15% to 20% rate of exploitation of the moose population

Transcription

1 MOOSE KILLED ON THE HIGHWAY IN THE LAURENTIDES PARK QUEBEC, 1962 TO 1972 Abstract: Pascal Grenier, Forest Engineer Quebec Wildlife service Between 1962 and 1972, 324 moose were recorded killed on Talbot Boulevard in the Laurentides Park, Quebec. ~is mortality factor represents a 15% to 20% rate of exploitation of the moose population living near the road. The number of moose killed on the highway has more than doubled during this II-year period. ~ere is a positive correlation between the number of moose killed each month and each year and the number of vehicles. ~e increase in the number is accompanied by a decrease in the average age of the animal's killed. This fact and the apparent stability of the moose population along the road suggests a higher vulnerability of young moose to car accidents. More adult females than males are killed but we could not find any significant difference in the sex ratio of calves. According to the sex ratio of the hunted population there is no difference between male and female calves with regard to vulnerability. Significantly more females than males were killed from July to November, but no difference was observed for the May-June period. ~e average age of moose killed on the road is significantly lower for some years than the average age of moose harvested by hunters and both are decreasing. Most accidents occur between June and August. More than 80% occur at night. ~e number of moose killed per vehicle registered in the park is the highest in June and July and lower in August,

2 September and october. Traffic density and moose mortality suggest that the moose is active all night long. Moose movement and mortality were studied in relation to ponds located on each side of the road. The high concentration of sodium and calcium in these ponds suggests strongly that it is due to winter salt application on the road. Moose frequentation of the ponds is related to the salt concentration. Very little relation has been found between moose mortality and the frequentation or salt concentration of the ponds, but 2.3 times as many moose are killed where there are ponds than where there are none. The average age of moose killed in sectors with ponds is significantly higher than in sectors without ponds. This may indicate a difference in vulnerability by age group for those two sectors. Highway accidents involving moose constitute a serious problem in several regions of Quebec. collisions and drivers' efforts to avoid these result in (1) death, injuries and inconvenience for the people involved; (2) considerable damage to vehicles; (3) the death of members of an important animal species. This type of accident may be attributed to two main groups of factors: those related to the vehicles (number and speed) and roads (number, type of construction and maintenance) and those related to the animals (density and structure of population,

3 behavior and environmental factors). Knowledge of these variables must be increased in order to decrease the number of road accidents involving moose. To the best of our knowledge no work on this subject has as yet been published. The only document mentioning moose killed on the road is by Thompson (1967) who reports a total of 46 moose killed on the highway in three American states. We conducted a study in the Laurentides Park on some of the abovementioned factors: the number of vehicles, maintenance of roads with sodium and calcium chloride, the structure of the subject moose population and the behavioral aspect of the moose being near the road. The aim of this report is (1) to give the results of an analysis of the data on moose accidentally killed on roads in the Laurentides Park between 1962 and 1972; (2) to evaluate the effect of this mortality factor on the moose population living in the vicinity of roads; (3) to analyse certain causes of the increased number of collisions and (4) to study the effect of sodium and calcium chloride on the behavior and mortality rate of the moose along the road. We wish to thank Messrs. Pierre DesMeules and Benjamin R. Simard for having furnished some of the data on the moose killed. This work was carried out for the Quebec Wildlife Service.

4 DESCRIPTION OF THE REFERENCE AREA The Laurentides Park is a wooded area of 4,060 square miles situated on the Canadian Shield 30 miles north of Quebec city. Talbot Boulevard crosses the park from north to south and divides in two in the middle to service two cities to the north. It is a two-lane highway km long. In winter, the surface is kept clear by applying large quantities of sodium chloride (28.2 metric tons/km/year) and a lesser amount of calcium chloride (0.45 metric tons/km/year) (Langlois, personal communication). The speed limit is 96 kph. All vehicles going through the park (about 800,000 a year) are registered at the gates at either end. The surrounding area is practically uninhabited. For the purposes of this study, the road has been divided into three sections with the junction of the two northern branches serving as the dividing point. These three sections will be identified as the southern section (78.9 km long), the northeastern section (50.7 km long) and the northwestern section (59.6 km long). The Laurentides Park has been open to controlled moose hunting since The number of moose bagged is relatively stable and the rate of exploitation in the accessible sector is between eight and ten percent, calculated on the basis of Bouchard's data (1972).

