The effect of parental condition on egg-size and reproductive success in short-tailed shearwaters Puffinus tenuirostris

Eggs were exchanged between 50 pairs of shorttailed shearwaters Puffinus tenuirostris on Great Dog Island, Bass Strait, Australia, in an attempt to distinguish the intrinsic effects of egg-size from any effects stemming from differential quality of parental care. At 64 experimental nests, large and small eggs were exchanged whereas at 36 control nests, eggs of equivalent, medium, size were exchanged. Egg-size appeared independent of maternal effects. In both groups, hatching and fledging success were independent both of eggsize and of the body condition of the attending parents. This suggests that breeding success in these birds may be more closely related to the behavioural traits of parents than to physiological factors.     

Parasitism rates in relation to nest site in bees and wasps (Hymenoptera: Apoidea)

To account for differences in occurrence of social behavior in different lineages of bees, Michener (1985) hypothesized that ground nests are more easily located by parasites than are twig nests. In the former case parasites search in two dimensions, while in the latter they search in three-dimensional space. One prediction derived from this hypothesis is that ground nests will have higher rates of parasitism than twig nests. A survey of published reports on rates of cell parasitism for 92 species of nesting bees and wasps (Apoidea) shows no significant differences in mean parasitism rates between these two classes of nests. The analyses were repeated at the generic level (N=44), yielding the same pattern. These data may be biased due to phylogenetic effects. Paired comparisons (n=11 pairs) of related taxa that differ in nest site show that ground-nesting taxa more often have higher rates of parasitism than twig-nesters. The use of artificial trap-nests to study twig-nesters significantly enhances the success rate of parasites. This bias, as well as several other limitations, suggests that experimental studies of the host-searching capabilities of parasites and predators may be more efficacious than such comparative tests.     

Supplemental food increases ornamentation of male nestling Eastern Bluebirds

Although the condition‐dependence and signaling function of ornamental plumage coloration among adult males is well studied, less research has focused on the information content of ornamental coloration among juvenile birds. Eastern Bluebird (Sialia sialis) nestlings grow their nuptial plumage while in the nest and dependent on parents for food, making them an ideal species for studying the development and function of elaborate plumage. Previous research suggests that plumage brightness of Eastern Bluebirds functions, in the juvenile stage, in parent–offspring interactions as a sexually selected trait in adults. Using an experimental approach, we tested the effects of supplemental food on the structural plumage coloration (i.e., tips of primary feathers) of Eastern Bluebird nestlings in Watauga County, North Carolina, during the 2011 breeding season. We provided supplemental mealworms daily to breeding pairs from the onset of incubation through the nestling period, and measured plumage brightness, UV chroma, and mass of nestlings (N = 89 males and 71 females). Male nestlings of supplementally fed parents exhibited brighter plumage. The mass and UV chroma of young bluebirds were not significantly affected by food supplementation. However, the relationship between mass and brightness differed between male nestlings in the control and supplementally fed treatments. Males reared in food‐supplemented territories exhibited a positive relationship between color and mass. Nestlings in control territories, however, exhibited a negative relationship between size and brightness, suggesting that reduced food availability results in a tradeoff between allocating resources toward somatic growth and development of bright plumage. Our results suggest that UV‐blue structural plumage in male juvenile Eastern Bluebirds is at least partially condition‐dependent and may help to explain why plumage color can influence social interactions in Eastern Bluebirds.     

Artificial nests for Barn Swallows Hirundo rustica: a conservation option for a declining passerine?

Capsule: Barn swallows Hirundo rustica using artificial nest cups had greater reproductive success than those building and using natural nests.

Aims: To quantify reproductive success of Barn Swallows breeding in artificial man-made nests and compare with those using natural nests.

Methods: In 2012–16, the breeding attempts of 231 pairs of Barn Swallows were monitored in artificial and natural nests in an urban habitat in Denmark.

Results: Pairs breeding in old natural nests and artificial nests bred earlier, laid more eggs, and produced more nestlings and fledglings than pairs breeding in new natural nests. Inter-clutch intervals were shorter in Barn Swallow pairs using artificial nests and old natural nests. Nest cup volume and nest volume of newly built nests were significantly larger and more variable than artificial nests excluding an effect of nest size as an explanation for the larger clutches laid in artificial nests. Increased energy and time costs of nest construction may have reduced reproductive success for pairs building natural nests.

