Temperature differences associated with colour do not determine where the acorn ant Temnothorax crassispinus (Hymenoptera: Formicidae) chooses to nest
Temperature is an important factor for invertebrates. Social insects build nests, which along with their ability to thermoregulate, provide shelter from extreme temperatures. However, for many species of ants the most common method of controlling the temperature inside a nest is to choose a suitable nest site. During a fi eld experiment, the choice of nest site by the acorn ant Temnothorax crassispinus, a species which lives in coniferous and mixed forests, was studied. It typically occupies ephemeral nest sites and can move to a new nest site several times in one season. It was predicted that in early spring, dark coloured nest sites would be warmer and thus more frequently occupied by ant…
Impact of plant cover on the cavity-nesting antTemnothorax crassispinus
1. Plant communities influence the availability of important resources for ants, such as nest sites and food, as well as environmental conditions. Thus, plants affect the abundance and distribution of ants. 2. In a field experiment, the influence of plant cover on the settlement of nest sites and per-capita productivity of sexual individuals by the ant Temnothorax crassispinus was analysed. In July 2014, in five areas with patches of alien balsam Impatiens parviflora, and another five of native balsam I. noli-tangere, transects composed of artificial nests were established; the nest sites were situated inside patches of balsams, and outside of them. Four hundred and forty artificial nests w…
Acorn Ants May Create and Use Two Entrances to the Nest Cavity
Many ant species construct large nests that are inhabited by numerous workers, but other species dwell in ready-for-use cavities and live in small colonies. Ants of the genus Temnothorax inhabit small cavities, e.g., in acorns, twigs, and under rocks. Although a preference for nest sites with a narrower entrance is known, recent studies have shown that they also use cavities with wider entrances and may modify the size of such entrances. As good cavities for nest sites are a limited resource, the possibility to modify a potential nest site, including a reduction in the size of the hole, should be a favorable matter for the ants. Through field and laboratory experiments, I studied the acorn …
The Body Size of Headstarted and Wild Juvenile European Pond Turtles (<i>Emys orbicularis</i>)
Headstarting is a popular conservation technique in which animals are raised under artificial conditions, and then released into natural habitat. The objective of this procedure is to grow animals to a size at which they are less vulnerable to predators. However, there is still little empirical evidence for the long-term effectiveness of the technique. Therefore, we compared body size of juvenile «wild» (= not taken to artificial rearing) and headstarted European pond turtles ( Emys orbicularis ), from two populations (in central and western Poland). Immediately after hatching there were no differences in size of the turtles, but after seven-ten years headstarted turtles were smaller. This …
Migrations of hatchling European pond turtles (Emys orbicularis) after nest emergence
Distances between nest sites of Emys orbicularis and the nearest water bodies can be long. We studied whether a longer distance could affect the probability of hatchling survival, migration time, and body mass loss. In our research area (Lubuskie district, western Poland), nest sites were situated on a slope; the closest water body was in a distance of 72-290 m. Near the water body we constructed a 550 m long drift fence to recapture hatchlings migrating down the slope. We monitored 32 hatchlings from 7 different nests deposited in the years 2008-2010. The hatchlings started to emerge from their nests on 9 and 13 April 2009, 7 and 9 April 2010, 30 March, 7 and 8 April 2011. Then, hatchlings…
No effect of lack of wood for acorn ant colonies development
Acorn ants mostly inhabit cavities in fallen twigs and hollow acorns. Such places, e.g., dead wood, provide an attractive living resource for many groups of microorganisms, like fungi and bacteria, which can be important for ants. However, during experiments in laboratories, acorn ant colonies are typically kept without dead wood. During laboratory experi-ments, the preferences of the ant Temnothorax crassispinus for nest sites with pieces of dead wood were checked, and whether the presence of such wood influenced productivity. In binary choice tests, colonies had to choose a nest site when presented with two potential nest sites, one empty, or two cavities with different contents. The ant …