5 METHOD The data on the moose killed were gathered by employees of the Wildlife Service permanently stationed in the park. A form was filled out for every carcass examined. Some accidents were not registered since the injured animal fled into the forest. The same form was not used for the whole reference period. Between 1969 and 1972, however, the following information was recorded: location by Mercator projection (~100 m), date and time of accident, sex and age of moose (age group based on Passmore et al. 1955). An inventory of the ponds situated near and on each side of the road was made at the end of July and the beginning of August 1969 for the southern and northeastern sections and for a secondary road which was not treated with sodium or calcium chloride. The technique consisted of driving slowly along the side of the road and locating the ponds. Each pond was indicated on a 1:50,000-scale map. The distance from the roadside was measured as well as the size of the pond (length and width). Frequentation by moose was also evaluated and divided into three classes based on the number of tracks: scarce (no more than one), occasional (from 2 to 4) and regular (more than 4 tracks, often trails maintained by moose). Water samples from 61 ponds along the southern section and 20 near the secondary road were analyzed quantitatively for sodium and calcium concentration and tested for specific

6 conductivity The specific conductivity was evaluated using the conductance cell method and the concentration in ppm of the two ions was obtained through the atomic absorption method. RESULTS Moose Killed On The Highway Between 1962 and 1972, 324 moose were recorded killed on the km highway in the Laurentides Park; that is, an average of 29.5 moose a year or one moose every 6.4 km every year (Table 1). The number of moose killed per year has more than doubled during this ll-year period. On an average, 38.2 moose were registered killed during the last five years. There is no significant difference between the number of female and male calves killed (96:100). The sex ratio among the adults (one year and over) indicates a considerably greater number of females killed (58:100). The mean age (l) of the adult moose (one year and over) killed on the road decreased more or less regularly since 1966 (Figure 1). It dropped from 3.79 years in 1966 to 2.17 in This difference is highly significant (p <.025). A similar tendency may be noted in the hunted population of the Laurentides Park (Figure 1). In 1967, 1970 and 1971, the average age of the animals killed by hunters was significantly higher (p <'.05) than that of moose killed on the road.

7 Table 1. Annual mortality of moose on Talbot Boulevard in the Laurentides Park, Male Female Age and/or Total Year Calf Adult Calf Adult sex unknown a b Total a fu11 data unavailable: killed and registered. an estimated 20 moose were b.. 11 reg~strat~on ended on November

8 Average age of moose killed by hunters 6 Average age of moose ki lied on the road * 5 4 w (!) 3 <! 2 I I. I' I I' II ",I ~\ ': i. I I \... \' /,... II I I I, I : \:,,/ I... ~ I" \v/, I " I:, ' I" I '- I,, I" --.!-... : -- -!I I I I I I I I, I Figure 1. Average age* of adult moose killed on the road and by hunters in Laurentides Park from 1966 to *Age class (Passmore et al. 1955) being taken as the actual age.

9 Almost all the highway accidents involving moose occur between the beginning of May and mid-november (Figure 2), almost three-quarters (72.4%) between the beginning of June and the end of August and almost one half (46.2%) between the middle of June and the end of July. The sex ratio of adult moose killed on the road was studied in relation to the time of year in order to determine whether high mortality of females was constant throughout the year. The Chi-square test applied to the sum values of the monthly male percentages for the months of May and June and July to November showed a significant difference (p <.01) for the two periods. Table 2 shows that the sex ratio in May and June approached equality (91:100) whereas it tended towards the female (39:100) during the other months under study. Highway accidents involving moose occur at almost any hour (Figure 3), but 75.1% take place between 8:00 a.m. and 3:00 a.m. and 58.8% between 8 porn. and midnight. If the night is taken as beginning at sunset and ending at sunrise, 83.6% of the fatal moose accidents occur at night and 16.4% during the day (Figure 4).

10 ~ 36 ::::! 34 ~ 32 ~ o ~ 26 I.L : 20 ~ 18 ~ 16 :J z r- r- r- - r- r- r- r- r- r- r- - - n, I If ~ r- - JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC TIME OF YEAR Figure 2. Time of year in which moose were accidentally killed on the road in the Laurentides Park between 1963 and 1972*. *1964 data is not considered here. In six other cases, the date of death was not recorded.