Conclusion: Artificial nests were readily accepted by Barn Swallows, they had a similar low predation rate as natural nests, and they proved to be a possible conservation option for this declining passerine breeding in urban habitats as evidenced by their 75% higher reproductive success in artificial nests.     

Condition and size of damselflies: a field study of food limitation

Summary Based on evidence from field manipulations, several authors have recently suggested that interference competition among larval odonates reduces individual growth rates and biomass by reducing foraging rates. This study was designed to test the effects of food shortage on condition (relative mass per unit head width) of larval Ischnura verticalis (Odonata: Coenagrionidae) under laboratory conditions and to use these results to estimate the degree of food shortage of larvae under naturally occurring field conditions. In the laboratory, there were marked differences in condition of larvae fed diets ranging from ad libitum feeding with worms to ad libitum feeding with Daphnia 1 day out of every 8. Condition of larvae collected from May through October from 17 different sites in southern Ontario indicated that, for most of the year, larvae had conditions similar to those fed ad libitum with Daphnia in the laboratory. There was no evidence that larval condition was related to population density. Condition of larvae in most sites during July was similar to that of larvae fed poor diets in the laboratory. It is unlikely that the low conditions were due to competition as there were no correlations with density across sites and population densities during July were at their lowest. Adult head widths showed a seasonal decline from mid June to the end of the flight season. There was no evidence that head widths were related to population density although there was some evidence that head widths of males were positively related to larval condition. My results do not support the hypothesis that competition is important in affecting foraging rates and subsequent development of larvae. Contrasts between my results and other studies may stem from difficulties with the interpretation of field experiments, that densities in my study may have been low due to fish predation, and/or that I. verticalis larvae are slow moving relative to other larvae and thus less likely to interact.     

Exotic shrubs as ephemeral ecological traps for nesting birds

Certain exotic plants may increase risk of nest predation, and, in this way, may act as ecological traps. We hypothesized that the greater vulnerability to predation was a consequence of either (1) reduced nest height due to architectural differences among plant species or (2) seasonal changes in the distribution of nests among forest strata. To test this, we examined temporal variation in nest survival of 888 nests of Northern Cardinal (Cardinalis cardinalis) in native substrates and two exotic shrubs (Lonicera maackii and Rosa multiflora) in Ohio, USA, 2001–2006. We evaluated evidence for an ecological trap by monitoring the annual reproductive productivity of 245 breeding pairs of cardinals. Only nests in Rosa experienced relatively constant survival rates across the season, whereas probability of survival increased over the season for nests in other substrates. Interestingly, the relative vulnerability of nests in different substrates varied across the season. Most strikingly, nests in Lonicera in early spring showed the lowest survival rates but exceeded survival rates of nests in native substrates late in the season. Nest height failed to explain seasonal changes in nest survival, as only nests in native plants significantly increased in height as the season progressed. Rather, predation risk seemed to be a function of the proportion of nests within each substrate, as illustrated by the decreased predation in Lonicera as the relative proportion of nests in native substrates increased. The patterns of temporal variation in predation risk that we detected show that impacts of Lonicera are not a function of plant architecture alone and may be related to leaf phenology, changes in nest density, nest site location, and/or nest synchrony. Examination of the reproductive productivity of cardinals showed that pairs that made their first nest attempt in Lonicera fledged 20% fewer cardinal young than birds that began the season using other substrates. Thus, we suggest that exotic plants may represent an ephemeral ecological trap for certain nesting birds, where negative effects persist only during certain periods.     

Dietary shifts,niche relationships and reproductive output of coexisting Kestrels and Long-eared Owls

Summary Food samples of breeding Kestrels (Falco tinnunculus) and Long-eared Owls (Asio otus) were collected in the peak and low phase of their preferred prey (Microtus voles) in western Finland. Diets of pairs that bred as neighbours (1 km) with interspecifics were compared with those of non-neighbours. In both species, neighbouring pairs fed less on Microtus voles and more on alternative prey than did non-neighbours. Competition theory predicts that diet overlap should be lower during prey shortage and that diet similarity should be especially reduced in neighbouring pairs. Observations were consistent with expectations: diet similarity was lower in the low vole years and neighbouring pairs showed less diet overlap that non-neighbours. Differences in habitat composition and prey availability at the sample sites should not confuse the results. In addition to the high diet similarity, hunting habitats and nest sites of the species overlapped almost completely; they only showed clear temporal segregation in hunting. Probably because of food competition, the neighbouring pairs of both species produced significantly fewer young than the non-neighbours. These results contrast with the view that the diet composition and dietary shift of rodent-feeding predatory birds can be interpreted in terms of simple opportunistic foraging. In the breeding season, interspecific competition for food seems to be an important factor that affects the niches of these species, especially in northern areas, where the seasonal low phase of voles in spring and the number of alternative prey are lower than in more southern areas.     

