Captive Adults Research Articles

A comparison of pedigree‐ and DNA‐based measures for identifying inbreeding depression in the critically endangered Attwater's Prairie‐chicken

The primary goal of captive breeding programmes for endangered species is to prevent extinction, a component of which includes the preservation of genetic diversity and avoidance of inbreeding. This is typically accomplished by minimizing mean kinship in the population, thereby maintaining equal representation of the genetic founders used to initiate the captive population. If errors in the pedigree do exist, such an approach becomes less effective for minimizing inbreeding depression. In this study, both pedigree- and DNA-based methods were used to assess whether inbreeding depression existed in the captive population of the critically endangered Attwater's Prairie-chicken (Tympanuchus cupido attwateri), a subspecies of prairie grouse that has experienced a significant decline in abundance and concurrent reduction in neutral genetic diversity. When examining the captive population for signs of inbreeding, variation in pedigree-based inbreeding coefficients (f(pedigree)) was less than that obtained from DNA-based methods (f(DNA)). Mortality of chicks and adults in captivity were also positively correlated with parental relatedness (r(DNA)) and f(DNA), respectively, while no correlation was observed with pedigree-based measures when controlling for additional variables such as age, breeding facility, gender and captive/release status. Further, individual homozygosity by loci (HL) and parental rDNA values were positively correlated with adult mortality in captivity and the occurrence of a lethal congenital defect in chicks, respectively, suggesting that inbreeding may be a contributing factor increasing the frequency of this condition among Attwater's Prairie-chickens. This study highlights the importance of using DNA-based methods to better inform management decisions when pedigrees are incomplete or errors may exist due to uncertainty in pairings.

When the Seasons Don't Fit: Speedy Molt as a Routine Carry-Over Cost of Reproduction

The failure of animals to fit all life-cycle stages into an annual cycle could reduce the chances of successful breeding. In some cases, non-optimal strategies will be adopted in order to maintain the life-cycle within the scope of one year. We studied trade-offs made by a High Arctic migrant shorebird, the red knot Calidris canutus islandica, between reproduction and wing feather molt carried out in the non-breeding period in the Dutch Wadden Sea. We compared primary molt duration between birds undertaking the full migratory and breeding schedule with birds that forego breeding because they are young or are maintained in captivity. Molt duration was ca. 71 days in breeding adults, which was achieved by an accelerated feather replacement strategy. Second-year birds and captive adults took ca. 22% and 27% longer, respectively. Second-year birds start molt in late June, more than four weeks before captive adults, and almost seven weeks before adults that return from breeding in late July–August. Adults finish molt in October when steeply increasing thermostatic costs and reductions in food availability occur. Primary molt duration was longer in female than in male knots (all ages), which was accordance with the somewhat larger body size of females. Since fast growth leads to lower quality feathers, the speedy wing molt shown by Arctic-breeding birds may represent a time constraint that is an unavoidable and routine cost of reproduction. So far it was hypothesized that only birds over 1 kg would have difficulty fitting molt within a year. Here we show that in birds an order of magnitude smaller, temporal imperatives may impose the adoption of non-optimal life-cycle routines in the entire actively breeding population.

Sources of Variation in Blood Glucose Concentrations of Free-Living Birds

Three issues concerning avian peripheral blood glucose concentrations that require more investigation are: (a) whether they are as variable and high in free-living as in captive and domesticated adults, (b) the sources of variation in adult concentrations and (c) if and how they change during nestling development. Whole blood glucose concentrations (BGlu) of wild adults of four native passerine and one exotic dove species varying in mass and diet were measured in south-east Australia. There was significant inter-specific variation in BGlu, but the range in mean values (11.1 to 17.0 mmol L−1) conformed with that published for many adult captive and domestic birds of similar size and was well above that for adult mammals of comparable mass. BGlualso varied markedly intra-specifically in four species (coefficients of variation 17.5-32%). Trapping procedure and timing of sampling did not explain this variation, but adult body mass was associated with BGluin two species. If whole blood haemoglobin concentrations (Hb) reliably reflect body condition, most of the adults sampled were in good condition. Wild nestling Welcome swallows (Hirundo neoxena) and Spotted doves (Streptopelia chinensis), respectively, underwent 20% and 40% continuous, linear, developmental increases in BGlu. Swallows fledged with a mean BGlu23% greater than, and doves with a mean similar to, that of adults. The developmental increase probably reflected an increase in metabolic rate as nestlings gained mass and became more active.