11 f-, t- 20 l- 0 lj.j -l 18 t- -l :"c 16 lj.j (f) 0 14 r- 0 :::?! 12 LL r t- 0:: ~ lj.j III 8 I- :::?! - ::::> 6 z ~ 4 l- I m 2 h-n I II TIM~ Figure 3. Hourly rate of moose mortality on the road in the Laurentides Park, 1967 to *The time of death was not recorded in 51 cases. **Eastern Standard Time.

12 DEC NOV OCT SEP AUG 00 J: JUL I- 0 Z 0 ~ JUN MAY APR MAR FEB 0 0 o 0 " ',' '". :::.. ", ". I I,: _" ':. : :. I,,: :. 00 I,::.. I, I,... DAY NIGHT DAY JAN~~~~~~~~~~~~~~~~L-L I II TIME 00 Figure 4. Hourly and monthly occurence of moose deaths on the road in the Laurentides Park between 1967 and * In 51 cases, the time of death was not recorded. **Eastern Standard Time.

13 Table Sex ratio of adult moose killed on the road in the Laurentides Park between 1963 and 1972 a, by monthb. May June July Aug. Sept. Oct. Nov. Total Males Females Percentage of males (a) 1964 data are not considered. Ten other cases for which the date or the sex are unknown, have been excluded. (b) The months of December, January, February, March and April were not included because of scant information. 2 - Salt Ponds A total of 132 ponds were discovered on the two road sections under study, the southern and the northeastern sections, which total km in length. This gives an average of 1.02 ponds per km. Two types of ponds were identified on the basis of their location and form: ditches (Figure 5), which are narrow, of varying lengths (less than 1 m to about 100 m) and found close to the roadside, and pools (Figure 6), which are more or less circular in shape and also of varied

14 i ~ Figure 5. Ditch along Talbot Boulevard in the Laurentides Park.

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16 size (184 m 2 to 2,30b m 2 ) but generally situated somewhat further from the roadside (l to 3 m). Of the 132 ponds, 102 were ditches and 30 were pools. Moose frequentation was scarce at 55 of these ponds (43%), occasional at 30 (24%), regular at 42 (33%) and unknown for 5 ponds. Of the ponds which are regularly or occasionally visited by moose, 52 (72%) were ditches and 20 were pools. The specific conductivity and the sodium and calcium concentration of the water in the ponds in the southern section and on the secondary road are compared in Table 3. Table 3. Mean specific conductivity and sodium and calcium concentration in pond water of the south section and in the secondary road ponds. Parameters analyzed Specific conductivity (mhos/cm) Sodium concentration (ppm) Calcium concentration (ppm) South Section Secondary Road Ponds Ponds (n = 61) (n = 20) Table 3 indicates that specific conductivity and sodium and calcium concentration are much higher in the pond water of the south section than in the secondary road ponds. In Table 4, mean specific conductivity and sodium and calcium concentration are compared with the rate of use of the ponds by moose.

17 Table Mean specific conductivity and sodium and calcium concentration of water of sampled ponds in the south section compared with the rate of use of these ponds by moose. category Mean sodium Mean calcium Specific concentration concentration conductivity (ppm) (ppm) (mhos/cm) Scarce * * * occasional 86.0 * 5.46 * * Number of samples Regular Unclassified * Significant difference (P <.05). Frequency of use increased significantly with increased specific conductivity and sodium and calcium concentration of pond water. However, there is no significant difference (p >.05) between specific conductivity and sodium and calcium concentration in occasionally and regularly used ponds. Among the 158 moose registered on the three road sections under study from 1969 to 1972, 79 were killed on the south section, 40 on the northeast section and 34 on the northwest section; 5 cases have not been localized. During this period, the localization of site accidents was precise enough (± 700 m)

18 to make it possible to establish a relation with the location of the ponds. We considered a distance of 0.4 km on both sides of the accident site in order to relate it to one or more ponds. Between 1969 and 1972, a total of 119 moose were killed in the south and northeast sections where an inventory of ponds had been carried out, 87 (73.1%) within a 0.4 km distance of one or more ponds. The ponds with which accidents are associated show various rates of use. This aspect is studied in Table 5. Of a total of 119 moose killed on these two road sections during a four-year period, 32 (27%) were killed on a road sector where there is no pond, 23 (19%) near scarecly used ponds, 61 (51%) near occasionally or regularly used ponds and 3 (3%) near ponds which have not been classified with respect to rate of use by moose. Table 5 does not take the relative importance of the ponds into account. This aspect can be studied from two angles: (1) by considering the total number of ponds in each category of rate of use or (2) by assigning each pond a certain length of road. In this analysis, only cases where moose are killed near a single pond whose rate of use is known or several ponds having the same rate of use can be considered. When accidents occur within 0.4 km of two or more ponds with different rates of use it is impossible to compare these cases with the rate of use of the ponds.