Mammal hair in nests of four cavity-nesting songbirds: occurrence,diversity and seasonality

Capsule: The diversity of mammal hair found in nest linings varied between bird species and with season.

Aims: We examined mammal species composition in the guard hair material of four cavity-nesting songbirds, focusing on their numbers and occurrence, nest predation and seasonality.

Methods: We surveyed 219 nests of four cavity-nesting songbirds breeding in a Central European woodland and identified hairs from 28 mammal species.

Results: Roe Deer Capreolus capreolus hair was the most commonly used hair type in the nests of all four songbird species. This was especially the case in Blue Tit Cyanistes caeruleus nests, which may suggest a preference for Roe Deer hair. The greatest diversity of hairs was found in the nests of Great Tits Parus major, while the lowest was found in the Collared Flycatcher Ficedula albicollis. In flycatchers, 59% of females used only plant material for nest construction. Interestingly, we found a strong seasonal effect in hair use. Flycatcher nests that were initiated early in the season were more likely to contain mammal hair than those initiated later in the season. Similar, albeit weaker, negative seasonal effect was detected in Great and Blue Tit nests. There were no significant effects of any potential anti-predatory functions of mammalian hair in nests.

Conclusion: Our study showed a clear prevalence of Roe Deer in the hair material of all bird species and certain preferences of birds for particular mammal species. When the aim is to detect a wide range of mammal species, for example, during biodiversity surveys, we advise to consider sampling effort and to focus on early breeding birds.     

Patches and the responses of lake benthos to sunfish nest-building

Summary Males of three sunfish species (Centrarchidae) construct nests for spawning and often share them sequentially in the littoral zone of a 4-hectare lake in New York State. To determine spatial and temporal effects of this reproductive behavior on zoobenthos in patches, I sampled bottom assemblages from inside nests and from adjacent (<1 m from nest perimeter), relatively undisturbed sites during the reproductive season of 1986 and immediately prior to nest-building in 1987. The reproductive behaviors of largemouth bass (Micropterus salmoides), redbreast sunfish (Lepomis auritus), and pumpkinseeds (L. gibbosus) altered relative abundances and significantly decreased benthic invertebrate diversity and density. These effects were extremely pronounced during the reproductive season and were partially detectable the following year. Community changes were probably the result of both bioturbation (modification of sediment size and organic content) and predation. The ecosystem-wide effects of nest-building are evaluated in terms of the number, distribution, and longevity of patches.     

Effects of male removal on the behaviour and reproductive success of female Eastern Bluebirds Sialia sialis

We removed male Eastern Bluebirds Sialia sialis to examine the importance of male parental care and the behavioural responses of unaided females to loss of male assistance. Unaided females fed young significantly more than control females (females with male assistance) fed young, but young in experimental nests were fed significantly less frequently in total than young in control nests. Unaided females had significantly lower nesting success (fledged at least one young) than control females. At control nests, males defended the young more strongly than did their mates. Unaided females defended their young as strongly as control females. Unaided and control females spent the same amount of time brooding young, and there was no tradeoff between feeding and brooding young. Most early season experimental nests failed, but late in the season many unaided females were as successful as pairs. Unaided females were able to match the feeding rat'e in control broods at late nests but not at early nests, where control nestlings were fed at a higher rate. In our population, male bluebirds played an important role in provisioning young, and early in the season unaided females were unable to provide sufficient bod to raise any young to fledging.     