Adaptations to captive breeding of the longhorn beetle Morimus funereus (Coleoptera: Cerambycidae); application on amylase study

Captive breeding has been suggested as a method of conservation for many vertebrates, and is increasingly being proposed as a strategy for invertebrates. In this study, the growth, development and fertility of adults of the vulnerable cerambycid Morimus funereus reared in captivity are examined. Two oviposition cycles; from May to September and from January to March were studied and larvae from wild adults and from the progeny of captive adults (second generation larvae) were examined. Five to 12 instars were observed during larval development. Larval development was completed in 218 days (average) for the progeny of wild adults with an average mortality rate of 10.3% and in 226 days (average) for larvae from captive adults with mortality rate of 34.9%. First generation larval body weights were disparate during development, while second generation larvae had similar weights with no significant differences. In this study we have tested the potential of captive breaded M. funereus larvae as a model for investigation of digestive enzymes. Amylase from the midgut of larvae reared under laboratory conditions showed twofold higher specific activities with a decreased number of isoforms expressed, as compared to the enzyme from field-collected larvae. Captive breeding of M. funereus can be used in the future as a part of an effective conservation strategy for this rare insect species.

Precision of Striped Bass Fry Density Estimates

AbstractMany fisheries for striped bass Morone saxatilis in the United States are supported by stocking hatchery‐reared fish. Fingerlings are usually obtained by spawning adults in captivity, collecting fry in large (25–100‐L) collection containers (vats), moving them to rearing facilities (e.g., earthen ponds and raceways), and subsequently harvesting the fish that remain after some predetermined period. The number of fry stocked is estimated, and the accuracy and precision are seldom known or reported. The effect of treating fry stocking estimates as “error free, complete counts” on survival and production estimates is, therefore, also unknown. The objective of this study was to document and determine the statistical precision of the procedures used at Texas Parks and Wildlife Department's Dundee Fish Hatchery through the 1990s (standard procedures still in use at many hatcheries) for estimating fry densities in vats. The precision of fry density estimates was directly correlated with the mean density and sample volume. Such estimates could be improved by reducing the water volume (especially when densities are low) in vats and using a standard sample volume (at least 15 mL) instead of adjusting the sample volume based on visual inspection of fry in vats. The number of samples could be reduced from 10 to 8 without substantially affecting precision. Further, the practice of removing the highest and lowest sample values should be discontinued. The resulting precision of subsequent fingerling survival and production statistics could benefit from these changes without a substantial increase in data analysis.Received August 5, 2010; accepted October 4, 2010

Validating age in southern calamary (Sepioteuthis australis) over seasonal and life history extremes

Through rearing known age individuals and maintaining chemically marked adults in captivity, this study explored the rate of increment formation in southern calamary (Sepioteuthis australis) statoliths over seasonal (summer and winter) and ontogenetic (hatchlings and adults) extremes. A ‘one increment–one day’ relationship was verified for captive-reared hatchlings up to 40 days post-hatching which remained stable across the seasonal extremes. This relationship, however, was not evident in the chemically marked adults as inconsistencies of up to 44 days were detected between the number of days elapsed post-stain and the increment count. No seasonal effect was detected in the ratio between increment count and days elapsed, however, the degree of underestimation was consistently greater for winter-caught adults by approximately 2.5 increments relative to summer-caught adults. This less-than-daily increment formation in adults may be due to: (1) the periodicity of increment formation changing throughout the squid's lifespan; (2) deleterious effects associated with rearing squid in captivity; and/or (3) compromised interpretation of the statolith microstructure as a result of the preparation method.

