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During the last half-century, the distribution of golden jackals (Canis aureus) has rapidly increased throughout Europe. Today, golden jackals are thriving in human-dominated landscapes across Southeastern and Central Europe. Most studies on golden jackals have focused on large-scale distribution patterns; to date, little is known about the species’ fine-scale spatial ecology. In this study, we analyzed the movement behavior, space-use and resource selection of six golden jackals fitted with GPS-GSM collars in two study areas in Hungary and Serbia. Two of the jackals were a breeding pair. We found that home range size averaged 11.2 km2 (90% autocorrelated kernel density estimation), and was characterized by significant individual-level variability (range 1.3–32.5 km2). Golden jackal movements and resource selection were strongly influenced by circadian patterns: during the day, jackals travelled an average of 300 m every 6 h, and all monitored individuals selected for vegetation cover, often near edges. At night, golden jackals travelled significantly further (1 km 6 h−1), and were more likely to venture outside of cover into agricultural areas. Movement analysis of the breeding pair revealed that the male and female tended to remain in close proximity during the day, but ranged more independently at night. Altogether, our findings suggest that golden jackals’ ability to thrive in human-dominated landscapes rely on a fine spatio-temporal avoidance of humans.

Parental care is defined as any behavioral trait of the parents that improves the fitness of the offspring, and that probably evolved or is currently maintained by this function. There is variation in the type and amount of care allocated by parents depending on fluctuation in brood demands that respond to growth and developmental environment. Each sex, within the breeding pair, may respond differently to changing brood demands, and such variation might impact offspring development and fitness. Even though there is a plethora of studies evaluating sex differences in parental care, proximate factors influencing distribution of parental duties within the breeding pairs have received far less attention. In a wild population of Western Bluebirds, we assessed sex differences in parental care (i.e. brood attendance, food deliveries, nest cleaning) through nestling development, and evaluated whether distribution of parental care between sexes is associated with offspring growth. We found that females adjusted their parental behavior according to changes in brood demands more often than males, and fed, attended, and cleaned more than males. Moreover, a more female-biased distribution of care through nestling development was positively associated with the growth of fledglings. We conclude that sex differences in parental care may be a measure of specialization in parental duties within breeding pairs favored by natural selection. These findings are in marked contrast to earlier studies in Northern populations of Western Bluebirds that have failed to detect differences in parental care between sexes, and suggest that differences in the social environment or ecological conditions between populations of the same species might lead to differences in parental cooperation between males and females.

Swooping is a defensive behavior used against potential nest predators. Here, we tested the hypothesis that swooping intensity in a pair of Brown Goshawks (Accipiter fasciatus) rearing chicks would differ according to the number of human observers present near the nest. We standardized the number of swoops per min for 16 visits during which there were combinations of one, two and four observers. There was a significant difference in swooping intensity between one-observer and two-observer visits. Intensity ranged from 0.10 to 0.40 swoops per min during single-observer visits, in contrast to only one of four two-observer visits recording a single swoop, and goshawks performing no swoops during four-observer visits, thus confirming our hypothesis. Despite being based on a single breeding pair of goshawks, these observations demonstrate variation in nest defense towards humans.

The honey badger is a widespread, but understudied African carnivore, with high potential as a bone accumulator in cave and fossil deposits. This study serves as the first investigation into the taphonomic modifications of this species when feeding on small to medium-sized prey. Domestic rabbit (Oryctolagus cunniculus) carcasses where fed experimentally to a breeding pair of captive honey badgers housed at the Johannesburg Zoo. Bones from the feeding refuse and the carnivore scats were analysed for anatomical composition, fragmentation patterns, tooth marks and digestion. The results were compared with feeding studies with various small carnivores on leporid prey. Honey badgers preferentially opened their prey at the belly and focussed their feeding on nutritionally high-yield soft parts, often discarding low-yield parts like distal appendages, crania and the skins. Bones from the refuse assemblage were often complete and unmodified but stripped of flesh. Bones from the scat assemblage displayed very high fragmentation, light digestive modification and high numbers of tooth marked bones. This latter character was particularly diagnostic for the honey badger. This study investigates a carnivore that has received little interest and shows the high potential of this carnivore to act as a bone accumulator. Further taphonomic research into this species will greatly enhance our understanding of this species and its activity in the fossil record.

According to theory, habitat selection by organisms should reflect underlying habitat-specific fitness consequences and, in birds, reproductive success has a strong impact on population growth in many species. Understanding processes affecting habitat selection also is critically important for guiding conservation initiatives. Northern pintails (Anas acuta) are migratory, temperate-nesting birds that breed in greatest concentrations in the prairies of North America and their population remains below conservation goals. Habitat loss and changing land use practices may have decoupled formerly reliable fitness cues with respect to nest habitat choices. We used data from 62 waterfowl nesting study sites across prairie Canada (1997-2009) to examine nest survival, a primary fitness metric, at multiple scales, in combination with estimates of habitat selection (i.e., nests versus random points), to test for evidence of adaptive habitat choices. We used the same habitat covariates in both analyses. Pintail nest survival varied with nest initiation date, nest habitat, pintail breeding pair density, landscape composition and annual moisture. Selection of nesting habitat reflected patterns in nest survival in some cases, indicating adaptive selection, but strength of habitat selection varied seasonally and depended on population density and landscape composition. Adaptive selection was most evident late in the breeding season, at low breeding densities and in cropland-dominated landscapes. Strikingly, at high breeding density, habitat choice appears to become maladaptive relative to nest predation. At larger spatial scales, the relative availability of habitats with low versus high nest survival, and changing land use practices, may limit the reproductive potential of pintails.

In 2006, after centuries of absence, a pair of white-tailed eagles (Haliaeetus albicilla) bred successfully in the Netherlands. Since then, the species has slowly spread across the country. The white-tailed eagle’s return is a consequence of its spectacular increase in Northern Europe and Germany, and the westward expansion of the breeding area. At least one bird of the first breeding pair hatched in Schleswig-Holstein, Northern Germany.