19 Table 5. Number of moose killed on the road near ponds having different rates of use on south and northeast sections of the Talbot Boulevard from 1969 to Scarce Scarce and a Scarce and a Occasional Occasional regular occasional a Regular Unclassified and regular Number of moose killed Number of moose b killed I-' ~ w asometimes the accident took place near two ponds used by moose at different rates. bresult obtained by assigning the accident to the pond used more frequently.

20 Table 6 shows no overall difference between the number of moose killed and the ponds used at various rates, if all ponds are considered. However, there are twice as many moose killed per pond at regularly used ponds than at scarcely used ponds when the total number of sufficiently isolated ponds is used as the divisor. The Chi-square test shows that the values in question are significantly different (p <.05). The second method, which considers the length of road assigned to the ponds, gives another estimate of the importance of each. It takes the proximity of the ponds into account and makes it possible to obtain an estimate with respect to moose killed on sectors where there is no pond. Table 7 indicates that 2.3 times more moose per km are killed where there are ponds as where there are none. The Chi-square test applied to the values of these sectors shows a significant difference (p <.01). The same test shows no significant difference (p >.95) between the number of moose killed and the ponds having various rates of use, all things considered with respect to the number of ponds in each category of frequency of use. There are not sufficient data available to calculate a coefficient of correlation between the chemical composition of pond water and the number of moose killed near the ponds. The fact that moose are frequently killed near several ponds considerably reduces the dataavailable.

21 Table 6. Number of moose killed on the road near ponds according to their rate of use, Laurentides Park, 1969 to Frequency of use category Scarce occasional Regular Unclassified Number of moose killed near one (A) or several ponds having the same rate of use Total number of (B) ponds sufficiently isolated a Number of ponds (e) involved in accidents in ~) Index AIBb Index Ale b * a OnlY ponds more than one quarter of a mile from each other were taken into account since moose killed near ponds too close together, with different rate of use could not be considered in ~). b ehi2 tests of the ratios AlB and Ale showed no significant differences (P>.05) over the 4 categories of use. However, there is a significant difference (p <.05) between the index values AlB for the ponds scarcely or regularly used.

22 Table 7. Number of moose killed per road-mile taking into account the presence or absence of ponds and their rate of use by moose, Laurentide Park, 1969 to Characteristics of the road according to the presence or absence of ponds and the rate of use by moose. No pond Scarcely used ponds Occasionally used ponds Regularly used ponds Use of ponds unknown Number of moose killed near one (A) or several ponds having the same rate of use (B) Length of the road in km in the south and northeast sections (1) 16.6 (1) 16.2 (1) 2.6 I-' ~ Cl'I Index AlB (1) When several ponds were close together (less than.40 km) a length equal to half the distance considered was assigned to each one.

23 The Chi-square test applied to the number of moose killed and the number of ponds involved in accidents for the three categories of each chemical analysis (Table 8) shows no significant difference (p >.05). Therefore, there is no relation between the number of moose killed and the sodium and calcium concentration and specific conductivity of pond water. Table 9 shows the sex ratio of animals killed on road sectors with or without ponds, with a view to attributing the difference in distribution of the sexes observed in the total population killed on the road to the presence or absence of ponds. rhe Chi-square test applied to Table 9 shows that there is no significant difference (p >.05) between the sex ratio of moose killed on sectors with or without ponds with respect to the two age groups considered. However, there is a significant difference (p <.10) between the average age of adult moose killed near one or more ponds and on sectors without ponds. rhe average is higher in the case of moose killed near one or more ponds, 2.54 years as compared with 1.81 years for those killed on sectors without ponds. 3 - Traffic There is a significant linear correlation (r =.54; P <.05) between the number of vehicles passing through the

24 Table 8. Number of moose killed on the road near a single pond; sodium and calcium concentration and specific conductivity of a water sample of these ponds, Laurentides Park, 1969 to 1972 Sodium concentration (ppm) Calcium concentration (ppm) Specific conductivity (mhos/cm) (0-10.0) ( ) (+60.1) (0-2.0) ( ) (+5.1) (0-50.0) ( ) (+500.1) (A) Number of moose killed near single pond analyzed chemically Number of ponds located (B) near the scene 4 of the accidents in (A) i-' -.,J CXl