Conservation initiatives for an endangered migratory passerine: field propagation and release

AbstractThe term ‘field propagation and release’ refers to the breeding of captive adults in large field enclosures, allowing them to raise their young, and then releasing those young from that location. This technique is currently being implemented in Canada as one of several recovery tools for the endangered eastern loggerhead shrike Lanius ludovicianus migrans. During 2001–2007 a total of 360 shrike fledglings were produced in field propagation enclosures and 301 were released from these enclosures. Annual return rates of birds released since 2004 are 2–6.6%. Seventeen released birds have been re-sighted, including 10 birds that have returned to the breeding grounds the following season to produce young with wild mates. The high annual return rate of release birds and the successful integration of these birds into the wild breeding population represent important milestones for the recovery of this population. The management technique we describe here has the potential to be applicable to other species that require natural habitat for breeding and/or are reliant on a suite of parent-learned behaviours that cannot be accommodated for or adequately replicated within intensive close captive-breeding or hand-rearing conditions.

Comparison of total calcium, ionised calcium and albumin concentrations in the plasma of captive tortoises (Testudo species)

Plasma total calcium, ionised calcium and albumin levels in Hermann's tortoises (Testudo hermanni), spur-thighed tortoises (Testudo graeca), marginated tortoises (Testudo marginata) and Horsfield's tortoises (Testudo horsfieldi) were investigated. The animals...

The recovery programme for the Lord Howe Island Phasmid (Dryococelus australis) following its rediscovery

Summary Until its rediscovery on Balls Pyramid in February 2001, the Lord Howe Island Phasmid or Stick Insect (Dryococelus australis) was thought to be extinct. It disappeared from Lord Howe Island soon after the accidental introduction of the Ship Rat (Rattus rattus) in 1918. In this paper, we report on the recovery actions undertaken for this critically endangered species since its rediscovery. Monitoring of the small surviving population on Balls Pyramid has shown it to fluctuate between about 9 and 35 adult individuals. As a safeguard against extinction, two adult pairs were removed from Balls Pyramid in February 2003 to establish captive populations in Melbourne and Sydney. Although all four founders bred readily in captivity, one pair died only a month after capture. The second female would have also died soon after capture had it not been for veterinary intervention using novel untested techniques. The single surviving pair bred successfully but the hatch rate of eggs was poor. For the next generation, both fecundity and hatch rates were low. The lack of knowledge regarding the specific husbandry requirements of this particular species undoubtedly contributed to these problems. Careful management, together with a cautious scientific approach, eventually led to all problems being resolved. Presently, there are more than 700 individuals and 14 000 eggs in captivity. Approximately 80% of incubated eggs are expected to hatch. To establish additional captive colonies, adults and eggs have been sent to other institutions, both within Australia and overseas. Now that the species is reasonably secure in captivity, the opportunity exists to reintroduce this iconic insect back onto Lord Howe Island, but this can occur only after the introduced rodents have been removed. A programme to eradicate both the Ship Rat and the House Mouse (Mus musculus) from Lord Howe Island is currently being developed.

Molt and gastroliths inAustropotamobius pallipes(Lereboullet, 1858)

Knowledge of the molting cycle in crayfish may contribute (1) to improving a population analysis for monitoring and conservation purposes and (2) to imposing significant constraints on practices involved in culture. Two populations of Austropotamobius pallipes in central Italy were monitored from April to November for five years (2002–2006). Crayfish were collected, sexed, and the carapace length (CL) was measured. Molt cycle stages (premolt, molt, postmolt and intermolt) were identified depending on the exoskeleton hardness and color, and the abdomino-thorax splitting. The molt lasted for 6 minutes in juveniles, and maximally 16 minutes in adults in captivity. Males and females were treated separately, and divided into five age classes (0+; 1+; 2+; 3+; >4+). No significant differences were observed between females and males of the same age class. The molting event mainly occurred in April and May ongoing to November. The molting cycle occurred less frequently between July and August, and during the study period it was rarely observed between the last five days of July and the first week of August. Moreover, we measured and counted the gastrolith layers from a total of 124 crayfish (73 females + 51 males) collected twelve years ago, in order to discuss possible correlations between CL and gastrolith size.