The developmental environment an animal experiences can have a pervasive and sustained effect on phenotype throughout its life. Animals exposed to suboptimal conditions during development can experience physiological trade-offs, leading to seemingly negative phenotypic changes in later life that have been hypothesised to have detrimental effects on fitness. However, few studies have investigated how exposure to suboptimal developmental conditions affects an animal’s reproductive behavior and fitness. Here, we determine if elevated levels of corticosterone (CORT; the dominant avian stress hormone) during development affect fitness via changes in reproductive investment in adult zebra finches (Taeniopygia guttata). To do this, we exposed nestling zebra finches to either CORT supplemented or control treatments and assessed their mate selection and reproductive investment as adults, using free choice breeding experiments. We found that breeding pairs of birds from matched developmental treatments (CORT or control) had a shorter latency to lay clutches compared to pairs with mismatched developmental treatments. We found no indication that clutch size or egg mass were affected by developmental treatment. Also, we found no evidence that birds choose mates to match their own developmental treatment. Our results demonstrate that developmental experience may affect reproductive investment through changes to reproductive timing and add to the literature suggesting that pairs with similar developmental backgrounds can coordinate their reproduction more effectively. Developmental stress may reduce the fitness of a breeding pair as a result of its detrimental effect on phenotype and performance. Alternatively, individuals could use indicators of developmental stress to influence mate choice in order to compensate for a poor start to life. Previous studies suggest that birds do assortatively mate by developmental environment, but this has not been tested in a free choice mating context. Using a free choice breeding experiment, we show that pairs of breeding birds lay eggs faster when they have matching developmental environments, regardless of the quality of their developmental environment. This evidence suggests that assortatively mated pairs can potentially offset a bad start to life and maintain fitness in spite of the deleterious effects of developmental stress.

Leucism is a color aberration characterized by the absence of pigmentation which can either be partial or complete. Abnormally colored birds have reduced chances of survival and mating success compared to normally colored individuals. We present a documented record of a complete leucistic adult Rufous-bellied Thrush ( Turdus rufiventris ) breeding successfully in Carilo, centraleast Argentina. In the winter of 2016 we observed a completely white thrush. In the subsequent spring we observed it collecting food and delivering it to two fledglings, which were normally colored. The adult thrush survived its own post-fledging period despite its increased predation risk due to conspicuousness, managed to get a breeding pair and breed successfully. Since reports of abnormally colored birds breeding in wild populations are rare, we emphasize the importance of making this information available., Facultad de Ciencias Naturales y Museo

The Black-collared Hawk Busarellus nigricollis is widespread from southern Mexico throughout Central America and east of the Andes in South America. Although rather common in most of its distribution range, little is known about its breeding biology as nests are often built in inaccessible areas. The discovery in 2013 of four nests of this hawk in the coastal region of French Guiana, where it is found near brackish or fresh water in semi-open to open country, allowed us to increase our knowledge of its breeding behavior. The population is estimated at c. 200 pairs. Aerial displays of a breeding pair cover a large area around the nest tree. The nest is a large structure of sticks with a shallow cup lined with finer branches and a layer of twigs with leaves. It is mostly built at a height between 15 and 35 m, in the crown of an isolated tree or in a tree crown emerging above the surrounding vegetation. A single egg per nest is laid in French Guiana. The fledgling period for one nest was 55 days. Both male and female incubate and feed the nestling, although the female's share in both activities is more important. During the entire nesting period male and female add fresh twigs with leaves and to a lesser extent, fine dead branches to the nest.

The damselfly Coenagrion ornatum is a threatened species, specialized for lowland headwater streams. As the species is declining and protected across Europe, it represents a species of particular conservation interest. This work aims to provide the first evaluation of fine-scale spatial ecology in this species, especially to assess its general mobility and distribution of adults in relation to larval habitats, and to suggest implications for conservation and efficient monitoring of this species. Adults were captured-recaptured along four distinct streams (5.2 km together) in the Radovesicka spoil heap, Czech Republic. Immature adults and breeding individuals were recorded simultaneously. Larvae were sampled in 64 sections of 27 m, evenly distributed across the studied streams. In total, 1152 adult individuals were marked; from these, 240 individuals were recaptured at least once. Larvae were detected in 21 sites with a total number of 61 individuals. The adults were highly sedentary, with a median lifetime dispersal of 11 m. Only one male was reported to move between two distinct streams. Model comparisons revealed that female and breeding pair abundances are a significantly more reliable indicator of larval abundance than male and total adult abundances, especially when used along with records of the immature adults. Moreover, the weighted least square models showed that the female abundances are spatially more specific (i.e., less autocorrelated) than male abundances. These results imply that surveying the adult females, along with the breeding and immature adults, offers the best method for local habitat quality assessment for this Natura 2000 species.

Universal predictions on the occurrence of cooperative breeding are still elusive. This breeding strategy is strongly linked to phylogeny; therefore, studies on species within groups where cooperative breeding is more prevalent could improve our understanding. Many diurnal raptors exhibit cooperative breeding, although occurrence rates are mostly based on anecdotal observations at nests. Here, we present a detailed study of the reproductive output and social organisation of the African pygmy falcon. Using data from six breeding seasons, we found helpers at 19% of nests. Helper presence had a positive effect on the body condition of the chicks as brood size increased, likely due to their contribution to feeding the chicks. Cooperative breeding groups were more likely to occur following years of higher reproductive output. Indeed, most of the helpers (77%) were non-dispersed offspring from the previous year, whereas the other helpers were immigrant adults (23%). We identified groups that included retained offspring (46%), immigrant adults (27%) or both types of helpers (27%). Breeding groups were also described as multi-male (65%), multi-female (26%) and multi-male-female (9%). Pygmy falcon group composition proved to be highly variable and diverse compared to other raptor species, in which helpers are generally unrelated adult males, showing that selection pressures leading to group formation in diurnal raptors may be more diverse than previously thought. Cooperative breeding occurs when more than two individuals contribute to raising a brood of young. It occurs in approximately 9% of bird species and it is particularly frequent in diurnal raptors. We studied the breeding performance and social organisation of the African pygmy falcon and found that they form breeding groups at 19% of the nests. These breeding groups included the breeding pair plus helpers that are either males or females. Helpers were also either adult immigrants or retained offspring. We also found that groups produced healthier fledglings than pairs and that groups are more likely to occur following years with high fledgling success. With this work, we expand the number of studies on raptor cooperative breeding and explore the fitness advantages of group breeding in this species as well as the mechanisms behind group formation.

Male-male reproductive competition occurs in many animal societies and can be costly, both through aggression or energy expenditure prior to mating and lost paternity. In most cooperative breeders, socially dominant males breed more often than do subordinates, but the costs of pre-copulatory subordinate male reproductive competition (including unsuccessful competition) have rarely been investigated in these systems. Here, we examine the association between such competition and the fitness of dominant males in the cooperatively breeding southern pied babbler (Turdoides bicolor). Babbler groups comprise a dominant breeding pair with adult subordinates of both sexes. Roughly 35 % of adult subordinate males live in groups with unrelated adult females, but despite their common engagement in active reproductive competition, these subordinate males rarely successfully breed (extra-group mating has never been detected). Overall, active reproductive competition with subordinate males is not costly to dominant males, notwithstanding that rare episodes of breeding by subordinate males cause large paternity losses (50–100 %). Specifically, the presence of an actively competing subordinate male does not affect the proportion of successful nests, the number of fledglings fathered by the dominant male or dominant male retention of dominance to the next breeding season. Instead, dominant male breeding success is likely to be more affected by factors such as food availability and group size. In the social context of cooperative breeding, a competing subordinate male may provide benefits of a larger group size or increased help; these may offset the low risk of paternity loss, possibly promoting tolerance of reproductive competitors by dominant males.