25 Table Sex ratio of moose killed on the Laurentides Park road from 1969 to on sectors without ponds and with one or more ponds. Sectors without ponds With ponds Males Calves Adults ~F~e~m~a~l~e~s~~_ Male percentage Calves Adults Calves Adults (1) In two cases, the sex of the moose killed during this this period was unknown. Laurentides Park annually and the number of moose killed on the road from 1969 to 1972 (Fig. 7). There is also a significant linear correlation (r =.77; P <.01) between monthly traffic and the corresponding death rate of moose on the road (Fig. 8). DISCUSSION 1. Effect on the population Highway accidents involving moose in the Laurentides Park constitute an important mortality factor for the population adjacent to this main traffic artery. Grenier (1970) evaluated the population density for the entire Park at.34 moose/km 2. No appreciable difference in density has been observed along the roads. Consequently, that figure may be considered as

26 c w...j...j ;2 40 w U) 0 ~ 30 IJ... 0 a:: ~ 20 ::E ::> z * NUMBER OF VEHICLES (X 1000) Figure 7. Number of moose killed and annual traffic rate, 1965 to * 1he total number of moose killed in 1972 has been estimated at 52.

27 Cl 50 w -1-1 ~ 40 w (J) o ~ 30 I.L o 5 20 CD ::2: :::J Z 10 JUL. JUN FEB NUMBER OF VEHICLES (X 1000) Figure 8. Number of moose killed and monthly traffic rate, 1968 to 1972.

28 representative of the population oensity of this area also. This stuoy shows that an average of 0.16 moose are killeo per km of roao yearly. It is oifficult to assess precisely the moose population along the roaos. However, several stuoies inoicate that moose move arouno very little in summer (Murie 1944, McMillan 1954, DeVos ano Pearson 1955, Cook 1968). Knowlton (1960) reporteo that the territory of the male has a raoius of approximately 1.6 km ano the female 0.8 km. Houston (1968) mentions that 95% of the summer territory of 25 adults constituteo 3.9 km 2 or less. That of yearlings varieo from 5.8 km 2 for 62.5% of the cases observeo to 59 km 2 In the light of these oata, the territory of moose running the risk of being killed by motor vehicles can be estimateo as extenoing 1.6 km on each sioe of the roao. This figure enables us to establish the mortality rate per surface unit at moose 2 per km Compareo to the population oensity, the figure shows that 14.2% of the moose living along the roaos are killed by motor vehicles. This percentage ooes not incluoe the number of moose hit ano not reporteo, which may be fairly high: one case was reporteo in 1965, 13 in 1966, two in 1968 ano four in 1969; information on this point is not available for the other years. A certain number of these animals surely oie as the result of their injuries. In two places we found the carcasses of moose which were probably hit on the road some years before.

29 At one spot located approximately 320 m from Talbot Boulevard, near a path used by the moose for access to a pool along the road, two carcasses were found some 65 m apart. Another carcass was found the same distance from the road near a path used by the moose to travel between two lakes located on either side of Talbot Boulevard. It thus seems that the percentage of moose killed is closer to 15% to 20% if unreported accidents are included. Such a mortality rate is undoubtedly an important factor in the total death rate. Pimlott (1959) considered a rate of exploitation of 20% to 25% as high. Simkin (1965) determined moose net productivity at 24% for northern ontario. rhe very young mean age of the moose killed on the road also seems to indicate that the death rate resulting from highway accidents represents great exploitation of the animals living nearby. Since controlled hunting of moose is carried out only on secondary roads, very few animals living along Talbot Boulevard are taken in this way. Simkin (1964) reported a large difference between the age structures of two populations; the one hunted intensively and the other little. rhese data suggest a lower mean age for those which are heavily hunted. However, the mean age under consideration, that of the animals killed on the road, may simply reflect the greater vulnerability of young moose to motor vehicle accidents.