Non-invasive measurement of faecal glucocorticoid metabolites in Upland Geese Chloephaga picta

Glucocorticoid (GC) hormones rise in response to stressors, including natural events including weather or predator presence, and human activities, such as hunting, scientific research or recreational visits. However, because blood sampling itself causes stress and is dangerous or even impossible in some wildlife species, feedback-free methods for GC determination are needed to assess stress in these animals. Faecal GC analyses have thus gained interest. Here, we validate a non-invasive method to estimate the physiological stress in the Upland goose Chloephaga picta. An adrenocorticotropin hormone (ACTH) challenge was conducted in captive adults (female and male), and droppings were collected before, during and after the experiment. Corticosterone metabolite (CM) secretion in response to the ACTH challenge was measured with several enzyme immunoassays (EIA) to find the most appropriate test. We used CM levels during the periods before and after the experiment as control data. An EIA for 11-oxoetiocholanolone achieved the highest response to the ACTH challenge and also reflected a stress response to unfamiliar environment. Furthermore, CM concentrations of dry samples were highly correlated with the corresponding non-dried (frozen) samples. The data suggest that this method is appropriate to measure the stress in Upland geese, and that samples can be stored either frozen or dry form.

Hyperplastic goitre and mortality in captive-reared black stilts (Himantopus novaezelandiae)

AIM: To study the gross, histopathological and clinicopathological findings in cases of hyperplastic goitre in sub-adult captive-reared black stilts following their release on riverbeds in the south Canterbury region of New Zealand. METHODS: Necropsies were undertaken on the recovered carcasses of 48 black stilts over a 3-year period (1997–1999). The cause of death was determined, and thyroid glands were examined histopathologically and compared with those of free-living pied stilts. Concentrations of triiodothyronine (T3) and thyroxine (T4) in the serum of sub-adult and adult stilts were measured before and after iodine supplementation. RESULTS: The main causes of death of captive-reared black stilts following release were trauma, predation and starvation. An increase in size of the thyroid gland due to follicular hyperplasia and dilation was seen in all birds with intact thyroid glands (n=27). Dysplastic follicular changes such as epithelial desquamation, lipid deposition and haemorrhage were common in a large proportion of individuals with goitre. Dietary supplementation with iodine greatly improved survival rates in sub-adults following release, and significantly increased concentrations of T3 and T4 in serum. CONCLUSIONS: Subclinical goitre due to thyroid hyperplasia and dysplasia was the cause of hypothyroidism and this contributed to the poor survival of released sub-adult black stilts raised in captivity. Iodine supplementation of the diet of captive adults and sub-adults resulted in increased concentrations of T3 and T4 in serum and improved survivability.

How do different releasing techniques affect the survival of reintroduced grey partridges Perdix perdix?

Abstract The quality of released individuals can have a significant impact on the success of reintroduction projects. We tested which of the following release techniques resulted in the highest survival of released grey partridges Perdix perdix in Switzerland : 1) translocation of wild adult birds, 2) release of captive parent-reared adults as family groups, and 3) fostering of captive parent-reared chicks to wild barren pairs. Wild hatched offspring (F1 birds) from our re-established breeding pairs served as the control group. We used a multi-state capture-recapture model to estimate monthly survival rates from the data based on monitoring of radio-tagged individuals and reobservation and recovery of ringed individuals. Survival tended to be highest in wild-hatched partridges of the founder population (mean±SE; 0.90±0.03), followed by that of fostered chicks (0.86±0.03) and translocated adult wild birds (0.82±0.06). While survival of these groups was not statistically different from each other, survival ...

25‐OH‐D3, calcium, phosphorus, and alkaline phosphatase content in sera from captive polar bear (Ursus maritimus) cubs at the Denver Zoological Foundation

After the development of rickets in two hand-reared polar bear (Ursus maritimus) cubs at the Denver Zoological Foundation we initiated a project opportunistically evaluating sera 25-OH-D(3), calcium, phosphorus, and alkaline phosphatase levels in seven mother-reared polar bear cubs. From one to three serum samples were obtained while the cub was still in the den with no access to natural sunlight and one after the cub exited the den. The sera 25-OH-D(3) increased as the cubs grew (108+/-37 nmol/L [n=7] while in den, 184.6+/-48.3 nmol/L [n=7] out of the den) but were substantially lower then captive adults (348+/-215 nmol/L [n=36]) or free-ranging adults (360+/-135 nmol/L [n=56]). We found that age was correlated significantly with 25-OH-D(3) levels but den status (in or out) was not significant. Sera calcium and phosphorus values were highest in denned cubs (calcium, 2.9+/-0.4 mmol/L [n=13]; phosphorus, 3.1+/-0.5 mmol/L [n=13]) and then declined as the cubs matured and left the den (calcium, 2.5+/-0.1 mmol/L [n=7]; phosphorus, 2.4+/-0.4 mmol/L [n=7]). The enzyme alkaline phosphatase (presumably the bone isoenzyme) was high in denned growing cubs (831+/-426 IU/L [n=13]) and then declined gradually as the cubs aged and exited the den (96+/-83 IU/L [n=7]). Zoo Biol 0:1-7, 2007. (c) 2007 Wiley-Liss, Inc.