As a model for understanding the population dynamics of the quail, captive breeding was used to monitor reproduction in expanding and declining populations. Twelve pairs of quail were managed, with or without mate switching, to simulate phases of population expansion and decline. Failure of reproduction was explained by non-acceptance of the mate, infertility as a result of stress due to captivity or physiological problems. During population increase, the number of pairs that bred successfully (11 vs. 9), the clutch size (72 vs. 43, P = 0.0003) and the number of hatched chicks (23 vs. 7, P = 0.0001) were higher than in the decline phase. In the expansion phase, females laid more eggs, whereas in the decline phase, they laid heavier eggs (7.9 vs. 8.3 g, P = 0.0001). During expansion, the number of mate switches was higher, while during decline, a higher no breeding pair rate was observed. Reproductive parameters of pairs are conditioned by density and sexual selection depending on the mate choice. Clutch size and egg mass varied between years and between breeding pairs. Our findings suggest that mating interactions and sexual selection account for the biological success of the species.

Aerial insectivorous birds depend highly on favourable weather conditions for successful foraging because flight activity of insects is constrained by daily weather. Thus, the variation in weather conditions during reproduction, mediated by prey limitations, should be mirrored in annual reproduction performance, and finally in annual breeding success. We analysed the effect of local weather conditions on the availability of airborne insects and on the variation in brood size and nestling condition of European bee-eaters Merops apiaster at the northern edge of their range where years with adverse weather frequently occur. The availability of large flying insects, the common prey of bee-eaters, increased with air temperatures and duration of daily sunshine. As predicted, local weather conditions affected reproductive performance with annual breeding success (mean 3.7 nestlings per breeding pair, range 1.7–4.9 nestlings) being up to 32 % higher in extraordinary dry and hot summers. Additionally, a nestling's body condition (residual mass) was also affected by sunshine duration during their growth period and internally was co-affected by the number of siblings and the individual rank within the sibling hierarchy. Thus, a prolonged duration of daily sunshine causes a cascade from higher insect flight activity, and, thus, higher food availability for chick-rearing bee-eaters, which finally translates into better chick body conditions and higher annual breeding success. Consequently reproduction and population development of European bee-eaters might be especially susceptible to regional changes in weather and climatic conditions.

The demographic performance of avian predators is influenced by climate variations. The Plant Area Index (PAI) is considered a key descriptor of the (evolving) vegetation sensitive to climate and soil aridity and drought stress. To assess if the increased aridity regime in the mediterranean region affects the reproduction of a forest predator, the breeding success of the Tawny Owl Strix aluco was studied over 7 years (1997–2003) in Castelporziano, central Italy. The inter-annual fluctuations in owl demographic output observed in neighbor forest and agricultural sites were compared with climatic variables (rainfall, minimum and maximum air temperature, aridity index) and changes in the PAI estimated by satellite imagery. Out of 326 breeding attempts, the percentage of successful pairs per year ranged between 4 and 28 %, the number of fledglings per successful pair ranged between 1.0 and 1.8 and breeding rate (i.e. the number of fledglings per breeding pair) ranged between 0.1 and 0.4. Demographic, climatic and remotely sensed indexes showed coherent variations among years. Rainfall and lower aridity index are associated with a higher breeding success. The relationship between PAI and breeding rate was found significant only in forest sites. Results suggest that Tawny Owls may positively respond to drier weather conditions by reducing the breeding rate.

Nests of White Stork Ciconia ciconia are commonly used by various passerines as nesting sites. In this study, we investigated factors determining presence and number of pairs of species breeding within White Stork nests in an extensive farmland in NE Poland. In 133 (57%) out of 233 White Stork nests, we found at least one breeding pair of passerine bird. These were from three species: House Sparrows Passer domesticus (68% of 133 nests with co-breeding), Tree Sparrows Passer montanus (65%), and Starlings Sturnus vulgaris (30%). The probability of breeding passerines within White Stork nests increased with increasing nest thickness, and was significantly higher in currently occupied nests. Sparrows were more likely to breed in White Stork nests located on electricity poles, situated closer to settlements and surrounded mainly by arable fields where meadows were not prevalent. In this paper, we show that White Stork nests are favorable nesting sites for passerines, as they are well insulated and provide an anti-predatory shield.

Assessing whether conservation management actions are effective requires a good understanding of the demographic parameters that contribute to the population growth rate. Among the key demographic parameters influencing a population, immigration is one of the most difficult to measure empirically but may mask or accentuate the effects of conservation measures. We use an integrated population model to assess whether a population increase of a large raptor species can be explained by high fecundity and survival resulting from local conservation measures, or whether immigration may have contributed to population growth. We monitored the Eastern Imperial Eagle (Aquila heliaca) population in Bulgaria from 1998 to 2014, and tracked juveniles using satellite transmitters to estimate survival probability over the first three years of life. We used intensive territory monitoring of breeding birds to estimate survival probabilities and fecundity of birds older than 3 years. The Imperial Eagle population in Bulgaria increased by about 11 % per year between 1998 and 2014 (λ = 1.111, 95 % credible interval 1.076–1.156). While local conservation measures have succeeded in reducing nest loss and the mortality of adults (adult survival = 0.924; 0.887–0.955), high mortality of juveniles during their first year of life resulted in only 12 % of fledglings surviving to adult age. Based on these survival probabilities and the estimated fecundity of breeding pairs in Bulgaria (1.063; 0.932–1.203), some immigration may have contributed to the population growth in Bulgaria. Because the integrated population model accounts for all the uncertainty associated with disparate data sources, the estimated immigration rate was too imprecise (0.143–2.862 young birds per breeding pair) to quantify the relative importance of immigration. Future conservation measures for Imperial Eagles need to focus on improving the survival of juvenile birds, particularly the reduction of electrocution risk in Eastern Europe and the Middle East.

Sex allocation in cooperative breeding species may be influenced by the return in fitness that parents receive when producing offspring of each sex, especially if helping behavior is sex-specific. Factors such as the presence of helpers assisting the breeding pair, resource availability, and timing of breeding may also influence brood sex ratio. In this study, we evaluated brood sex allocation in a neotropical cooperative breeding, the White-banded Tanager Neothraupis fasciata, which shows a slightly higher numbers of males, the helping sex, in the adult population. We tested brood sex allocation in relation to the presence of helpers in the groups, nest initiation date, and territory quality. At the population level, we found strictly equal numbers of offspring of both sexes. At the individual level, there was no effect of the ecological, environmental, and temporal variables we tested in the sex allocation of tanagers’ offspring. We suggest that brood sex allocation is unlikely to occur in the study species, and that high levels of nest predation may inhibit the development of sex allocation strategies in neotropical open nesting species, such as White-banded Tanager.