30 Causes of the rise in the death rate The increase in the number of moose killed on the road may be attributed to several factors. We have found that the number of motor vehicles is an important factor. However, the correlation only explains 54% of the variation. No information is available regarding changes in the speed of traffic during the period considered, but no important change seems to have occurred. Nor was there any appreciable change in road maintenance (Langlois, pers. comm.). The rise in the number of moose killed does not seem attributable to a change in their numbers in the Park as a whole. DesMeules (1965) reported a density of 0.29 moose per km 2 and Grenier (1970) estimated it at 0.34 moose per km 2. However, this difference is not significant (p>.05). It is, however, possible that there has been an increase in the local population along the road. such a change has not been noted in our observations nor in those of other people working in the Laurentides Park over the past few years. The increase in the number of moose killed is accompanied by a rejuvenation of the population, which can be attributed to a rise in the percentage of younger animals in the roadside population. This may be the result of an increase in productivity and/or an influx of young moose from elsewhere. simkin's data (1964) suggested that a population which is highly exploited will increase its productivity rate. Houston (1968) and Peterson

31 (1955) noted that young moose (up to two years old) are more mobile and have no well-defined territory. Goddard (1969) showed that the movements of, young moose (2.4 years and younger) between summer and autumn can be greater than those of older animals. The same author mentioned that the large areas which are intensely hunted are not repopulated by moose from faraway regions. According to pimlott (1959 b), if the mortality rate exceeds the net productivity near access roads, a dispersion and repopulation by the moose of adjacent habitats may result. We have no data enabling us to confirm with certainty that this does take place but, if it does, the rise in the number of moose killed may be partially attributable to an increase in the numbers of young moose along the roadsides, those young being more vulnerable to accidents than the older animals. 3. Sex ratio The sex ratio of adults killed on the road (56:100) indicates that there is a much higher number of females killed. From the available data on the sex ratio of the Park's population, it is difficult to establish the vulnerability of the sexes to motor vehicle accidents. An aerial inventory made in 1972 (Beaumont, pers. comm.) reported a sex ratio of 59:100 for the total Park population. The sampling is nevertheless too small (n=32) to be able to draw definitive conclusions. The sex

32 ratio obtained during controlled hunting periods from 1962 to 1972 was 145:100. The sex ratio data being too imprecise or biased by the hunters' choice, it is impossible to attribute greater vulnerability to the females with regard to highway accidents. The monthly differences in the distribution of the sexes shows that adult females are more vulnerable from July to November. Bellis and Graves (1971) found similar results for white-tailed deer (Odocoileus virginianus) killed on roads in pennsylvania. In this case, however, a monthly difference in the sex ratio was observed for every month of the year except November. Jahn (1959) found a greater vulnerability for the adult male white-tailed deer to death on the roads in Wisconsin. He also found a variation in the vulnerability of adults to highway accidents according to the month. The sex ratio of the calves killed on the road (96:100) is similar to that observed in the population hunted (100:100) calculated on the basis of Bouchard's data (1972) (n=69). We believe that the sex ratio of the calves killed by hunting is representative of the distribution of the sexes for that age group in the population because hunters do not choose between the sexes at that age, and there is no reason to believe that one sex is more vulnerable than the other. There is thus no greater vulnerability to highway accidents for males or females in this age group. Bellis and Graves (1971) obtained similar

33 results for the white-tailed deer population killed on Pennsylvania roads. Jahn's data (1959) covering ten years suggested, however, that there is a greater vulnerahility among the male white-tailed deer of the fawn age group. 4. The mean age The difference in the mean ages of the moose killed on highways and in hunting may represent the difference in ages hetween the two populations or the greater vulnerahility of the young moose living along roadsides. However, the hunters' choice can considerahly hias the age of the animals which are killed hy hunting. It is thus impossihle from these data to attrihute greater vulnerahility of the young to road accidents. 5. Monthly and hourly variations in the numher of moose killed The data showing the seasonal variation in the total numher of moose killed in road accidents suggest that moose do not often frequent highways in winter. During this period, snow limits their travels (DesMeules 1965). The numher of moose killed in proportion to the density of traffic indicates that accident risks are particularly high in June and July and reduced in August, Septemher and octoher, if we consider only those months when moose hehavior is not affected hy the snow.

34 Hourly variations in the number of moose killed in highway accidents suggest different activities during the day. Several authors, notably Denniston (1956), DeVos (1958), McMillan (1954) and Bouchard (1967), noted that moose activity is particularly high at dawn and dusk. Geist (1963) reported four principal activity periods: one at dawn, two during the day and one at dusk. our results suggest intense activity throughout the night with a period of maximum activity between 8 p.m. and midnight. These results are, however, biased by the variation in traffic and by different behavior as a reaction to vehicles and their lights during the day and at night. During the day it is difficult, in view of this bias factor, to infer hourly differences in activity. It seems logical to assume that the reactions of the moose to motor vehicles will be homogeneous throughout the night. Unfortunately, we do not have data on hourly variations ~n traffic but we have good reason to believe that it decreases after midnight. Our data suggests a high activity period among the moose during the night. Rausch (date unknown) found in a study carried out in Alaska that 80% of the accidents involving moose and trains took place during the night. Altmann (1956) and Geist (1959) studied various moose activities during the night. Hosley (1949) found that most of their summer movements took place at night. The few moose sighted along roads during the day and the heavier traffic lead us to believe that moose are more active at night than in daylight along highways.

