spotted Woodpeckers (Picoides minor) provisioned in relation to brood size perhaps because females had lower survival rates and valued the current brood more than males (Rossmanith et al. 2009). In contrast, survival rates do not differ between male and female flickers (Fisher and Wiebe 2006), and indeed females may be less invested in the current brood than males because they have FIGURE 3. Per-nestling provisioning (trips per hour per nestling) by parent Northern Flickers in relation to brood size for 3 nestling stages: (A) age 5-7 days, (B) age 10-13, and (C) age 18-21). The best-fit models were linear for Stages 1 (n ¼ 53 nests) and 2 (n ¼ 51 nests), and quadratic for Stage 3 (n ¼ 41 nests). ...
Brood enlargement experiments have been conducted in several species of birds to investigate how parents of both sexes adjust their investment in the current breeding attempt. We studied parental feeding effort in the Northern Flicker (Colaptes auratus), a species with partially reversed sex roles where males invest more in parental care than females and in which there is facultative polyandry and no extra-pair young. By experimentally manipulating brood sizes to be either larger or smaller by about 40%, we tested the flexibility of provisioning responses by each sex and whether the upper limit to provisioning corresponded to the maximum clutch size in the population. Both male and female parents increased feeding rates to enlarged broods, but per-nestling provisioning declined so that they fledged lighter nestlings with shorter wings. Mortality in reduced broods was lower than in control broods, but there was no difference in the incidence of mortality between control and enlarged broods. Parents with enlarged broods raised lighter fledglings than control parents with the same brood size suggesting clutch size is individually optimized. We conclude that, although flickers were able to raise extra offspring, brood size may be individually optimized if the smaller mass and wing length of offspring lead to lower recruitment.
... In particular, 50% of six studies on long-lived species, and 89% of 28 studies on shortlived species found that parents increased feeding rates to enlarged broods. Flickers have a relatively short lifespan compared with most birds (40% annual adult apparent survival rate; Fisher & Wiebe 2006b), and so they are atypical for a short-lived species by maintaining their feeding rates when given more young. However, flickers responded similarly to other species by reducing feeding rates when broods were reduced ( Table 1). ...
Manipulations of brood size measure the willingness or ability of parents to invest in offspring and different reproductive roles may lead to differences in feeding effort between the sexes. Parental investment in birds is usually assessed by quantifying feeding rates, but this provides an incomplete picture of parental effort because it fails to account for how parents collect food on the landscape. We studied northern flickers (Colaptes auratus), a woodpecker in which males provide the majority of parental care and used a repeated measures design and short‐term (24 h) brood enlargements (N = 35) and reductions (N = 27) to assess effects of treatment on feeding rates to nestlings and parental foraging behaviour. Parents of enlarged broods did not significantly increase feeding rate, resulting in a decline in nestling mass. Parents of reduced broods decreased their feeding rates by 84%, but increased per capita feeding rates, resulting in nestling mass gain. The variation in feeding rates to enlarged broods was not influenced by feather corticosterone, body condition, feather re‐growth rate or mass change between the incubation and nestling periods. Foraging pattern on the landscape remained the same during the enlarged treatment for both sexes. We conclude that flickers respond to proximate cues in brood demands, but do not increase feeding rates to enlarged broods, at least in the short term. A literature review suggested that this lack of response is atypical for short‐lived species. We hypothesize that parents in species with large home ranges and long nestling periods face energetic limitations that constrain their ability to respond to enlarged broods. We encourage future studies to assess foraging behaviour on the landscape to document important trade‐offs for parents such as predation risk and energy expenditure while feeding offspring.
... We attached the devices using a leg loop backpack harness (see Appendix S1). The return rate of Flickers with geolocators was 39% of 76 birds, equal to Flickers without geolocators (~42%; Fisher & Wiebe 2006), and geolocators did not affect the birds' ability to enter a cavity. ...