Changes in the timing of reproduction of birds should provide good evidence of large-scale climate fluctuations. However, geographically separate populations of one species may respond variably. We analyzed egg laying dates of nine Eurasian populations of the Common Redstart Phoenicurus phoenicurus collected between 1969 and 2010. The timing of breeding differed greatly with latitude: the populations in the north started later, a breeding pair produced only one brood per season and the breeding season was shorter. Both yearly minimum and median first-egg laying dates advanced with increases in local air temperature, but the more northern populations had started at much lower temperatures, which was probably caused by the stimulation of photoperiod. The effects of large-scale climatic patterns (North Atlantic Oscillation, East Atlantic, Scandinavia/Eurasia-1) on the first-egg laying date were low. The egg laying dates advanced over the observed decades in all populations, although at a variable rate. Seven selected populations with the most complete data for the period 1986–2010 revealed an advancement of median first-egg laying dates of 0.11 days/year and 1.31 days/°C. The effect on minimum first-egg laying dates was smaller. The changes observed in two populations in Ural and western Siberia were smaller than those found in more westerly populations (Finland, central Europe). The timing of the start of breeding is probably less affected by climate change than the timing of spring migration, documented by European ornithological stations.

Food availability can impact group formation in Carnivora. Specifically, it has been suggested that temporal variation in food availability may allow a breeding pair to tolerate additional adults in their territory at times when food abundance is high. We investigate group occurrence and intraspecific tolerance during breeding in a socially flexible canid, the arctic fox (Vulpes lagopus). We compare Iceland and Sweden where resource conditions differ considerably. A breeding pair was the most common social unit in both populations, but as predicted, groups were more frequent where food abundance varied substantially between years (Sweden: 6 %) than where food availability was stable (Iceland: ≤2 %). Within Sweden, supplemental feeding increased group occurrence from 6 to 21 %, but there was no effect of natural variation in lemming (Lemmus lemmus) availability since group formation was rare also at lemming highs. Thus, additional factors appeared to influence the trade-off between intraspecific territoriality and tolerance. We report two cases where related females showed enduring social relationships with good-neighbour strategies. Related females also engaged in alloparental behaviour in a ‘fox town’ with 31 foxes (4 adults, 3 litters). In contrast, when unrelated foxes bred close to each other, they moved or split their litters during summer, presumably because of territorial conflict. We suggest that fluctuating food availability is linked to group formation in this Arctic carnivore, but also when food availability increases, additional factors such as relatedness, alloparental benefits, competition and predator defence appear necessary to explain group formation.

Parental investment varies in mammalian species, with male care of young being more common in social and monogamous species. Monogamy is commonly observed in canid species, with both males and females, and often ''helper'' individuals, providing some degree of care for the young. Social units of the swift fox (Vulpes velox), a small North American canid species, usually consist of a male- female pair and occasionally helpers. The role of parental investment and behavior in swift fox society is currently poorly understood. We observed swift fox dens during the pup-rearing season in each of 2 years to evaluate attendance and frequency of visits to natal dens by adult males and females. Female foxes remained at dens longer and visited them more frequently than did male foxes. Female attendance and visitation decreased throughout the pup-rearing season as pups became older and more independent. Environmental factors, including climate and its effect on prey, appeared to contribute to differences in fox behavior between the 2 years. We observed only one fox outside of the breeding pair attending a den in each of the 2 years, both of which were males. We concluded that each of these two foxes were living within the social unit of the male-female pair as a trio, but not serving as a helper and contributing to the care of the pups. Our results increased knowledge of the ecology and behavior of the swift fox, a species of conservation concern in the Great Plains of North America.

Anemonefishes (genus Amphiprion) are well known as protandrous sex-changing fish. They live symbiotically with sea anemones and form a social unit that consists of a breeding pair and several sexually immature individuals with ambisexual gonads. In general, the hierarchy of the social rank is strictly maintained in a group, and this hierarchy is considered to be one of the critical factors that induce sex change or sex differentiation in anemonefishes. Field observations have shown that behavioural characteristics of anemonefishes vary depending on the environment. In this study we examined the differences in territorial aggression directed at conspecific intruders according to sexual status in the false clown anemonefish, Amphiprion ocellaris, under laboratory conditions. Resident–intruder tests were conducted on groups consisting of three anemonefish: a dominant female, a second-ranked male and a subordinate ambisexual individual. Females and males showed more aggressive behaviour than did ambisexual individuals, and behaviours were specifically directed at intruders of the same sexual status, not at those of the opposite sex. Notably, the female residents displayed fierce aggressive behaviours particularly toward female intruders, whereas male residents engaged more often in side-by-side swimming with male intruders than with female or ambisexual intruders. Ambisexual intruders were threatened by all residents, rarely attacked. We observed only few aggressive acts towards tank mates. These results suggest that sexually mature resident anemonefish in a confined space, such as under laboratory conditions, perceive intruders of the same sexual status as competitors for reproductive status and thus, dominant social rank.

The Ansell’s mole-rat (Fukomys anselli, Bathyergidae) is a small-sized social subterranean rodent whose distribution is confined to the Lusaka area in Zambia. It is an established model species for various laboratory studies, but until now the knowledge of its biology under natural conditions has been limited. Here, we provide the first comprehensive natural history and ecological data on a free living population from Miombo woodland. The Ansell’s mole-rat lives in groups of up to 13 individuals (mean 9.7 ± 2.5; N = 9 complete, fully established family groups) with a single breeding pair per group. The family groups occupy very large and complex burrow systems consisting of 0.5–2.8 km of tunnels (mean = 1.2 ± 0.6 km, N = 15), which are densely branched and reticulated especially around nests. Burrow systems of neighbouring family groups were often interconnected by a freely passable tunnel, which has never before been documented in any African mole-rats. Mole-rat food density in the study area was relatively low (10.0 ± 8.4 m−2) but its biomass was large (457 ± 889 g m−2). This, together with a relatively workable soil (cone resistance = 529 ± 26 N cm−2 at the end of June, with 10% soil humidity), indicates moderate ecological conditions, which disagrees with the aridity food-distribution hypothesis (AFDH) considering small body size and sociality in bathyergids adaptations to harsh environments.

Ansell's mole-rats ( Fukomys anselli ) live in families of a breeding pair and several overlapping generations of their non-breeding offspring. Locomotor activity of 47 Ansell's mole-rats from six laboratory families was recorded for a week using radio frequency identification (RFID). This technique allowed monitoring each animal's activity without isolating them from other members of their family. Animals were active about 17% of the recording time, and older animals were significantly less active than younger ones. Females tended to be slightly more active than males. There was no significant difference in the amount of activity between breeding and non-breeding individuals. Consequently, the activity pattern does not seem to account for previously reported differences in longevity between breeding and non-breeding animals.

