Updated 2/19/21

The following graphs show the number of juveniles killed by vehicle collision on Alma Bridge Rd. at Lexington Reservoir between Jan. 2019 - Feb 2021.

Figure 1 shows that many more juveniles have been killed this year compared to previous migration seasons (~6% of total deaths). More than twice as many have been killed this year compared to last year. Also, more juveniles are killed in December than any other month, probably because juveniles begin to disperse from the lakes and streams in late fall with the first rains.

Figure 1.

Figure 2 shows both juvenile and sub-adult newt mortality by newt size and migration season. Note that we didn't collect data on juveniles during the first season (2017-2018).

Figure 2.

Figure 3a shows the large increase in percentage of juvenile vs adults killed per season; Figure 3b shows that juvenile newt mortality is more severe in the northern half of our study area, which is recreational, compared to the southern half, which is residential.

Figure 3.

Figure 4 shows juvenile newt mortality by newt size and migration season. These pie charts show the relative number of juveniles in each size category. (NR means the newt wasn't measured because no there was no reference scale in the picture or the newt was too smashed to accurately measure.)

Figure 4.