Reproductive Strategies in Lemur catta: Balance Among Sending, Receiving, and Countermarking Scent Signals

Our goal is to go deep into behavioral olfactory strategies possibly used by ring-tailed lemurs in reproductive competition and to shed some light on the function of female scent marks deposited outside the breeding season. We followed 16 captive adults at the Pistoia Zoo (Tuscany, Italy) for > 1,500 h from May 1997 to March 1999. Male direct and indirect olfactory investigation on females showed complementary distributions, the former peaking during the breeding and the latter during the birth season. Males are thus able to monitor female reproductive conditions throughout the whole year. During the birth season there was an increase of female genital marking. The olfactory advertisement probably guarantees that the extremely brief estrus does not remain unnoticed and allows male intrasexual competition a long period to operate. Male indirect olfactory monitoring and countermarking on female signals peaked during the birth season, which suggests that male intrasexual competition is achieved both by getting female chemical messages and by concealing them from other males. Female countermarking on other female genital marks peaked during the breeding season. High-ranking females had higher frequencies of countermarking than those of low-ranking females, which suggests that the advantage of obliterating scent signals of other females is greater than the disadvantage of revealing one's own reproductive condition.

A winged weta, Pterapotrechus (Orthoptera: Gryllacrididae), established in New Zealand

Pterapotrechus sp. (Gryllacrididae) is established at two New Zealand localities, Pukekohe (South Auckland) and on the Coromandel Peninsula. Biology and life cycle of the genus Pterapotrechus are little studied, this species appears to be carnivorous, adults in captivity have been observed spinning silk to make shelters amongst leaves.

Visual behavior of juvenile Limulus in their natural habitat and in captivity.

Limulus polyphemus, the common horseshoe crab, inhabits coastal estuaries of North America and the Yucatan peninsula. It has been an admirable model for vision research because its relatively simple visual system has marked functional similarities to those of many species, including humans (1). Adult male horseshoe crabs use their lateral eyes to find mates (2), and their ability to see underwater has been studied in the estuaries where mating occurs (3, 4, 5). However, studies of the visually guided behavior of adults in captivity have not been successful (R.B., pers. obs.). On the other hand, juvenile horseshoe crabs do exhibit visually guided behavior under laboratory conditions (6). Here we report a comprehensive investigation into the visually guided behavior of juveniles, both in their natural habitat and in captivity. Between May 15 and June 30, 2002, we studied the behavior of juvenile specimens of Limulus in Nantucket Sound, along the Western shore of the North Monomoy Island Refuge in Chatham, Massachusetts. The sand bars on the tidal flats of the island are a protected natural habitat for both juveniles and adults; the waters are relatively clear and calm. Juveniles were most active near shore at depths ranging from 30–120 cm, usually during the late afternoon and evening. In testing the visually guided behavior of a juvenile horseshoe crab, we followed the procedure of a previous study of such behavior in adults (4). First we determined its direction of travel along the bottom and then placed a small object directly in front of it at a distance of 20–40 cm. We used three cylindrical acrylic plastic objects (diameter 7.6 cm, height 5.2 cm): one was painted matte black, one matte gray, and one remained unpainted. Because these objects were designed for experiments with adults, their size was reduced proportionally for small juveniles (prosomal width range 2–14 cm). We filmed 713 trials, defined as an approach of an animal to an object, on a Sony camcorder (model DCR-PC110 NTSC; underwater housing by Gates Underwater Products) and then analyzed the behavior with a computer. All videotaped trials were analyzed with an eMac computer using iMovie software (copyright 2001–2002 Apple Corporation). We categorized each trial as representing one of three behaviors: “hit,” an animal moves directly toward an object and makes direct contact with it; “pass-by,” an animal passes by an object without changing direction; and “turn-away,” an animal turns away from an object. For turn-away behavior, we measured the distance from the center of the object to the middle of the animal at the point where it turned. For the pass-by behavior, we measured the distance of closest approach to the object. Figure 1 (top) shows percentages for all three behaviors. We performed a similar set of experiments in the laboratory, where we observed the behavior of 10 juveniles in a large trough (130 62 cm; the water 6.5 cm deep). The bottom of the trough was covered with a thin fiberglass mesh screen, giving the crabs traction for walking and righting themselves if overturned. The crabs were maintained in ambient diurnal lighting in a separate trough before being placed in the experimental trough, where we used diffuse overhead illumination to simulate, as closely as possible, an overcast day. The same three objects used in the ocean observations were now placed in the center of the trough and rotated every 15 min. The crab’s behavior was filmed and analyzed, as in the ocean trials. We defined a behavioral event as a crab entering the camera’s field of view (51 74 cm). We filmed 797 trials, mostly in the evening hours when the crabs were most active. Figure 1 (bottom) gives percentages for the laboratory trials.