A mechanistic understanding of species’ geographic range dynamics requires an understanding of the dynamics of populations at the edge of that range. Several ibis species are currently expanding their ranges, and the Hadeda Ibis (Bostrychia hagedash) has increased its southern African range more than 2.5 fold over the past century. We studied the demography of a Hadeda population near the expanding range edge. Estimating survival on a quarterly time interval we found that it was lowest over the first 3 months of life, and then slightly higher over the rest of the 1st year (annual survival: 0.27, SE = 0.04). After the first year, survival was constant (0.75, SE = 0.09). Breeding success increased from 1.5 to 3 fledglings per year with increasing experience of the breeding pair. A matrix population model showed that the growth rate of this population was most sensitive to changes in adult survival and least sensitive to variation in reproduction. Hadedas in our study population thus showed characteristics of long-lived birds but were also able to achieve a high reproductive output in good conditions. Together with their ability to take advantage of a human modified landscape, this may explain the remarkable success of this species in expanding its range.

In cooperatively breeding birds, breeders can adjust their parental care investment without affecting nestling survival probability and save energy to invest in other activities, such as feeding, mating or territory defense. Furthermore, helpers at the nest can improve nestling nutrition and hence the reproductive performance of the breeding pair. We determined the influence of helpers on nestling feeding effort and reproductive success of breeders in the neotropical White-banded Tanager (Neothraupis fasciata). We monitored nests during the breeding seasons of 2006 and 2007 in central Brazil. Males showed a compensatory reduction of their food delivery rate in the presence of helpers, whereas females exhibited the same parental effort regardless of having helpers. Total food delivery rate was higher for nests with helpers, but there was no effect of helpers on reproductive performance of breeders (clutch size, hatching rate, fledgling productivity and reproductive success). Our results indicate that cooperative breeding in the White-banded Tanager appears to be important for males to reduce their parental care effort and, hence, invest in their survival or future reproductive attempts.

Monitoring populations of elusive large carnivores like wolves (Canis lupus), which are often distributed at low density in widespread forested areas, is difficult or exceedingly expensive. Aiming to assess the power of two indirect monitoring methods, non-invasive genetic sampling and camera trapping, we designed a small-scale pilot study that was carried out from 2006 to 2008 in and around the Corno alle Scale Regional Park, Bologna, northern Italian Apennine. We collected 103 non-invasive samples (mainly scats) that were genotyped at 12 microsatellite loci and sexed using the ZFX gene. We identified 11 distinct wolf genotypes within the park and four wolf genotypes outside. Spatial locations and kinship analyses showed that the wolves belong to three different packs. The breeding pair of the ‘Park’ pack showed a complete turnover in the two sampling seasons. Two dogs, but no hybrids, were identified in the area. Up to five unbaited camera traps were activated (for 1,250 trapping-nights) close to recent wolf presence marks. We obtained 103 photos of wolves, documenting the reproduction events, the minimum number of adult and young wolves, and phenotype information each year. We obtained information on health conditions detecting probable sarcoptic mange in three individuals. Camera trapping also showed that the presence of wolves in a chase area during wild boar (Sus scrofa) hunting sessions was significantly higher in the nights just after a chase (P

Mating behaviour is an important component of species’ life histories. Knowledge of natural patterns of mating can lead also to more effective management strategies for populations of conservation concern. Despite a high conservation profile many aspects of the biology of the common dormouse (Muscardinus avellanarius) remain unknown, potentially limiting present conservation efforts. We determine the mating behaviour of M. avellanarius at two woodland sites in the UK: (1) Bontuchel (a natural population in Wales) and (2) Wych (a population in England that was established by reintroducing captive-bred animals) by genotyping mothers and litters at a panel of 10 microsatellite loci. Adult female body weight positively correlates with litter size and no apparent reproductive skew was evident. We found that multiple mating by female dormice is prevalent at both sites, with litters containing three or more offspring sired by multiple fathers; moreover, multiple mating is adopted by released animals even after a period of captive breeding where females are mated singly or as a breeding pair. We also present evidence for low proportion of fathers identified in our samples that probably related to unsampled individuals and/or larger than anticipated population sizes. This first report of mating behaviour in M. avellanarius highlights the role of genetic studies to uncover species’ reproductive behaviours and include these data for conservation management.

Conspecific avoidance and attraction hypotheses have been proposed to explain patterns of animal spacing behavior and have been frequently used to explain habitat selection by dispersers. In birds, tests of these hypotheses have been limited to fine spatial scales and have not considered dispersal distance. We used discriminant function analysis (DF) of feather δ34S, δD, δ15N and δ13C values to identify yearling female Mallards (Anas platyrhynchos) that dispersed long distances (>400 km relative latitude) from natal areas to settle at 22 breeding locations in the Canadian parklands, 1993–2000; these sites varied in social (breeding pair density) and breeding habitat (wetland density and percent nest cover) conditions. DF indicated that the proportion of yearling female recruits estimated to be long-distance immigrants in these breeding populations averaged 12% across sites (range 0–38%). Yearling immigration rates were positively correlated with conspecific breeding pair density and negatively correlated with percent wetland habitat. Settling patterns by yearling immigrants were most consistent with the prediction of social attraction, but effects were statistically weak possibly because inter-regional movements were less variable annually due to relatively stable wetland conditions in the southern prairies during the period of study. Our results suggest immigrants arriving from distant natal sites used conspecific abundance as a positive cue of habitat quality when choosing the new breeding sites. Fitness consequences of these choices should be evaluated.

Intensification of farming over the past 50 years has homogenised the landscape structure and contributed to the decline of bird populations in Europe. To better target the conservation of the Barn Owl Tyto alba, we assessed the influence of the landscape structure on breeding performance in western Switzerland. The analyses considered a 23-year data set of breeding parameters collected in an area dominated by intensive agriculture. Using a Geographic Information System approach, landscape characteristics were described around 194 nest sites. Our analyses showed that nest-box occupancy, laying date, clutch and brood size, egg volume and probability of producing a second annual clutch were not significantly associated with any of the eight principal landscape variables (agricultural land, woodland, urban area, hedgerows, cereals, sugar beet, maize and meadow). Nevertheless, the probability that a breeding pair occupied a nest-box decreased the more roads there were surrounding the nest-box. The absence of strong associations between habitat features and breeding parameters suggests that prey availability may be relatively similar between the different breeding sites. In our study area Barn Owls can always find suitable foraging habitats around most nest-boxes.