35 Hourly variations in the sex ratio tend to show that male and female activity is similar during the various hours of the day. 6. Salt and the moose killed on highways One of the hypotheses of this work was that the spreading of salt on the road resulted in a higher concentration of sodium and calcium in pool water along the roadside. Attracted by the salt, moose frequented those pools where salt concentrations were highest. This higher frequentation resulted in a greater mortality rate near the pools. The considerable difference in the concentration of calcium and sodium in samples from secondary roads and those from the southern section suggest that winter spreading of calcium and sodium chloride greatly increases the concentration of these salts in roadside pools. The specific conductivity, which is representative of the quantity of ions in a solution, obviously follows the same tendency as the sodium and calcium concentrations. An equivalent concentration of sodium (X=72 ppm) was obtained by Hutchinson (1967) in pools located approximately 5 m from the major highways in Maine. The higher frequency of use observed at pools having high calcium and sodium concentrations and maximum specific conductivity demonstrates the attraction of the moose to salt. The very high

36 concentration of sodium suggests that this element is one of the main attraction factors. This phenomenon has already been pointed out by several authors. Rush (1932) found a high concentration of sodium in the licks used by large game in Yellowstone National Park. Honess and Frost (1942) came to a similar conclusion while studying 12 licks. Knight and Mudge (1967) found that certain compounds of sodium were the only substances more abundant in the licks than in surrounding areas. studies in Montana and Idaho (stockstad et al. 1953) show that sodium compounds are the minerals most sought after by ruminants at the licks. The same authors carried out a study" where the ruminants had a choice of 23 compounds. "cafeteria The sodium compounds were those constituting the greatest attraction. In similar studies, Dalke et al. (1965) carried out studies on the use of prepared salt. The reasons why ruminants prefer sodium compounds are too little understood to allow anything but conjecture on the subject (Knight and Mudge 1967). The results shown on Table 7 indicate that the chances of accidents are 2.3 times higher in places where there are pools than elsewhere. Pools are thus especially dangerous places for collisions involving moose. This increase in accident risk is not linked to the frequency of use of the pools by moose, howeve and remains difficult to explain. It is possible that the observations relating to the frequency of use, made in July and August of 1969, are not valid for the period in which the facts

37 about the animals killed were studied (1969 to 1972). There are certainly cases where the frequency of use of the pools has changed over this four year period. However, our observations tend to show a fairly constant frequency of use over the years. It is also improbable that the concentration of sodium has varied a great deal during that period since salt spreading has remained the same (Langlois, pers. comm.). The higher average age of the moose killed near the pools in relation to that of animals killed elsewhere would suggest that older, more experienced animals, who are less vulnerable to road accidents, frequent the pools in contrast to the younger, less experienced animals, who are more vulnerable and who cross the road at random. This younger population, which travels more or less aimlessly might be largely constituted by animals from elsewhere. Such a hypothesis would explain the absence of a relation between the frequency of use and the mortality rate of moose near the pools. It remains true, however, that even a little used pool is as condusive to accidents as one that is much frequented. The absence of a difference in the sex ratio of the moose killed in areas with or without pools indicates that the presence or absence of pools does not change the vulnerability of the sexes. The results shown on Table eight suggest that the mortality rate of moose on highways is not related to the chemical