Predation on artificial,solitary and aggregated wader nests on farmland

Predation rates on artificial wader nests, solitary curlew (Numenius arquata) and lapwing (Vanellus vanellus) nests and lapwing nests in colonies were studied on a farmland site in central Sweden. Predation rates were highest on artificial wader nests, intermediate on solitary curlew and lapwing nests and lowest on lapwing nests in colonies, probably because of active defence of adults at real nests and/or because of selection of nest sites with lower predation risk by breeding birds. A comparison of nests close to (50 m) and far away from (200 m) forest edges revealed no increased predation risk close to edges for any of the studied nest types. Predation risk changed during the season for artificial nests (highest in the middle of May), while predation rates on lapwing and curlew nests were more stable. Artificial nests seem to be inappropriate for measuring actual predation rates and temporal differences in predation rates on real nests, but they might be suitable for use as an index of spatial differences.     

Supplementary feeding increases nestling feather corticosterone early in the breeding season in house sparrows

Several studies on birds have proposed that a lack of invertebrate prey in urbanized areas could be the main cause for generally lower levels of breeding success compared to rural habitats. Previous work on house sparrows Passer domesticus found that supplemental feeding in urbanized areas increased breeding success but did not contribute to population growth. Here, we hypothesize that supplementary feeding allows house sparrows to achieve higher breeding success but at the cost of lower nestling quality. As abundant food supplies may permit both high‐ and low‐quality nestlings to survive, we also predict that within‐brood variation in proxies of nestling quality would be larger for supplemental food broods than for unfed broods. As proxies of nestling quality, we considered feather corticosterone (CORT_f), body condition (scaled mass index, SMI), and tarsus‐based fluctuating asymmetry (FA). Our hypothesis was only partially supported as we did not find an overall effect of food supplementation on FA or SMI. Rather, food supplementation affected nestling phenotype only early in the breeding season in terms of elevated CORT_f levels and a tendency for more variable within‐brood CORT_f and FA. Early food supplemented nests therefore seemed to include at least some nestlings that faced increased stressors during development, possibly due to harsher environmental (e.g., related to food and temperature) conditions early in the breeding season that would increase sibling competition, especially in larger broods. The fact that CORT_f was positively, rather than inversely, related to nestling SMI further suggests that factors influencing CORT_f and SMI are likely operating over different periods or, alternatively, that nestlings in good nutritional condition also invest in high‐quality feathers.     

Ecological analyses of nesting success in evening grosbeaks

Summary We studied the nesting success of Evening Grosbeaks (Coccothraustes vespertinus) inhabiting two areas of the Front Range of the Rocky Mountains of Colorado from 1983–1987. Sixty-four nests were followed during building, incubating, brooding, and fledging; 54.7% were successful (young fledged). The largest number of nests failed during incubation. Nests started later were more successful than nests begun earlier in the season. Failure was most likely due to severe weather, abandonment during building, or predation. Specific habitat characteristics of grosbeak nesting sites and where nests were placed in trees were consistently associated with nesting success. Successful nests, when compared with nests that failed, were: (1) built in more open areas characterized by dispersed vegetation and a higher minimum canopy, (2) oriented in more southerly directions, (3) built closer to the main trunk of the nest tree, and (4) built in larger trees. Current ideas about whether or not birds actually select nest-sites are briefly discussed. We conclude that some grosbeaks optimally select nest sites where the likelihood of producing fledglings is higher than in other areas.     

Effects of algal diets and temperature on the growth and fatty acid content of the cichlid fish Oreochromis niloticus L. – A laboratory study

The effects of different algal foods and water temperatures on the growth and fatty acid content of the Nile Tilapia, Oreochromis niloticus L., were studied. Four types of algae, given in the same amounts as the control diet, were used as food: Microcystis aeruginosa, colonial and single-celled forms; Arthrospira fusiformis; and Scenedesmus quadricauda. The control group was fed a commercial diet of cichlid pellets, while another group was left unfed. The feeding experiment was run at 25 °C. The condition factor decreased in all algal fed fish groups, except the one fed on Microcystis colonies, whereas the control group showed no significant change. Both food quantity and quality were responsible for this result. Some short-chained fatty acids in the diets could be traced in the long-chained counter-parts in the fish tissue. Both saturated fatty acids and monounsaturated fatty acids were higher in the control vs. treatment groups, whereas the polyunsaturated fatty acids displayed no significant differences amongst any of the treatment groups studied, including the unfed group. Direct quantitative comparison of individual fatty acid in the diet vs. tissue lipids in the fish proved to be difficult due to the great capacity of these tilapias to elongate and desaturate 18 carbon acids into long-chained homologues. The effect of temperature was studied by growing the fish at 16, 20 and 25 °C. All groups were fed commercial cichlid pellets. The level of saturated and monounsaturated fatty acids increased at 20 °C, whereas polyunsaturated fatty acids showed little variation. Docosahexaenoic acid, belonging to the important omega 3 group where the first double bond starts at carbon number three, was highest at 16 °C, resulting in a markedly elevated omega-3/omega-6 ratio at that temperature.     