The diet and breeding ecology of Yellow-legged Gulls (Larus michahellis atlantis) were studied on Selvagem Grande, North Atlantic in the nesting season of 2007. We collected and analyzed 715 pellets from adults. The most frequent prey were White-faced Storm-petrels (Pelagodroma marina; present on 40.8% of all pellets) and the endemic land snails (Theba macandrewiana; present on 36.5% of all pellets). Other birds, namely Cory’s Shearwaters (Calonectris diomedea), Macaronesian Shearwaters (Puffinus assimilis), Bulwer’s Petrels (Bulweria bulwerii), and Band-rumped Storm-petrels (Oceanodroma castro) were relatively less frequent, but overall, seabirds were present in ca. 50% of all pellets, representing an estimated 60.4% of all mass consumed by gulls. We estimate that the contribution of seabirds to the overall caloric balance accounted for 82.5% of all energy consumed. The number of gull pairs breeding on Selvagem Grande was 12 on 2005 and 2007. Breeding success was low (0.92 and 0.25 juveniles per breeding pair, respectively). Using a simple bioenergetics model, we estimate the breeding gull population to have the potential to consume approximately 4,847 adult/sub-adult seabirds in 3.5 months in order to meet its energetic requirements. The importance of the estimated predation levels is discussed and some management actions are suggested.

Understanding the effect of protection measures on recovery of endangered populations is crucial for assessing the efficiency of management plans. Following the ban of DDT, PCB and other detrimental chemicals in the 1970s, the German white-tailed eagle population recovered rapidly. Using nest monitoring data, dead recovery data and population dynamics models, we examined both short and long-term viabilities of the population. Between 1991 and 2005 the proportion of breeding pairs with an active nest among territorial pairs was α = 0.88 ± 0.007. Annual breeding success was γ = 0.62 ± 0.014. Mean fledged brood size was b = 1.50 ± 0.010 fledged/successful breeding pair. The analysis of dead recovery data of 1,273 individuals ringed as nestling between 1991 and 2006 allowed survival rates to be estimated. We needed to distinguish between “young” (5 years old) and “old” (older than 5 years) adults. Furthermore the annual survival rate was higher for juvenile and immature birds (0.921 ± 0.024) than for adults (s“young” = 0.760 ± 0.097 and s“old” = 0.875 ± 0.079), a pattern presumably explained by territorial fights. Finally, an age structured model was used to examine the joint effect of population regulation, environmental and demographic stochasticities. All results indicated that only pessimistic scenarios could lead to substantial extinction probabilities within 100 years. We conclude that management measures were successful in removing the main extinction factors of the population and that future conservation efforts need to focus on the remaining ultimate extinction causes.

We studied the activity and movements of a male and a female wolf during breeding in the Bieszczady Mountains, Poland. The female was less active and mobile and on average closer to the den than the male. The male was less active and mobile when the pack size was seven compared to a year when the pack consisted only of the breeding pair. We conclude that the roles played by breeding males and females rearing pups influence their activity, and that breeding males in larger packs move less during the nursing period because of help by other pack members.

Since 1981, when the first breeding pair of Mediterranean Gull Larus melanocephalus was recorded in Poland, the population of this gull has increased considerably. Its population size was stable until 1997, not exceeding ten pairs annually; thereafter, an increasing number of sightings were made, and during the last 5 years between 26 and 39 breeding pairs have been recorded in Poland. To date, breeding sites have been established in a total of 45 sites (maximum of 19 sites in a given year), with 27% of these (43% of all broods) found on islands located in the middle course of the Vistula River. Breeding sites have also included artificial reservoirs, such as dam reservoirs (20% of sites, 19% of broods), gravel pits (9% of sites, 13% of broods) and fishponds (24% of places, 8% of broods). Mediterranean Gulls were found to nest only within the colonies of other Laridae. Single pairs were recorded at 40% of the breeding sites, whereas a maximum of two to five pairs were recorded at 47% of the other sites. The great majority of breeding attempts were recorded in Black-headed Gull L. ridibundus colonies. In two cases, Mediterranean Gulls bred within mono-specific colonies of Common Gulls L. canus consisting of 60–150 pairs. The biggest concentrations of breeding sites were along the middle course of the Vistula river and in the southern part of Poland.

The breeding performance and population trends of Adelie penguins (Pygoscelis adeliae) was studied at Esperanza/Hope Bay, Antarctic Peninsula, by comparing an area with low levels of human disturbance (LLD) and an area with high levels of human disturbance (HLD), close to an Argentine research station. From 1995/1996 to 2004/2005 (except for 1999/2000 and 2003/2004), the following population parameters were measured in both areas: (1) the number of breeding pairs, (2) the number of chicks in creches and (3) the number of chicks produced by breeding pairs. Counts were made for 26 breeding groups situated in the LLD area and 63 breeding groups located in the HLD area. The number of chicks per breeding pair was obtaobtained by following 100 marked nests in each area. All parameters were measured as described in the CCAMLR Monitoring Program protocols. The magnitude and direction (increasing or decreasing) of the changes in breeding population size and the number of chicks creched were similar in both areas. Overall, the number of breeding pairs decreased from 4,744 to 2,968 (37.4%) in the LLD area, and from 8,744 to 5,378 (38.6%) in the HLD area. The number of chicks fledged increased from 3,808 to 4,065 (6.7%) in the LLD area, and decreased from 6,991 to 6,712 (4%) in the HLD area. Breeding success (chicks fledged per marked nest) did not differ significantly between areas for most of the seasons compared. In 1996/1997, breeding success was significantly higher in the HLD area. Our data suggest that environmental influences currently exert greater effects than human disturbance on the penguin population at Esperanza Bay.

During May and June 2003, a mixed breeding pair consisting of a male western Bonelli’s warbler (Phylloscopus bonelli) and a female wood warbler (P. sibilatrix) successfully raised six young in a broad-leafed forest near Junkerath, western Germany, an area far outside the regular breeding range of P. bonelli. The identity of the adult birds was confirmed by song, calls, colouration, and wing measurements. Based on blood samples taken from both parents and three juveniles, the potential interbreeding was analysed by molecular methods. Sequences of the mitochondrial cytochrome b gene differed between male and female by 8.7% and confirmed the identification of both parents. Sequences of the mitochondrial cytochrome b gene revealed that the male was a western Bonelli's and the female a wood warbler. The hybridisation and the parentage of male and female were corroborated by multilocus DNA fingerprinting. This is the first documented and genetically proven hybridisation event between these two warbler species.

Helpers in primitively eusocial and cooperatively breeding animal societies forfeit their own reproduction to rear the offspring of a queen or breeding pair, but may eventually attain breeding status themselves. Kin selection1 provides a widely accepted theoretical framework for understanding these societies, but differences in genetic relatedness do not explain a universal societal feature: the huge variation between individuals in helping effort2,3,4,5,6,7,8,9,10. An alternative explanation for this variation lies in a fundamental trade-off faced by helpers: by working harder, they increase the indirect component of their fitness, but simultaneously decrease their own future survival and fecundity2,4,8. Here, we show that individuals work less hard when they stand to lose more future fitness through working. We experimentally manipulated two components of future fitness in social queues of hover wasps (Stenogastrinae): a helper's chance of inheriting an egg-laying position, and the workforce available to rear her offspring should she inherit. After each manipulation, helpers increased or decreased their effort as appropriate to the change in expected future fitness that they experienced. Although helping provides significant indirect fitness benefits for hover wasps11, our study shows that variation in the costs associated with helping is the major determinant of helping effort.