Emigration speed and the production of sexuals in colonies of the ant Temnothorax crassispinus under high and low levels of disturbance
A nest relocation is costly for social insects, and involves hazards. Emigrations were studied in Temnothorax crassispinus ant colonies, which inhabit ephemeral nest sites, and which frequently change their nests. In a laboratory experiment, ant colonies from one group were forced to change their nest sites 10 times over a ca. 3-month period, whilst colonies from the second group were forced to adopt this practice twice (on the beginning of May, and in the second half of July). Colonies of the ant from both the groups reduced their total emigration duration. However, the duration of the transport phase remained unchanged. In the case of colonies with higher level of disturbance, there was n…
Disappearance rates of old nest material from tree cavities : an experimental study
Numerous forest organisms critically depend on availability of tree cavities. Some birds and rodents fill their cavities with bulky nests, which – if not removed – could accumulate and render cavities unusable, as recorded in nest-box studies. Data from earlier studies indicate that old nests can disappear from tree cavities so fast that practically no remnants are detectable the following spring. Rapid decomposition of nests in situ, augmented by physical removal of nest material by the cavity-users have been proposed as possible causative mechanisms. We tested these hypotheses in cavities used by tits (Parus major L., Poecile palustris L.) in the Białowieża National Park (E Poland). To mi…
High winter survival rate of acorn ants inside artificial nest sites (Hymenoptera: Formicidae)
Although most species of ants overwinter underground to avoid low temperatures, the acorn ants of the genus Temnothorax remain in nests situated at ground level. During a field experiment, I studied the winter mortality of acorn ants in nest sites situated aboveground, as well as in sites experimentally buried in the soil. Despite the low air temperatures (even reaching –19°C, recorded 1.5 m above the ground), the survivorship was very high: all of the 18 queens used in the experiment survived, while the survival rate of workers was 61.9-100%, and for most colonies it exceeded 95%. The rate of survival in the nest sites aboveground and those experimentally buried in the soil was similar. Su…
The cavity-nest ant Temnothorax crassispinus prefers larger nests
Colonies of the ant Temnothorax crassispinus inhabit mostly cavities in wood and hollow acorns. Typically in the field, nest sites that can be used by the ant are a limited resource. In a field experiment, it was investigated whether the ants prefer a specific size of nest, when different ones are available. In July 2011, a total of 160 artificial nests were placed in a beech-pine forest. Four artificial nests (pieces of wood with volume cavities, ca 415, 605, 730, and 980 mm3, respectively) were located on each square meter of the experimental plot. One year later, shortly before the emergence of new sexuals, the nests were collected. In July 2012, colonies inhabited more frequently bigger…
Cost to the cavity-nest ant Temnothorax crassispinus (Hymenoptera : Formicidae) of overwintering aboveground
Most species of ants inhabiting the temperate zone overwinter underground, whereas those of the genus Temnothorax remain in nests aboveground. I studied the cost of aboveground overwintering. Workers of Temnothorax crassispinus survived in higher numbers (median = 88%) in artificial nests experimentally buried at a depth of 5 cm than those in nests on the surface (48%) of the soil. The results support the hypothesis that overwintering aboveground could be a consequence of a limited supply of nests and/or the advantage of being able to respond quickly to warm temperatures in spring.
Cohabitation of tree holes by ants and breeding birds in a temperate deciduous forest
A previously unknown association of ants with birds breeding in tree holes is described. Ants Lasius brunneus Latreille (Hymenoptera: Formicidae) were found in c. 15% of nests of Parus major L. and Poecile palustris L. (Paridae) breeding in tree holes in the primeval deciduous forest located in the Białowieża National Park (Poland). The ants preferably used holes located higher above the ground. As such holes are warmer than the unused holes or other nest sites, it is suggested that the ants cohabit holes utilized by the tits to gain thermal benefits.