Blood chemistry and haematocrit of the black vulture ( Aegypius monachus)

We determined the values of haematocrit and blood chemistry of the black vulture ( Aegypius monachus) in Extremadura (Spain). We analysed 57 nestlings, five feral adults, seven captive individuals in their first year and five captive adults. Free-living adults had a higher haematocrit and lower calcium and alkaline phosphatases concentrations than captive birds. There were differences in haematocrit and in the concentrations of glucose, uric acid, total proteins, alkaline phosphatases, phosphorus and aspartate aminotransferase between nestlings and young in their first year and adults. The estimated age of the nestlings was significantly correlated with haematocrit, plasma glucose and total protein concentrations. The physical condition of nestlings was significantly correlated with plasma alkaline phosphatases levels.

Costs of Caregiving: Weight Loss in Captive Adult Male Cotton-Top Tamarins (Saguinus oedipus) Following the Birth of Infants.

We examined changes in weight for 10 captive adult male cotton-top tamarins (Saguinus oedipus) from before the birth of infants through the first 16 weeks of infant life. Compared to before birth, males weighed significantly less in Weeks 1-4, 5-8, and 9-12 following the birth. Weights in Weeks 13-16 did not differ significantly from prebirth weights. Maximum weight loss for individual males ranged from 1.3 to 10.8% of prebirth body weight. Males in groups with fewer helpers lost significantly more weight than ones in groups with more helpers. For the 3 males that had no helper other than their mates, weight loss was particularly striking, ranging from 10.0 to 10.8% of their prebirth body weight. These results suggest that caring for infants is energetically costly, and that in this cooperatively breeding species, the presence of more individuals to share the burden of infant carrying reduces the cost to individual caregivers.

Duration and frecuency of chorus howling of the mexican wolf (Canis lupus baileyi)

El lobo mexicano (Canis lupus baileyi) es una especie amenazada de extinción y su biología básica ha sido poco estudiada. En este artículo se aporta información sobre la duración en tiempo y la frecuencia diaria de los aullidos en grupo del lobo mexicano a lo largo de un año. Los datos fueron obtenidos de una manada de cinco individuos adultos (tres machos y dos hembras), mantenidos en cautiverio en la Reserva de la Biosfera "La Michilía", en la Sierra Madre Occidental en el Estado de Durango, México. Doscientos ochenta y seis aullidos fueron registrados para la manada durante un año. Los aullidos en grupo fueron más comunes durante el período de apareamiento (Enero/Febrero) y tendieron a escucharse en el amanecer y anochecer, como en las poblaciones norteñas. La frecuencia diarias de aullidos en grupo, presentó una variación significativa a lo largo del año (p<0.005); durante la temporada de apareamiento, se encontró un promedio de 2.3 aullidos por día y con una duración de 59.2 ± 6.6 seg; mientras que en Agosto sólo se registraron 0.9 aullidos al día y con menor duración (26.7 ± 3.5 seg). La duración promedio del coro de aullidos de este grupo fue de 41 ± 9 seg, tiempo más reducido con respecto a lo encontrado para las manadas de lobos en E.U.A. y Canadá.