38 composition of the water in roadside pools. The small number of animals killed near a single pool which had been chemically analysed prevents us from drawing definitive conclusions on this subject. However, since the chemical composition of pool water is strongly linked to frequency of use, the data in Tables 6 and 7 lead us to believe that an increase in mineral salts in roadside pool water does not result in a parallel increase in the number of animals killed near these points. LITERATURE CITED Altmann, M Patterns of herd behaviour in free ranging elk of Wyoming (Cervus canadensis nelsoni) Zoologica 41, 65 W. Bellis, E.D. and H.B. Graves Pennsylvania interstate highway Deer mortality of a J. Wildl. Mgmt. 35: Bouchard, R Etude d'un habitat d'ete de l'orignal dans Ie Parc des Laurentides, Quebec Wildlife Service. Report No.4. pp Bouchard, R Resultats globaux de la chasse controlee a l'orignal 1971 et analyse comparative avec les annees anterieures. Quebec wildlife Service. Mimeo. 38 pp. Bouchard, R. and G. Moisan Chasses controlee a l'orignal dans les parcs et reserves du Quebec ( ). Quebec Wildlife Service. Mimeo. 42 pp. Dalke, P.D., et al wildl. Mgmt. 29(2): Use of salt by elk in Idaho J. Denniston, R.H Ecology, behavior and population dynamics of the Wyoming or Rocky Mountain moose. Zoologica 41:

39 DesMeules, P Hyemal food and shelter of moose (Alces alces americana Cl.) in Laurentide Park, Quebec. A thesis presented to graduate studies of the University of Guelph. 130 pp. DeVos, A. and P.L. Pearson preliminary moose movement studies, Fish and Wildl. Mgmt. Rept. ontario Dept. Lands and Forests, Toronto. 24: Mimeo. DeVos, A Summer observations on moose behaviour in ontario. J. Mammal. 39(1): Geist, V On the behavior of the North American moose (Alces alces andersoni Peterson 1950) in British columbia. Behaviour 20: Goddard, J Movements of moose in a heavily hunted area of Ontario. J. Wildl. Mgmt. 34: Grenier, P.A Travail en cours sur l'habitat de l'orignal. Quebec Wildlife Service. Mimeo. 18 pp. Honess, R.F. and N.M. Frost, A wyoming Bighorn Sheep study. wyoming Game and Fish Dept. Bull. No pp. Hosley, N.W The moose and its ecology. U.S. Fish and Wildlife Service, Leaflet pp. Houston, D.B The Shiras moose in Jackson Hole Wyoming. U.S. Dept. Int., Technical Bulletin No pp. Hutchinson, F.E The relationship of road salt applications to sodium and chloride ion levels in the soil bordering major highways. Highway Research Record 193 pp Jahn, L.R Highway mortality as an index of deerpopulation change. J. Wildl. Mgmt. 23: Knight, R.R. and M.R. Mudge Characteristics of some natural licks in the Sun River area, Montana. J. Wildl. Mgmt. 31: Knowlton, F.F Food habits, movements and populations of moose in the Gravelly Mountains, Montana. J. Wildl. Mgmt. 24:

40 McMillan, J.F Some observations on moose in Yellowstone Park. Am. Midl. Nat. 42(3}: Murie, A The Wolves of Mount Mckinley. Fauna of the Natl. Parks of the u.s. Dept. Int., Natl. Parks Serv., Faune ser no. 5: 238 pp. Passmore, R.C., R.L. Peterson and A.T. cringan A study of mandibular tooth-wear as an index to age of moose. p. 233-: In: R.L. Peterson. North American moose. university of Toronto Press. Peterson, R.L North American moose. university of TOronto Press. 280 pp. Pimlott, D.H a. Reproduction and productivity of Newfoundland moose. J. Wildl. Mgmt. 23: Pimlott, D.H b. Moose harvests in Newfoundland and Fennoscandian countries. Twenty-fourth North Amer. wildl. Conf., 24: Raush, R.A. (und.). The problem of railroad-moose conflicts in the Susitna Valley, Mimeo. sept., u.s. Wildlife Service. Rognrud, J.M Evaluation of artificial salting and aerial salt distribution. Montana Fish and Game Comm., Mimeo. 30 pp. Rush, W.M Northern Yellowstone Elk study. Montana Fish and Game Comm., Helena, Montana. 131 pp. Simkin, D.W Some differences in ages of moose shot in heavily hunted and lightly hunted areas. ontario Fish and Wildl. Rev. 3(3}: smith, D.R The bighorn sheep in Idaho, its status, life history and management. Idaho Dept. of Fish and Game, Wildl. Bull. 1: 154 pp. stockstad, D.S., M.S. Morris and E.C. Lory Chemical characteristics of natural licks used by big game animals in Western Montana. Trans. of the Eighteenth North Amer. Wildl. Conf. 1953: 24~-258. Thompson, F.A Deer on highways. Department of Game and Fish State Capitol, Santa Fe, New Mexico. Mimeo. 8 pp.