update the generation time

stdpopsim/catalog/SusScr/species.py

@@ -15,6 +15,16 @@
     },
 )
 
+# Generation time in wild boar
+_ZhangEtAl = stdpopsim.Citation(
+    doi="https://doi.org/10.1111/j.1365-2664.2011.02017.x",
+    year=2011,
+    author="Servanty et al.",
+    reasons={
+        stdpopsim.CiteReason.GEN_TIME,  # on page 835
+    },
+)
+
 # Genetic variation in recombination rate in the pig
 _JohnssonEtAl = stdpopsim.Citation(
     doi="https://doi.org/10.1186/s12711-021-00643-0",
@@ -106,19 +116,13 @@
     common_name="Pig",
     genome=_genome,
     ploidy=_ploidy,
-    # Zhang et al. (2022) on page 1042 write:
-    # "The age at first pregnancy varies in the wild from about 10 to
-    # 20 months [26], while boars begin rut when they are three to five
-    # years old. The first rut age of 4–5 years was documented in
-    # Russian wild boars [27], and 3–4 years was recorded in Chinese
-    # wild boars [28]. Pigs are multiparous animals, and the gestation
-    # period lasts about 114–130 days [29].
-    # ...
-    # Therefore, we set the generation interval of pigs as 3 years,
-    # which is roughly equivalent to the average age of
-    # the first pregnancy in sows and the beginning of rut in boars
-    # plus the pregnant gestation period of sows."
-    generation_time=3,
+    # Servanty et al. (2011) on page 835 write:
+    # "Generation times were 3.6 years in the lightly hunted population and 
+    # only 2.3 years in the heavily hunted population."
+    # Servanty et al. (2011) on page 837 write:
+    # "We Calculated generation time as the inverse of the relative elasticity of 
+    # the population growth rate to a change in all recruitment parameters."
+    generation_time=3.6,
     # Zhang et al. (2022) on page 1045 write:
     # "... Ne of pigs (the maximum Ne was ~4x10^4; see Figure S6D) ..."
     # and on page 1048 write:
@@ -127,7 +131,7 @@
     # [2,3] (Figure 3A, Figure S9)"
     population_size=270_000,
     citations=[
-        _ZhangEtAl,  # POP_SIZE & GEN_TIME
+        _ZhangEtAl,  # POP_SIZE
     ],
 )