A population of grey wolvesCanis lupus Linnaeus, 1758 inhabiting Bialowieza Primeval Forest (BPF) on the Polish-Belarussian border has recovered after near extermination in the 1970s. Currently, it is intensively hunted in the Belarussian part of BPF and protected in the Polish part. We used a combination of molecular analysis, radiotracking, and field observation to study genetic diversity of the population after natural recolonisation and the consequences of heavy hunting for the genetic composition and social structure of wolf packs. Both microsatellite and mtDNA analyses revealed high genetic diversity. For 29 individuals and 20 microsatellite loci, the mean expected heterozygosity was 0.733. Four mtDNA haplotypes were found. Three of them had earlier been described from Europe. Their geographic distribution suggests that wolves recolonising BPF immigrated mainly from the north-east, and less effectively from the east and south-east. We traced the composition of 6 packs for a total of 26 pack-years. Packs were family units (a breeding pair with offspring) with occasional adoption of unrelated adult males, which occurred more frequently in packs living in the Belarussian part of the BPF, due to heavy hunting and poaching. Breeding pairs were half-sibs or unrelated wolves. Pair-bonds in the breeding pair lasted from 1 to 4 years and usually broke by the death of one or both mates. Successors of breeding females were their daughters, while a successor of a breeding male could be either his son or an alien wolf. As is evident from Bialowieza’s wolves, high genetic diversity may result from immigration of outside individuals, which are easily recruited to a heavily exploited local population.

In cooperatively breeding birds, the presence of helpers is expected to increase the reproductive success of the breeding pair. However, some studies fail to find this effect. A positive effect of helpers may be restricted to cases in which a breeding pair has a poor likelihood of raising the entire brood on its own, as would be the case under stressful environmental conditions or with enlarged brood sizes. We conducted brood size manipulations in a cooperative breeder, the sociable weaver, Philetairus socius, to investigate the relationship between the difficulty of raising nestlings and the effort and impact of helpers. Overall, sociable weavers did not work harder to raise the enlarged broods. However, the presence of helpers significantly increased the feeding rates at enlarged nests, but not controls. This was insufficient to prevent generalised brood reduction in enlarged broods, whether attended by pairs alone or with helpers. Nonetheless, the presence of helpers was associated with decreased nestling mortality and an increase in the numbers of young fledged. Our results suggest that groups are better able to respond to the needs of enlarged broods than pairs alone and that the presence of helpers has a beneficial effect on overall reproductive success.

Since 1956, Southern Giant Petrels on the Frazier Islands, East Antarctica, have been counted with different census techniques, sometimes varying within seasons and among islands, which hindered analysis of the data. Protective measures for the islands from 1986 onwards have increased the need for reliable long-term census data, but reduced the ways to collect these data. Published and unpublished data were re-examined, and population trends were reconstructed based on two relatively standardised techniques: the number of active chicks (AC) and the number of apparently occupied nests (AON) around hatching. AC-values from Nelly Island from 1959 to 1998 indicate substantial periodic fluctuations, but no consistent long-term change. Since the late 1970s, AC-values on the other two islands and AON-values suggest that the breeding population may have grown by 35%. This recent growth, however, is within the extent of periodic fluctuations observed in Southern Giant Petrel population that is stable over the long term.

Urban regions have a high percentage of impervious surfaces which are critical nonpoint pollution sources. To evaluate the role of impervious surfaces on stream quality, a mobile field station was constructed into which stream water was pumped. Study sites were located within one low, two intermediate and two high percent impervious surface watersheds. Stream water entered three 20-gallon, flow-through aquaria which were divided by 1/8′′ mesh plastic screen into four equal compartments, each containing one male-female fathead minnow breeding pair (n= 12 pairs), and one 4′′ diameter PVC tube (4′′×4′′, cut lengthwise) as a breeding substrate. Temperature within the mobile unit (18–25 °C) maintained by air conditioners or heaters; water temperature in the aquaria (20–24 °C) maintained by aquarium heaters. Daily observations included: reproductive behavior, development of male secondary sexual characteristics, and egg counts. Time spent conducting nest and/or egg care activities, average daily spawn attempts, development of male secondary sexual characteristics (tubercles, dorso-ventral banding, head and body coloration) and male-initiated chasing of female were directly related to percent impervious surface in the watershed (ANOVA, p < 0.05). While spawning frequency and average day to first oviposition were not significantly different between study sites, average daily egg count, number of pairs breeding per day and number of eggs per breeding pair were all associated with land use patterns (ANOVA, p < 0.05). Using reproductive measures in a mobile field station show promise as a flexible method of evaluating water quality in watersheds in urban and urbanizing regions.

We examined the growth rate of the breeding population of king penguins of Crozet archipelago over 41 years. Most colonies showed positive growth rates from the 1960s. However, there was evidence for a decrease in the larger colonies since the early 1990s, and for lower growth rates in the smaller colonies during the 1990s. The overall population size was estimated using log linear models, and the average annual growth rate was +6.3% for the 41-year period. Four change points were detected in the annual growth rate: +21.1% during 1978-1985, +4.3% during 1985-1995, � 19.2% during 1995-1999, and +10.9% during 1999-2003. Time-series analyses of the population-size estimates and the rela- tionship between growth rate and population size both indicated density-dependence in population growth rate. Variations in population sizes are also discussed in relation to environmental fluctuations. Our results sug- gest that important changes occurred over the past 10 years.

The stability of animal societies depends on individuals’ decisions about whether to tolerate or evict others and about whether to stay or leave. These decisions, in turn, depend on individuals’ costs and benefits of living in the group. The clown anemonefish, Amphiprion percula, lives in groups composed of a breeding pair and zero to four non-breeders. To determine why breeders accept the presence of non-breeders in this species I investigated the effect of non-breeders on multiple components of the breeders’ fitness. Non-breeders did not assist breeders in any obvious way. Experimental removal of non-breeders had no significant effect on the survival, growth, or reproductive success of breeders. Experimental removal of one of the breeding pair showed that non-breeders had little effect on the time taken for a widowed breeder to recommence breeding. The results indicate that the presence of non-breeders neither enhances, nor reduces, the fitness of breeders in A. percula. I suggest that non-breeders might modulate their effect on the fitness of breeders, either by reducing the costs they inflict or by increasing the benefits they provide, such that it just pays breeders to tolerate, rather than to evict, them. This study illustrates that animal societies can be stable even when some individuals gain nothing from the association.

