Numerous entries in Drupal log upon viewing Search for Volunteer Opportunities page

[bsilvern]

Each time the Search for Volunteer Opportunities page is displayed, I get about 160 entries in the Drupal log of the form:

Desc	Value
LOCATION	.../civicrm/ajax/rest?entity=VolunteerNeed&action=getsearchresult&json=%7B%7D
REFERRER	.../civicrm/vol/
MESSAGE	Deprecated function CRM_Core_OptionGroup::getValue, use CRM_Core_PseudoConstant::getKey. Array ( [civi.tag] => deprecated )
SEVERITY	debug

I also get 3 entries of the form:

Desc	Value
LOCATION	.../civicrm/ajax/rest?entity=VolunteerNeed&action=getsearchresult&json=%7B%7D
REFERRER	.../civicrm/vol/
MESSAGE	Notice: Undefined index: start_time in CRM_Volunteer_BAO_NeedSearch::usortDateAscending() (line 300 of .../org.civicrm.volunteer/CRM/Volunteer/BAO/NeedSearch.php).
SEVERITY	notice

• PHP Version: PHP Version 7.2.15-1+ubuntu16.04.1+deb.sury.org+1
• Civi Version: 5.10.3
• Volunteer Version: 4.7.31-2.3.1 (and same results with Master)