The importance of cavities as roost sites in migratory species is often unknown because it is challenging to monitor cavity use during the non-breeding period. We documented cavity use throughout the annual cycle of a woodpecker using light-level geolocators. Northern Flickers Colaptes auratus spent 63–90% of nights roosting in a cavity throughout the year, including during migration. The high frequency of year-round cavity use by Flickers suggests that cavities provide benefits beyond nest-sites. Our work highlights the potential use of geolocators to examine cavity use.
... There is little information in the literature on survival rates in the sexes. However, a study in wild birds also observed no differences in survival between the sexes (Fisher and Wiebe, 2006). ...
This study was conducted at the grasscutter section of the University of Education, Winneba, Ghana, to estimate non-genetic effects on reproductive and survival traits. Data consisted of records on 136 does from 2006 to 2010. Litter size at weaning, litter weight and lactation weight loss all increased (P < 0.01) with increasing litter size at birth. Litter weight and lactation weight loss increased (P < 0.05) at weaning, whilst days of joining decreased (P < 0.01), with increasing years. Minor rainy season was found to be the most suitable mating season. Dams that kidded in dry season took fewer (P < 0.05) days to conceive than in other seasons. Nursing dams lost more (P < 0.05) weight in dry and minor rainy seasons than in major rainy season. Increasing parity led to decreasing (P < 0.05) pre-weaning survival of offspring. Post-weaning survival of offspring decreased (P < 0.01) with increasing years. Kids conceived in the minor rainy and dry seasons had significantly higher (P < 0.05) post-weaning survival rates than those conceived in the major rainy season. Post-weaning survival rates of kids born in the minor rainy season were lower (P < 0.05) than those born in other seasons. It was concluded that non-genetic factors influenced fitness traits and must therefore be considered when designing grasscutter breeding programmes.
... In contrast, we hypothesized that nest survival of aerial-ground insectivores would increase with time since fire in accordance with increases in their nesting densities, and that partial-salvage logging would have little effect on their nest survival because increased space between trees might facilitate foraging maneuvers and therefore their ability to obtain food (Haggard and Gaines 2001, Wightman and Germaine 2006, Saab et al. 2007. Last, we hypothesized that nests placed at greater heights from the ground and farther from unburned forests would have higher survival because those nests would be more difficult to access by nest predators (Nilsson 1984, Li and Martin 1991, Saab et al. 2004, Fisher and Wiebe 2006. ...
Salvage logging practices in recently burned forests often have direct effects on species associated with dead trees, particularly cavity-nesting birds. As such, evaluation of postfire management practices on nest survival rates of cavity nesters is necessary for determining conservation strategies. We monitored 1,797 nests of 6 cavity-nesting bird species: Lewis's woodpecker (Melanerpes lewis), hairy woodpecker (Picoides villosus), black-backed woodpecker (P. arcticus), northern flicker (Colaptes auratus), western bluebird (Sialia mexicana), and mountain bluebird (S. currucoides) from 1994 to 2004 in ponderosa pine (Pinus ponderosa), mixed-severity burned forests (partially logged and unlogged) of Idaho, USA. Based on a priori hypotheses, we modeled daily survival rate (DSR) of nests as a function of abiotic (temperature, precipitation), temporal (time since fire, calendar year) and biotic factors (distance to unburned forest, nest height, and tree harvest [partial-salvage logging vs. unlogged]). Multiple abiotic and biotic factors, other than direct effects of salvage logging, affected daily survival rates of breeding cavity-nesting birds. Hairy woodpecker was the only species in which partial-salvage logging had a measurable, negative impact on DSR. Managers implementing carefully planned salvage logging prescriptions that include both unlogged reserves and partially logged areas can expect to maintain habitat for successfully breeding cavity-nesting birds of the interior northwestern United States. Our results also suggest that nest survival for some species of cavity-nesting birds could be improved if unlogged reserves are located centrally in postfire forests, distant from unburned habitats that potentially serve as sources of nest predators. © 2011 The Wildlife Society.