The effect of predation of western widow spiders (Araneae: Theridiidae) on harvester ants (Hymenoptera: Formicidae)

Summary Spiders have been shown to be important predators on ant populations, although ant mortality may be low. Western widow spider (Latrodectus hesperus) predation on Pogonomyrmex rugosus ant nests is slight, less than 0.2% of the nest population per day. Yet, the ants respond by halting foraging temporarily and may even close the nest entrace with pebbles. If spiders are removed from such nests, the ants become active within 24 h and within five days foraging activity reaches higher levels than at any previous time of the year.Ants have at least four responses to spiders predation: 1) Moving the nest entrace; 2) posting of guards; 3) attacking the spiders; 4) halting foraging. Pogonomyrmex rugosus practices the fourth response, although it results in losses of food intake into the nest. This is apparently the only option available. If the ants continue to forage, the spider density may increase, resulting in heavy mortality of the ants.     

European starlings: nestling condition, parasites and green nest material during the breeding season

Male European starlings (Sturnus vulgaris) intermingle fresh herbs, preferably species rich in volatile compounds, into their dry nest material. In a field study, we investigated whether these herbs affect the mite and bacteria load of the nests and the condition of the nestlings either directly or via parasite control. We examined the amount of herbs and the number of plant species males carried into their nests, the variation of volatile compounds in the headspace air of the nest boxes and mite/bacteria load of the nests throughout the season. The amount of herb material and the number of plant species, the number of substances emanated by these plants and the infestation of the nests with bacteria and mites (Dermanyssus gallinae) increased with season. In a field experiment, we exchanged natural starling nests with experimental nests with or without herbs. We found that the herbs had no effect on the mites but fewer bacteria were sampled in nests with herbs than in nests without herbs. The body mass of the fledging was not related to the season or the mite/bacteria load of the nests. However, nestlings from nests with herbs fledged with higher body mass than nestlings from nests without herbs. Both bacteria and mite load were related to nestling mortality. In nests containing no herbs, the numbers of fledglings declined significantly with the increasing mite load while the mites had no effect on the number of fledglings in nests with herbs. Thus, the nest herbs counteracted the effect of the mites. In conclusion, it seems that volatile herbs can reduce bacterial but not mite infestation of the starling nests. The positive influence of herbs on nestling growth indicates that herbs either directly (perhaps as immunostimulants) improve the condition of the nestlings and help them cope with the harmful effects of mites, or they provide a nest environment beneficial for the nestlings‘ development by the reduction of germs.     

Behavioral Response of Resident Jamaican Birds to Dry Season Food Supplementation1

We used plot‐level manipulations and analyses to test the effects of food availability on the behavior and condition of resident dry‐forest birds in Jamaica. Two control plots were monitored in each of 2 yr. Food was supplemented on five plots over 2 yr with piles of cut oranges distributed around plots, which served as a direct source of carbohydrates and water, and an indirect source of ground arthropods due to increased above‐ground activity. We reduced ants on five plots over 2 yr; however, we found no difference in total ground arthropod biomass between control and reduction treatments, so we pooled these plots for analysis. We selected nine focal resident bird species for study of relative abundance, body condition, and breeding condition. Birds were sampled prior to, and 5 to 6 weeks after the initiation of treatments. Seven of nine species had higher relative abundance following food supplementation. Three species were recaptured more frequently in supplementation plots than in control plots. These abundance and persistence responses did not cause any changes in body condition. In one species, Bananaquit (Coereba flaveola), food supplementation resulted in higher concentrations of individuals in breeding condition. These results demonstrate a functional response to dry‐season food availability and suggest a limiting mechanism. This study helps explain mechanisms by which bird populations respond to resource availability, and is the first successful plot‐level food supplementation experiment for tropical forest birds.     