Size-related mortality during overwintering in cavity-nesting ant colonies (Hymenoptera: Formicidae)
The ongoing process of climate change will result in higher temperatures during winter and therefore might increase the survival of overwintering invertebrates. However, the process may also lead to a reduction in snow cover and expose overwintering invertebrates to lower temperatures, which could result in higher mortality. During a field experiment, I investigated the effects of a reduction in snow cover on the survival of the ant Temnothorax crassispinus, which overwinters in nests located on the ground. Ant colonies differed in the survival rate of the workers in the experimental (from which snow cover was removed) and control group. In the control group, the survival rate was unrelated…
Effect of tin and lead chlorotriphenyl analogues on fruit fly Drosophila hydei and liposomes membrane
This article presents the results of a study investigating the biological activity of triphenyltin chloride (TPhT) and two metalloorganic compounds, triphenyllead chloride (TPhL) and triphenylmethane chloride (TPhC), in their interaction with model membranes and the living organisms of fruit flies Drosophila hydei. The study of model membranes (sonicated liposomes) was conducted using the electron spin resonance (ESR) spin probe technique, whereas the experiment on fruit flies involved investigating their viability on media containing the studied compounds. The test results clearly demonstrate that TPhT affects fruit flies more actively than TPhL (complete lethality after 7 days of culture …
Population differentiation of the European pond turtle (Emys orbicularis) in Poland inferred by the analysis of mitochondrial and microsatellite DNA : imlications for conservation
We investigated the genetic diversity of Polish populations of the European pond turtle (Emys orbicularis) using complete sequences of the mitochondrial cytochrome b gene and allelic variation at thirteen microsatellite loci. We collected data from 146 turtles from 28 locations covering most of the species’ range in Poland. Our results showed a low haplotype diversity and high levels of microsatellite diversity in all populations. We applied two Bayesian approaches using the multilocus data and determined relationships of mtDNA haplotypes by constructing a parsimony network. We observed relatively consistent results of the two Bayesian clustering methods and largely concordant differentiati…
Decomposition Rate of Old Nest Material in Tree Holes
Abstract. We experimentally tested whether old nest material could decompose fast enough to clear tree holes between the consecutive seasons. To mimic the nest material we filled litter-bags with either 1 g of cellulose, or with 0.5 g of dog moulted hair. In August 2009 we placed pairs of these bags in 23 tree holes used by breeding birds in a deciduous forest in SW Poland. For reference, we placed the same sets of bags in the litter, at 23 random sites in the forest. The bags were removed in March 2010. After seven months of exposure almost all cellulose (median 92%) and most of hair (median 57%) disappeared from bags in the holes. These values were as high as (for cellulose) or even highe…
Decomposition of nest material in tree holes and nest-boxes occupied by European Starlings Sturnus vulgaris: an experimental study
Numerous bird species depend on the availability of tree cavities, and most non-excavators fill their cavities with considerable amounts of nest material. If not removed, this material can accumulate and render cavities unusable, as recorded in some nest-box studies. Data from earlier studies of tree cavities, however, showed that nest material can decrease mostly due to in situ decomposition, but the relative difference between nest decomposition in tree holes and nest-boxes is still unknown. We undertook parallel studies of decay in tree holes and nest-boxes used by European Starlings Sturnus vulgaris in oak-hornbeam stands (SW Poland). We inserted into its tree holes and nest-boxes litte…
The headstarting technique is an ineffective method for conservation of the European pond turtle – elasticity analysis
The European pond turtle ( Emys orbicularis ) is endangered in many areas within its distribution range. Thus, protection programmes for the turtle populations are in place. However, the efficiency of some techniques (including a highly manipulative one - headstarting) is questionable. Elasticity analysis was conducted using the life history data gathered in central Poland during the period 1986 - 2002. The analysis revealed that headstarting is a fairly ineffective method. The most effective methods are those that protect adult individuals. Thus, methods that can sustain a decreasing adult mortality rate should be recommended for turtle conservation.
Overwintering Site Fidelity in the European Pond Turtle (Emys orbicularis) in Western Poland
The location of overwintering sites of six male and six female European pond turtles (Emys orbicularis) were studied using radiotelemetry in Western Poland, over a period of four consecutive seasons. Most of the studied individuals overwintered in the same area during the research; most distances between two consecutive overwintering sites were 0–25 m. However, changes related to the overwintering area were observed, and in such cases the distance between overwintering sites on two consecutive seasons could exceed 2 km. These results can support an efficient conservation strategy of the turtle population.