Using Parensky's approach for estimating the number of breeding pairs, we determined effective subpopulation size Ne in early-run sockeye salmon Oncorhynchus nerka from Azabach'e Lake (Kamchatka) in 1977 through 1981. On average (over years and populations), biased sex ratio decreased Ne by 7% as compared to the number of fish on the spawning sites (Ni). High density reduced the Ne /Ni ratio by 62–66% because some fish were excluded from spawning. Dominance polygyny as compared to monogamy and random union of gametes could reduce Ne by about 17%.

The breeding ecology of the Australian magpie Gymnorhina tibicen in suburban and rural areas was compared as part of a study into the synanthropy of the species in southeast Queensland, Australia. During the two years of the study suburban magpies were found to have significantly advanced breeding dates compared to rural magpies. Suburban magpies typically re-nested when an initial nest failed, although this did not result in greater productivity than that of the rural magpies. Suburban magpies had similar mean numbers of young per breeding pair; they also showed higher mortality between fledging and a final count in February. This study suggests that introduced predators and deaths due to motor vehicles may account for this mortality in suburban areas. Anthropogenic factors present within suburban areas such as the watering of lawns and the widespread provision of food for wildlife are likely to play an important role in the differences in the timing of breeding. In addition, temperature may also have an inhibitory effect on the onset of breeding, an influence lessened in the suburban areas due to higher temperatures.

From 1997 to 1999, we monitored the reproductive success of individual rufous-crowned sparrows (Aimophila ruficeps) in coastal sage scrub habitat of southern California, USA. Annual reproductive output of this ground-nesting species varied strongly with annual variation in rainfall, attributed to the El Niño-Southern Oscillation. Birds fledged 3.0 young per breeding pair in 1997, when rainfall was near the long-term mean, 5.1 offspring per pair in 1998, a wet El Niño year, and 0.8 fledglings per pair in 1999, a dry La Niña year. Variation in many components of reproductive output was consistent with the hypothesis that food availability was positively correlated with rainfall. However, the factor most responsible for the high reproductive output in 1998 was low early season nest predation which, combined with favorable nesting conditions, enabled more pairs to multiple-brood. Cool, rainy El Niño conditions may have altered the activity of snakes, the main predator of these nests, in the early season of 1998. Overall, more of the annual variation in fecundity was attributable to variation in within-season components of reproductive output (mean number of nests fledged per pair) than to within-nest components (mean brood size). Annual variation in rufous-crowned sparrow fecundity appears to be driven primarily by food resource-mediated processes in La Niña years and by predator-mediated processes in El Niño years.

Neolamprologus pulcher, a cooperatively breeding cichlid fish from Lake Tanganyika, lives in per- manent social groups comprising one breeding pair and helpers of both sexes. Variation in group size (1-14 help- ers) provides an opportunity to investigate factors that affect how many helpers remain in a group and in turn how group size affects reproductive success. This field study showed that larger groups live in larger territories with more shelter. Group size was more strongly corre- lated with territory quality than with breeder size. Exper- imental enhancement of territory quality did not affect group size but group size decreased when territory qual- ity was reduced. Breeders living in a large group benefit because such individuals feed more often and have lower workloads and greater reproductive success. Helpers in larger groups also fed more frequently but did not have lower workloads. This is one of the first experimental studies to examine the factors influencing group size in cooperative breeders.

Pterapogon kauderni differs from most apogonids in several aspects of its reproductive biology. A breeding pair often allows a secondary male to intervene during mating. Each clutch consists of about 40 eggs 3 mm in diameter, held together by chorionic filaments and is incubated in the buccal pouch of the male for approximately 19 days. P. kauderni is the first apogonid in which direct development is described. Embryos hatch at post-flexion stages measuring about 6 mm SL and remain in the male's oral cavity for another ten days. When released as juveniles they measure 8 mm SL, their large yolksac is almost entirely consumed, and they do not pass through a planktonic interval. After release, juveniles do not return to the male's mouth for refuge, and any association between the male and newly released juveniles ceases. Juveniles reach 30 mm TL after four months and mature in another five to seven months. The embryo and juvenile development is presented.

During the breeding season 1996/97 we compared the foraging and diving behaviour of adult Magellanic penguins (Spheniscus magellanicus), growth rates of their chicks and their breeding success at two colonies in the south of Chile. One of the colonies is located on Magdalena Island in the Strait of Magellan, where a commercial fishery existed several years ago; the other, on the shores of the yet unexploited Otway Sound. Thirty adult Magellanic penguins were equipped with time–depth recorders (TDR) to investigate their behaviour at sea. In each colony 15 adults returning from the sea were stomach flushed to analyse dietary composition. Chicks of TDR-nests and of 12 additional control nests were weighed regularly. Foraging effort was significantly higher at Magdalena than at Otway. The Magdalena-birds usually remained at sea overnight and foraged with a mean duration of 18 h, whereas the penguins of Otway Sound foraged during 1-d trips with a mean duration of only 9 h. Compared to Magdalena, penguins at Otway dived shallower (mean depth 14.9 vs 16.5 m), shorter (mean duration 57.8 vs 64.3 s) and showed more searching and feeding as opposed to travelling activity (on average 69 vs 55%) during the foraging trips. Compared to other breeding locations both colonies were characterised by high chick growth rates, high fledging body masses (>3 kg) and early fledging date (after 70 to 80 d), and a very high reproductive success of >1.75 chicks per breeding pair. Comparison of the diet (almost exclusively sprats) with former investigations suggests for both areas an unchanged food structure over the last decade. The results in both colonies indicate ample food availability in the season 1996/97. However, compared to the much smaller Otway colony, penguins on Magdalena have to cope with more competition for food. Therefore, future prey limitation, through resumed fishery operations or effects of El Nino, might affect the penguin population on the island more negatively than in Otway Sound.

We studied waterfowl use of grass-sage stock ponds in north-central Wyoming during the 1988 and 1989 breeding seasons. Dabbling ducks, particularly mallards, were the most common breeders. Indicated breeding pair density averaged 2.7 pairs/ha of wetland surface, while brood density averaged 1.0 brood/ha of wetland surface. Waterfowl use and productivity were greatest on large (> 3 ha), clear, deep ponds with grass shorelines and abundant submergent macrophytes. Pair use was positively correlated with water clarity, pond area, and macroinvertebrate diversity. Brood use was related to macroinvertebrate diversity, pond depth, and Shoreline Development Index. We recommend management priority be given to ponds that are deeper than 1 m to provide more water that is clear so macrophytes can be established. Macroivertebrates should be artificially introduced into ponds. Fencing should be used to improve ponds for waterfowl use and brood rearing.