Opportunistic Predation of Wild Turkey Nests by Wild Pigs

Wild pigs (Sus scrofa; i.e., feral hogs, feral swine) are considered an invasive species in the United States. Where they occur, they damage agricultural crops and wildlife habitat. Wild pigs also depredate native wildlife, particularly ground-nesting bird species during nesting season. In areas inhabited by wild turkeys (Meleagris gallopavo), nest destruction caused by wild pigs may affect recruitment. There is debate whether wild pigs actively seek ground-nesting bird nests or depredate them opportunistically. To address this debate, in 2016 we examined the movements of wild pigs relative to artificial wild turkey nests (i.e., control [no artificial nests], moderate density [12.5–25 nests/km²], and high density [25–50 nests/km²]) throughout the nesting season (i.e., early, peak, and late) in south-central Texas, USA. We found no evidence that wild pigs learned to seek and depredate wild turkey nests relative to nest density or nesting periods. Despite wild pigs being important nest predators, depredation was not a functional response to a pulsed food resource and can only be associated with overlapping densities of wild pigs and nests. Protecting reproductive success of wild turkeys will require reducing wild pig densities in nesting habitat prior to nesting season. © 2019 The Wildlife Society.     

Ants on the Move: Resource Limitation of a Litter‐nesting Ant Community in Costa Rica1

The leaf litter of tropical wet forests is replete with itinerant ant nests. Nest movement may help ants evade the constraints of stress and disturbance and increase access to resources. I studied how nest relocation and environmental factors may explain the density, size, and growth of leaf litter ant nests. I decoupled the relationships among litter depth, food abundance, and nest availability in a 4‐mo manipulation of food and leaf litter in a community of litter‐nesting ants in a lowland wet forest in Costa Rica. Over 4 mo, 290 1 m² treatment and control plots were sampled without replacement. Nest densities doubled in response to food supplementation, but did not decrease in response to litter removal or stress (from litter trampling). The supplementation of food increased the utilization of less favored nesting materials. In response to food supplementation and litter trampling, arboreal ants established nests in the litter, and growth rates of the most common ants (Pheidole spp.) increased. Colony growth was independent of colony size and growth rates of the most abundant ants. In general, I conclude that litter‐nesting ant density is driven primarily by food limitation, that nest relocation behavior significantly affects access to resource and the demographic structure of this community, and that nest fission may be a method to break the growth–reproduction trade‐off.     

Food partitioning by lake-dwelling triclads and glossiphoniid leeches: field and laboratory experiments

The triclads Polycelis tenuis and Dugesia polychroa and the glossiphoniid leeches Glossiphonia complanata and Helobdella stagnalis are abundant on the stony shores of productive British lakes. All species are food limited and there is considerable overlap in the diets of these triclads and leeches. This paper investigates interactions between the two groups using field and laboratory experiments to try to identify the mechanism of their co-existence. Triclad and leech numbers were manipulated inside experimental enclosures, mathced by controls, erected on the stony shore of an eutrophic English lake. Increasing the numbers of P. tenuis and D. polychroa prior to the reproductive season in spring resulted in a significant decrease in the numbers and body size of G. complanata and H. stagnalis compared with control populations in the summer months, and vice versa. However, increases and decreases were temporary with a readjustment of numbers and body size to control levels in the autumn after reproduction had ceased. It is suggested that increasing the numbers of either group elevated the severity of both intra- and interspecific competition for food. The condition of prey may, in part, determine the strength of competition, and this was examined in laboratory experiments in which different densities and ratios of P. tenuis and H. stagnalis were offered either live of recently crushed Asellus aquaticus. In monospecific controls, growth rates of P. tenuis were greater when fed on crushed than live Asellus, but there was no significant difference in the growth of H. stagnalis fed either live or crushed prey. In mixed cultures of predators, P. tenuis and H. stagnalis were the superior competitors when fed on crushed and live Asellus, respectively. However, when competitive pressure was low, at low densities of predators, the presence of H. stagnalis in mixed cultures fed on live prey was beneficial to the growth of P. tenuis. These results are explained in terms of the greater ability of triclads to detect damaged prey, leaking body fluids, due to their sophisticated chemosensory system, and the ability of leeches to capture live prey due to the presence of suckers. It is concluded that co-existence of the two groups in British lakes is assisted by the partitioning of food on a live or damaged basis.